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Biomedical subjects

M J McNeil

Publications and source records attributed to M J McNeil.

3 recordsLinked to original sources
PubMed1991

Caffeine effects on behavioral thermoregulation.

Caffeine has a wide range of behaviorally active properties. Varying doses of caffeine solutions were administered (ip) prior to fixed-interval 2-min. schedules of microwave reinforcement in rats tested in a cold environment. Four Sprague-Dawley rats were conditioned to regulate their thermal environment with 5-sec. exposures of microwave reinforcement. Graphic descriptions showed that small doses of caffeine produced higher response rates for microwave heat than high doses of caffeine and saline controls, yet Friedman's nonparametric test showed no significant differences between dose levels. Synergism between thermogenic and discriminative properties of caffeine is proposed.

Animals↗
PubMed1990

Short-term memory digit-span performance under auditory and visual contexts as a function of rate of digit presentation.

This exploratory investigation concerned the effects of both auditory and visual context variations on the immediate recall of a series of digits presented on a computer screen (CRT). 5 intensities of background noise and 5 background hues were presented randomly to 110 undergraduate volunteers as they studied 25 numerals ranging from 1 to 5 at rates of change of either 1 or 3 sec. per numeral timed from the onset of the previous numeral. A 2 x 2 x 5 mixed split-plot factorial analysis of variance gave a significant difference in mean immediate-recall scores between rates of digit presentation with better recall associated with the 3-sec. rate. There was no significant main effect in recall scores for auditory vs color contexts, yet a post hoc analysis of variance for successive stages followed by Scheffé comparisons showed that across auditory intensities, Stages 3 and 4 and 5 (combined) had significantly higher immediate recall scores than Stages 1 and 2 (combined). This improvement across stages was not found under the visual (color) series. There was a three-way interaction for modality-contexts x rates x levels explained by the partitioning of stages which differed for auditory and for visual contexts. Results are discussed in terms of effects of modality.

Adolescent↗