Effects of Antisocial Personality, Cocaine and Opioid Dependence, and Gender on Eye Movement Control

Inter-trial variability in postural control and brain activation: Effects of previous opiate abuse

There is an abundant literature demonstrating the superiority of inter-trial variability (ITV) of reaction time over mean reaction time in the early identification of subtle cognitive processing decrements. The present study extends these ideas by examining brain activation and postural control ITV among participants with versus without a history of chronic opiate abuse. Participants enrolled in opiate abuse (n = 82) and control (n = 112) groups completed tasks that challenged selective attention and balance. During the respective tasks, the inter-trial variabilities in frontal P300a electroencephalographic responses and sway strategy scores outperformed their mean levels in differentiating the groups. The relevance of several potential alternative explanations for the differences, including premorbid conduct disorder and comorbid alcohol abuse, depression, and methadone use, was discounted via simultaneous or post hoc analyses. It appears that chronic opiate abuse has adverse CNS effects that persist into the protracted abstinence period. These effects alter the temporal stability of its response to external and internal stimuli.

Neuroticism, schizotypy, and scale anchors influence eye movement behaviour in the visual exploration of abstract art: An exploratory study

The same piece of artwork can attract both admiration and rejection from different people. One potential explanation for this effect is individual differences in perceptual biases, which influence the way in which we see different aspects of the same image. We explored the relationship between individual differences (i.e., personality) and eye movements for examinations of abstract art. Images were presented for 5000ms, after which participants judged aesthetic appeal and perceived value using visual analogue scales. Scale anchor labels (Looks Good/Looks Bad; $0/$5000) were counterbalanced between participants such that positive labels were on the left half of the time and on the right half of the time. Overall, more fixations occurred to the right and upper visual fields. Neuroticism significantly predicted the proportion of fixations to the left, whereas cognitive disorganisation negatively predicted the proportion of fixations to upper space. Participants found images more aesthetically pleasing and more valuable when positive anchors were on the left. Findings demonstrate that personality traits influence fixation patterns. Further, the positioning of positive anchor labels on the left leads to higher ratings of visual stimuli.

Eye tracking dysfunction in schizophrenia: characterization and pathophysiology

Eye tracking dysfunction (ETD) is one of the most widely replicated behavioral deficits in schizophrenia and is over-represented in clinically unaffected first-degree relatives of schizophrenia patients. Here, we provide an overview of research relevant to the characterization and pathophysiology of this impairment. Deficits are most robust in the maintenance phase of pursuit, particularly during the tracking of predictable target movement. Impairments are also found in pursuit initiation and correlate with performance on tests of motion processing, implicating early sensory processing of motion signals. Taken together, the evidence suggests that ETD involves higher-order structures, including the frontal eye fields, which adjust the gain of the pursuit response to visual and anticipated target movement, as well as early parts of the pursuit pathway, including motion areas (the middle temporal area and the adjacent medial superior temporal area). Broader application of localizing behavioral paradigms in patient and family studies would be advantageous for refining the eye tracking phenotype for genetic studies.