Everyday, people flexibly perform different categorizations of common faces, objects and scenes. Intuition and scattered evidence suggest that these categorizations require the use of different visual information from the input. However, there is no unifying method, based on the categorization performance of subjects, that can isolate the information used. To this end, we developed Bubbles, a general technique that can assign the credit of human categorization performance to specific visual information. To illustrate the technique, we applied Bubbles on three categorization tasks (gender, expressive or not and identity) on the same set of faces, with human and ideal observers to compare the features they used.

Bubbles: A Technique to Reveal the Use of Information in Recognition Tasks EOA Report

The increasing prevalence of infectious diseases in recent decades has posed a serious threat to public health. Routes of transmission differ, but the respiratory droplet or airborne route has the greatest potential to disrupt social intercourse, while being amenable to prevention by the humble face mask. Different types of masks give different levels of protection to the user. The ongoing COVID-19 pandemic has even resulted in a global shortage of face masks and the raw materials that go into them, driving individuals to self-produce masks from household items. At the same time, research has been accelerated towards improving the quality and performance of face masks, e.g., by introducing properties such as antimicrobial activity and superhydrophobicity. This review will cover mask-wearing from the public health perspective, the technical details of commercial and home-made masks, and recent advances in mask engineering, disinfection, and materials and discuss the sustainability of mask-wearing and mask production into the future.

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Face Masks in the New COVID-19 Normal: Materials, Testing, and Perspectives.

To memorize both feature and spatiotemporal information of moving objects is a critical human activity.Much research has been done to explore the storage of visual information from a static scene in working memory and to investigate how visual information is dynamically updated in a multiple object tracking task;however,the storage of motion information of multiple objects in working memory has been rarely discussed.By combining multi-object tracking and change detection paradigms,with individual moving objects as stimuli,the present research investigated the capacity of visual working memory for moving objects and the results indicated that about 3 objects can be retained in visual working memory.

The Capacity of Visual Working Memory for Motion Direction of Objects

The identification of emotional expressions is vital for social interaction, and can be affected by various factors, including the expressed emotion, the intensity of the expression, the sex of the face, and the gender of the observer. This study investigates how these factors affect the speed and accuracy of expression recognition, as well as dwell time on the two most significant areas of the face: the eyes and the mouth. Participants were asked to identify expressions from female and male faces displaying six expressions (anger, disgust, fear, happiness, sadness, and surprise), each with three levels of intensity (low, moderate, and normal). Overall, responses were fastest and most accurate for happy expressions, but slowest and least accurate for fearful expressions. More intense expressions were also classified most accurately. Reaction time showed a different pattern, with slowest response times recorded for expressions of moderate intensity. Overall, responses were slowest, but also most accurate, for female faces. Relative to male observers, women showed greater accuracy and speed when recognizing female expressions. Dwell time analyses revealed that attention to the eyes was about three times greater than on the mouth, with fearful eyes in particular attracting longer dwell times. The mouth region was attended to the most for fearful, angry, and disgusted expressions and least for surprise. These results extend upon previous findings to show important effects of expression, emotion intensity, and sex on expression recognition and gaze behaviour, and may have implications for understanding the ways in which emotion recognition abilities break down.

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Identification of Emotional Facial Expressions: Effects of Expression, Intensity, and Sex on Eye Gaze

Covid-19 pandemics has fostered a pervasive use of facemasks all around the world. While they help in preventing infection, there are concerns related to the possible impact of facemasks on social communication. The present study investigates how emotion recognition, trust attribution and re-identification of faces differ when faces are seen without mask, with a standard medical facemask, and with a transparent facemask restoring visual access to the mouth region. Our results show that, in contrast to standard medical facemasks, transparent masks significantly spare the capability to recognize emotional expressions. Moreover, transparent masks spare the capability to infer trustworthiness from faces with respect to standard medical facemasks which, in turn, dampen the perceived untrustworthiness of faces. Remarkably, while transparent masks (unlike standard masks) do not impair emotion recognition and trust attribution, they seemingly do impair the subsequent re-identification of the same, unmasked, face (like standard masks). Taken together, this evidence supports a dissociation between mechanisms sustaining emotion and identity processing. This study represents a pivotal step in the much-needed analysis of face reading when the lower portion of the face is occluded by a facemask.

/pdf/the-impact-of-facemasks-on-emotion-recognition-trust-l83864pudp.pdf

The impact of facemasks on emotion recognition, trust attribution and re-identification

When distinguishing whether a face displays a certain emotion, some regions of the face may contain more useful information than others. Here we ask whether people differentially attend to distinct regions of a face when judging different emotions. Experiment 1 measured eye movements while participants discriminated between emotional (joy, anger, fear, sadness, shame, and disgust) and neutral facial expressions. Participant eye movements primarily fell in five distinct regions (eyes, upper nose, lower nose, upper lip, nasion). Distinct fixation patterns emerged for each emotion, such as a focus on the lips for joyful faces and a focus on the eyes for sad faces. These patterns were strongest for emotional faces but were still present when viewers sought evidence of emotion within neutral faces, indicating a goal-driven influence on eye-gaze patterns. Experiment 2 verified that these fixation patterns tended to reflect attention to the most diagnostic regions of the face for each emotion. Eye movements appear to follow both stimulus-driven and goal-driven perceptual strategies when decoding emotional information from a face.

Eye movements during emotion recognition in faces.

Almost all models of visual memory implicitly assume that errors in mnemonic representations are linearly related to distance in stimulus space. Here we show that neither memory nor perception are appropriately scaled in stimulus space; instead, they are based on a transformed similarity representation that is nonlinearly related to stimulus space. This result calls into question a foundational assumption of extant models of visual working memory. Once psychophysical similarity is taken into account, aspects of memory that have been thought to demonstrate a fixed working memory capacity of around three or four items and to require fundamentally different representations—across different stimuli, tasks and types of memory—can be parsimoniously explained with a unitary signal detection framework. These results have substantial implications for the study of visual memory and lead to a substantial reinterpretation of the relationship between perception, working memory and long-term memory. Schurgin et al. propose a model of visual memory, arguing against a distinction between how many items are represented and how precisely they are represented, and in favour of a view based on continuous representations in noisy channels.

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Psychophysical scaling reveals a unified theory of visual memory strength.

Models of visual memory have operated on the assumption that memory representations can be explained in physical stimulus space, leading to proposals that we have fixed limits on visual working memory capacity and there is a strong distinction between working memory and longterm memory representations. Here we show that perception and memory are not based on physical stimulus space, and instead rely on a transformed representation that is non-linearly related to the physical stimulus space. This result calls into question the fundamental basis of nearly all extant models. We show that when psychophysical distance rather than physical distance is considered, aspects of memory that have required fundamentally different models -- across different stimuli, tasks, and even the distinction between working and long-term memory -- can be explained with a unitary signal detection framework. These results lead to a substantial reinterpretation of the relationship between perception, working memory and longterm memory.

https://www.biorxiv.org/content/biorxiv/early/2019/08/16/325472.full.pdf

Psychophysical Scaling Reveals a Unified Theory of Visual Memory Strength

The majority of research on visual memory has taken a compartmentalized approach, focusing exclusively on memory over shorter or longer durations, that is, visual working memory (VWM) or visual episodic long-term memory (VLTM), respectively. This tutorial provides a review spanning the two areas, with readers in mind who may only be familiar with one or the other. The review is divided into six sections. It starts by distinguishing VWM and VLTM from one another, in terms of how they are generally defined and their relative functions. This is followed by a review of the major theories and methods guiding VLTM and VWM research. The final section is devoted toward identifying points of overlap and distinction across the two literatures to provide a synthesis that will inform future research in both fields. By more intimately relating methods and theories from VWM and VLTM to one another, new advances can be made that may shed light on the kinds of representational content and structure supporting human visual memory.

https://link.springer.com/content/pdf/10.3758%2Fs13414-018-1522-y.pdf

Visual memory, the long and the short of it: A review of visual working memory and long-term memory.

Limits on the storage capacity of working memory have been investigated for decades, but the nature of those limits remains elusive. An important but largely overlooked consideration in this research concerns the relationship between the physical properties of stimuli used in visual working memory tasks and their psychological properties. Here, we show that the relationship between physical distance in stimulus space and the psychological confusability of items as measured in a perceptual task is non-linear. Taking into account this relationship leads to a parsimonious conceptualization of visual working memory, greatly simplifying the models needed to account for performance, allowing generalization to new stimulus spaces, and providing a mapping between tasks that have been thought to measure distinct qualities. In particular, performance across a variety of working memory tasks can be explained by a one-parameter model implemented within a signal detection framework. Moreover, despite the system-level distinctions between working and long-term memory, after taking into account psychological distance we find a strong affinity between the theoretical frameworks that guide both systems, as performance is accurately described using the same straightforward signal detection framework.

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Mark W. Schurgin

Papers

Eye movements during emotion recognition in faces.

Psychophysical scaling reveals a unified theory of visual memory strength.

Psychophysical Scaling Reveals a Unified Theory of Visual Memory Strength

Visual memory, the long and the short of it: A review of visual working memory and long-term memory.

Psychological Scaling Reveals a Single Parameter Framework For Visual Working Memory