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Biomedical subjects

R M Ashbrook

Publications and source records attributed to R M Ashbrook.

2 recordsLinked to original sources

Personality style differences in visual search performance.

The present study continues the examination of the personality styles in normal populations that have been described in the clinical literature. Earlier work has focused on behavioral, attitudinal, and cognitive components of the personality styles. The present study extends our exploration of the cognitive domain by examining the performance of different personality groups on a visual scanning task. Hysterics searched a stimulus array for letter targets at a mean rate of 0.04 +/- SD 0.177 seconds per unit of information, which was slower than the control rate of 0.0225 +/- SD 0.0078 seconds. The results indicated that hysterics used a serial search strategy to compensate for an inability to process information efficiently and thus differed from compulsives who conformed to task demands and performed similarly to controls.

Achievement↗

Cross-tolerance between two brainstem sites supporting stimulation-produced analgesia.

Male albino Holtzman rats were stereotaxically implanted with two bipolar stimulating electrodes, aimed at the periaqueductal gray matter of the brainstem. Focal brain stimulation-produced analgesia was assessed by the tail-flick method. After establishing that focal brain stimulation elicited analgesia at both sites, behavioral tolerance (i.e., reduced analgesia) was induced at one site through repeated stimulation. Upon elicitation of tolerance at one site, stimulation was immediately switched to the other site (which had not been previously rendered tolerant) and analgesia was assessed. Tail-flick latencies revealed transfer of behavioral tolerance from the site given repeated stimulation to the site not given repeated stimulation. While the mechanism involved in this cross-tolerance is not known, a neurochemical substrate may be involved.

Animals↗