Michael J. Cohen

Marijuana induced state-dependent verbal learning

Human, male subjects from our light marijuana usage category were given paired associate learning under either placebo or marijuana intoxication. A 2×2 experimental design was used to test for dissociation effects. Marijuana intoxicated subjects needed significantly more trials to reach criterion learning than subjects under placebo. Testing of recall, ten days later, demonstrated a significant state-dependent effect. The results were discussed in terms of state-dependent theory and the effects of centrals nervous system active drugs on learning models.

Group outpatient physical and behavioral therapy for chronic low back pain

Conducted a treatment-outcome study to investigate the effectiveness of behavioral (BT) or physical therapy (PT) for treating chronic low back pain (CLBP). Thirteen patients received BT; 12 patients received PT. All patients had at least a 6-month history of seeking treatment of CLBP. Prior to treatment patients were assessed in four principal areas of functioning: (1) physical abilities; (2) current physical functioning; (3) psychological and psychosocial functioning; and (4) pain intensity and pain perception. Treatments were conducted in a group (5-8 patients) outpatient setting. Both BT and PT met for 10 weekly 2-hour sessions. BT was designed to address the environmental, social, and emotional influences of the pain experience, depression, and decreased activity from CLBP. PT was based upon traditional rehabilitation theory and was designed to improve low back function. The posttreatment results showed general improvement for patients in both groups, but few treatment-specific differences in outcome measures.

Physiological and metabolic responses to brief stress in non-insulin dependent diabetic and control subjects

Eight non-insulin dependent diabetic subjects and eight controls were studied during physical and psychological stress. Physiological measures of heart rate, finger pulse amplitude and blood pressure, as well as metabolic measures of blood glucose, insulin, catecholamines and glucagon were sampled during the experiment. Results indicate substantial physiological arousal during the tasks for both groups, but no changes in blood glucose. Despite signs of mild autonomic neuropathy, the diabetic subjects showed responses similar to the controls on the stress tasks. Overall, this study suggests that diabetic instability does not necessarily follow from physiological activity and stress hormone elevations.

Performance on a Verbal Learning Task by Subjects of Heavy Past Marijuana Usage

Human, male subjects (Ss) from our heavy usage category were given paired associate learning in a 2×2 state-dependent learning design. No significant effects were found between marijuana and placebo groups on trials to criterion, and recall of the task seven days later was not found to be state-dependent. The results were compared to a previous study using light usage subjects that reported a state-dependent effect. The effects of Ss past-marijuana usage history and the drugs acute effects on learning and recall were discussed.

Frequency of MMPI Profile Types in Three Chronic Illness Populations.

Clinical interpretation of the MMPI most often utilizes configural or profile analysis. However, most MMPI research has focused only on single scale comparisons. In this study sorting rules to identify four common MMPI configurations were developed and applied to four S populations (N = 157): Chronic low back pain patients, migraine headache patients, hypertensives, and diabetics. No differences in frequencies of these profile types were found among the groups, although the chronic low back pain patients did have more elevated profiles. Variables of age, chronicity of illness and gender did not seem to influence profile type, while some differences were found between patients who rated themselves high and low in activity limitation due to the illness.

Marijuana influenced changes in GSR activation peaking during paired-associate learning☆

Activation Peaking (AP) refers to a patterned physiological response occurring during learning. Marijuana has been found to interfere with both paired-associate learning and phasic GSR activity. Therefore, a study was performed to assess the effects of marijuana intoxication on paired-associate learning and concomitant GSR AP. Two marijuana usage categories were employed--light and heavy usage Ss. Within each category four groups were run in a design to test state-dependent effects. Each S was seen twice with a seven-day inter-session interval. The groups were P-P, P-M, M-M and P-M with P equals placebo and M equals 14 mg delta-9 THC. At each sessions S learned a nine-word paired-associate list to a criterion of one correct recitation, and then received 100 percent overlearning. No usage or group differences were found in level of basal conductance, except lights showed habituation over sessions and heavies did not. Magnitude of phasic GSR activation, aligned for AP, was significantly reduced for both heavy usage and marijuana intoxicated Ss. Also, only on placebo days was an AP effect evident. The results were discussed in terms of marijuanas effects on learning and physiology with emphasis on possible mechanisms of action.