Sorting between dimensions: conditions of cognitive flexibility in preschoolers

The Dimensional Change Card Sorting task frequently is used to measure extradimensional shifting abilities in preschool children. In two studies, we investigated what makes this extradimensional shifting task difficult. In Study 1 with 61 2- to 4-year-olds, we showed that extradimensional shifts from one dimension to another are more difficult than reversal shifts within a dimension (even with irrelevant variation on a second dimension). Study 2 with 77 3- and 4-year-olds further confirmed this finding using a computerized paradigm and showed that sorting instructions are critical for 3-year-olds' difficulties with extradimensional shifts. This finding is taken to suggest that 3-year-olds have particular problems with spontaneously classifying one object in two different ways.     

The Importance of Interpersonal Similarities in the Teacher Mentor/Protégé Relationship

The present study assessed the effect of interpersonal similarities between mentors and protégés in a large formal teacher mentoring program. The dependent variables included protégés’ satisfaction with the services provided by the program and perception of the program as influencing the decision to continue as a New York City Public School teacher. Two years of responses to surveys indicated that mentor-protégés similarities, most notably in the relatively intangible areas of outside interests, teaching styles, or personality types, fostered stronger relationships between mentors and protégés.     

Aging and strategic retrieval in a cued-recall test: the role of executive functions and fluid intelligence

Cued-recall in episodic memory was investigated in relation to low and high cognitive support at retrieval, executive function level and fluid intelligence level in 81 healthy adults divided first into two age groups (young and elderly adults). The first analyses showed that age-related differences were greater when a low cognitive support was provided to recall the words. An individual index of loss of performance when the number of cues was decreased was then calculated. Hierarchical regression analysis revealed that the executive functions measure (perseverative errors on the Wisconsin Card Sorting Test) was a better candidate than the fluid intelligence measure (Cattell's culture fair test) to account for the age-related variance of the size of performance loss. These findings suggest that age differences in implementing strategic retrieval may be mainly due to a decline in executive functions.     

客体的视觉工作记忆研究进展

近年来,客体信息的视觉工作记忆问题引发了大量研究,并获得不少成果。本文对视觉工作记忆的研究范式,客体在视觉工作记忆中的存储方式、容量及保持时间等相关研究进行了概述,重点介绍关于视觉工作记忆存储单元和容量问题的"强客体"假设、"弱客体"假设和双重存储机制假设,并提出进一步的研究思路。     

A derived transfer of functions and the implicit association test

Participants were trained in a series of interrelated conditional discriminations that aimed to establish four 4-member equivalence classes (i.e., A1-B1-C1-D1, A2-B2-C2-D2, A3-B3-C3-D3, A4-B4-C4-D4). During this training, the four A stimuli (i.e., A1, A2, A3, and A4) were compounded with pictures containing positive or negative evaluative functions (A1/A2 negative & A3/A4 positive). The transfer of evaluative functions to directly and indirectly related members of the equivalence classes (i.e., B, C, and D stimuli) was measured using an Implicit Association Test (IAT). During consistent test blocks, participants were required to press the same response key for target words that were related to those A stimuli that possessed similar evaluative functions (A1/A2-left key & A3/A4-right key). During inconsistent test blocks, target words that were related to those A stimuli with different evaluative functions were assigned to the same response key (A1/A4-left key & A2/A3-right key). Results showed that all 8 participants, who passed a matching-to-sample equivalence test following the IAT, responded more rapidly on consistent relative to inconsistent test blocks. This typical IAT effect was not observed for those participants who did not pass the equivalence test. The results suggest that the IAT effect may arise from formally untested derived relations, and supports the argument that such relations could provide a valid behavioral model of semantic categories in natural language.     

前临床期痴呆的认知特征：当前研究进展和未来研究展望

在这篇文章中, 我将讨论从正常老化到痴呆, 这一通常被称为痴呆前临床阶段的认知功能的转变。研究表明, 阿尔茨海默症和血管性痴呆病人在临床确诊之前的几年中, 会出现明显的认知损伤。早期最突出的损伤存在于情节记忆、加工速度以及执行功能。这些功能性损伤与神经生物学研究证实的边缘系统和新皮层区存在多重损伤是相一致的。虽然早在临床诊段之前, 病人组和控制组的平均成绩存在巨大差异, 但同时这两组测试成绩的分布在很大程度上是重叠的。寻求降低这种重叠度的方法是未来研究的一个重要任务。这有可能通过将认知的和其他指标(如基于脑的、基因的、临床的、社会的)相结合构建预测模型来实现。此外, 在未来研究中以下三方面也是急需考虑问题: (a) 找出在 前临床期间认知功能急速下降的时间点: (b) 评估从前临床到临床诊断变化速率中存在的个体差异; (c) 确定特定因素与随后发生的痴呆之间的关联强度是如何随时间向临床确诊推进而逐渐变化的。     

Use of samples differing markedly in salience may encourage use of a single-code/default strategy in matching-to-sample in pigeons

To test the hypothesis that pigeons will only code the more salient sample when samples differ markedly in salience, pigeons were trained with samples consisting of a 2-s presentation of food (highly salient sample) and an 8-s presentation of keylight (less salient sample). During retention testing, pigeons tended to respond at longer delays as if an 8-s keylight sample had been presented. This finding is consistent with use of a single-code/default strategy in which only the 2-s food sample was coded and the comparison associated with an 8-s keylight sample was selected by default in the absence of memory for the salient 2-s food sample. Hence, a marked difference in sample salience appears to encourage use of a single-code/default strategy.     

Executive functions after age 5: Changes and correlates

Research and theorizing on executive function (EF) in childhood has been disproportionately focused on preschool age children. This review paper outlines the importance of examining EF throughout childhood, and even across the lifespan. First, examining EF in older children can address the question of whether EF is a unitary construct. The relations among the EF components, particularly as they are recruited for complex tasks, appear to change over the course of development. Second, much of the development of EF, especially working memory, shifting, and planning, occurs after age 5. Third, important applications of EF research concern the role of school-age children’s EF in various aspects of school performance, as well as social functioning and emotional control. Future research needs to examine a more complete developmental span, from early childhood through late adulthood, in order to address developmental issues adequately.     

Executive functions in children with Autism Spectrum Disorders

Executive dysfunction is a characteristic impairment of individuals with Autism Spectrum Disorders (ASD). However whether such deficits are related to autism per se, or to associated intellectual disability is unclear. This paper examines executive functions in a group of children with ASD (N = 54, all IQ?70) in relation to a typically developing control group individually matched on the basis of age, gender, IQ and vocabulary. Significant impairments in the inhibition of prepotent responses (Stroop, Junior Hayling Test) and planning (Tower of London) were reported for children with ASD, with preserved performance for mental flexibility (Wisconsin Card Sorting Task) and generativity (Verbal Fluency). Atypical age-related patterns of performance were reported on tasks tapping response inhibition and self-monitoring for children with ASD compared to controls. The disparity between these and previous research findings are discussed. A multidimensional notion of executive functions is proposed, with difficulties in planning, the inhibition of prepotent responses and self-monitoring reflecting characteristic features of ASD that are independent of IQ and verbal ability, and relatively stable across the childhood years.     

Perceived distance of targets in convex mirrors

We investigated the perceived distance of targets in convex and plane mirrors. In Experiment 1, 20 subjects matched the distance of targets in a real scene to the distance of a virtual target in different mirrors. The matched distances were much larger for convex mirrors than for a plane mirror. In Experiment 2, 20 subjects viewed two targets in a mirror and adjusted their own positions so that the distance to the closer target was perceived to equal the distance between the targets. The mean distance to the closer target was smaller for the convex mirrors than for the plane mirror. In Experiment 3, 20 subjects adjusted the position of a target so that the distance to it in a mirror was perceived to equal the distance designated by the experimenter. The best-fitting power functions showed that the scaling factors were larger for the convex mirrors than for the plane mirror, but the exponents were smaller for the convex mirrors than for the plane mirror. It is suggested that distance in the convex mirrors was perceived to be larger than in the plane mirror, and that the growth of perceived distance in the convex mirrors was slower than in the plane mirror.