Areas of Research
The External Environment
(The Social and Physical Environment)
Environmental preferences in children
Adults demonstrate pervasive preferences for natural environments over urban ones, and while research demonstrates that people of all ages benefit from nature exposure, environmental preferences have only been assessed in adult populations. To test whether a preference for natural environments was also present in children, a large, diverse sample of 4-to-11-year-old children and their parents completed a tablet-based environmental preference rating task. Unexpectedly, kids showed a preference for urban environments and this preference weakened with age. Children’s preferences were overall, more similar to those of their own parent/guardian relative to other adults in the study, and the similarity between child and parent preferences increased with age. Interestingly, nature exposure (near home, school, or at play) did not predict children’s environmental preferences, but children with more nature near their homes did have lower levels of inattentiveness, controlling for household income. Together, this suggested that 1) the preference for natural environments develops or is learned over time, and 2) that exposure to nature is still related to improved cognitive functioning in children who do not show a preference for natural environments.
Environmental Influences on Thought Content
In this line of work, we investigate the influence of the physical environment on thought content. In one set of studies, we used topic modeling to determine topics that were commonly thought about by visitors to parks (Figure 1). We then saw how the prevalence of these topics varied by park and if that variation was associated with the visual features that were present in the parks. First, and unsurprisingly, we found that people were more likely to think about “Nature” in parks that looked more natural. More surprisingly, we also found that people were more likely to think about a topic related to “Spiritual & Life Journey’ in parks with more non-straight (curved or jagged) edges. We experimentally tested these findings by showing people pictures with different levels of naturalness or non-straight edges and found that these patterns of thoughts replicated, demonstrating a potential causal effect for visual features influencing thought content. We then created scrambled edge versions of the same images which retained their edge features but removed the overt semantic content (Figure 2). We extend previous findings by showing that non-straight edges retain their influence on the selection of a “Spiritual & Life Journey” topic after scene identification removal. These results strengthen the implication of a causal role for the perception of low-level visual features on the influence of higher-order cognitive function, by demonstrating that in the absence of overt semantic content, low-level features, such as edges, influence cognitive processes.
In ongoing work, we are examining the relationship between thought content and visual features in a wider range of environments, using data from Twitter, for example. We are also conducting experimental studies which use experience sampling methods to record the thought content of individuals as they actively explore natural and commercial spaces.
Prospect-Refuge Theory and Aesthetic Preference in Urban Spaces
Architects, urban planners, and researchers alike have been attempting to find ways to engineer the optimal urban environment that pedestrians aesthetically prefer. One theory that lends itself to an individual’s environmental preference is prospect-refuge theory. Prospect-refuge theory is defined as an evolutionary preference for environments that offer a sense of refuge (a place to hide, ensuring safety) while also having prospect (the ability to survey the area around you for resources, potential threats, other organisms) in order to survive. In addition to prospect and refuge, complexity (which is a degree of visual complexity that offers safety and lends itself to preference) and mystery (which implies a sense of discoverability that allows an individual to be able to gather information about surroundings to discern safety) have been shown to contribute to prospect-refuge theory, and ultimately, confer environmental preference. A lack of quantitative studies on urban environments through the lens of prospect-refuge theory have lent the question of prospect-refuge theory’s validity of conferring aesthetic preference, in addition to how urban environments could be quantified in order to answer the former question. By obtaining ratings of each requirement for prospect-refuge theory on 552 sidewalk Google street view images, and decomposing each image into mid- and low-level visual features, both which have demonstrated results that confer environmental preference, we can test the validity of prospect-refuge theory in an urban context.
Evidence and Theory for Lower Rates of Depression in Larger U.S. Urban Areas
Depression is the global leading cause of disability and related economic losses. Cities are associated with increased risk for depression, but how do depression risks change between cities? We developed a mathematical theory for how the built urban environment influences depression risk and predict lower depression rates in larger cities. We demonstrate that this model fits empirical data across four large-scale datasets in U.S. cities. If our model captures some of the underlying causal mechanisms, then these results suggest that depression within cities can be understood, in part, as a collective ecological phenomenon mediated by human social networks and their relationship to the urban built environment.
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The role of preference in the emotional benefits of nature exposure
Nature interactions have been demonstrated to produce reliable affective benefits. While adults demonstrate strong preferences for natural environments over urban ones, it is not clear whether these emotional benefits result from exposure to nature stimuli per se, or whether analogous benefits would be observed from viewing anything that is highly preferred. This question was examined using a set of pre-registered experiments. In one study using preference-equated stimuli, we find that changes in positive and negative affect are not greater for nature images when they are just as preferred as urban images. Next, we induced a negative mood in some participants to see if nature’s affective benefits would be more evident when baseline emotional state was low and compared affect change after viewing really beautiful nature images with equally beautiful cityscapes and cute animals. Results showed that baseline mood didn’t matter, and there was no added benefit of viewing nature images over cityscapes or animals, but individuals’ own ratings of how much they liked the images did predict change in affect. Lastly, we found that preference ratings (“liking”) were equivalent to aesthetics ratings (“beauty”), suggesting that there isn’t some additional factor beyond beauty that makes nature images so highly preferred. Though this study was limited to using nature images and not actual nature exposure, the results suggest that nature has a positive effect on our mood because it is such a highly preferred environment.
Neighborhood greenspace and health in a large urban center
Studies have shown that natural environments can enhance health and here we build upon that work by examining the associations between comprehensive greenspace metrics and health. We focused on a large urban population center (Toronto, Canada) and related the two domains by combining high-resolution satellite imagery and individual tree data from Toronto with questionnaire-based self-reports of general health perception, cardio-metabolic conditions and mental illnesses from the Ontario Health Study. Results from multiple regressions and multivariate canonical correlation analyses suggest that people who live in neighborhoods with a higher density of trees on their streets report significantly higher health perception and significantly less cardio-metabolic conditions (controlling for socio-economic and demographic factors). We find that having 10 more trees in a city block, on average, improves health perception in ways comparable to an increase in annual personal income of $10,000 and moving to a neighborhood with $10,000 higher median income or being 7 years younger. We also find that having 11 more trees in a city block, on average, decreases cardio-metabolic conditions in ways comparable to an increase in annual personal income of $20,000 and moving to a neighborhood with $20,000 higher median income or being 1.4 years younger.
Is the preference of natural versus man-made scenes driven by bottom-up processing of the visual features of nature?
Previous research has shown that viewing images of nature scenes can have a beneficial effect on memory, attention, and mood. In this study, we aimed to determine whether the preference of natural versus man-made scenes is driven by bottom–up processing of the low-level visual features of nature. We used participants’ ratings of perceived naturalness as well as esthetic preference for 307 images with varied natural and urban content. We then quantified 10 low-level image features for each image (a combination of spatial and color properties). These features were used to predict esthetic preference in the images, as well as to decompose perceived naturalness to its predictable (modeled by the low-level visual features) and non-modeled aspects. Interactions of these separate aspects of naturalness with the time it took to make a preference judgment showed that naturalness based on low-level features related more to preference when the judgment was faster (bottom–up). On the other hand, perceived naturalness that was not modeled by low-level features was related more to preference when the judgment was slower. A quadratic discriminant classification analysis showed how relevant each aspect of naturalness (modeled and non-modeled) was to predicting preference ratings, as well as the image features on their own. Finally, we compared the effect of color-related and structure-related modeled naturalness, and the remaining unmodeled naturalness in predicting esthetic preference. In summary, bottom–up (color and spatial) properties of natural images captured by our features and the non-modeled naturalness are important to esthetic judgments of natural and man-made scenes, with each predicting unique variance.
The perception of naturalness correlates with low-level visual features of environmental scenes
Previous research has shown that interacting with natural environments vs. more urban or built environments can have salubrious psychological effects, such as improvements in attention and memory. Even viewing pictures of nature vs. pictures of built environments can produce similar effects. A major question is: What is it about natural environments that produces these benefits? Problematically, there are many differing qualities between natural and urban environments, making it difficult to narrow down the dimensions of nature that may lead to these benefits. In this study, we set out to uncover visual features that related to individuals’ perceptions of naturalness in images. We quantified naturalness in two ways: first, implicitly using a multidimensional scaling analysis and second, explicitly with direct naturalness ratings. Features that seemed most related to perceptions of naturalness were related to the density of contrast changes in the scene, the density of straight lines in the scene, the average color saturation in the scene and the average hue diversity in the scene. We then trained a machine-learning algorithm to predict whether a scene was perceived as being natural or not based on these low-level visual features and we could do so with 81% accuracy. As such we were able to reliably predict subjective perceptions of naturalness with objective low-level visual features. Our results can be used in future studies to determine if these features, which are related to naturalness, may also lead to the benefits attained from interacting with nature.
Social rejection shares somatosensory representations with physical pain
How similar are the experiences of social rejection and physical pain? Extant research suggests that a network of brain regions that support the affective but not the sensory components of physical pain underlie both experiences. Here we demonstrate that when rejection is powerfully elicited—by having people who recently experienced an unwanted break-up view a photograph of their ex-partner as they think about being rejected—areas that support the sensory components of physical pain (secondary somatosensory cortex; dorsal posterior insula) become active. We demonstrate the overlap between social rejection and physical pain in these areas by comparing both conditions in the same individuals using functional MRI. We further demonstrate the specificity of the secondary somatosensory cortex and dorsal posterior insula activity to physical pain by comparing activated locations in our study with a database of over 500 published studies. Activation in these regions was highly diagnostic of physical pain, with positive predictive values up to 88%. These results give new meaning to the idea that rejection “hurts.” They demonstrate that rejection and physical pain are similar not only in that they are both distressing—they share a common somatosensory representation as well.