Measures of angularity in digital images

In light of the growing interest in studying the affective and aesthetic attributes of curvature, the present paper describes four digital image processing techniques that can be used to objectively discriminate between angular and curvilinear stimuli. MATLAB scripts for each of the techniques accompany the paper. Three studies are then reported that evaluate the efficacy of five metrics, derived from the four techniques, at quantifying the degree of angularity depicted in an image. Images of simple polygons (Study 1), artistic drawings of everyday objects (Study 2), and real-world objects, typefaces, and abstract patterns (Study 3) were analyzed. Logistic regression models were used to determine the relative importance of the metrics at distinguishing between angular and curvilinear items. With one exception, all of the metrics were capable of distinguishing between angular and curvilinear items at a level above chance, but some metrics were better at doing so than others, and their discriminative capacity was influenced by the characteristics of the image. The strengths and limitations of the metrics are discussed, as well as some practical recommendations.

Current evidence on urbanicity and the impact of neighbourhoods on anxiety and stress-related disorders

PURPOSE OF REVIEW

To synthesize recent knowledge on the association of urbanization (and neighbourhood factors) and anxiety and stress-related disorders.

RECENT FINDINGS

The quality of urban neighbourhoods and neighbourhood factors - physical (e.g. green space), social (e.g. social cohesion) and biological (e.g. stress response) factors - are directly linked to the presence and severity of anxiety disorders, although data on posttraumatic stress disorder (PTSD) are pauce. Preliminary data indicate that architectural and space design elements in PTSD can either increase anxiety and lead to trauma triggers or relieve symptoms and reinforce safety. In addition, there is emerging evidence that being raised in urban environments with a wide range of microbial exposure dampens the immune response to psychosocial stressors.

SUMMARY

Evidence points to a higher prevalence of anxiety disorders and PTSD in urban environments. Current research is focused on the role of neighbourhood factors in prevention and treatment. Few studies have assessed comprehensive treatment models in urban populations and the potential moderating role of these factors on treatment outcomes. Several lines of inquiry are starting to address how urban living impacts on biological stress regulation pathways. As urbanization continues, improved understanding of urban mental health is central to informing mental health promotion policies.

An Investigation into Three Visual Characteristics of Complex Scenes that Evoke Human Emotion

Prior computational studies have examined hundreds of visual characteristics related to color, texture, and composition in an attempt to predict human emotional responses. Beyond those myriad features examined in computer science, roundness, angularity, and visual complexity have also been found to evoke emotions in human perceivers, as demonstrated in psychological studies of facial expressions, dance poses, and even simple synthetic visual patterns. Capturing these characteristics algorithmically to incorporate in computational studies, however, has proven difficult. Here we expand the scope of previous computer vision work by examining these three visual characteristics in computer analysis of complex scenes, and compare the results to the hundreds of visual qualities previously examined. A large collection of ecologically valid stimuli (i.e., photos that humans regularly encounter on the web), named the EmoSet and containing more than 40,000 images crawled from web albums, was generated using crowd-sourcing and subjected to human subject emotion ratings. We developed computational methods to the separate indices of roundness, angularity, and complexity, thereby establishing three new computational constructs. Critically, these three new physically interpretable visual constructs achieve comparable classification accuracy to the hundreds of shape, texture, composition, and facial feature characteristics previously examined. In addition, our experimental results show that color features related most strongly with the positivity of perceived emotions, the texture features related more to calmness or excitement, and roundness, angularity, and simplicity related similarly with both of these emotions dimensions.

Preference for Curvature: A Historical and Conceptual Framework

That people find curved contours and lines more pleasurable than straight ones is a recurrent observation in the aesthetic literature. Although such observation has been tested sporadically throughout the history of scientific psychology, only during the last decade has it been the object of systematic research. Recent studies lend support to the idea that human preference for curved contours is biologically determined. However, it has also been argued that this preference is a cultural phenomenon. In this article, we review the available evidence, together with different attempts to explain the nature of preference for curvature: sensoriomotor-based and valuation-based approaches. We also argue that the lack of a unifying framework and clearly defined concepts might be undermining our efforts towards a better understanding of the nature of preference for curvature. Finally, we point to a series of unresolved matters as the starting point to further develop a consistent research program.

The mechanism of valence-space metaphors: ERP evidence for affective word processing

Embodied cognition contends that the representation and processing of concepts involve perceptual, somatosensory, motoric, and other physical re-experiencing information. In this view, affective concepts are also grounded in physical information. For instance, people often say “feeling down” or “cheer up” in daily life. These phrases use spatial information to understand affective concepts. This process is referred to as valence-space metaphor. Valence-space metaphors refer to the employment of spatial information (lower/higher space) to elaborate affective concepts (negative/positive concepts). Previous studies have demonstrated that processing affective words affects performance on a spatial detection task. However, the mechanism(s) behind this effect remain unclear. In the current study, we hypothesized that processing affective words might produce spatial information. Consequently, spatial information would affect the following spatial cue detection/discrimination task. In Experiment 1, participants were asked to remember an affective word. Then, they completed a spatial cue detection task while event-related potentials were recorded. The results indicated that the top cues induced enhanced amplitude of P200 component while participants kept positive words relative to negative words in mind. On the contrary, the bottom cues induced enhanced P200 amplitudes while participants kept negative words relative to positive words in mind. In Experiment 2, we conducted a behavioral experiment that employed a similar paradigm to Experiment 1, but used arrows instead of dots to test the attentional nature of the valence-space metaphor. We found a similar facilitation effect as found in Experiment 1. Positive words facilitated the discrimination of upper arrows, whereas negative words facilitated the discrimination of lower arrows. In summary, affective words might activate spatial information and cause participants to allocate their attention to corresponding locations. Valence-space metaphors might be grounded in attention allocation.