Embedded figures detection in autism and typical development: preliminary evidence of a double dissociation in relationships with visual search

Individuals with autism show relatively strong performance on tasks that require them to identify the constituent parts of a visual stimulus. This is assumed to be the result of a bias towards processing the local elements in a display that follows from a weakened ability to integrate information at the global level. The results of the current study showed that, among children with autism, ability to locate a figure embedded in a larger stimulus was only related to performance on visual search trials where the target was identified by a unique perceptual feature. In contrast, control children's embedded figures performance was specifically related to their performance on visual search trials where the target was defined by a conjunction of features. This double dissociation suggests that enhanced performance on perceptual tasks by children with autism is not simply a consequence of a quantitative difference in ability to engage in global processing.     

ProtoMatch: a tool for analyzing high-density, sequential eye gaze and cursor protocols

ProtoMatch is a software tool for integrating and analyzing fixed-location and movement eye gaze and cursor data. It provides a comprehensive collection of protocol analysis tools that support sequential data analyses for eye fixations and scanpaths as well as for cursor “fixations” (dwells at one location) and “cursorpaths” (movements between locations). ProtoMatch is modularized software that integrates both eye gaze and cursor protocols into a unified stream of data and provides an assortment of filters and analyses. ProtoMatch subsumes basic analyses (i.e., fixation duration, number of fixations, etc.) and introduces a method of objectively computing the similarity between scanpaths or cursorpaths using sequence alignment. The combination of filters, basic analyses, and sequence alignment in ProtoMatch provides researchers with a versatile system for performing both confirmatory and exploratory sequential data analyses (Sanderson & Fisher, 1994).     

Toward a taxonomy of attention shifting: Individual differences in fMRI during multiple shift types

Although task switching is often considered one of the fundamental abilities underlying executive functioning and general intelligence, there is little evidence that switching is a unitary construct and little evidence regarding the relationship between brain activity and switching performance. We examined individual differences in multiple types of attention shifting in order to determine whether behavioral performance and fMRI activity are correlated across different types of shifting. The participants (n=39) switched between objects and attributes both when stimuli were perceptually available (external) and when stimuli were stored in memory (internal). We found that there were more switchrelated activations in many regions associated with executive control—including the dorsolateral and medial prefrontal and parietal cortices—when behavioral switch costs were higher (poor performance). Conversely, activation in the ventromedial prefrontal cortex (VMPFC) and the rostral anterior cingulate was consistently correlated with good performance, suggesting a general role for these areas in efficient attention shifting. We discuss these findings in terms of a model of cognitive-emotional interaction in attention shifting, in which reward-related signals in the VMPFC guide efficient selection of tasks in the lateral prefrontal and parietal cortices.     

Measuring health beliefs on the Internet: A comparison of paper and Internet administrations of the Multidimensional Health Locus of Control Scale

A growing number of studies have supported the use of unidimensional psychometric test instruments administered via the Internet; however, support for the use of multidimensional scales is weak. The present study compares paper and Internet administrations of the Multidimensional Health Locus of Control (MHLC) Scale (Wallston & Wallston, 1981). In terms of reliabilities and factor structures, the Internet data were found to be at least as good as the paper data. MHLC scores were comparable for paper and Internet administrations, although the Internet sample scored significantly lower on the Powerful Others subscale. Overall, the results show that administration of the MHLC Scale via the Internet can produce data comparable to that obtained by pen-and-paper methods. However, it is concluded that generalization of these findings beyond the psychometric test instrument and sampling procedures used here is not warranted.     

Hierarchical model of vulnerabilities for anxiety: replication and extension with a clinical sample

This study served to replicate and extend our previously obtained hierarchical model of the relationships among general anxiety vulnerabilities, specific anxiety vulnerabilities and specific anxiety manifestations including panic symptoms, health anxiety, obsessive-compulsive symptoms and worry. Questionnaires assessing these variables, as well as positive affectivity and depressiveness, were administered to 125 outpatients seeking treatment for panic disorder, social anxiety disorder, obsessive-compulsive disorder, generalized anxiety disorder or major depressive disorder. The results, using a clinical sample, were highly consistent with the hierarchical model obtained in the previous study using a student sample. A more elaborate model, based on published theoretical and empirical evidence, was identified and tested, and similar results were obtained. Negative affectivity had expected direct positive effects on all of the specific anxiety and depression manifestations, with the exception of health anxiety, which showed a negative relationship, and OCD symptoms, which showed no relationship. Positive affectivity was found to be a specific risk factor for depression, while intolerance of uncertainty was found to be a specific risk factor for worry and depression. Finally, anxiety sensitivity appears to be a significant risk factor for panic and health anxiety.