Regular or decaffeinated coffee and subsequent human aggressive behavior.

A new methodology was used to study the effects of coffee on human aggressive behavior in a laboratory situation. Aggressive responding was elicited by subtracting money from the research subjects, an action which was attributed to a fictitious person. Regular coffee compared to decaffeinated coffee produced decreases in aggressive responses, but increased nonaggressive monetary reinforced responding. Thus, the suppressing effect of regular coffee on aggressive responding was not due to a nonspecific depressant action.

Effects of caffeine on human aggressive behavior.

A new methodology was employed to study the effects of caffeine on human aggressive behavior in a laboratory situation. Aggressive responding was elicited by subtracting money from the research subjects, which was attributed to a fictitious person. Caffeine compared to placebo produced decreases in two types of aggressive responses, but increased nonaggressive monetary reinforced responding. Thus, the suppressing effect of caffeine on aggressive responding was not due to a nonspecific depressant action.

Effects of cigarettes on saliva cortisol levels.

We determined the effects of cigarette deprivation and smoking on saliva cortisol levels in the presence and absence of an operant, monetarily reinforced work task. Subjects were randomly exposed to the following four experimental conditions over successive sessions: no smoking, smoking, no smoking + work, and smoking + work. Measurements of cortisol levels in saliva were determined before and after each daily session. Saliva cortisol levels declined from the beginning to the end of sessions and the end-of-session saliva cortisol levels were not affected by any of the four experimental conditions. Increased cigarette smoking in the presence of the work task also did not affect saliva cortisol levels. Our data do not support: reports of increased cortisol levels as a consequence of smoking or theories relating cortisol and endorphin release to nicotine habituation.

Effects of increasing urinary pH on cigarette smoking.

We evaluated the effects of increasing urinary pH on sensitive automated measures of cigarette smoking behavior. Urine was alkalized by oral doses of 50 or 75 mg/kg sodium bicarbonate. Measurements of cigarette smoking behavior included the number of cigarettes smoked and automated measures of puff frequency and duration. The sodium bicarbonate resulted in little or no change in the number of cigarettes smoked, but in five of the seven subjects frequency and duration of cigarette puffs after sodium bicarbonate decreased 10% to 15%. The small decreases in cigarette smoking brought about by sodium bicarbonate cannot be expected to have significant overall effects.

Amantadine reduces haloperidol-induced dopamine receptor hypersensitivity in the striatum.

In this report evidence is presented that amantadine hydrochloride greatly reduced the development of dopaminergic receptor hypersensitivity in the striatum, which normally results following chronic haloperidol administration using both a stereotyped behavior bioassay and a [3H]spiroperidol receptor binding assay. Amantadine prophylaxis reduced maximal ligand binding to near control levels and also significantly reduced apomorphine induced stereotypy. These results clearly demonstrate that amantadine greatly reduced haloperidol-induced striatal dopamine receptor hypersensitivity and support the hypothesis that amantadine given concurrently with neuroleptic agents might serve to prevent the development of human tardive dyskinesia.

Limits to conceptual rule-learing by schizophrenic patients.

Two studies of conceptual rule-learning by 36 hospitalized psychiatric patients revealed that (a) while all were clinically diagnosed as schizophrenic, they differed widely in their ability to discover abstract rules; (b) the Whitaker Index of Schizophrenic Thinking (WIST) strongly predicted the patients' ability to learn and to apply a conceptual rule; and (c) regardless of severity of conceptual impairment, the patients were unaffected by modest levels of externally generated irrelevant information as presented through the modality of vision. Deficits in abstractive ability, when they exist, are believed to be due to a schizophrenic patient's inability to prevent task-irrelevant information that originates in long-term memory from spilling into and despoiling the operations of working memory.