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Biomedical subjects

J J Tecce

Publications and source records attributed to J J Tecce.

10 recordsLinked to original sources
PubMed1979

Methadone effects on brain functioning and type A and B CNV shapes.

Twelve male outpatients participating in a methadone maintenance treatment program were evaluated for the effects of acute administration of methadone on brain functioning (contingent negative variation or CNV), attention performance (reaction time and continuous performance test), and psychophysiological activity (heart rate and eye blink rate). Individual differences in response to methadone were assessed by classifying patients into two groups on the basis of basal CNV shapes: Type A (quick rise time) and type B (slow rise time). Methadone produced a pattern of increased electrical brain activity (CNV) and enhanced attention performance in type B patients and elevated heart rate and lowered eye blink rate in type A subjects. Results are interpreted in terms of the distraction-arousal and the eye blink-hedonia hypotheses.

Adult↗
PubMed1979

A CNV rebound effect.

Fifty normal volunteers were tested in two conditions: (1) a constant-foreperiod reaction time situation consisting of a flash-tone-key press sequence (control trials); (2) a '50%-letters' condition, in which two types of trials occurred randomly--no letters trials, which were identical to control trials, and letters trials, which were similar to control trials but also involved the presentation of four auditory letters within the flash-tone interval as part of a short-term memory task. Compared to control trials, CNV amplitude showed a pattern of reduction in letters trials accompanied by slower reaction times to tone (CNV distraction effect). Compared to control trials, CNV amplitude showed an unexpected supranormal increase in no-letters trials. The CNV rebound effect observed in no-letters trials was interpreted as reflecting a switching of attention from the divided attention set intrinsic to letters trials (listening for letters and preparing for response to tone) to an undivided attention set in no-letters trials (simply preparing for response to tone). The CNV rebound effect, which is diminished in aging individuals and absent in psychosurgery patients, appears to represent a non-invasive technique of possible value in assessing pathophysiology of human brain functioning.

Adult↗
PubMed1976

Contingent negative variation and the distraction--arousal hypothesis.

Thirty-two normal volunteers were tested in three conditions: (1) a constant-foreperiod reaction-time situation consisting of a flash--tone--key-press sequence (control condition); (2) the addition of a short-term memory task consisting of four letters presented within the flash--tone interval with the requirement that they be repeated after key-press to tone (letters--recall); (3) the presentation of letters without short-term memory (letters--no recall). The task involving short-term memory of letters produced a significant reduction in amplitude of CNV for central (Cz) and parietal (Pz) recording sites. The association of CNV decrease and lengthened reaction time to tone was interpreted as a CNV distraction effect. The accompaniment of this distraction effect by elevated heart rate levels and increased frequency of eyeblinks was considered a distraction--arousal association and an important source of disruption in CNV development. These results were interpreted as support for the distraction--arousal hypothesis and appear to provide a sensitive complex of four measures for the evaluation of psychological processes, including the assessment of psychotropic drug effects. Eyeblink frequency in particular appears to be a sensitive indicator of distraction--arousal processes and a potentially useful measure of disturbed psychological functioning. The finding in control conditions of lower CNV amplitude in frontal than in central and posterior recording sites was viewed as a distraction effect due to efforts at eye movement control. The possibility was raised that frontal areas of the brain mediate sustained (tonic) distraction effects whereas centro-parietal regions mediate phasic distraction effects, at least when produced by stimuli of a lexical nature.

Adolescent↗
PubMed1975

EEG correlates of impaired attention performance under secobarbital and chlorpromazine in the monkey.

The effects of secobarbital and chlropromazine upon behavior in a continuous, rapidly presented successive (go-no go) discrimination ("attention") task were evaluated in six Macaca mulatta monkeys. Simultaneous monitoring of EEG activity from epidural and subcortical electrodes permitted an evaluation of the nature of altered central nervous system events during erroneous performance (errors of omission) on this task. The computer-assisted analysis of pre-stimulus and post-stimulus EEG frequency activity (baseline crossings) suggests that the best measure of attentive behavior from the pre-stimulus EEG is percentage of beta 2 (25-40 cps) activity. No difference could be observed between drugs or among cerebral placements in this regard. This was determined by comparing measures of EEG frequency, pooled for a given test period, with performance from the same test period. On a trail-by-trail basis. however, the beta 2 measure in the pre-stimulus epoch failed to ditinguish correct responses from errors of omission. Separation between correct responses and errors of omission is possible if comparisons are made between the changes in percentage of beta 2 activity in the pre-stimulus vs. post-stimulus occurs with correct positive trials and the smallest change with correct negative trials. For secobarbital, no difference could be detected between correct and incorrect positive trials. For chlorpromazine, however, there was significantly less change in beta 2 for incorrect positive than for correct positive trials. The results were interpreted in terms of the hypothesis that secobarbital produces errors by depression of the general level of activation whereas chlorpromazine acts by reducing the sensory input which is necessary for correct discrimination performance.

Animals↗