Doss, M. K., Bluestone, M. R., & Gallo, D. A. (2016). Two mechanisms of constructive recollection: Perceptual recombination and conceptual fluency. Journal of Experimental Psychology: Learning, Memory & Cognition, 42, 1747-1758.

Abstract: Recollection is constructive and prone to distortion, but the mechanisms through which recollections can become embellished with rich yet illusory details are still debated. According to the conceptual fluency hypothesis, abstract semantic or conceptual activation increases the familiarity of a nonstudied event, causing one to falsely attribute imagined features to actual perception. In contrast, according to the perceptual recombination hypothesis, details from actually perceived events are partially recollected and become erroneously bound to a nonstudied event, again causing a detailed yet false recollection. Here, we report the first experiments aimed at disentangling these 2 mechanisms. Participants imagined pictures of common objects, and then they saw an actual picture of some of the imagined objects. We next presented misinformation associated with these studied items, designed to increase conceptual fluency (i.e., semantically related words) or perceptual recombination (i.e., perceptually similar picture fragments). Finally, we tested recollection for the originally seen pictures using verbal labels as retrieval cues. Consistent with conceptual fluency, processing-related words increased false recollection of pictures that were never seen, and consistent with perceptual recombination, processing picture fragments further increased false recollection. We also found that conceptual fluency was more short-lived than perceptual recombination, further dissociating these 2 mechanisms. These experiments provide strong evidence that conceptual fluency and perceptual recombination independently contribute to the constructive aspects of recollection.

Gallo, D. A., & Lampinen, J. M. (2016). Three pillars of false memory prevention: Orientation, evaluation, and corroboration. In J. Dunlosky & S. K. Tauber (Eds), The Oxford Handbook of Metamemory (pp. 387-403). New York: Oxford University Press.

Abstract: Conscious recollections of past experiences are prone to distortion, but retrieval monitoring processes help control memory accuracy and avoid false memories. This chapter overviews the metacognitive aspects of three retrieval processes that are fundamental for determining whether or not a questionable event had occurred in one’s past: (1) selectively searching memory for evidence of the questionable event (orientation), (2) diagnosing the validity of retrieved evidence by comparing it to one’s expectations about the questionable event’s memorability (evaluation), and (3) using various kinds of collateral information to converge upon the truth (corroboration). Such collateral information could include recollections of surrounding events that confirm or disqualify the questionable event’s occurrence, as well as other kinds of knowledge pertaining to the questionable event’s likelihood or plausibility. The chapter discusses laboratory research on each of these processes and considers how these processes recursively interact when remembering the more complex autobiographical events of our lives.

Weafer, J., Gallo, D. A., & de Wit, H. (2016). Acute effects of alcohol on encoding and consolidation of memory for emotional stimuli. Journal of Studies on Alcohol and Drugs, 77, 86-94.


Objective: Acute doses of alcohol impair memory when administered before encoding of emotionally neutral stimuli but enhance memory when administered immediately after encoding, potentially by affecting memory consolidation. Here, we examined whether alcohol produces similar biphasic effects on memory for positive or negative emotional stimuli.

Method: The current study examined memory for emotional stimuli after alcohol (0.8 g/kg) was administered either before stimulus viewing (encoding group; n = 20) or immediately following stimulus viewing (consolidation group; n = 20). A third group received placebo both before and after stimulus viewing (control group; n = 19). Participants viewed the stimuli on one day, and their retrieval was assessed exactly 48 hours later, when they performed a surprise cued recollection and recognition test of the stimuli in a drug-free state.

Results: As in previous studies, alcohol administered before encoding impaired memory accuracy, whereas alcohol administered after encoding enhanced memory accuracy. Critically, alcohol effects on cued recollection depended on the valence of the emotional stimuli: Its memory-impairing effects during encoding were greatest for emotional stimuli, whereas its memory-enhancing effects during consolidation were greatest for emotionally neutral stimuli. Effects of alcohol on recognition were not related to stimulus valence.

Conclusions: This study extends previous findings with memory for neutral stimuli, showing that alcohol differentially affects the encoding and consolidation of memory for emotional stimuli. These effects of alcohol on memory for emotionally salient material may contribute to the development of alcohol-related problems, perhaps by dampening memory for adverse consequences of alcohol consumption.

Wong, J. T., & Gallo, D. A. (2016). Stereotype threat reduces false recognition when older adults are forewarned. Memory, 24, 650-658.

Abstract: Exposing older adults to ageing stereotypes can reduce their memory for studied information-a phenomenon attributed to stereotype threat-but little is known about stereotype effects on false memory. Here, we assessed ageing stereotype effects on the Deese-Roediger-McDermott false memory illusion. Older adults studied lists of semantically associated words, and then read a passage about age-related memory decline (threat condition) or an age-neutral passage (control condition). They then took a surprise memory test with a warning to avoid false recognition of non-studied associates. Relative to the control condition, activating stereotype threat reduced the recognition of both studied and non-studied words, implicating a conservative criterion shift for associated test words. These results indicate that stereotype threat can reduce false memory, and they help to clarify mixed results from prior ageing research. Consistent with the regulatory focus hypothesis, threat motivates older adults to respond more conservatively when error-prevention is emphasised at retrieval.

Gray, S. J., & Gallo, D. A. (2015). Paranormal psychic believers and skeptics: A large-scale test of the cognitive differences hypothesis. Memory & Cognition, 44, 242-261.

Abstract: Belief in paranormal psychic phenomena is widespread in the United States, with over a third of the population believing in extrasensory perception (ESP). Why do some people believe, while others are skeptical? According to the cognitive differences hypothesis, individual differences in the way people process information about the world can contribute to the creation of psychic beliefs, such as differences in memory accuracy (e.g., selectively remembering a fortune teller’s correct predictions) or analytical thinking (e.g., relying on intuition rather than scrutinizing evidence). While this hypothesis is prevalent in the literature, few have attempted to empirically test it. Here, we provided the most comprehensive test of the cognitive differences hypothesis to date. In 3 studies, we used online screening to recruit groups of strong believers and strong skeptics, matched on key demographics (age, sex, and years of education). These groups were then tested in laboratory and online settings using multiple cognitive tasks and other measures. Our cognitive testing showed that there were no consistent group differences on tasks of episodic memory distortion, autobiographical memory distortion, or working memory capacity, but skeptics consistently outperformed believers on several tasks tapping analytical or logical thinking as well as vocabulary. These findings demonstrate cognitive similarities and differences between these groups and suggest that differences in analytical thinking and conceptual knowledge might contribute to the development of psychic beliefs. We also found that psychic belief was associated with greater life satisfaction, demonstrating benefits associated with psychic beliefs and highlighting the role of both cognitive and noncognitive factors in understanding these individual differences.

Gray, S. J., Brookshire, G., Casasanto, D., & Gallo, D. A. (2015). Electrically stimulating prefrontal cortex at retrieval improves recollection accuracy. Cortex, 73, 188- 194.

Abstract: Neuroimaging and brain damage studies suggest that dorsolateral prefrontal cortex (dlPFC) is involved in the cognitive control of episodic recollection. If dlPFC is causally involved in retrieval, then transcranial direct current stimulation (tDCS) of this brain region should increase recollection accuracy, especially when recollection is difficult and requires cognitive control. Here, we report the first brain stimulation experiment to directly test this hypothesis. We administered tDCS to dlPFC immediately after studying to-be-learned material but just prior to recollection testing, thereby targeting retrieval processes. We found that stimulation of dlPFC significantly increased recollection accuracy, relative to a no-stimulation sham condition and also relative to active stimulation of a comparison region in left parietal cortex. There was no significant difference in the size of this increase between hemispheres. Moreover, these dlPFC stimulation effects were behaviorally selective, increasing accuracy only when participants needed to recollect difficult information. Electrically stimulating dlPFC allowed people to more accurately recollect specific details of their experiences, demonstrating a causal role of dlPFC in the retrieval of episodic memories.

Ballard, M. E., Weafer, J., Gallo, D. A., & de Wit, H. (2015). Effects of acute methamphetamine on emotional memory formation in humans: Encoding vs consolidation. Plos One, 10, 1-15.

Abstract: Understanding how stimulant drugs affect memory is important for understanding their addictive potential. Here we examined the effects of acute d-methamphetamine (METH), administered either before (encoding phase) or immediately after (consolidation phase) study on memory for emotional and neutral images in healthy humans. Young adult volunteers (N = 60) were randomly assigned to either an encoding group (N = 29) or a consolidation group (N = 31). Across three experimental sessions, they received placebo and two doses of METH (10, 20 mg) either 45 min before (encoding) or immediately after (consolidation) viewing pictures of emotionally positive, neutral, and negative scenes. Memory for the pictures was tested two days later, under drug-free conditions. Half of the sample reported sleep disturbances following the high dose of METH, which affected their memory performance. Therefore, participants were classified as poor sleepers (less than 6 hours; n = 29) or adequate sleepers (6 or more hours; n = 31) prior to analyses. For adequate sleepers, METH (20 mg) administered before encoding significantly improved memory accuracy relative to placebo, especially for emotional (positive and negative), compared to neutral, stimuli. For poor sleepers in the encoding group, METH impaired memory. METH did not affect memory in the consolidation group regardless of sleep quality. These results extend previous findings showing that METH can enhance memory for salient emotional stimuli but only if it is present at the time of study, where it can affect both encoding and consolidation. METH does not appear to facilitate consolidation if administered after encoding. The study also demonstrates the important role of sleep in memory studies.

Gray, S. J., & Gallo, D. A. (2015). Disregarding familiarity during recollection attempts: Content-specific recapitulation as a global retrieval orientation strategy. Journal of Experimental Psychology: Learning, Memory & Cognition, 41, 134-147.

Abstract: People can use a content-specific recapitulation strategy to trigger memories (i.e., mentally reinstating encoding conditions), but how people deploy this strategy is unclear. Is recapitulation naturally used to guide all recollection attempts, or is it only used selectively, after retrieving incomplete information that requires additional monitoring? According to a retrieval orientation model, people use recapitulation whenever they search memory for specific information, regardless of what information might come to mind. In contrast, according to a postretrieval monitoring model, people selectively engage recapitulation only after retrieving ambiguous information in order to evaluate this information and guide additional retrieval attempts. We tested between these models using a criterial recollection task, and by manipulating the strength of ambiguous information associated with to-be-rejected foils (i.e., familiarity or noncriterial information). Replicating prior work, foil rejections were greater when people attempted to recollect targets studied at a semantic level (deep test) compared to an orthographic level (shallow test), implicating more accurate retrieval monitoring. To investigate the role of a recapitulation strategy in this monitoring process, a final test assessed memory for the foils that were earlier processed on these recollection tests. Performance on this foil recognition test suggested that people had engaged in more elaborative content-specific recapitulation when initially tested for deep compared to shallow recollections, and critically, this elaboration effect did not interact with the experimental manipulation of foil strength. These results support the retrieval orientation model, whereby a recapitulation strategy was used to orient retrieval toward specific information during every recollection attempt.

Ballard, M. E., Gallo, D. A., & de Wit, H. (2014). Amphetamine increases errors during episodic memory retrieval. Journal of Clinical Psychopharmacology, 34, 85-92.

Abstract: Moderate doses of stimulant drugs are known to enhance memory encoding and consolidation, but their effects on memory retrieval have not been explored in depth. In laboratory animals, stimulants seem to improve retrieval of emotional memories, but comparable studies have not been carried out in humans. In the present study, we examined the effects of dextroamphetamine (AMP) on retrieval of emotional and unemotional stimuli in healthy young adults, using doses that enhanced memory formation when administered before encoding in our previous study. During 3 sessions, healthy volunteers (n = 31) received 2 doses of AMP (10 and 20 mg) and placebo in counter-balanced order under double-blind conditions. During each session, they first viewed emotional and unemotional pictures and words in a drug-free state, and then 2 days later their memory was tested, 1 hour after AMP or placebo administration. Dextroamphetamine did not affect the number of emotional or unemotional stimuli remembered, but both doses increased recall intrusions and false recognition. Dextroamphetamine (20 mg) also increased the number of positively rated picture descriptions and words generated during free recall. These data provide the first evidence that therapeutic range doses of stimulant drugs can increase memory retrieval errors. The ability of AMP to positively bias recollection of prior events could contribute to its potential for abuse.

McDonough, I. M., Cervantes, S. N., Gray, S. J. & Gallo, D. A. (2014). Memory's aging echo: Age-related decline in neural reactivation of perceptual details during recollection. NeuroImage, 98, 346-358.

Abstract: Episodic memory decline is a hallmark of normal cognitive aging. Here, we report the first event-related fMRI study to directly investigate age differences in the neural reactivation of qualitatively rich perceptual details during recollection. Younger and older adults studied pictures of complex scenes at different presentation durations alongwith descriptive verbal labels, and these labels subsequentlywere used during fMRI scanning to cue picture recollections of varying perceptual detail. As expected fromprior behavioralwork, the two age groups subjectively rated their recollections as containing similar amounts of perceptual detail, despite objectively measured recollection impairment in older adults. In both age groups, comparisons of retrieval trials that varied in recollected detail revealed robust activity in brain regions previously linked to recollection, including hippocampus and both medial and lateral regions of the prefrontal and posterior parietal cortex. Critically, this analysis also revealed recollection-related activity in visual processing regions that were active in an independent picture-perception task, and these regions showed age-related reductions in activity during recollection that cannot be attributed to age differences in response criteria. These fMRI findings provide newevidence that aging reduces the absolute quantity of perceptual details that are reactivated frommemory, and they help to explain why aging reduces the reliability of subjective memory judgments.

McDonough, I. M., Cervantes, S. N., Gray, S. J. & Gallo, D. A. (2014). Memory's aging echo: Age-related decline in neural reactivation of perceptual details during recollection. NeuroImage, 98, 346-358.
Roediger, H. L., III, Meade, M. L., Gallo, D. A., & Olson, K. R. (2014). Bartlett revisited: Direct comparison of repeated reproduction and serial reproduction techniques. Journal of Applied Research in Memory and Cognition, 3, 266-271.

Abstract: Bartlett developed the procedures of repeated reproduction (the same person repeatedly recalling infor-mation) and serial reproduction (people transmitting information from one person to another). Ourexperiment directly compared recall accuracy across these two techniques, which has not previously been reported, using DRM word lists. Recall of the initial study list words remained constant across repeated reproductions but declined markedly across serial reproductions. In contrast, recall of associated wordsthat were not originally studied (i.e. critical words) was steady across both conditions. Because more ofthe original list words were forgotten across each link of the serial reproduction chain, the proportion ofcritical items recalled (relative to list words) increased significantly as the list passed between people. Using output bound scoring, serial reproduction resulted in lower accuracy than repeated reproduction by the final recall trial. Our results are broadly consistent with Bartlett’s (1932) informal observations: Serial reproduction produces greater forgetting of the original material than does repeated reproductionand also leads to greater distortion relative to the proportion of correct material recalled.

Weafer, J., Gallo, D. A., & de Wit, H. (2014). Amphetamine fails to alter cued recollection of emotional images: Study of encoding, retrieval, and state-dependency. Plos One, 9, 1-8.

Abstract: Stimulant drugs facilitate both encoding and retrieval of salient information in laboratory animals, but less is known about their effects on memory for emotionally salient visual images in humans. The current study investigated dextroamphetamine (AMP) effects on memory for emotional pictures in healthy humans, by administering the drug only at encoding, only at retrieval, or at both encoding and retrieval. During the encoding session, all participants viewed standardized positive, neutral, and negative pictures from the International Affective Picture System (IAPS). 48 hours later they attended a retrieval session testing their cued recollection of these stimuli. Participants were randomly assigned to one of four conditions (N = 20 each): condition AP (20 mg AMP at encoding and placebo (PL) at retrieval); condition PA (PL at encoding and AMP at retrieval); condition AA (AMP at encoding and retrieval); or condition PP (PL at encoding and retrieval). Amphetamine produced its expected effects on physiological and subjective measures, and negative pictures were recollected more frequently than neutral pictures. However, contrary to hypotheses, AMP did not affect recollection for positive, negative, or neutral stimuli, whether it was administered at encoding, retrieval, or at both encoding and retrieval. Moreover, recollection accuracy was not state-dependent. Considered in light of other recent drug studies in humans, this study highlights the sensitivity of drug effects to memory testing conditions and suggests future strategies for translating preclinical findings to human behavioral laboratories.

Ballard, M. E., Gallo, D. A., & de Wit, H. (2013). Pre-encoding administration of amphetamine or THC selectively modulates emotional memory in humans. Psychopharmacology, 226, 515-529.

Abstract: Stimulant drugs facilitate both encoding and retrieval of salient information in laboratory animals, but less is known about their effects on memory for emotionally salient visual images in humans. The current study investigated dextroamphetamine (AMP) effects on memory for emotional pictures in healthy humans, by administering the drug only at encoding, only at retrieval, or at both encoding and retrieval. During the encoding session, all participants viewed standardized positive, neutral, and negative pictures from the International Affective Picture System (IAPS). 48 hours later they attended a retrieval session testing their cued recollection of these stimuli. Participants were randomly assigned to one of four conditions (N = 20 each): condition AP (20 mg AMP at encoding and placebo (PL) at retrieval); condition PA (PL at encoding and AMP at retrieval); condition AA (AMP at encoding and retrieval); or condition PP (PL at encoding and retrieval). Amphetamine produced its expected effects on physiological and subjective measures, and negative pictures were recollected more frequently than neutral pictures. However, contrary to hypotheses, AMP did not affect recollection for positive, negative, or neutral stimuli, whether it was administered at encoding, retrieval, or at both encoding and retrieval. Moreover, recollection accuracy was not state-dependent. Considered in light of other recent drug studies in humans, this study highlights the sensitivity of drug effects to memory testing conditions and suggests future strategies for translating preclinical findings to human behavioral laboratories.

Gallo, D. A. (2013). Retrieval expectations affect false recollection: Insights from a criterial recollection task. Current Directions in Psychological Science, 22, 316-323.

People use retrieval expectations to guide the accuracy of recollection attempts. This retrieval monitoring process minimizes illusory or false recollection, especially when the to-be-remembered events are distinctive. Our work with a criterial recollection task reveals that this monitoring process primarily depends on qualitative features of recollected information, an aspect of memory that can be dissociated from traditional measures of recollection frequency and familiarity. Neuroimaging and brain damage studies further indicate that this monitoring process relies on prefrontal regions that coordinate memory retrieval. This research helps explain why older adults are sometimes more susceptible to false recollection. More generally, this research highlights the importance of different kinds of recollected events and corresponding retrieval expectations in determining memory accuracy.

Gallo, D. A., & Wheeler, M. E. (2013). Episodic memory. In D. Reisberg (Ed). Oxford Handbook of Cognitive Psychology (pp. 189-205). New York: Oxford University Press.

Abstract: This chapter provides a brief overview of episodic memory, or the ability to consciously recall events from one’s personal past. The historical context of this concept is sketched, as well as its relationship to other kinds of memory. Defining characteristics are then outlined, including its role in consciousness and sense of self, the dynamics of encoding and retrieval, and the phenomena of amnesia, forgetting, and false memories. Recollection is described as being cue dependent, and it is argued that this principle can explain three major encoding factors that influence episodic retrieval (distinctiveness, depth, and organization). Finally, the major neural substrates are summarized, as well as the effects of development and aging. The chapter concludes with some far-reaching questions for future research.

McDonough, I. M., & Gallo, D. A. (2013). Impaired retrieval monitoring for past and future autobiographical events in older adults. Psychology & Aging, 28, 457-466.

Abstract: Older adults are more likely than younger adults to confuse real and imagined events in episodic memory. This deficit may be attributed to a reduction in the specific features available for recollection (i.e., retrieval success) or to a deficit in the search and decision processes operating during recollection attempts (i.e., retrieval monitoring). The present experiments used a two-phase event-generation task to manipulate retrieval success and test for age-related deficits in retrieval monitoring. In the first phase, participants generated real autobiographical events from their past and imagined plausible future events in response to cue words. We used elaboration instructions to experimentally manipulate the amount of features associated with these generated events. In the second phase administered 24 hours later, we gave recollection tests that required participants to discriminate between these previously generated past and future events in memory. As predicted, the elaboration manipulation increased the amount of features that could be recollected in association with the generated events in both age groups (including cognitive operations in Experiment 1 and perceptual details in Experiment 2). However, older adults were more likely than younger adults to confuse past and future events in memory, and critically, elaboration did not minimize these age-related confusions. These findings imply that aging impairs the ability to accurately monitor retrieval for features that are characteristic of autobiographical events, above and beyond age-related impairments in the retrieval of the recollected information itself.

McDonough, I. M., Wong, J. T., & Gallo, D. A. (2013). Age-related differences in prefrontal cortex activity during retrieval monitoring: Testing the compensation and dysfunction accounts. Cerebral Cortex, 23, 1049-1060.

Abstract: Current theories of cognitive aging emphasize that the prefrontal cortex might not only be a major source of dysfunction but also a source of compensation. We evaluated neural activity associated with retrieval monitoring—or the selection and evaluation of recollected information during memory retrieval—for evidence of dysfunction or compensation. Younger and older adults studied pictures and words and were subsequently given criterial recollection tests during event-related functional magnetic resonance imaging. Although memory accuracy was greater on the picture test than the word test in both groups, activity in right dorsolateral prefrontal cortex (DLPFC) was associated with greater retrieval monitoring demands (word test > picture test) only in younger adults. Similarly, DLPFC activity was consistently associated with greater item difficulty (studied > nonstudied) only in younger adults. Older adults instead exhibited high levels of DLPFC activity for all of these conditions, and activity was greater than younger adults even when test performance was naturally matched across the groups (picture test). Correlations also differed between DLPFC activity and test performance across the groups. Collectively, these findings are more consistent with accounts of DLPFC dysfunction than compensation, suggesting that aging disrupts the otherwise beneficial coupling between DLPFC recruitment and retrieval monitoring demands.

Ballard, M. E., Gallo, D. A., & de Wit, H. (2012). Psychoactive drugs and false memory: Comparison of dextroamphetamine and delta-9-tetrahydrocannabinol on false recognition. Psychopharmacology, 219, 15-24.


Rationale: Several psychoactive drugs are known to influence episodic memory. However, these drugs’ effects on false memory, or the tendency to incorrectly remember nonstudied information, remain poorly understood. Objectives Here, we examined the effects of two commonly used psychoactive drugs, one with memory-enhancing properties (dextroamphetamine; AMP), and another with memory-impairing properties (Ä9-tetrahydrocannabinol; THC), on false memory using the Deese/Roediger–McDermott (DRM) illusion.

Methods: Two parallel studies were conducted in which healthy volunteers received either AMP (0, 10, and 20 mg) or THC (0, 7.5, and 15 mg) in within-subjects, randomized, double-blind designs. Participants studied DRM word lists under the influence of the drugs, and their recognition memory for the studied words was tested 2 days later, under sober conditions.

Results:As expected, AMP increased memory of studied words relative to placebo, and THC reduced memory of studied words. Although neither drug significantly affected false memory relative to placebo, AMP increased false memory relative to THC. Across participants, both drugs’ effects on true memory were positively correlated with their effects on false memory.

Conclusions: Our results indicate that AMP and THC have opposing effects on true memory, and these effects appear to correspond to similar, albeit more subtle, effects on false memory. These findings are consistent with previous research using the DRM illusion and provide further evidence that psychoactive drugs can affect the encoding processes that ultimately result in the creation of false memories.

Gallo, D. A., Cramer, S. J., Wong, J. T., & Bennett, D. A. (2012). Alzheimer’s disease can spare local metacognition despite global anosognosia: Revisiting the confidence accuracy relationship in episodic memory. Neuropsychologia, 50, 2356-2364.

Abstracts: Alzheimer’s disease (AD) can impair metacognition in addition to more basic cognitive functions like memory. However, while global metacognitive inaccuracies are well documented (i.e., low deficit awareness, or anosognosia), the evidence is mixed regarding the effects of AD on local or task-based metacognitive judgments. Here we investigated local metacognition with respect to the confidence– accuracy relationship in episodic memory (i.e., metamemory). AD and control participants studied pictures of common objects and their verbal labels, and then took forced-choice picture recollection tests using the verbal labels as retrieval cues. We found that item-based confidence judgments discriminated between accurate and inaccurate recollection responses in both groups, implicating relatively spared metamemory in AD. By contrast, there was evidence for global metacognitive deficiencies, as AD participants underestimated the severity of their everyday problems compared to an informant’s assessment. Within the AD group, individual differences in global metacognition were related to recollection accuracy, and global metacognition for everyday memory problems was related to task-based metacognitive accuracy. These findings suggest that AD can spare the confidence– accuracy relationship in recollection tasks, and that global and local metacognition measures tap overlapping neuropsychological processes.

McDonough, I. M., & Gallo, D. A. (2012). Illusory expectations can affect retrieval monitoring accuracy. Journal of Experimental Psychology: Learning, Memory & Cognition, 38, 391-404.

The present study investigated how expectations, even when illusory, can affect the accuracy of memory decisions. Participants studied words presented in large or small font for subsequent memory tests. Replicating prior work, judgments of learning indicated that participants expected to remember large words better than small words, even though memory for these words was equivalent on a standard test of recognition memory and subjective judgments. Critically, we also included tests that instructed participants to selectively search memory for either large or small words, thereby allowing different memorial expectations to contribute to performance. On these tests we found reduced false recognition when searching memory for large words relative to small words, such that the size illusion paradoxically affected accuracy measures (d scores) in the absence of actual memory differences. Additional evidence for the role of illusory expectations was that (a) the accuracy effect was obtained only when participants searched memory for the aspect of the stimuli corresponding to illusory expectations (size instead of color) and (b) the accuracy effect was eliminated on a forced-choice test that prevented the influence of memorial expectations. These findings demonstrate the critical role of memorial expectations in the retrieval-monitoring process.

Wong, J. T., Cramer, S. J., & Gallo, D. A. (2012). Age-related reduction of the confidence-accuracy relationship in episodic memory: Effects of recollection quality and retrieval monitoring. Psychology & Aging, 27, 1053-1065.

Abstracts: We investigated age-related reductions in episodic metamemory accuracy. Participants studied pictures and words in different colors and then took forced-choice recollection tests. These tests required recollection of the earlier presentation color, holding familiarity of the response options constant. Metamemory accuracy was assessed for each participant by comparing recollection test accuracy with corresponding confidence judgments. We found that recollection test accuracy was greater in younger than older adults and also for pictures than font color. Metamemory accuracy tracked each of these recollection differences, as well as individual differences in recollection test accuracy within each age group, suggesting that recollection ability affects metamemory accuracy. Critically, the age-related impairment in metamemory accuracy persisted even when the groups were matched on recollection test accuracy, suggesting that metamemory declines were not entirely due to differences in recollection frequency or quantity, but that differences in recollection quality and/or monitoring also played a role. We also found that age-related impairments in recollection and metamemory accuracy were equivalent for pictures and font colors. This result contrasted with previous false recognition findings, which predicted that older adults would be differentially impaired when monitoring memory for less distinctive memories. These and other results suggest that age-related reductions in metamemory accuracy are not entirely attributable to false recognition effects, but also depend heavily on deficient recollection and/or monitoring of specific details associated with studied stimuli.

Gallo, D. A., Korthauer, L. E., McDonough, I. M., Teshale, S., & Johnson, E. L. (2011). Age-related positivity effects and autobiographical memory detail: Evidence from a past/future source memory task. Memory, 19, 641-652.

Abstract: This study investigated whether the age-related positivity effect strengthens specific event details in autobiographical memory. Participants retrieved past events or imagined future events in response to neutral or emotional cue words. Older adults rated each kind of event more positively than younger adults, demonstrating an age-related positivity effect. We next administered a source memory test. Participants were given the same cue words and tried to retrieve the previously generated event and its source (past or future). Accuracy on this source test should depend on the recollection of specific details about the earlier generated events, providing a more objective measure of those details than subjective ratings. We found that source accuracy was greater for positive than negative future events in both age groups, suggesting that positive future events were more detailed. In contrast, valence did not affect source accuracy for past events in either age group, suggesting that positive and negative past events were equally detailed. Although ageing can bias people to focus on positive aspects of experience, this bias does not appear to strengthen the availability of details for positive relative to negative past events.

Pierce, B. H., & Gallo, D. A. (2011). Encoding modality can affect memory accuracy via retrieval orientation. Journal of Experimental Psychology: Learning, Memory & Cognition, 37, 516-521.

Abstract: Research indicates that false memory is lower following visual than auditory study, potentially because visual information is more distinctive. In the present study we tested the extent to which retrieval orientation can cause a modality effect on memory accuracy. Participants studied unrelated words in different modalities, followed by criterial recollection tests that selectively oriented retrieval toward one study modality at a time. Memory errors were lower when oriented toward visual than toward auditory information, thereby generalizing the modality effect to an explicit source memory task. Moreover, these effects persisted independent of the test presentation modality, indicating that retrieval orientation overrode the potential cuing properties of the test stimulus. An independent manipulation check confirmed that visual recollections were subjectively experienced as more distinctive than auditory recollections. These results suggest that retrieval orientation is sufficient to cause a modality effect on memory accuracy by focusing monitoring processes on the recollection of studied features that are diagnostic of prior presentation.

Scimeca, J. M., McDonough, I. M., & Gallo, D. A. (2011). Quality trumps quantity at reducing memory errors: Implications for retrieval monitoring and mirror effects. Journal of Memory and Language, 65, 363-377.

Abstract: Memories have qualitative properties (e.g., the different kinds of features or details that can be retrieved) and quantitative properties (e.g., the frequency and/or strength of retrieval). Here we investigated the relative contribution of these two properties to the retrieval monitoring process. Participants studied a list of words, and memory for these words was enhanced either by studying an associated picture or by word repetition. Subsequent memory tests required participants to selectively monitor retrieval for these different kinds of stimuli. Compared to words that were studied only once, test words associated with either pictures or repetitions were more likely to be correctly recognized, but critically, false recognition was reduced only when monitoring memory for picture recollections. Subjective judgments and speeded tests indicated that study repetition increased the number of test words that elicited recollection and familiarity (a quantitative difference), but studying pictures maximized the recollection of unique or distinctive details (a qualitative difference). These results indicate that memory quality is more critical than quantity for retrieval monitoring accuracy.

Gallo, D. A. (2010). False memories and fantastic beliefs: 15 years of the DRM illusion. Memory & Cognition, 37, 833-848.

Abstract: This article reviews research using the Deese/Roediger–McDermott (DRM) associative memory illusion, whereby people falsely remember words that were not presented. This illusion has broadly influenced basic theories of memory in cognitive psychology and neuroscience and naturally raises the question as to how these theories apply to more complex autobiographical memories. Some applicability is evident from research linking individual differences in the DRM illusion to false autobiographical memories (e.g., misremembering public events) and fantastic autobiographical beliefs (e.g., memories from past lives). But which aspects generalize? Here it is argued that a process-oriented approach is needed in order to answer this question. Many productive years of DRM research indicate that multiple and often opposing psychological processes cause even the most basic false memories. In light of these discoveries, more researchers need to use methods that isolate these component processes if the goal is to understand false memories both in the lab and in life.

*Won article of the year for the journal.

Gallo, D. A., Foster, K. T., Wong, J. T., & Bennett, D. A. (2010). False recollection of emotional pictures in Alzheimer’s disease. Neuropsychologia, 48, 3614-3618.

Abstract: Alzheimer’s Disease (AD) can reduce the effects of emotional content on memory for studied pictures, but less is known about false memory. In healthy adults, emotionally arousing pictures can be more susceptible to false memory effects than neutral pictures, potentially because emotional pictures share conceptual similarities that cause memory confusions. We investigated these effects in AD patients and healthy controls. Participants studied pictures and their verbal labels, and then picture recollection was tested using verbal labels as retrieval cues. Some of the test labels had been associated with a picture at study, whereas other had not. On this picture recollection test, we found that both AD patients and controls incorrectly endorsed some of the test labels that had not been studied with pictures. These errors were associated with medium to high levels of confidence, indicating some degree of false recollection. Critically, these false recollection judgments were greater for emotional compared to neutral items, especially for positively valenced items, in both AD patients and controls. Dysfunction of the amygdala and hippocampus in early AD may impair recollection, but AD did not disrupt the effect of emotion on false recollection judgments.

Gallo, D. A., McDonough, I. M., & Scimeca, J. (2010). Dissociating source memory decisions in prefrontal cortex: fMRI of diagnostic and disqualifying monitoring. Journal of Cognitive Neuroscience, 22, 955-969.

Abstract: We used event-related fMRI to study two types of retrieval monitoring that regulate episodic memory accuracy: diagnostic and disqualifying monitoring. Diagnostic monitoring relies on expectations, whereby the failure to retrieve expected recollections prevents source memory misattributions (sometimes called the distinctiveness heuristic). Disqualifying monitoring relies on corroborative evidence, whereby the successful recollection of accurate source information prevents misattribution to an alternative source (sometimes called recall to reject). Using criterial recollection tests, we found that orienting retrieval toward distinctive recollections (colored pictures) reduced source memory misattributions compared with a control test in which retrieval was oriented toward less distinctive recollections (colored font). However, the corresponding neural activity depended on the type of monitoring engaged on these tests. Rejecting items based on the absence of picture recollections (i.e., the distinctiveness heuristic) decreased activity in dorsolateral prefrontal cortex relative to the control test, whereas rejecting items based on successful picture recollections (i.e., a recall-toreject strategy) increased activity in dorsolateral prefrontal cortex. There also was some evidence that these effects were differentially lateralized. This study provides the first neuroimaging comparison of these two recollection-based monitoring processes and advances theories of prefrontal involvement inmemory retrieval.

McDonough, I. M., & Gallo, D. A. (2010). Separating past and future autobiographical events in memory: Evidence for a reality monitoring asymmetry. Memory & Cognition,38, 3-12.

After thinking about the past and imagining the future, how do people separate these real and imagined events in memory? We had subjects engage in past and future autobiographical elaboration, then later take memory tests that required them to recollect these earlier generated events. In Experiment 1, testing memory for previously generated past or future autobiographical events led to fewer source memory confusions than did an elaborative control task, suggesting that the distinctive features of autobiographical elaboration improved subsequent retrieval monitoring accuracy. In Experiment 2, we directly compared retrieval monitoring accuracy for previously generated past and future autobiographical events and found that subjects made fewer source confusions when searching memory for future events. This asymmetry suggests that the features characterizing future elaborations (e.g., cognitive operations) were used more effectively during reality monitoring than were the features characterizing past elaborations (e.g., perceptual details), and has implications for future-oriented theories of memory.

Wheeler, M. E., & Gallo, D. A. (2010). Episodic memory. In I. B. Weiner & W. E. Craighead (Eds.) The Corsini Encyclopedia of Psychology, 4th Ed (pp. 588-590).Hoboken, NJ: Wiley.

Abstracts: When we think back to a past experience, such as a childhood birthday party, we can bring to mind faces of people in attendance, the appearance and location of the event, the sounds of voices or music, and our mood and thoughts. This contextually rich form of retrieval is the basis for episodic memory. As defined by Endel Tulving (1983), an episodic memory contains three critical elements that delineate it from other forms of memory. The first is that the memories are embedded in a spatiotemporal context in which some aspects of the location and timing of the event are available to consciousness. The second is that they are personal memories associated with a distinct impression of self-involvement. The third is that they are accompanied by a subjective awareness of remembering in which sights, sounds, and other experiences are replayed in the present moment.

Fenn, K. M., Gallo, D. A., Margoliash, D., Roediger, H. L., III, & Nusbaum, H. C. (2009). Reduced false memory after sleep. Learning & Memory, 16, 509-513.

Abstract: Several studies have shown that sleep contributes to the successful maintenance of previously encoded information. This research has focused exclusively on memory for studied events, as opposed to false memories. Here we report three experiments showing that sleep reduces false memories in the Deese-Roediger-McDermott (DRM) memory illusion. False recognition of nonstudied words was reduced after sleep, relative to an equal retention interval of wakefulness, with no change in correct recognition of studied words. These experiments are the first to show that false memories can be reduced following sleep, and they extend the benefits of sleep to include increased accuracy of episodic memory.

Gallo, D. A., Foster, K. T., & Johnson, E. L. (2009). Elevated false recollection of emotional pictures in younger and older adults. Psychology and Aging, 24, 981-988.

Abstract: Current theories predict opposing effects of emotionally arousing information on false memory. If emotion enhances true recollection, then false recollection might be lower for emotional than for neutral pictures. However, if emotion enhances conceptual relatedness, then false recollection might increase for nonstudied but emotionally related pictures. We contrasted these 2 factors in young and older adults, using the International Affective Pictures Systems set (Lang, Bradley, & Cuthbert, 2005). Although both age groups used recollection in our task, false recollection was greatest for emotional pictures, supporting a conceptual relatedness account. Finally, even after accuracy differences were controlled, age was related to high-confidence false recollection of emotional pictures.

Meyersburg, C. A., Bogdan, R., Gallo, D. A., & McNally, R. J. (2009). False memory propensity in people reporting recovered memories of past lives. Journal of Abnormal Psychology, 118, 399-404.

Abstract: Are elevated rates of false recall and recognition in the Deese–Roediger–McDermott (DRM) paradigm associated with false autobiographical memories in everyday life? To investigate this issue, the authors recruited participants who reported improbable memories of past lives and compared their DRM performance with that of control participants who reported having lived only one life (i.e., their current one). Relative to control participants, those reporting memories of past lives exhibited significantly higher false recall and recognition rates in the DRM paradigm, and they scored higher on measures of magical ideation and absorption as well. The groups did not differ on correct recall, recognition, or intelligence. False memory propensity in the DRM paradigm may tap proneness for developing false memories outside the laboratory.

Yang, S., Gallo, D. A., & Beilock, S. L. (2009). Embodied memory judgments: A case for motor fluency. Journal of Experimental Psychology: Learning, Memory, & Cognition, 35, 1359-1365.

Abstract: It is well known that perceptual and conceptual fluency can influence episodic memory judgments. Here, the authors asked whether fluency arising from the motor system also impacts recognition memory. Past research has shown that the perception of letters automatically activates motor programs of typing actions in skilled typists. In this study, expert typists made more false recognition errors to letter dyads which would be easier or more fluent to type than nonfluent dyads, while no typing action was involved (Experiment 1). This effect was minimized with a secondary motor task that implicated the same fingers that would be used to type the presented dyads, but this effect remained with a noninterfering motor task (Experiment 2). Typing novices, as a comparison group, did not show fluency effects in recognition memory. These findings suggest that memory is influenced by covert simulation of actions associated with the items being judged—even when there is no intention to act—and highlight the intimate connections between higher level cognition and action.

Cotel, S. C., Gallo, D. A., & Seamon, J. G. (2008). Evidence that nonconscious processes are sufficient to produce false memories. Consciousness & Cognition, 17, 210-218.

Abstracts: Are nonconscious processes sufficient to cause false memories of a nonstudied event? To investigate this issue, we controlled and measured conscious processing in the DRM task, in which studying associates (e.g., bed, rest, awake…) causes false memories of nonstudied associates (e.g., sleep). During the study phase, subjects studied visually masked associates at extremely rapid rates, followed by immediate recall. After this initial phase, nonstudied test words were rapidly presented for perceptual identification, followed by recognition memory judgments. On the perceptual identification task, we found significant priming of nonstudied associates, relative to control words. We also found significant false recognition of these nonstudied associates, even when subjects did not recall this word at study or identify it at test, indicating that nonconscious processes can cause false recognition. These recognition effects were found immediately after studying each list of associates, but not on a delayed test that occurred after the presentation of several intervening lists. Nonconscious processes are sufficient to cause this memory illusion on immediate tests, but may be insufficient for more vivid and lasting false memories.

McDonough, I. M., & Gallo, D. A. (2008). Autobiographical elaboration reduces false recognition: Cognitive operations and the distinctiveness heuristic. Journal of Experimental Psychology: Learning, Memory & Cognition, 34, 1430-1445.

Abstract: Retrieval monitoring enhances episodic memory accuracy. For instance, false recognition is reduced when subjects base their decisions on more distinctive recollections, a retrieval monitoring process called the distinctiveness heuristic. We tested the hypothesis that autobiographical elaboration during study (i.e., generating autobiographical memories in response to cue words) would lead to more distinctive recollections than other item-specific encoding tasks, enhancing retrieval monitoring accuracy at test. Consistent with this hypothesis, false recognition was less likely when subjects had to search their memory for previous autobiographical elaborations, compared to previous semantic judgments. These false recognition effects were dissociated from true recognition effects across four experiments, implicating a recollection-based monitoring process that was independent from familiarity-based processes. Separately obtained subjective measures provided converging evidence for this conclusion. The cognitive operations engaged during autobiographical elaboration can lead to distinctive recollections, making them less prone to memory distortion than other types of deep or semantic encoding.

Gallo, D. A., Meadow, N. G., Johnson, E. L., & Foster, K. T. (2008). Deep levels of processing elicit a distinctiveness heuristic: Evidence from the criterial recollection task. Journal of Memory and Language, 58, 1095-1111.

Abstract: Thinking about the meaning of studied words (deep processing) enhances memory on typical recognition tests, relative to focusing on perceptual features (shallow processing). One explanation for this levels-of-processing effect is that deep processing leads to the encoding of more distinctive representations (i.e., more unique semantic or conceptual features that can be recollected to differentiate the words). This recollective distinctiveness hypothesis predicts that deep processing should reduce false recognition errors, because expecting more distinctive recollections can facilitate retrieval monitoring accuracy (i.e., a distinctiveness heuristic). We report several experiments confirming this prediction, while ruling out explanations based on familiarity or overall memory strength. Additional support for the distinctiveness hypothesis was that a manipulation designed to selectively enhance the distinctiveness of words in the shallow condition eliminated the levels-of-processing effect on false recognition. These findings suggest that conceptual processing can elicit the distinctiveness heuristic, and that recollective distinctiveness drives levels-of-processing effects.

Gallo, D. A., Perlmutter, D. H., Moore, C. D., & Schacter, D. L. (2008). Distinctive encoding reduces the Jacoby-Whitehouse illusion. Memory & Cognition, 36, 461-466.

Abstract: We investigated the influence of distinctive encoding on the Jacoby and Whitehouse (1989) illusion. Subjects studied visually presented words that were associated with either an auditory presentation of the same word (nondistinctive encoding) or a picture of the object (distinctive encoding). In both conditions, words were visually presented on the recognition test, and half were preceded by brief repetition primes. Priming test items increased hits and false alarms in the auditory condition, demonstrating the Jacoby-Whitehouse illusion. This illusion was reduced in the picture condition. In order to test whether this distinctiveness effect was caused by a recollection-based response strategy (i.e., the distinctiveness heuristic), we minimized recollection-based responding by having subjects make speeded recognition decisions. Contrary to the distinctiveness heuristic hypothesis, speeded responding did not eliminate the distinctiveness effect on the Jacoby-Whitehouse illusion. Picture encoding may reduce this illusion via a shift in preretrieval orientation, as opposed to a postretrieval editing process.

Wiseman, A. L., Schacter, D. L., & Budson, A. E. (2007). Retrieval monitoring and anosognosia in Alzheimer's disease: Evidence from the criterial recollection task. Neuropsychology, 21, 559-568.

Abstract: This study explored the relationship between episodic memory and anosognosia (a lack of deficit awareness) among patients with mild Alzheimer’s disease (AD). Participants studied words and pictures for subsequent memory tests. Healthy older adults made fewer false recognition errors when trying to remember pictures compared with words, suggesting that the perceptual distinctiveness of picture memories enhanced retrieval monitoring (the distinctiveness heuristic). In contrast, although participants with AD could discriminate between studied and nonstudied items, they had difficulty recollecting the specific presentation formats (words or pictures), and they had limited use of the distinctiveness heuristic. Critically, the demands of the memory test modulated the relationship between memory accuracy and anosognosia. Greater anosognosia was associated with impaired memory accuracy when participants with AD tried to remember words but not when they tried to remember pictures. These data further delineate the retrieval monitoring difficulties among individuals with AD and suggest that anosognosia measures are most likely to correlate with memory tests that require the effortful retrieval of nondistinctive information.

*Figure chosen for the APA Publication Manual (6th Ed.)

Gallo, D. A., Cotel, S. C., Moore, C. D., & Schacter, D. L. (2007). Aging can spare recollection-based retrieval monitoring: The importance of event distinctiveness. Psychology & Aging, 22, 209-213.

Abstract: The authors investigated two retrieval-monitoring processes. Subjects studied red words and pictures and then decided whether test words had been studied in red font (red word test) or as pictures (picture test). Memory confusions were lower on the picture test than on the red word test, implicating a distinctiveness heuristic. Memory confusions also were lower when study formats were mutually exclusive (the same item was never studied as both a red word and a picture), compared with a nonexclusive condition, implicating a recall-to-reject process. When the to-be-recollected events were pictures, older adults used each monitoring strategy as effectively as did younger adults.

Hwang, D. Y., Gallo, D. A., Ally, B. A., Black, P. M., Schacter, D. L., & Budson, A. E. (2007). Diagnostic monitoring of memory retrieval in patients with frontal lobe lesions: Further exploration of the distinctiveness heuristic. Neuropsychologia, 45, 2543-2552.

Abstract: The distinctiveness heuristic is a diagnostic monitoring strategy whereby a subject expects a vivid recollection if a test item has been seen during the study session; the absence of a vivid recollection suggests the test item is novel. Consistent with the hypothesis that memory monitoring is dependent upon the frontal lobes, previous work using a repetition-lag paradigm found that patients with frontal lobe lesions were unable to use the distinctiveness heuristic. Evidence from recent neuroimaging studies, however, has suggested that use of the distinctiveness heuristic decreases the need for frontal processing. The present study used the criterial recollection task to revisit the question of whether patients with frontal lobe lesions are able to use a distinctiveness heuristic. Subjects studied black words paired with the same word in red font, a corresponding picture of the word, or both. They then took three memory tests designed to elicit false recognition of presented items. Both frontal lesion patients and matched control subjects showed intact ability to use the distinctiveness heuristic to reduce false recognition when tested on whether items were previously presented as pictures compared to red words. This use of the distinctiveness heuristic is evidence that patients with frontal lesions can use certain diagnostic monitoring strategies during recognition memory tasks when given guidance in coordinating their decision-making processes. This result suggests that the frontal lobes are necessary for self-initiation of this strategy during recognition memory tasks.

Schacter, D. L., Gallo, D. A., & Kensinger, E. A. (2007). The cognitive neuroscience of implicit and false memories: Perspectives on processing specificity. In J. S. Nairne (Ed.), The Foundations of Remembering: Essays in Honor of Henry L. Roediger, III (pp. 353-377). New York: Psychology Press.
Gallo, D. A., Bell, D. M., Beier, J. S., & Schacter, D. L. (2006). Two types of recollection-based monitoring in younger and older adults: Recall-to-reject and the distinctiveness heuristic. Memory, 14, 730-741.

Abstract: People often use recollection to avoid false memories. At least two types of recollection-based monitoring processes can be identified in the literature. Recall-to-reject is based on the recall of logically inconsistent information (which disqualifies the false event from having occurred), whereas the distinctiveness heuristic is based on the failure to recall to-be-expected information (which is diagnostic of non-occurrence). We attempted to investigate these hypothetical monitoring processes in a single task, as a first step at delineating the functional relationship between them. By design, participants could reject familiar lures by (1) recalling them from a to-be-excluded list (recall-to-reject) or (2) realising the absence of expected picture recollections (the distinctiveness heuristic). Both manipulations reduced false recognition in young adults, suggesting that these two types of monitoring were deployed on the same test. In contrast, older adults had limited success in reducing false recognition with either manipulation, indicating deficits in recollection-based monitoring processes. Depending on how a retrieval task is structured, attempts to use one monitoring process might interfere with another, especially in older adults.

Gallo, D. A., Kensinger, E. A., & Schacter, D. L. (2006). Prefrontal activity and diagnostic monitoring of memory retrieval: fMRI of the criterial recollection task. Journal of Cognitive Neuroscience, 18, 135-148.
Abstract: According to the distinctiveness heuristic, subjects rely more on detailed recollections (and less on familiarity) when memory is tested for pictures relative to words, leading to reduced false recognition. If so, then neural regions that have been implicated in effortful postretrieval monitoring (e.g., dorsolateral prefrontal cortex) might be recruited less heavily when trying to remember pictures. We tested this prediction with the criterial recollection task. Subjects studied black words, paired with either the same word in red font or a corresponding colored picture. Red words were repeated at study to equate recognition hits for red words and pictures. During fMRI scanning, alternating red word memory tests and picture memory tests were given, using only white words as test stimuli (say “yes” only if you recollect a corresponding red word or picture, respectively). These tests were designed so that subjects had to rely on memory for the criterial information. Replicating prior behavioral work, we found enhanced rejection of lures on the picture test compared to the red word test, indicating that subjects had used a distinctiveness heuristic. Critically, dorsolateral prefrontal activity was reduced when rejecting familiar lures on the picture test, relative to the red word test. These findings indicate that reducing false recognition via the distinctiveness heuristic is not heavily dependent on frontally mediated postretrieval monitoring processes.
Gallo, D. A., Shahid, K. R., Olson, M. A., Solomon, T. M., Schacter, D. L., & Budson, A. E. (2006). Overdependence on degraded gist memory in Alzheimer's disease. Neuropsychology, 20, 625-632.

Abstract: Alzheimer’s disease (AD) reduces associative effects on false recognition in the Deese-Roediger-McDermott task, either due to impaired memory for gist or impaired use of gist in memory decisions. Gist processes were manipulated by blocking or mixing studied words according to their associations and by varying the associative strength between studied and nonstudied words at test. Both associative blocking and associative strength had smaller effects on false recognition in AD patients than in control participants, consistent with gist memory impairments. However, unlike the case with control participants, blocking influenced true and false recognition equally in AD patients, demonstrating an overdependence on gist when making memory decisions. AD also impaired item-specific recollections, relative to control participants, as true recognition of studied words was reduced even when the two groups were equated on gist-based false recognition. We propose that the overdependence on degraded gist memory in AD is caused by even larger impairments in item-specific recollections.

Chan, J. K. C., McDermott, K. B., Watson, J. M., & Gallo, D. A. (2005). The importance of material-processing interactions in inducing false memories. Memory & Cognition, 33, 389-395.

Abstract: Deep encoding, relative to shallow encoding, has been shown to increase the probability of false memories in the Deese/Roediger-McDermott (DRM) paradigm (Thapar & McDermott, 2001; Toglia, Neuschatz, & Goodwin, 1999). In two experiments, we showed important limitations on the generalizability of this phenomenon; these limitations are clearly predicted by existing theories regarding the mechanisms underlying such false memories (e.g., Roediger, Watson, McDermott, & Gallo, 2001). Specifically, asking subjects to attend to phonological relations among lists of phonologically associated words (e.g., weep, steep, etc.) increased the likelihood of false recall (Experiment 1) and false recognition (Experiment 2) of a related, nonpresented associate (e.g., sleep), relative to a condition in which subjects attended to meaningful relations among the words. These findings occurred along with a replication of prior findings (i. e., a semantic encoding task, relative to a phonological encoding task, enhanced the likelihood of false memory arising from a list of semantically associated words), and they place important constraints on theoretical explanations of false memory.

Pierce, B. H., Gallo, D. A., Weiss, J. A., & Schacter, D. L. (2005). The modality effect in false recognition: Evidence for test-based monitoring. Memory & Cognition, 33, 1407-1413.

Abstract: False recognition in the Deese/Roediger-McDermott (DRM) paradigm has been shown to be greater following auditory study than following visual study, but there are competing explanations for this effect. We generalized this phenomenon in Experiment 1, finding an equivalent modality effect for associative (DRM) lists and categorized lists. Because conscious generation and subsequent monitoring of related lures during study is infrequent for categorized lists, this result is inconsistent with the idea that the modality effect is due to a study-based monitoring process. An alternative explanation is that visual study impairs relational processing relative to auditory study, which could cause a modality effect by lowering false recognition of related lures. We tested this idea in Experiment 2, by switching to a meaning-based test that is sensitive only to the retrieval of relational information. A modality effect was not obtained for either type of list on this test. The results from both experiments were predicted by a test-based monitoring account, rather than by the study-based monitoring or relational processing accounts.

Roediger, H. L., III, & Gallo, D. A. (2005). Associative memory illusions. In R. F. Pohl (Ed.), Cognitive Illusions: A Handbook on Fallacies and Biases in Thinking, Judgment and Memory (pp. 309-326). New York: Psychology Press.

No abstract available.

Gallo, D. A. (2004). Using recall to reduce false recognition: Diagnostic and disqualifying monitoring. Journal of Experimental Psychology: Learning, Memory, and Cognition, 30, 120-128.

Abstract: Whether recall of studied words (e.g., parsley, rosemary, thyme) could reduce false recognition of related lures (e.g., basil) was investigated. Subjects studied words from several categories for a final recognition memory test. Half of the subjects were given standard test instructions, and half were instructed to use recall to reduce false recognition. Manipulation checks indicated that the latter instructions did elicit a recall-to-reject strategy. However, false recognition was selectively reduced only when all the words from a category could be recalled (Experiment 1). When longer categories were used, thereby minimizing exhaustive recall, a recall-to-reject strategy was ineffective at reducing false recognition (Experiment 2). It is suggested that exhaustively recalling a category allowed subjects to disqualify the lure as having occurred, analogous to recall-to-reject demonstrations in other tasks. In contrast, partially recalling a category did not help to diagnose the lure as nonstudied.These findings constrain theories of recall-based monitoring processes.

Gallo, D. A., & Seamon, J. G. (2004). Are nonconscious processes sufficient to produce false memories? Consciousness & Cognition, 13, 158-168.

Abstract: Seamon, Luo, and Gallo (1998) reported evidence that nonconscious processes could produce false recognition in a converging-associates task, whereby subjects falsely remember a nonstudied lure (e.g., sleep) after studying a list of related words (bed, rest, awake…). Zeelenberg, Plomp, and Raaijmakers (see record 2003-07789-006; 2003) failed to observe this false recognition effect when list word recognition was at chance. We critically evaluate the evidence for nonsconscious processing and report the results of a new experiment designed to overcome previous methodological limitations. Consistent with Seamon et al., we found that conscious activation of a related lure during study was not necessary for its subsequent recognition; consistent with Zeelenberg et al., we found no evidence for recognition of related lures under conditions where there was no memory for studied words. It is currently unknown whether conscious recollection of the studied items is necessary for false recognition or if nonconscious activation of the lure is sufficient.

Gallo, D. A., Sullivan, A. L., Daffner, K. R., Schacter, D. L., & Budson, A. E. (2004). Associative recognition in Alzheimer's disease: Evidence for impaired recall-to-reject. Neuropsychology, 18, 556-563.

Abstract: Patients with mild Alzheimer’s disease (AD) were compared with age-matched control subjects on an associative recognition task. Subjects studied pairs of unrelated words and were later asked to distinguish between these same studied pairs (intact) and new pairs that contained either rearranged studied words (rearranged) or nonstudied words (nonstudied). Studied pairs were presented either once or 3 times. Repetition increased hits to intact pairs in both groups, but repetition increased false alarms to rearranged pairs only in patients. This latter pattern indicates that repetition increased familiarity of the rearranged pairs, but only the control subjects were able to counter this familiarity by recalling the originally studied pairs (a recall-to-reject process). AD impaired this recall-to-reject process, leading to more familiarity- based false alarms. These data support the idea that recollection-based monitoring processes are impaired in mild AD.

Gallo, D. A., Weiss, J. A., & Schacter, D. L. (2004). Reducing false recognition with criterial recollection tests: Distinctiveness heuristic versus criterion shifts. Journal of Memory & Language, 51, 473-493.

Abstract: We devised criterial recollection tests to investigate why testing memory for pictures elicits lower false recognition than testing memory for words. Subjects studied unrelated black words paired either with the same word in red font, a corresponding picture, or both. They then took three memory tests, always using black words: a recognition test (say “yes” to all studied items), a red word-test, and a picture-test (say “yes” only if you recollect a red word or a picture, respectively). Regardless of whether pictures were more or less familiar than red words, false recognition was lowest on the picture test. These results cannot be explained easily by familiarity or strength-based criterion shifts. Instead, they suggest that subjects expected more detailed recollections for pictures, thereby facilitating a diagnostic monitoring process (the “distinctiveness heuristic”). This recollective difference also influenced source monitoring errors (an “ithad- to-be-a-word” effect), again suggesting that detailed recollective expectations influence monitoring processes.

Roediger, H. L., III, McDermott, K. B., Pisoni, D. B., & Gallo, D. A. (2004). Illusory recollection of voices. Memory, 12, 586-602.

We investigated source misattributions in the DRM false memory paradigm (Deese, 1959, Roediger & McDermott, 1995). Subjects studied words in one of two voices, manipulated between-lists (pure-voice lists) or within-list (mixed-voice lists), and were subsequently given a recognition test with voice-attribution judgments. Experiments 1 and 2 used visual tests. With pure-voice lists (Experiment 1), subjects frequently attributed related lures to the corresponding study voice, despite having the option to not respond. Further, these erroneous attributions remained high with mixed-voice lists (Experiment 2). Thus, even when their related lists were not associated with a particular voice, subjects misattributed the lures to one of the voices. Attributions for studied items were fairly accurate in both cases. Experiments 3 and 4 used auditory tests. With pure-voice lists (Experiment 3), subjects frequently attributed related lures and studied items to the corresponding study voice, regardless of the test voice. In contrast, with mixed-voice lists (Experiment 4), subjects frequently attributed related lures and studied items to the corresponding test voice, regardless of the study voice. These findings indicate that source attributions can be sensitive to voice information provided either at study or at test, even though this information is irrelevant for related lures.

Gallo, D. A., & Roediger, H. L., III. (2003). The effects of associations and aging on illusory recollection. Memory & Cognition, 31, 1036-1044.

Abstract: Younger and older adults (mean years = 20.5 and 75) studied lists of associated words for a final recognition test. The length (5,10, or 15 associates) and modality (auditory or visual) of study lists were manipulated within subjects. For both groups, increasing the number of associates increased illusory recollections of a related lure’s presentation (measured by source judgments and the Memory Characteristics Questionnaire). This pattern suggests that associative activation of the lure influenced illusory recollection, and aging spared this process. In contrast, age impaired the recollection of source for studied words (auditory or visual) and had identical effects on source attributions for related lures. This pattern suggests that the true recollection of source influenced illusory recollection of source, and age impaired this process. To account for these and other results, we propose that associative activation drives an attribution process that binds subjectively detailed features to a false memory.

Pilotti, M., Meade, M. L., & Gallo, D. A. (2003). Implicit and explicit measures of memory for perceptual information in young adults, healthy older adults, and patients with Alzheimer’s disease. Experimental Aging Research, 29, 15-32.

Abstract: In this study, we examined how implicit and explicit memory for perceptual information (modality and voice) and lexical information varied across three subject groups: healthy young adults, healthy older adults, and age-matched older adults with dementia of the Alzheimer’s type (DAT). These groups exhibited cross-modality (abstract) priming of the same magnitude. However, young adults produced greater modality- and voice-specific priming than the other two groups, whose performance was equivalent, suggesting that aging, but not DAT, reduced form-specific priming. Young adults demonstrated better recognition memory than healthy older adults, who in turn exhibited better recognition memory than older adults with DAT. In young adults, recognition memory was also sensitive to perceptual information. These findings indicate that aging can affect implicit memory for perceptual information, whereas DAT magnifies the effect of aging on explicit memory.

Gallo, D. A., & Roediger, H. L., III. (2002). Variability among word lists in evoking memory illusions: Evidence for associative activation and monitoring. Journal of Memory & Language, 47, 469-497.

Abstract: Associative lists created by the same means are remarkably different in their propensity to elicit false memories in the DRM (J. Deese, 1959; H. L. Roediger and K. B. McDermott, 1995) paradigm. The authors confirmed this variability in Experiment 1 (N = 80 undergraduate students) by constructing lists in the typical fashion but with words that were weakly associated to their critical words. Low levels of false recall occurred. In Experiment 2 (N = 90 undergraduate students) these results were replicated at three presentation rates. Also, slower presentation rates yielded lower false recall for both strong and weak lists. Experiment 3 (N = 90 undergraduate students) showed that false recognition rates also varied across lists, as did subjective ratings accompanying false recognition. The authors interpret these findings as supporting an activation/monitoring framework. Lists vary in a principled way in their tendency to activate the critical item, and slowing the presentation rate permits greater accrual of item-specific information that makes monitoring of retrieval more accurate.

Roediger, H. L., III, & Gallo, D. A. (2002). Levels of processing: Some unanswered questions. In M. Naveh-Benjamin, M. Moscovitch, and H. L. Roediger (Eds.), Perspectives on Human Memory and Cognitive Aging: Essays in Honour of Fergus Craik (pp. 28-47). Philadelphia: Psychology Press.

No abstract available.

Roediger, H. L., III, Gallo, D. A., and Geraci, L. (2002). Processing approaches to cognition: The impetus from the levels of processing framework. Memory, 10, 319-322.

Abstract: Processing approaches to cognition have a long history, from act psychology to the present, but perhaps their greatest boost was given by the success and dominance of the levels-of-processing framework. We review the history of processing approaches, and explore the influence of the levels-of-processing approach, the procedural approach advocated by Paul Kolers, and the transfer-appropriate processing framework. Processing approaches emphasizes the procedures of mind and the idea that memory storage can be usefully conceptualized as residing in the same neural units that originally processed information at the time of encoding. Processing approaches emphasize the unity and interrelatedness of cognitive processes and maintain that they can be dissected into separate faculties only by neglecting the richness of mental life. We end by pointing to future directions for processing approaches.

Gallo, D. A., McDermott, K. B., Percer, J. M., & Roediger, H. L., III. (2001). Modality effects in false recall and false recognition. Journal of Experimental Psychology: Learning, Memory, and Cognition, 27, 339-353.

Abstract: R. E. Smith and R. R. Hunt (1998) reported a dramatic reduction in false remembering in a list-learning paradigm by switching from auditory to visual presentation at study. The current authors replicated these modality effects in college students, using written recall and visual recognition tests but obtained smaller effects than those in Smith and Hunt’s study. In contrast, no modality effect occurred on auditory recognition tests. Manipulating study and test modality within-subjects (Experiment 2) and between-subjects (Experiment 3) yielded similar results. It was also found that subjectss frequently judged critical nonstudied words as having been presented in the modality of their corresponding study lists. The authors concluded that subjects could retrieve distinctive information about a study list’s presentation modality to reduce false remembering but only did so under certain conditions. The modality effect on false remembering is a function of both encoding and retrieval factors.

Gallo, D. A., Roediger, H. L., III, & McDermott, K. B. (2001). Associative false recognition occurs without liberal criterion shifts. Psychonomic Bulletin & Review, 8, 579-586.

Abstract: In the DRM (Deese/Roediger and McDermott) false memory paradigm, 96 college students studied lists of words associated with nonpresented critical words. They were tested in one of four instructional conditions. In a standard condition, subjects were not warned about the DRM Effect. In three other conditions, they were told to avoid false recognition of critical words. One group was warned before study of the lists (affecting encoding and retrieval processes), and two groups were warned after study (affecting only retrieval processes). Replicating prior work, the warning before study considerably reduced false recognition. The warning after study also reduced false recognition, but only when critical items had never been studied; when critical items were studied in half the lists so that subjects had to monitor memory for their presence or absence, the warning after study had little effect on false recognition. Because warned subjects were trying to avoid false recognition, the high levels of false recognition in the latter condition cannot be due to strategically guessing that critical test items were studied. False memories in the DRM paradigm are not caused by such liberal criterion shifts.

Roediger, H. L., III, & Gallo, D. A. (2001). Processes affecting accuracy and distortion in memory: An overview. In M. L. Eisen, J. A. Quas, and G. S. Goodman (Eds.), Memory and Suggestibility in the Forensic Interview (pp. 3-28). London: Lawrence Erlbaum.

No abstract available.

Roediger, H. L., III, Watson, J. M., McDermott, K. B., & Gallo, D. A. (2001). Factors that determine false recall: A multiple regression analysis. Psychonomic Bulletin & Review, 8, 385-407.

Abstract: In the Deese-Roediger-McDermott (DRM) paradigm, Ss study lists of words that are designed to elicit the recall of an associatively related critical item. The 55 lists developed provided levels of false recall ranging from .01 to .65, and understanding this variability should provide a key to understanding this memory illusion. The authors assessed the contribution of seven factors in creating false recall of critical items in the DRM paradigm. This analysis accounted for approximately 68% of the variance in false recall, with two main predictors: associative connections from the study words to the critical item and recallability of the lists. Taken together, the variance in false recall captured by these predictors accounted for 84% of the variance that can be explained, given the reliability of the false recall measures. Therefore, the results of this analysis strongly constrain theories of false memory in this paradigm, suggesting that at least two factors determine the propensity of DRM lists to elicit false recall. The results fit well within the theoretical framework postulating that both semantic activation of the critical item and strategic monitoring processes influence the probability of false recall and false recognition in this paradigm.

Pilotti, M., Bergman, E. T., Gallo, D. A., Sommers, M., & Roediger, H. L., III. (2000). Direct comparison of auditory implicit memory tests. Psychonomic Bulletin & Review, 7, 347-353.

Abstract: In this experiment, we examined the degree to which four implicit tests and two explicit tests, all involving auditory presentation, were sensitive to the perceptual characteristics of the stimuli presented during study. Presenting stimuli visually decreased priming in all the implicit memory tests, relative to auditory presentation. However, changing voice between study and test decreased priming only in the implicit memory tests requiring identification of words degraded by noise or by low-pass filtering, but not in those tests requiring generation from word portions (stems and fragments). Modality effects without voice effects were observed in cued recall, but the opposite pattern of results (voice effects without modality effects) was obtained in recognition. The primary new finding is the demonstration that auditory memory tests, both explicit and implicit, differ in their sensitivity to the perceptual information encoded during study.

Pilotti, M., Gallo, D. A., & Roediger, H. L., III. (2000). Effects of hearing words, imaging hearing words, and reading on auditory implicit and explicit memory tests. Memory & Cognition, 28, 1406-1418.

Abstract:  In four experiments, we examined the degree to which imaging written words as spoken by a familiar talker differs from direct perception (hearing words spoken by that talker) and reading words (without imagery) on implicit and explicit tests. Subjects first performed a surface encoding task on spoken, imagined as spoken, or visually presented words, and then were given either an implicit test (perceptual identification or stem completion) or an explicit test (recognition or cued recall) involving auditorily presented words. Auditory presentation at study produced larger priming effects than did imaging or reading. Imaging and reading yielded priming effects of similar magnitude, whereas imaging produced lower performance than reading on the explicit test of cued recall. Voice changes between study and test weakened priming on the implicit tests, but did not affect performance on the explicit tests. Imagined voice changes affected priming only in the implicit task of stem completion. These findings show that the sensitivity of a memory test to perceptual information, either directly perceived or imagined, is an important dimension for dissociating incidental (implicit) and intentional (explicit) retrieval processes.

Roediger, H. L., III, & Gallo, D. A. (2000). False memory. In A. G. Kazdin (Ed.), Encyclopedia of Psychology (pp. 315-317). New York: Oxford University Press.

No abstract available.

Luo, C. R., Johnson, R. A., & Gallo, D. A. (1998). Automatic activation of phonological information in reading: Evidence from the semantic relatedness decision task. Memory & Cognition, 26, 833-843.

Abstract: A semantic relatedness decision task was used to investigate whether phonological recoding occurs automatically and whether it mediates lexical access in visual word recognition and reading. In this task, 82 Ss read a pair of words and decided whether they were related or unrelated in meaning. In Exp 1, unrelated word-homophone pairs (e.g., lion-bare) and their visual controls (e.g., lion-bean) as well as related word pairs (e.g., fish-net) were presented. Homophone pairs were more likely to be judged as related or more slowly rejected as unrelated than their control pairs, suggesting phonological access of word meanings. In Exp 2, word-pseudohomophone pairs (e.g., table-chare) and their visual controls (e.g., table-chark) as well as related and unrelated word pairs were presented. Pseudohomophone pairs were more likely to be judged as related or more slowly rejected as unrelated than their control pairs, again suggesting automatic phonological recoding in reading.

Seamon, J. G., Luo, C. R., & Gallo, D. A. (1998). Creating false memories of words with or without recognition of list items: Evidence for nonconscious processes. Psychological Science, 9, 20-26.

Abstract: Subjects exposed to lists of semantically related words falsely remember nonstudied words that are associated with the list items (e.g., Deese, 1959; Roediger & McDermott, 1995). To determine if subjects would demonstrate this false memory effect if they were unable to recognize the list items, we presented lists of semantically related words with or without a concurrent memory load at rates of 2 s, 250 ms, or 20 ms per word (Experiment 1, between-subjects design) and 2 s or 20 ms per word (Experiment 2, within-subjects design). We found that the subjects falsely recognized semantically related nonstudied words in all conditions, even when they were unable to discriminate studied words from unrelated nonstudied words. Recognition of list items was unnecessary for the occurrence of the false memory effect. This finding suggests that this memory illusion can be based on the nonconscious activation of semantic concepts during list presentation.

Gallo, D. A., Roberts, M. J., & Seamon, J. G. (1997). Remembering words not presented in lists: Can we avoid creating false memories? Psychonomic Bulletin & Review, 4, 271-276.

Abstract:  Can subjects avoid creating false memories as outlined in Roediger and McDermott’s (1995) false recognition paradigm if they are forewarned about this memory illusion? We presented subjects with semantically related word lists, followed by a recognition test. The test was composed of studied words, semantically related nonstudied words (critical lures), and unrelated nonstudied words. One group of subjects was uninformed about the false recognition effect, a second group was urged to minimize all false alarms, and a third group was forewarned about falsely recognizing critical lures. Compared with the uninformed and cautious subjects, the forewarned subjects reduced their false alarm rate for critical lures, and they made remember and know judgments equally often for recognized studied words and critical lures. But forewarning did not eliminate the false recognition effect, as these subjects and those in the other groups made numerous false recognitions in this task.

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