A. Michael Rossi

BEHAVIORAL AND BIOLOGIC ASPECTS OF MARIJUANA USE

Before the current decade, only three comprehensive studies of the effects of repeat-dose marijuana administration had been conducted.zs45,52 Our current data base has been expanded considerably and has been reviewed in part in several comprehensive publicatiorsz53 Yet, despite an exponential increment in our fund of information about the effects of marijuana on human biologic function and behavior, we are still far from certain about the type and nature of any subtle, and perhaps disastrous, consequences that may be associated with long-term marijuana use. Data presented in this paper reprint an overview of a series of multidisciplinary studies conducted in our laboratory. The major questions that we addressed in this research were similar to those we have posed in previous These questions were: “Does chronic use of marijuana systematically affect motivation to engage in a variety of social and goal-directed activities? Are there constant relationships between free-choice marijuana intake and antecedent and consequent mood states? What are the relationships between free-choice marijuana intake and patterns of verbal interaction? What are the relationships between free-choice marijuana intake and performance on psychologic tasks that assess such functions as problem solving and risk taking, memory, time estimation, and cognitive function? And, finally, are physiologic and biochemical changes associated with repeated doses of marijuana?” Some answers for these questions are provided in each of the topical sections of this manuscript. This report is a summary of the current “state of science” for ongoing research in our laboratory and clinical research facility. More detailed presentations of data obtained in studies of behavorial and social reactions, group interaction, and tolerance will be published by Dr. Babor and his associates. Dr. A. Michael Rossi and his colleagues will report in subsequent publications on studies of mood, short-term memory, vigilance, and reaction time. Drs. Kuehnle and Bernstein have submitted data for publication on psychiatric aspects and cardiac and pulmonary function. Drs. Greenberg and Mello and their associates have presented a detailed description of studies of operant behavior elsewhere in this monograph. One of the most important joints we would like to emphasize is the 35, 37.

Marihuana and mood in human volunteers.

Fifteen adult male marihuana smokers volunteered to live on a hospital research ward for a 31-day study which included a five-day baseline, a 21-day marihuana smoking period and a concluding five-day baseline. Subjects rated their moods and level of intoxication each day at scheduled occasions. Analyses of variance indicated a significant trend in the mood ratings which increased slightly in the euphoric direction just before smoking marihuana (compared to routine ratings) and further increased slightly after smoking marihuana. Level of intoxication ratings and mood ratings were not significantly correlated, but an intoxicated subjects mood ratings were significantly correlated with the average mood ratings of other subjects intoxicated or not. The results suggest that marihuana may increase a persons susceptibility to the moods of others and the feeling of being in harmony with others may be a positive reinforcer.

Propranolol and behavior of alcohol addicts after acute alcohol ingestion.

Sixty‐four adult male chronic alcoholic addicts were studied to assess the effects of propranolol pretreatment on behavioral changes induced by acute ingestion of alcohol. The study was carried out under controlled research ward conditions with a double‐blind technique. Pretreatment with 10, 20, and 40 mg of propranolol 4 times a day for 3 consecutive days prior to alcohol administration failed to block or attenuate cognitive, perceptual, motor, and affective changes induced by acute alcohol intoxication.

Effects of marihuana on reaction time and short-term memory in human volunteers ☆

Twenty-seven adult male marihuana smokers volunteered to participate in a hospital research ward study for a 31-day period. Following five days of baseline acclimatization, subjects could purchase and smoke marihuana cigarettes on a free choice basis for a period of 21 consecutive days. The marihuana smoking period was followed by a concluding five-day baseline. Measurements of simple reaction time, choice reaction time and short-term memory were carried out during the entire study. Analysis of variance revealed no statistically significant differences between control and marihuana performance; however, a correlational analysis showed that individual subject performances on all three tasks were significantly correlated from test session to test session during control conditions but not during marihuana smoking conditions. Findings are discussed in relation to attentional and motivational factors associated with performance on the three tasks.

Note on GSRS as Operants during Sensory Deprivation

In the course of conducting research on the reinforcing properties of visual stimuli during sensory deprivation (SD) operant conditioning procedures were applied i n which button-pressing was the reinforced response ( 2 ) . In a search for a response which was less susceptible to conscious control (and thus less susceptible to uncontrolled variation) che feasibility of using an autonomic response, GSR, as the operant response was investigated. Operant conditioning of the GSR in other settings has been investigated (1, 3) . Ss were 12 volunteer student nurses who were paid

Behavioral analysis of chronic alcoholism. Interaction of alcohol and human contact

1.50 an hour for participation. Their ages ranged from 17 to 23 yr. with a mean of 1 8 yr. Procedures used to create S D conditions and the equipment used to deliver visual reinforcers have been described in detail elsewhere ( 2 ) . Briefly, a closed-circuit TV system in which the brightness of the TV monitor was controlled by a conjugately programmed potentiometer was used to transmit slides depicting scenes from other countries. This equipment was modified so that a GSR of predetermined magnitude triggered the potentiometer and the TV monitor lit up, allowing S to view a slide for 7 sec. A Grass polygraph and a signal amplifier were used to record GSRs and occurrences of reinforcements. A drop in resistance of at least 1500 ohms was the average criterion for occurrence of an operant GSR, but the criterion was established separately for each S on the basis of initial levels of sensitivity. Criterion GSRs occurring during the presentation of a visual reinforcement were not effective as operants and were not included i n tally counts. Ss were in S D for 3 hr., and visual reinforcements were made available during the last hour on two different schedules of 5/2 hr. each. During the contingent-reinforcement schedule GSRs of criterion magnitude produced the visual reinforcers; during the noncontingent reinforcement schedule visual reinforcers were delivered independently of the occurrence of GSRs. The number and spacing of the reinforcements during the N C R schedule were based on and approximated those of the contingent-reinforcement schedule. The sequences of the two schedules were counterbalanced with 6 Ss receiving each sequence. The mean numbers of criterion GSRs that occurred were: 29 during the contingentreinforcement period; 16 during the non-contingent-reinforcement period; and 1 0 during the baseline period (first 2 hr. in S D ) . An analysis of variance indicated the differences between periods were statistically significant ( p < .05) . Visual examination of the record of occurrences of criterion GSRs during succeeding 5-min. intervals within the contingent and non-contingent reinforcement time periods seemed to indicate that criterion GSRs were occurring with increasing frequency over the course of contingent-reinforcement while remaining relatively stable over the non-contingent-reinforcement period. The relatively small numbers involved in these 5-min. segments counter-indicate a meaningful statistical analysis of the trend. These results were interpreted as indicaung an operant conditioning of the GSR with visual reinforcers and support use of GSR as an operant response in S D studies. Further exploration of this possibility will have to be accomplished by others since SD research has been discontinued in our laboratory.