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Biomedical subjects

M J Nellis

Publications and source records attributed to M J Nellis.

11 recordsLinked to original sources
PubMed1991

The role and function of drinking games in a university community.

Understanding the role of drinking games in college student life is critical for program planners who wish to develop education and prevention programs to reduce abusive drinking. Drinking games are popular social activities that provide a focus for social interactions but place students at considerable risk for serious consequences. This article reports preliminary results of a study using participant observation and in-depth interviews to develop a typology of drinking games and describe patterns and practices associated with the games.

Adolescent↗
PubMed1990

Motivational effects of smoked marijuana: behavioral contingencies and low-probability activities.

Six adult male research volunteers, in two groups of 3 subjects each, lived in a residential laboratory for 15 days. All contact with the experimenters was through a networked computer system, and subjects' behavior was monitored continuously and recorded. During the first part of each day, they were allowed to socialize. Two cigarettes containing active marijuana (2.7% delta 9-THC) or placebo were smoked during the private work period and the period of access to social activities. Three-day contingency conditions requiring subjects to engage in a low-probability work activity (instrumental activity) in order to earn time that could be spent engaging in a high-probability work activity (contingent activity) were programmed during periods of placebo and active-marijuana smoking. During placebo administration, the contingency requirement reliably increased the amount of time that subjects spent engaged in the low-probability instrumental activity and decreased the time spent engaged in the high-probability activity. During active-marijuana administration, however, the increases in instrumental activity were consistently larger than observed under placebo conditions. The decreases in contingent activity were similar to those seen under placebo conditions. Smoking active marijuana was thus observed to produce increments in instrumental activity under motivational conditions involving contingencies for "work activities."

Adult↗
PubMed1989

Motivational effects of smoked marijuana: behavioral contingencies and high-probability recreational activities.

Fifteen adult male research volunteers, in five groups of three subjects each, lived in a residential laboratory for up to 20 days. All contact with the experimenters was through a networked computer system, and subjects' behaviors were monitored continuously and recorded. During the first part of each day, subjects remained in their private rooms doing planned work activities, and during the remainder of each day, they were allowed to socialize. One or two cigarettes containing active marijuana (1.3-2.7% delta 9-THC) or placebo were smoked during both the private work period and the period of access to social activities. Two-or three-day contingency conditions requiring subjects to engage in a low-probability recreational activity in order to earn time that could be spent engaging in a high-probability recreational activity were programmed during periods of placebo and active marijuana smoking. During placebo administration, the contingency requirement reliably increased the amount of time that subjects spent engaged in the low-probability instrumental activity and decreased the time spent engaged in the high-probability contingent activity. During active marijuana administration, however, the increases in instrumental activity were consistently smaller than observed under placebo conditions. The decreases in high-probability contingent activity were similar across drug conditions. Smoking active marijuana was thus observed to produce instrumental decrements under motivational conditions involving recreational contingencies.

Adult↗
PubMed1986

Nicotine and caffeine effects on the task-elicited blood pressure response.

Nine subjects participated in four daily sessions during which a psychomotor task was performed prior to and following drug administration. Blood pressure was reliably increased by task performance, cigarette smoking, and caffeine administration. The effect of the combination of task performance, cigarette smoking and caffeine administration was additive, resulting in a markedly increased blood pressure during task performance for subjects smoking cigarettes and receiving caffeine.

Arousal↗
PubMed1985

Situational suppression of cigarette smoking.

Cigarette smoking rate was observed during work and recreation while subjects participated in two long-term residential experiments. In both experiments, the smoking rate observed during work was markedly lower than the smoking rate observed during recreation. In Experiment 1, activities were performed in successive 1-hour blocks. Smoking suppression during work was not associated with an increase in smoking rate following work. Experiment 2 consisted of treatment days of alternating 30-, 60-, and 120-minute work periods and recreation and control days when no work periods were presented. Performance of work was again associated with a marked suppression of smoking. In addition, the smoking rate for days during which no work was performed was greater than the smoking rate for days during which intermittent work was performed. This effect was not related to the length of the work periods. This finding indicates that subjects failed to compensate totally for work-related decreases in smoking. All subjects exhibited partial compensation.

Adult↗
PubMed1982

Event time-series relationship between cigarette smoking and coffee drinking.

Eight subjects resided in a programmed laboratory environment for seven to twelve successive days during which time cigarettes and coffee were freely available. An event time-series analysis based upon instances in time of each substance's use revealed a relationship between cigarette smoking and coffee drinking: a coffee-drinking event tended to occur late in the inter-cigarette interval, and a cigarette-smoking event was most probable during the twenty minutes immediately following a coffee-drinking event.

Coffee↗
PubMed1982

On the regularity of smoking.

The purpose of this paper is to provide fundamental information about individual subject smoking behavior when the behavior is characterized as an event time-series. Each subject's smoking series revealed a characteristic inter-cigarette interval frequency distribution but there was little evidence of sequential dependencies in the series with respect to either successive intervals or successive events in time. Several subjects exhibited possible characteristic peaks or troughs during successive 2-hour periods, a finding which was in agreement with previous studies, but even in these subjects temporal patterning accounted for only a small proportion of the total variance. The implications of these findings are discussed and recommendations for the future treatment of smoking data and for possible experimental approaches to the determinants of smoking are presented.

Adult↗
PubMedDate not supplied

Performance enhancement in a semi-autonomous confined microsociety.

Research in a continuously programmed human experimental laboratory has been directed toward identifying, defining, and expanding generalized knowledge concerning motivational factors within the structure of human behavioral repertoires that maintain and enhance performance. Participants (in groups of three) engaged in a series of repetitive work activities (e.g., word sorting and rug-hooking) for extended periods each day, while living continuously in a residential laboratory. Other parts of the day were spent either interacting socially with other participants or engaging in individual recreational activities. The percentage of time devoted to the various work tasks provided the basis for selecting one activity that occurred with high frequency and one with low frequency. Performance of the low-frequency activity was then required in order to gain access to the high-frequency activity. Under such contingencies, time devoted to the original low-frequency activity increased greatly, and the participants consistently did more than the required amount of the low-frequency work than was necessary to restore access to the restricted work activity. The theoretical significance of these findings resides in the clear demonstration that a time-based model of value applies as well to the enhancement of work-like performance as it does to voluntarily selected or preferred recreational activities.

Achievement↗
PubMedDate not supplied

Behavior analysis of cigarette smoking.

Patterns of cigarette smoking, treated as series of discrete events in time, were investigated with a variety of quantitative techniques designed to characterize individual subject smoking series and to illuminate the relationship between cigarette smoking and environmental events. Data were collected from a total of 35 subjects who were either participants in residential laboratory studies or in a smoking cessation program. Cigarette smoking events were found to be fairly irregularly distributed with respect to time within individual subject series. However, strong dependencies were found between the occurrence in time of individual acts of cigarette smoking and coffee drinking. In addition, the distribution and frequency of smoking events throughout one-hour activity sequences were found to be dependent upon the nature of the activity, and the temporal scheduling of activities was found to affect several quantitative indices of smoking patterns.

Adult↗