Short-term visual memory for contour curvature in a delayed discrimination task

Abstract: A two-interval forced-choice of constant stimuli was used to measure the point of subjective equality (PSE) and discrimination threshold for standard contour curvature (1.91, 3.24 deg⁻¹) held in short-term visual memory (STVM). At both standard curvatures, the PSE for remembered curvature was nearly constant for standard curvature from 2 s to 16 s retention intervals, while the discrimination threshold increased as a linear function of retention interval. These results show that the decay in STVM for contour curvature is due to the noisy representation of curvature, neither to fading of the represented curvature nor to converging to the constant curvature. Furthermore, the Weber fraction was nearly constant for both standard curvatures at any delay from 2 to 16 s.     

Individual Differences in Spatial Memory and Striatal ChAT Activity among Young and Aged Rats

Individual differences in spatial memory among young and aged rats were assessed using memory tasks related to integrity of the hippocampus and the neostriatum. Relationships were then examined between measures of spatial memory and regional choline acetyltransferase (ChAT) activity, a marker for cholinergic integrity. Twenty-four-month-old Long-Evans rats were impaired in comparisons with 6-month-old rats on measures of place learning, working memory, reference memory, and perseveration in water-maze tasks. Aged rats that were impaired on one measure of memory, however, were not necessarily impaired on other measures. ChAT activity in the ventromedial and dorsolateral neostriatum of aged rats was significantly reduced in comparisons with young rats whereas no difference was found in the hippocampus. Aged rats with the most ChAT activity in the anterior ventromedial neostriatum performed best on the place-learning and reference memory tasks but also made the most perseverative errors on the working memory task. In addition, young and aged rats with the most ChAT activity in the anterior dorsolateral neostriatum were those with the least accurate working memory. No relationships were found between ChAT activity in the hippocampus and spatial memory. Thus age-related memory impairment has components that can be segregated by measuring relationships between cholinergic integrity in subregions of the anterior neostriatum and memory tasks with different strategic requirements.     

分散空间注意条件下客体特征一致性对视觉特征错觉性结合的影响

本研究通过设置对空间注意资源的分配实施强行操作的情形下,探讨了主、次作业客体形状一致性和次作业客体间距对乏空间注意区次作业客体颜色、形状特征的检测及对特征错觉性结合的影响。实验结果表明：（１）分散空间注意使次作业区域注意减弱,对客体及其颜色和形状特征的识别均产生明显影响．而且对形状的影响又大于颜色;（２）特征错觉性结合率,主、次作业客体形状一致时比客体形状不一致时明显增大;（３）次作业客体间距对特征错觉性结合率无明显影响,但客体形状一致性和客体间距之间存在明显交互作用．     

幼儿二维心理旋转能力发展的研究

在以旋转的米老鼠图形作为测试项目,对每半岁为一个年龄段共１３３名３．５一６．５岁的幼儿进行心理旋转的实验研究中发现,幼儿在４岁时已经开始建立心理旋转能力．其发展特征呈连续性;男女幼儿间有一定的性别差异存在,但统计结果提示无显著性意义;男女幼儿在５－６岁间都发现有一个负增长阶段,其原因不明。     

Peak shift following simultaneous discriminations

Pigeons were exposed to stimuli presented on two keys. For some birds, the stimuli varied in a dimension of visual flicker-rate, and for others they varied in visual intensity. During differential training, concurrent schedules operated, with one stimulus correlated with one schedule and another stimulus correlated with a second schedule that arranged a lower, or zero, rate of reinforcement. The stimuli were alternated randomly on the two keys. Generalization tests were given in which the original two, and seven other stimuli lying in the same dimension, were presented in pairs on the two keys in various combinations. In the generalization test given after differential training, each bird showed peak shift. The data did not support explanation for peak shift that gave critical emphasis to whether stimuli were presented simultaneously or successively during differential training.     

The flip side of the other‐race coin: They all look different to me

Poorer recognition of other‐race faces than own‐races faces has been attributed to a problem of discrimination (i.e., telling faces apart). The conclusion that ‘they all look the same to me' is based on studies measuring the perception/memory of highly controlled stimuli, typically involving only one or two images of each identity. We hypothesized that such studies underestimate the challenge involved in recognizing other‐race faces because in the real world, an individual's appearance varies in a number of ways (e.g., lighting, expression, hairstyle), reducing the utility of relying on pictorial cues to identity. In two experiments, Caucasian and East Asian participants completed a perceptual sorting task in which they were asked to sort 40 photographs of two unfamiliar identities into piles such that each pile contained all photographs of a single identity. Participants perceived more identities when sorting other‐race faces than own‐race faces, both when sorting celebrity (Experiment 1) and non‐celebrity (Experiment 2) faces, suggesting that in the real world, ‘they all look different to me'. We discuss these results in the light of models in which each identity is represented as a region in a multidimensional face space; we argue that this region is smaller for other‐race than own‐race faces.     

Visual analysis of data in a multielement design

Ninety Board Certified Behavior Analysts (BCBAs) and 19 editorial board members evaluated hypothetical data presented in a multielement design. We manipulated the variability, trend, and mean shift of the data and asked the participants to determine if the data demonstrated experimental control. The results showed that variability, trend, and mean shift interacted to affect the participants’ ratings of experimental control. The level of agreement between participants was variable, but was generally lower than in previous research.     

The modality effect of ego depletion: Auditory task modality reduces ego depletion

An initial act of self‐control that impairs subsequent acts of self‐control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self‐control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion.     

Simple actions influence pop-out search

Recent research has revealed that a simple action (pressing a computer key) produced in response to a visual object prioritizes features of that object in subsequent visual search. The effects of simple action, however, have only been studied with search displays that required serial search. Here we explored whether simple actions have an effect when the target in visual search is always a salient singleton. Participants viewed a coloured shape at the beginning of each trial, and sometimes they acted (pressed the space bar) in response to it. In the subsequent search task, after acting (but not after viewing), the previously-seen colour affected search performance even though the target was always a salient singleton and the colour was uninformative. The results reveal that prior action can interact with bottom-up salience during search. Implications for our understanding of both visual search and repetition priming are discussed.