Perceptual learning in flavor-aversion learning: Alternating and blocked exposure to a compound of flavors and to an element of that compound

Rats received different schedules of pre-exposure to a compound flavor (AX) and to one element of that compound (X). In Group ALT, exposure consisted of alternating trials with AX and X; Group BLK received a block with all AX trials before a separate block with all X trials (or vice versa). Discrimination between AX and X was assessed then by establishing an aversion to X and measuring the generalization of this aversion to AX. In Experiments 1A and 1B, generalization was less in Group ALT than in Group BLK. In Experiment 2, this latter result was confirmed and furthermore only Group ALT, and not Group BLK, showed less generalization than a group that received exposure to X alone. These results are discussed in terms of their implications for theories of perceptual learning.     

Perceptual Learning of Intonation Contour Categories in Adults and 9‐ to 11‐Year‐Old Children: Adults Are More Narrow‐Minded

We report on rapid perceptual learning of intonation contour categories in adults and 9‐ to 11‐year‐old children. Intonation contours are temporally extended patterns, whose perception requires temporal integration and therefore poses significant working memory challenges. Both children and adults form relatively abstract representations of intonation contours: Previously encountered and novel exemplars are categorized together equally often, as long as distance from the prototype is controlled. However, age‐related differences in categorization performance also exist. Given the same experience, adults form narrower categories than children. In addition, adults pay more attention to the end of the contour, while children appear to pay equal attention to the beginning and the end. The age range we examine appears to capture the tail‐end of the developmental trajectory for learning intonation contour categories: There is a continuous effect of age on category breadth within the child group, but the oldest children (older than 10;3) are adult‐like.     

汉字部件水平的重复知盲效应

本研究采用不同部件特点的汉字材料考察在汉字部件水平的重复知盲效应。实验1探究在一组刺激序列中,当两个关键刺激R1和R2的相同部件在不同位置时对重复知盲效应的影响。实验1结果表明,不同条件的重复知盲效应存在显著差异,但其中两个关键字中相同部件的位置相同时与部件位置不同时之间的重复知盲效应无显著差异,这表明部件位置对重复知盲现象无显著影响。实验2探究当关键刺激R1和R2为部件包含关系时的重复知盲效应。实验2结果表明,当一个关键刺激为独体字,且是另一个关键刺激的部件时存在重复知盲效应,其效应的大小会受到具有包含关系的两个关键字（合体字和独体字）在刺激序列中出现顺序的影响,当第二个关键刺激为独体字时的重复知盲效应要显著强于第二个关键刺激为合体字条件。研究结论是不同的汉字部件特点会影响重复之盲效应,这表明重复知盲现象很可能发生在在线的知觉加工过程。     

视网膜离心率影响空间注意梯度分布

采用同步判断(Simultaneous judgment, SJ)的研究范式探讨空间注意梯度是否受到视网膜离心率的影响。实验中给被试呈现两个目标刺激, 调节它们的呈现距离和间隔时间, 让被试进行不限时的同步判断, 计算出各种距离上的主观等同点(Point of Subjective Simultaneous, PSS)变化情况。实验中对比了注视点和注意点重合与分离的两种状态。其中注视点和注意点分离的状态是指使用反向掩蔽后的线索刺激将注意点内隐地引导到外周。通过控制似动等影响因素, 发现在注意点和注视点分离的状态下存在距离效应—— 也就是随着距离的增长主观等同点变化越大, 但是在重合的状态下则没有。结果表明分离状态下存在传统意义上的注意梯度效应, 而重合时, 注意易化梯度受到一个抑制梯度的影响。这说明, 注意梯度分布受到视网膜离心率的影响, 而影响方式符合注意点为中心的易化梯度场和注视点为中心的抑制梯度场的双梯度场理论。     

How does reading direction modulate perceptual asymmetry effects?

Left-side bias effects refer to a bias towards the left side of the stimulus/space in perceptual/visuospatial judgments, and are argued to reflect dominance of right hemisphere processing. It remains unclear whether reading direction can also account for the bias effect. Previous studies comparing readers of languages read from left to right with those read from right to left (e.g., French vs. Hebrew) have obtained inconsistent results. As a language that can be read from left to right or from right to left, Chinese provides a unique opportunity for a within-culture examination of reading direction effects. Chinese participants performed a perceptual judgment task (with both face and Chinese character stimuli; Experiment 1) and two visuospatial attention tasks (the greyscales and line bisection tasks; Experiment 2) once before and once after a reading task, in which they read Chinese passages either from left to right or from right to left for about 20 min. After reading from right to left, participants showed significantly reduced left-side bias in Chinese character perceptual judgments but not in the other three tasks. This effect suggests that the role of reading direction on different forms of left-side bias may differ, and its modulation may be stimulus-specific.     

Young children's haptic exploratory procedures

Adults vary their haptic exploratory behavior reliably with variation both in the sensory input and in the task goals. Little is known about the development of these connections between perceptual goals and exploratory behaviors. A total of 36 children ages 3, 4, and 5 years and 20 adults completed a haptic intramodal match-to-sample task. Participants were instructed to feel the shape, texture, rigidity, or weight of a sample object and then were asked to find which of three test objects matched the sample on that specific property. Hand movements were examined to determine whether children produced the same exploratory procedures while gathering perceptual information about each property as adults who searched for the same kind of information. Children demonstrated that they had good haptic abilities in two ways: They matched the sample objects on the specified perceptual dimension at near ceiling levels, and they produced the same hand movement patterns to find the same properties as adults.     

Target-mask shape congruence impacts the type of metacontrast masking

Visual metacontrast masking may depend on the time intervals between target and mask in two qualitatively different ways: in type-A masking the smaller the mask delay from target the stronger the masking while in type-B masking maximal masking effect is obtained with a larger temporal delay of the mask. Variability in the qualitative apperance of masking functions has been explained by variability in stimuli parameters and tasks. Recent research on metacontrast masking has surprisingly shown that both of these types of functions can be found with an identical range of stimulation parameters depending on individual differences between observers. Here we show that obtaining clear-cut type-A masking depends on whether target and mask shapes are congruent or incongruent and whether observers use the cues available due to the congruence factor. Conspicuously expressed type-A masking is selectively associated with incongruent target-mask pairings. In the latter conditions target identification level significantly drops with the shortest target-to-mask delays.     

Contextual modulation of reading rate for direct versus indirect speech quotations

In human communication, direct speech (e.g., Mary said: “I’m hungry”) is perceived to be more vivid than indirect speech (e.g., Mary said [that] she was hungry). However, the processing consequences of this distinction are largely unclear. In two experiments, participants were asked to either orally (Experiment 1) or silently (Experiment 2, eye-tracking) read written stories that contained either a direct speech or an indirect speech quotation. The context preceding those quotations described a situation that implied either a fast-speaking or a slow-speaking quoted protagonist. It was found that this context manipulation affected reading rates (in both oral and silent reading) for direct speech quotations, but not for indirect speech quotations. This suggests that readers are more likely to engage in perceptual simulations of the reported speech act when reading direct speech as opposed to meaning-equivalent indirect speech quotations, as part of a more vivid representation of the former.     

Perceptual training strongly improves visual motion perception in schizophrenia

Schizophrenia patients exhibit perceptual and cognitive deficits, including in visual motion processing. Given that cognitive systems depend upon perceptual inputs, improving patients’ perceptual abilities may be an effective means of cognitive intervention. In healthy people, motion perception can be enhanced through perceptual learning, but it is unknown whether this perceptual plasticity remains in schizophrenia patients. The present study examined the degree to which patients’ performance on visual motion discrimination can be improved, using a perceptual learning procedure. While both schizophrenia patients and healthy controls showed decreased direction discrimination thresholds (improved performance) with training, the magnitude of the improvement was greater in patients (47% improvement) than in controls (21% improvement). Both groups also improved moderately but non-significantly on an untrained task—speed discrimination. The large perceptual training effect in patients on the trained task suggests that perceptual plasticity is robust in schizophrenia and can be applied to develop bottom-up behavioral interventions.     

Computational explorations of perceptual symbol systems theory

The aim of this paper is twofold. First, we provide a methodological pathway from theories of situated, embodied cognition to simulations with an eye to empirical evidence, and suggest a possible cross-fertilization between cognitive robotics and psychology. Psychological theories, in particular those formulated at an abstract level, include models which are often severely underspecified at the level of mechanisms. This is true in the synchronic, constructive perspective (how can the effects observed in experiments be concretely generated by the model's mechanisms?) and in the diachronic, developmental perspective (how can such mechanisms be learned and developed?). The synthetic method of artificial cognitive systems research, and in particular of cognitive robotics, can complement research in psychology (and neurosciences) by exploring the constructive and developmental aspects of theories. Our second aim is to provide an example of such a methodology by describing simulations aiming at developing a perceptual symbol system (PSS) (Barsalou, 1999). We then describe the two main theoretical constructs of the PSS, perceptual symbols and simulators, illustrate their development in an artificial system, and test the system in prediction, categorization, and abstraction tasks.