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).     

Visual skills in airport-security screening

Abstract— An experiment examined visual performance in a simulated luggage-screening task. Observers participated in five sessions of a task requiring them to search for knives hidden in x-ray images of cluttered bags. Sensitivity and response times improved reliably as a result of practice. Eye movement data revealed that sensitivity increases were produced entirely by changes in observers' ability to recognize target objects, and not by changes in the effectiveness of visual scanning. Moreover, recognition skills were in part stimulus-specific, such that performance was degraded by the introduction of unfamiliar target objects. Implications for screener training are discussed.     

Handedness and the fringe of consciousness: strong handers ruminate while mixed handers self-reflect

Previous research found that mixed handers (i.e., those that are more ambidextrous) were more likely than strong handers to update their beliefs (Niebauer, Aselage, & Schutte, 2002). It was assumed that this was due to greater degrees of communication between the two cerebral hemispheres in mixed handers. Niebauer and Garvey (2004) made connections between this model of updating beliefs and metacognitive processing. The current work proposes that variations in interhemispheric interaction (as measured by degree of handedness) contribute to differences in consciousness, specifically when consciousness is used in rumination versus the metacognitive task of self-reflection. Using the Rumination-Reflection Questionnaire (Trapnell & Campbell, 1999), predictions were supported such that strong handedness was associated with self-rumination; whereas, mixed handedness was associated with increased self-reflection p values<.01, (N=255). James's (1890) concept of the "fringe of consciousness" is used to make connections between metacognition, updating beliefs, and self-reflection. Several studies are reviewed suggesting that mixed handers experience fringe consciousness to a greater degree than strong handers.     

Treatment-resistant posttraumatic stress disorder: strategies for intervention

The mainstay of treatment for chronic posttraumatic stress disorder (PTSD) is a combination of psychotherapy and medication treatments. The first-line medications for PTSD are antidepressants, with two selective serotonin reuptake inhibitors (sertraline and paroxetine) currently Food and Drug Administration-indicated for PTSD. However, many patients do not have an adequate response to antidepressants, therefore, combinations with other antidepressants or with other classes of psychotropic medication are often utilized to enhance the therapeutic response. Other agents that have been used include mood stabilizers, anti-adrenergics, anxiolytics, and atypical antipsychotics. The heterogeneity of symptom clusters in PTSD as well as the complex psychiatric comorbidities (eg, with depression or substance abuse) further support the notion that combinations of medications may be needed. To date, there is a paucity of data to support specific strategies for augmenting antidepressants in PTSD. This review will address representative existing studies and discuss several potential pharmacologic strategies for patients suffering from treatment-refractory PTSD.     

Enhanced occipital and anterior cingulate activation in men but not in women during exposure to angry and fearful male faces

Blood-oxygenation-level-dependent signal was measured with functional magnetic resonance imaging in 24 healthy young subjects (12 men and 12 women) during viewing of angry, fearful, and neutral male and female face pictures. Exposure to angry male as opposed to angry female faces activated the visual cortex and the anterior cingulate gyrus significantly more in men than in women. A similar sex-differential brain activation pattern was present during exposure to fearful but not neutral faces. Previous behavioral studies indicate enhanced physiological arousal in men but not in women during exposure to angry male as opposed to female faces, and brain imaging studies have shown that the occipital cortex and the anterior cingulate gyrus are influenced by activity in the autonomic nervous system as well as by visual attention. Hence, we suggest that the elevated occipital and anterior cingulate activation in men during confrontation with other angry and fearful males may reflect enhanced vigilance in a potentially dangerous situation.