Perceptual learning and perceptual search are altered in male university students with higher Autism Quotient scores

Two experiments investigated the validity of the Autism Quotient (AQ) scale for measuring traits associated with Autism Spectrum Disorders (ASD) in a population of male university students. Both studies found evidence that individuals who scored higher on the AQ questionnaire performed in a similar way to individuals with ASD on tasks with a perceptual component. Experiment 1 demonstrated a difference in the degree to which higher scoring AQ individuals performed on a perceptual learning task; with higher AQ scorers showing no advantage for familiar over novel items less. In Experiment 2, higher scorers showed fewer errors when judging the elements, as opposed to the global configuration, of a Navon task letter. Both of these patterns of results had previously been noted in individuals with ASD. These results suggest that the AQ may have some validity in identifying individuals in the nonclinical population with similar performance profiles to those with ASD.     

Impairments in tactile search following superior parietal damage

The superior parietal cortex is critical for the control of visually guided actions. Research suggests that visual stimuli relevant to actions are preferentially processed when they are in peripersonal space. One recent study demonstrated that visually guided movements towards the body were more impaired in a patient with damage to superior parietal cortex. Whereas past studies have explored disordered movement in optic ataxic patients, there has been less exploration of space perception in terms of search capacity in this population. In addition, there is some debate concerning the relationship between deficits of visuomotor control and impaired attention/perception in optic ataxia. Given that the dorsal stream has been implicated in the spatial processing of stimuli in peripersonal space, and damage to this region is known to cause optic ataxia, we felt that further investigation was warranted. We examined tactile search behavior in the fronto-parallel and radial planes in a patient with right superior parietal damage and optic ataxia. We used a pegboard with removable cylindrical pegs that allowed for the reorganization of targets between trials. To better characterize three-dimensional search behavior, we included both horizontal and vertical search conditions. Results showed that the patient spent more time searching, was more accurate and revisited more targets in right versus left space. Interestingly, the patient spent the majority of her time specifically searching the lower right quadrant of the stimulus array. Further analysis revealed lower target detection rates along the outer borders of the pegboard on all sides. The search pattern observed here is unusual considering that all targets were within arm's reach. The present experiment demonstrates that damage to superior parietal cortex impairs tactile search and biases exploration towards lower right peripersonal space.     

不同视觉区域OUP效应的眼动研究

摘 要 采用眼动方法,通过两个实验考察了不同视觉区域的OUP效应。结果显示：（1）当刺激材料分别平行呈现于左侧视觉区域和右侧视觉区域时,在右侧视觉区域产生了OUP效应,而在左侧视觉区域没有OUP效应,我们假设是由于左侧视觉区域首字母距离中央凹的不利位置影响了OUP效应的产生。（2）当垂直方向呈现刺激时,在两侧视觉区域均产生了明显的OUP效应,表明首字母距离中央凹处于有利位置时不会影响OUP效应的产生。实验结果支持了大脑左半球和右半球在词汇识别时的策略为系列加工,对左半球平行加工右半球系列加工的结论提出了质疑。     

Shaping reality vs. hiding from reality: Reconsidering the effects of trait need for closure on information search

For tentative and final decisions on real and artificial issues, three studies revealed a positive relation between trait need for closure and selective approach to supportive (vs. unsupportive) information. Specifically, individuals with high (vs. low) trait need for closure selected more decision-supportive information and less decision-challenging information for viewing. Furthermore, Study 1 showed that the effect of trait need for closure functioned independently of authoritarianism and dogmatism, and Study 3 showed that the effect of trait need for closure on selective approach to decision-supportive information was mediated by a current concern to get closure on the experimental issue. These findings provide a new understanding of how trait need for closure shapes post-decisional information search and decision making.     

The impact of risk and affect on information search efficiency

We develop and test a theoretical framework of the joint influence of risk and affect on information search efficiency. Our framework proposes that information search is less efficient (i.e., less strategic) when risk is high, versus low. It further proposes that the influences of positive and negative affect on search efficiency are asymmetric and depend on the level of risk. Negative affect improves search efficiency when risk is high, but not when it is low. Positive affect degrades search efficiency when risk is low, but not when it is high. We find results consistent with our framework in two experiments. We discuss implications for affect research and for decision making in risky contexts, including financial statement auditing.     

No decision‐maker is an Island: integrating expert advice with information acquisition

The present research examined the social context of information acquisition. The main purpose was to examine how decision‐makers' information acquisition processes changed when they were provided access to expert advice. Results indicated that all decision‐makers opted to acquire advice; however, they typically did so only after completing over 75% of their own information search. Decision‐makers agreed more with the advice as task complexity increased, but, in general, searched information in two stages—i.e., a pre‐advice “hypothesis generation” stage and a post‐advice “hypothesis testing” stage. To behave in an adaptive manner, decision‐makers could have used expert advice either to increase their decision accuracy or to reduce their effort expenditure (or both); they chose the former. Implications and further extensions are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

工作搜索行为理论模型的述评

简要介绍了西方有关工作搜索行为的心理学理论模型,并进行了简要的述评。在此基础上,文章又根据已有的研究成果探讨了未来理论模型构建的趋向,并且认为自我决定理论、控制焦点理论以及洛克的工作动机模型对未来的模型建构具有重要的启示意义。     

Contrast as seen in visual search reaction times.

Three pigeons searched arrays of alphabetic letters displayed on computer monitors. On each trial, either an A or an E appeared, and the reaction time and accuracy with which the bird pecked at this target were measured. In each block of trials, each target (A or E) was displayed alone, or together with a number of distractor letters (2 or 18) that varied in their similarity to the target. During a baseline series of sessions, responses to the A and to the E each yielded food reinforcement on 10% of the trials. In the next series of sessions, reinforcement continued at 10% for A, but rose to 30% for E. In a final series, these reinforcement conditions were reversed. As expected, reaction times increased with target-distractor similarity and (for similar distractors) with the number of distractors. Increased reinforcement of E had no effect on reaction times to E, but produced a very consistent increase in reaction times to A; the average increase was constant across the various display conditions. Reversal of the differential reinforcement conditions reversed this contrast effect. Analysis of the reaction time distributions indicated that increased reinforcement to E decreased the momentary probability of response to A by a constant amount, regardless of display conditions. These results are discussed in relation to theories of contrast, memory, and of the search image.     

On the multivariate asymptotic distribution of sequential Chi-square statistics

The multivariate asymptotic distribution of sequential Chi-square test statistics is investigated. It is shown that: (a) when sequential Chi-square statistics are calculated for nested models on the same data, the statistics have an asymptotic intercorrelation which may be expressed in closed form, and which is, in many cases, quite high; and (b) sequential Chi-squaredifference tests are asymptotically independent. Some Monte Carlo evidence on the applicability of the theory is provided.This research was carried out while the first author was Visiting Professor in the Department of Statistics in the University of South Africa, and was supported in part by a research grant (NSERC #67-4640) from the National Sciences and Engineering Council of Canada to the first author. The support of both of these organizations is acknowledged with gratitude.     

Factors affecting conditional discrimination learning by pigeons

In Experiment 1 (within subjects) and Experiment 2 (between subjects) it was shown that the sequential training of pigeons on a color discrimination and then on its reversal, each in a different floor-tilt/texture context, failed to produce conditional control of discriminative performance by those contexts. Daily alternation between the two problems (with correlated contexts) was successful, however. In each of these experiments conditional control was better reflected in generalization test performance in extinction than during sessions of training with reinforcement.