Egocentric Distance Perception Disorder in Amblyopia

Egocentric distance perception is a psychological process in which observers use various depth cues to estimate the distance between a target and themselves. The impairment of basic visual function and treatment of amblyopia have been well documented. However, the disorder of egocentric distance perception of amblyopes is poorly understood. In this review, we describe the cognitive mechanism of egocentric distance perception, and then, we focus on empirical evidence for disorders in egocentric distance perception for amblyopes in the whole visual space. In the personal space (within 2 m), it is difficult for amblyopes to show normal hand-eye coordination; in the action space (within 2 m~30 m), amblyopes cannot accurately judge the distance of a target suspended in the air. Few studies have focused on the performance of amblyopes in the vista space (more than 30 m). Finally, five critical topics for future research are discussed: 1) it is necessary to systematically explore the mechanism of egocentric distance perception in all three spaces; 2) the laws of egocentric distance perception in moving objects for amblyopes should be explored; and 3) the comparison of three subtypes of amblyopia is still insufficient; 4) study the perception of distance under another theoretical framework; 5) explore the mechanisms of amblyopia by Virtual Reality.     

An evaluation of a three‐component multiple schedule to indicate attention availability

Students may engage in high rates of social approach responses at inappropriate times throughout the school day. One intervention that has been used to teach students appropriate and inappropriate times to access attention is a multiple schedule of reinforcement. In this study, we evaluated the efficacy of a multiple schedule that indicated when attention was available or not available in a bilingual preschool classroom during small‐group instruction. Results showed that the intervention was effective in bringing students’ social approaches under stimulus control.     

情绪学习促进无意识信息进入意识

采用突破连续闪烁抑制范式(b-CFS), 考察了经过情绪学习的刺激在无意识中是否存在加工优势。实验1使用不同朝向的光栅刺激, 结果发现情绪学习条件比对照条件的刺激在CFS中突破抑制时间更短。实验2考察了更复杂的朝向和颜色整合的光栅刺激, 发现情绪优势效应具有特异性, 仅局限于情绪学习的整合刺激。研究表明经过情绪学习后的刺激在无意识加工中存在优势。     

How Animals Classify Friends and Foes

A model of stimulus equivalence, which describes how non-similarity-based categories are formed, is used to describe aspects of animal social and communicative interactions such as kinship, friendship, coalitions, territorial behavior, and referential calling. Although this model was originally designed to deal with stimulus relations in linguistic behavior, it can be readily applied to understanding the cognitive mechanisms that underlie social as well as nonsocial categorizations in numerous taxa. This approach provides a new, parsimonious, and experimentally based understanding of how animals without language deal with problems of classification in their environment.     

Pseudoneglect in back space

Successful interaction with the environment depends upon our ability to retain and update visuo-spatial information of both front and back egocentric space. Several studies have observed that healthy people tend to show a displacement of the egocentric frame of reference towards the left. However representation of space behind us (back space) has never been systematically investigated in healthy people. In this study, by means of a novel visual imagery task performed within a virtual reality environment, we found that representation of right back space is perceived as smaller than the left. These results suggest that there is a selective compression or distortion for mental representation related to the right space behind us.     

Spatial limits on referred touch to an alien limb may reflect boundaries of visuo-tactile peripersonal space surrounding the hand

In this study, the spatial limits of referred touch to a rubber hand were investigated. Participants rated the strength of the perceived illusion when the rubber hand was placed in one of six different spatial positions (at a distance of 17.5-67.5cm horizontal from the participant's own hand). The results revealed a significant nonlinear relationship in the strength of the illusion, with the strongest ratings given when the two hands were closest; decaying significantly after a distance of 30cm. The time taken to elicit the illusion followed a similar trend. These results may reflect the response properties of bimodal visuo-tactile cells encoding peripersonal space around the hand.     

Contextual control by function and form of transfer of functions

This study investigated conditions leading to contextual control by stimulus topography over transfer of functions. Three 4-member stimulus equivalence classes, each consisting of four (A, B, C, D) topographically distinct visual stimuli, were established for 5 college students. Across classes, designated A stimuli were open-ended linear figures, B stimuli were circular, C stimuli three-sided, and D stimuli four-sided. Three different computer tasks then were trained with the B stimuli. Differential reinforcement and punishment procedures were then used to establish control over function transfer by the topography of the class members. For Task 1, function transfer, responding to C and D stimuli as subjects had to B stimuli, was reinforced. For Task 2, function transfer was reinforced for C stimuli but punished for D stimuli. For Task 3, function transfer was punished for both C and D stimuli. New equivalence classes were then established and tests for generalized contextual control were presented. All 5 subjects showed generalized contextual control of transfer of functions by stimulus topography. Implications of contextual control over function transfer in natural settings are discussed.     

PREFERENCE FOR A STIMULUS THAT FOLLOWS A RELATIVELY AVERSIVE EVENT: CONTRAST OR DELAY REDUCTION?

Several types of contrast effects have been identified including incentive contrast, anticipatory contrast, and behavioral contrast. Clement, Feltus, Kaiser, and Zentall (2000) proposed a type of contrast that appears to be different from these others and called it within-trial contrast. In this form of contrast the relative value of a reinforcer depends on the events that occur immediately prior to the reinforcer. Reinforcers that follow relatively aversive events are preferred over those that follow less aversive events. In many cases the delay reduction hypothesis proposed by Fantino (1969) also can account for such effects. The current experiments provide a direct test of the delay reduction and contrast hypotheses by manipulating the schedule of reinforcement while holding trial duration constant. In Experiment 1, preference for fixed-interval (FI) versus differential-reinforcement-of-other-behavior (DRO) schedules of reinforcement was assessed. Some pigeons preferred one schedule over the other while others demonstrated a position (side) preference. Thus, no systematic preference was found. In Experiment 2, a simultaneous color discrimination followed the FI or DRO schedule, and following training, preference was assessed by presenting the two positive stimuli simultaneously. Consistent with the contrast hypothesis, pigeons showed a significant preference for the positive stimulus that in training had followed their less preferred schedule.