任务定势对自动语义激活过程调节作用的ERP研究

摘要：本研究致力于探讨自上而下的因素对自动加工的影响。选取的自上而下因素为任务定势,自动加工过程为自动语义激活过程。研究采用ERPs技术,中文词汇为刺激,利用掩蔽启动范式,采用反应时和N400为指标。实验任务有三个：对问号后出现的词进行生物/非生物的词汇分类判断;对圆圈后出现的词进行是否含上下结构的字的词汇结构判断;对带“*”的词进行真词/假词判断。研究发现先前完成的任务形成的任务定势会对随后的自动语义激活过程产生调节作用：在词汇分类判断任务后,掩蔽启动刺激对靶刺激产生启动效应。在词汇结构判断任务后,掩蔽启动刺激对靶刺激没产生显著的启动效应。     

Correlation between gray/white matter volume and cognition in healthy elderly people

This study applied volumetric analysis and voxel-based morphometry (VBM) of brain magnetic resonance (MR) images to assess whether correlations exist between global and regional gray/white matter volume and the cognitive functions of semantic memory and short-term memory, which are relatively well preserved with aging, using MR image data from 109 community-dwelling healthy elderly individuals. We used the Information and Digit Span subtests of the Wechsler Adult Intelligent Scale-Revised as measures of semantic memory and short-term memory, respectively. We found significant positive correlations between the gray matter ratio, the percentage of gray matter volume in the intracranial volume, and performance on the Digit Span subtest, and between the regional gray matter volumes of the bilateral anterior temporal lobes and performance on the Information subtest. No significant correlations between performance on the cognitive tests and white matter volume were found. Our results suggest that individual variability in specific cognitive functions that are relatively well preserved with aging is accounted for by the variability of gray matter volume in healthy elderly subjects.     

Rugby versus Soccer in South Africa: Content familiarity contributes to cross-cultural differences in cognitive test scores

In this study, cross-cultural differences in cognitive test scores are hypothesized to depend on a test's cultural complexity (Cultural Complexity Hypothesis: CCH), here conceptualized as its content familiarity, rather than on its cognitive complexity (Spearman's Hypothesis: SH). The content familiarity of tests assessing short-term memory, attention, working memory, and figural and verbal fluid reasoning, was manipulated by constructing test versions with an item content derived from either Afrikaans or Tswana culture in South Africa. Both test versions were administered to children of both cultures. The sample consisted of 161 urban Afrikaans, 181 urban, and 159 rural Tswana children (M_age = 9.37 years). Children generally performed best on the test version that was designed for their own group, particularly on the cognitively and culturally complex working memory and figural fluid reasoning tests. This relation between content familiarity and cognitive test performance supports CCH and disconfirms SH.     

Disentangling the relationship between hemispheric asymmetry and cognitive performance

It is widely believed that advantages of hemispheric asymmetries originated in better cognitive processing, hence it is often implied that the relationship between hemispheric asymmetry and cognitive performance is linearly positive: the higher the degree of lateralization in a specific cognitive domain, the better the performance in a corresponding task. Yet, the empirical evidence for this notion is mixed and the statistical methods to analyze this relationship have been criticized. The present study therefore investigated the relationship between hemispheric asymmetries and cognitive performance in two behavioral tasks (a left-lateralized word-matching task and a right-lateralized face-decision task) in 230 participants (140 women, 90 men) by using two different approaches. Both methods correspondingly revealed that a relationship between hemispheric asymmetries and cognitive performance does exist. Contrary to a positive (linear) relationship however, the data could be best described by an inverted U-shaped curve. Although the optimal degree of lateralization seemed to be task-specific, a slight or moderate degree of hemispheric asymmetry achieved best cognitive performance in all tasks. Moreover, performances deteriorated towards extreme ends of lateralization (i.e., participants with either extreme left or right hemispheric biases). Taken together, the present study provides evidence against the notion that higher lateralization is related to enhanced cognitive performance.     

Correlates of intellectual ability with morphology of the hippocampus and amygdala in healthy adults

Several prior imaging studies of healthy adults have correlated volumes of the hippocampus and amygdala with measures of general intelligence (IQ), with variable results. In this study, we assessed correlations between volumes of the hippocampus and amygdala and full-scale IQ scores (FSIQ) using a method of image analysis that permits detailed regional mapping of this correlation throughout the surface contour of these brain structures. We delineated the hippocampus and amygdala in high-resolution magnetic resonance images of the brain from 34 healthy individuals. We then correlated FSIQ with overall volumes and with the surface morphologies of each of these structures. Hippocampus volumes correlated significantly and inversely with FSIQ independently of gender, age, socioeconomic status, and whole brain volume. Left and right hippocampus volumes correlated respectively with verbal and performance IQ subscales. Higher IQs were significantly associated with large inward deformations of the surface of the anterior hippocampus bilaterally. These findings suggest that a smaller anterior hippocampus contributes to an increased efficiency of neural processing that subserves overall intelligence.     

The tell-tale tasks: a review of saccadic research in psychiatric patient populations

This review focuses on saccade research with adult psychiatric patients. It begins with an introduction of the various types of saccades and the tasks used to evoke them. The functional significance of the different types of eye movements is briefly discussed. Research findings regarding the saccadic performance of different adult psychiatric patient populations are discussed in detail, with particular emphasis on findings regarding error rates, response latencies, and any specific task parameters that might affect those variables. Findings regarding the symptom, neurocognitive, and neural correlates of saccadic performance and the functional significance of patients’ saccadic deficits are also discussed. We also discuss the saccadic deficits displayed by various patient groups in terms of circuitry (e.g. cortical/basal ganglia circuits) that may be implicated in the underlying pathophysiology of several of these disorders. Future directions for research in this growing area are offered.     

The Effects of Incentives on Visual–Spatial Working Memory in Children with Attention-deficit/Hyperactivity Disorder

Working memory is one of several putative core neurocognitive processes in attention-deficit/hyperactivity disorder (ADHD). The present work seeks to determine whether visual–spatial working memory is sensitive to motivational incentives, a laboratory analogue of behavioral treatment. Participants were 21 children (ages 7–10) with a diagnosis of ADHD-combined type. Participants completed a computerized spatial span task designed to assess storage of visual–spatial information (forward span) and manipulation of the stored information (backward span). The spatial span task was completed twice on the same day, once with a performance-based incentive (trial-wise feedback and points redeemable for prizes) and once without incentives. Participants performed significantly better on the backward span when rewarded for correct responses, compared to the no incentive condition. However, incentives had no effect on performance during the forward span. These findings may suggest the use of motivational incentives improved manipulation, but not storage, of visual–spatial information among children with ADHD. Possible explanations for the differential incentive effects are discussed, including the possibility that incentives prevented a vigilance decrement as task difficulty and time on task increased.     

Working memory and arithmetic calculation in children: the contributory roles of processing speed, short-term memory, and reading

The cognitive underpinnings of arithmetic calculation in children are noted to involve working memory; however, cognitive processes related to arithmetic calculation and working memory suggest that this relationship is more complex than stated previously. The purpose of this investigation was to examine the relative contributions of processing speed, short-term memory, working memory, and reading to arithmetic calculation in children. Results suggested four important findings. First, processing speed emerged as a significant contributor of arithmetic calculation only in relation to age-related differences in the general sample. Second, processing speed and short-term memory did not eliminate the contribution of working memory to arithmetic calculation. Third, individual working memory components--verbal working memory and visual-spatial working memory--each contributed unique variance to arithmetic calculation in the presence of all other variables. Fourth, a full model indicated that chronological age remained a significant contributor to arithmetic calculation in the presence of significant contributions from all other variables. Results are discussed in terms of directions for future research on working memory in arithmetic calculation.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.     

The Effect of Anxiety on the Cognitive Functioning in Non-clinical Schizotypal Individuals

Schizotypal personality disorder (SPD) is characterized by eccentric behavior and perceptual distortions that closely resemble the patterns observed in those with schizophrenia. Schizophrenia and related personality disorders (i.e., SPD) are associated with deficits in sustained attention, slower than normal reaction times, and manifestations of working memory deficits and erratic cognitive tasks. The present study used the schizotypal personality scale (STA) to compare cognitive abilities of self-reported low schizotypic tendency subjects with high schizotypic tendency subjects. The group scores on the STA differed significantly. Those with high STA scores also tended to have higher state and trait anxiety scores based on the State-Trait Anxiety Inventory (STAI). The groups did not significantly differ on any of the demographic variables tested, including age, education, self-rated health status, and medication. Along with an executive function test, two computerized tasks tested subjects on reaction time and memory. Even when covariates (i.e., state, trait anxiety scores) were analyzed, there were no significant differences between the groups and tasks, although the gathered data showed trends in the expected direction.