Development of population receptive fields in the lateral visual stream improves spatial coding amid stable structural-functional coupling.

Human visual cortex encompasses more than a dozen visual field maps across three major processing streams. One of these streams is the lateral visual stream, which extends from V1 to lateral-occipital (LO) and temporal-occipital (TO) visual field maps and plays a prominent role in shape as well as motion perception. However, it is unknown if and how population receptive fields (pRFs) in the lateral visual stream develop from childhood to adulthood, and what impact this development may have on spatial coding. Here, we used functional magnetic resonance imaging and pRF modeling in school-age children and adults to investigate the development of the lateral visual stream. Our data reveal four main findings: 1) The topographic organization of eccentricity and polar angle maps of the lateral stream is stable after age five. 2) In both age groups there is a reliable relationship between eccentricity map transitions and cortical folding: the middle occipital gyrus predicts the transition between the peripheral representation of LO and TO maps. 3) pRFs in LO and TO maps undergo differential development from childhood to adulthood, resulting in increasing coverage of the central visual field in LO and of the peripheral visual field in TO. 4) Model-based decoding shows that the consequence of pRF and visual field coverage development is improved spatial decoding from LO and TO distributed responses in adults vs. children. Together, these results explicate both the development and topography of the lateral visual stream. Our data show that the general structural-functional organization is laid out early in development, but fine-scale properties, such as pRF distribution across the visual field and consequently, spatial precision, become fine-tuned across childhood development. These findings advance understanding of the development of the human visual system from childhood to adulthood and provide an essential foundation for understanding developmental deficits.

Seeing no pain: Assessing the generalizability of racial bias in pain perception.

Racial disparities in pain care may stem, in part, from perceptual roots. It remains unresolved, however, whether this perceptual gap is driven by general deficits in intergroup emotion recognition, endorsement of specific racial stereotypes, or an interaction between the two. We conducted four experiments (total N = 635) assessing relationships between biases in pain perception and treatment and biases in the perception of anger, happiness, fear, and sadness. Participants saw Black and White male targets making increasingly painful and angry (Experiment 1), happy (Experiment 2), fearful (Experiment 3), or sad expressions (Experiment 4). The effect of target race consistently varied based on the emotion displayed. Participants repeatedly saw pain more readily on White (vs. Black) male faces. However, while participants also saw sadness less readily on Black faces, perception of anger, fear, and happiness did not vary by target race. Moreover, the tendency to see pain less readily on Black faces predicted similar differences in recognizing (particularly negative) expressions, though only racial bias in pain perception facilitated similar biases in treatment. Finally, while endorsement of racialized threat stereotypes facilitated recognition of angry expressions and was marginally associated with impeded recognition of happy expressions on Black faces, gaps in pain perception were not reliably related to stereotype endorsement. These data suggest that while racial bias in pain perception is associated with a general bias in recognizing negative emotion on Black male faces, the effects of target race on pain perception are particularly robust and have distinct consequences for gaps in treatment. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The Delaware Pain Database: a set of painful expressions and corresponding norming data.

INTRODUCTION: Facial expressions of pain serve an essential social function by communicating suffering and soliciting aid. Accurate visual perception of painful expressions is critical because the misperception of pain signals can have serious clinical and social consequences. Therefore, it is essential that researchers have access to high-quality, diverse databases of painful expressions to better understand accuracy and bias in pain perception. OBJECTIVES: This article describes the development of a large-scale face stimulus database focusing on expressions of pain. METHODS: We collected and normed a database of images of models posing painful facial expressions. We also characterized these stimuli in terms of the presence of a series of pain-relevant facial action units. In addition to our primary database of posed expressions, we provide a separate database of computer-rendered expressions of pain that may be applied to any neutral face photograph. RESULTS: The resulting database comprises 229 unique (and now publicly available) painful expressions. To the best of our knowledge, there are no existing databases of this size, quality, or diversity in terms of race, gender, and expression intensity. We provide evidence for the reliability of expressions and evaluations of pain within these stimuli, as well as a full characterization of this set along dimensions relevant to pain such as perceived status, strength, and dominance. Moreover, our second database complements the primary set in terms of experimental control and precision. CONCLUSION: These stimuli will facilitate reproducible research in both experimental and clinical domains into the mechanisms supporting accuracy and bias in pain perception and care.