No abstract

No abstract

An influential account of neuronal responses in primary visual cortex is the normalized energy model. This model is often implemented as a two-stage computation. The first stage is the extraction of contrast energy, whereby a complex cell computes the squared and summed outputs of a pair of linear filters in quadrature phase. The second stage is normalization, in which a local population of complex cells mutually inhibit one another. Because the population includes cells tuned to a range of orientations and spatial frequencies, the result is that the responses are effectively normalized by the local stimulus contrast. Here, using evidence from human functional MRI, we show that the classical model fails to account for the relative responses to two classes of stimuli: straight, parallel, band-passed contours (gratings), and curved, band-passed contours (snakes). The snakes elicit fMRI responses that are about twice as large as the gratings, yet traditional energy models, including normalized energy models, predict responses that are about the same. Here, we propose a computational model, in which responses are normalized not by the sum of the contrast energy, but by the orientation anisotropy, computed as the variance in contrast energy across orientation channels. We first show that this model accounts for differential responses to these two classes of stimuli. We then show that the model successfully generalizes to other band-pass textures, both in V1 and in extrastriate cortex (V2 and V3). We speculate that high anisotropy in the orientation responses leads to larger outputs in downstream areas, which in turn normalizes responses in these later visual areas, as well as in V1 via feedback.

Generalization based on functional similarity is often summarized as acquired equivalence (AE). Acquired equivalence has been ubiquitously documented in humans and animals, but its nature remains not well understood. Here, we interpret the phenomenon by postulating that this generalization reflects the processes of representation compression. We formalize a representation compression framework based on the rate-distortion theory (RD), a branch of information theory that characterizes compression as a fundamental tradeoff between the complexity and accuracy of information processing. A reinforcement learning model derived from the RD theory was able to replicate human functional-similarity-based generalization as well as the behaviors in an extended acquired equivalence experiment paradigm where perceptual similarity was also incorporated. We identified from the model a set of low-level cognitive mechanisms proposed in the current AE theories to underlie the generalization in the acquired equivalence task. We conclude that the representation compression framework provides a unified explanation of human acquired equivalence.

Gender is the core component of self-concept and a key dimension of social categorization.Gender Nonconformity refers to the psychological phenomenon that individuals show gender norms that do not correspond or are inconsistent with their birth sex. In recent years, the phenomenon of Gender Nonconformity has become increasingly prominent among adolescents. previous studies have shown that adolescents with Gender Nonconformity face challenges in social adjustment such as peer relationships, but these studies have neglected the psychological mechanism and dynamics behind the influence of Gender Nonconformity on adolescent peer evaluation. To address these limitations, the current study follows the logic of "phenomenon -explanation -prediction" and focuses on the scientific issue concerning the effects of Gender Nonconformity on adolescent peer evaluation and related dynamics. The overall aim of the study is to focus on the attributes (different degrees/types) of Gender Nonconformity, and to explore the impact of Gender Nonconformity on peer evaluation and its pathway mechanisms. On this basis, the study will also explore the dynamic evolution of Gender Nonconformity and provide possible interventions for changing negative peer evaluations of Gender Nonconformity individuals.