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Biomedical subjects

M D Horner

Publications and source records attributed to M D Horner.

8 recordsLinked to original sources
PubMed1999

Self-report and objective measures of cognitive deficit in patients entering substance abuse treatment.

The relationship between self-reported cognitive deficits and objectively measured cognitive performance was examined in 86 patients entering substance abuse treatment. Self-ratings of cognitive impairment were strongly correlated with indices of depression and vulnerability to stress, but not with objective cognitive performance. Confirming the lack of relationship between self-report and objective cognitive measures, cognitive performance did not differ between patients at the extremes of the cognitive-complaint distribution; and cognitively impaired patients did not differ from cognitively intact patients in their self-ratings of impairment.

Adult↗
PubMed1999

Attentional functioning in abstinent cocaine abusers.

The effect of chronic cocaine use on attention is directly relevant to the treatment of cocaine dependence, since attention underlies most other cognitive processes, and thus the ability to profit from cognitively-based interventions. This paper reviews 17 studies examining attention in patients with cocaine abuse or dependence. Findings have been inconsistent, largely due to various methodological difficulties. There has been some suggestion of reduced cognitive speed, while focused and sustained attention have generally been unimpaired. Divided attention has been largely unexplored. Thus, there is insufficient evidence either to accept or reject the hypothesis of attentional dysfunction associated with chronic cocaine use.

Attention↗
PubMed1999

Declarative and procedural memory functioning in abstinent cocaine abusers.

BACKGROUND: We determined the nature and recovery of procedural and declarative memory functioning in a cocaine-abusing cohort in the 45-day period following use. METHODS: Thirty-seven cocaine abusers and 27 control subjects were administered the following memory and mood measures: California Verbal Learning Test, recall of the Rey-Osterrieth Complex Figure Test, Pursuit Rotor Task, and Profile of Mood States at 4 visits (within 72 hours of admission and at 10, 21, and 45 days following abstinence). RESULTS: Analysis of performance on the Rey-Osterrieth Complex Figure Test revealed that both groups improved in their recall over repeated administrations, though the control group recalled significantly more of the information than cocaine subjects during the 45-day interval. Results for the California Verbal Learning Test indicated improved learning for both subject groups over time, but no group x time interaction. On the Pursuit Rotor Task, cocaine abusers improved their performance at a faster rate than controls at visit 1. At day 45 (visit 4), cocaine abusers again showed improvement on the Pursuit Rotor Task, whereas controls demonstrated a relative plateau in rate of learning. CONCLUSIONS: This study documented a lasting detrimental effect on a sensitive nonverbal declarative memory task in cocaine-dependent subjects following abstinence of 45 days. In contrast, abstinence from cocaine during this 45-day period was associated with sustained improvement on a motor learning test in the cocaine abusers relative to controls.

Adult↗
PubMed1996

Temporal lobe epilepsy and performance on the Wisconsin Card Sorting Test.

The replicability of previous evidence for differential performance between left and right temporal lobe epileptic patients on the Wisconsin Card Sorting Test (WCST) was evaluated in a new sample of candidates for focal resection. Many subjects obtained high scores on indices of perseveration, which are commonly thought to reflect frontal dysfunction, but there were no differences in performance between patients with language-dominant and nondominant temporal foci. The findings confirm existing evidence that performance decrements on the WCST can be associated with epileptic foci and focal lesions in nonfrontal brain lesions.

Adult↗
PubMed1996

Effects of retinal eccentricity on the lateralized processing of categorical and coordinate spatial relations.

Kosslyn's (1987) hypothesized cerebral hemispheric asymmetries for processing categorical and coordinate spatial relations were explored, using stimuli presented at varying degrees of retinal eccentricity. Thirty-three adult males performed hemifield reaction-time tasks requiring categorical or coordinate judgements. The hypothesized asymmetries were observed when stimuli were presented at 3 degrees of visual angle, but not at 1 or 9 degrees. Nevertheless, correlational analyses supported the existence of separate neural subsystems for categorical and coordinate processing. The results suggest that the model accurately predicts performance asymmetries only under specific conditions.

Adult↗
PubMed1990

Psychobiological evidence for the distinction between episodic and semantic memory.

The evidence for discrete neurobiological mechanisms that underlie episodic and semantic memory is reviewed. Published data from three separate lines of research are considered: studies of human amnesic patients, psychopharmacological studies of normal human subjects, and studies of working and reference memory in rodents, a distinction that is arguably analogous to the episodic/semantic dichotomy. It is concluded that the available evidence does not indicate that episodic and semantic memory are mediated by discrete neural subsystems. An alternative model of human memory is discussed, based on the concept of parallel distributed processing.

Amnesia↗
PubMedDate not supplied

The relationship of cognitive functioning to amount of recent and lifetime alcohol consumption in outpatient alcoholics.

Previous investigations of the relationship between drinking patterns and cognitive functioning have generally studied severely alcoholic patients, in whom the neurocognitive effects of alcohol consumption can be obscured by other medical or psychosocial factors. In the present study, cognitive functioning was examined after a minimum of 4 days of abstinence in 69 mildly to moderately alcohol-dependent outpatients without comorbid psychiatric, neurologic, or systemic medical illness. Circumscribed decrements in reaction time and verbal memory were associated with higher amounts of alcohol consumption in the 90 days prior to enrollment in the study, and amount of recent consumption was correlated with scores on numerous cognitive tests. In contrast, longer drinking history was not associated with poorer performance on any neuropsychological measures. Thus, in this group of high-functioning, mildly to moderately alcohol-dependent outpatients, mild cognitive deficits were related to the amount of recent, but not lifetime, alcohol consumption.

Adult↗