Four experiments tested the effects of smoking one cigarette on verbal memory and attention. In Experiment I, 18 men were tested under three conditions in a repeated-measures design (pretrial smoking, posttrial smoking, no smoking). Recall of a 50-word list was tested immediately and after intervals of 10 and 45 min. Pretrial smoking resulted in improved recall 10 and 45 min after learning, but not immediately. Posttrial smoking was ineffectual. In Experiment II, three posttrial smoking intervals (1, 5, and 30 min after presentation of a 20-word list) were compared with pretrial smoking and no smoking using a between-subjects design. The 76 light, moderate, and heavy smokers in Experiment II smoked a 1.38 mg nicotine cigarette and were tested 24 h later. Improved recall occurred for pretrial smoking, but not for any posttrial smoking interval and for light and moderate smokers only. Experiment III compared a low (0.40 mg) and high (1.38 mg) level of nicotine cigarette in light and heavy smokers using pretrial smoking. The high-nicotine cigarette resulted in improved recall for both immediate- and delayed-recall tests. The low-nicotine cigarette was less effective. Light and heavy smokers differed in effect of smoking on heart rate, but not in effect of smoking on recall. Experiment IV found no effect of smoking on depth of processing. The possible mechanisms by which nicotine affects recall are discussed.

The effect of combining sleep deprivation and moderate alcohol consumption in male college students differed from the effects of each treatment alone. Following either alcohol or sleep deprivation, there was mild performance impairment, decreased alertness and reduced amplitude and increased latency of cortical evoked potential (EP) components. Heart rate increased after alcohol and anxiety increased after sleep deprivation. When alcohol and sleep deprivation were combined, antagonistic effects were found for most measures (reaction time, heart rate, alertness, anxiety, latency of early EP components), but synergistic effects also occurred (performance accuracy, latency of late EP components). These effects were found in a double-blind experiment using 24 subjects. The experimental treatments were alcohol doses of 0, 0.45 and 0.90 ml/kg of 95% ethanol and 0 and 26 h of sleep deprivation.

Mature male Siamese fighting fish (Betta splendens) were presented with a conspecific male confined in a clear plastic tube for either 15 minutes per day for 20 days (group E 15) or 60 minutes per day for 5 days (group E 60). A third group was presented with this aggression eliciting conspecific male stimulus for 15 minutes on days 1 and 2 and again on days 19 and 20. This group (group C 15) was designed to control for post-stimulation waning of aggressive behaviors independent of constant stimulation and also to control for response decrement as a simple function of time. Two components of the aggressive display and frequency of biting were recorded. It was found that with groups E 15 and E 60 all aggressive behaviors habituated. In general, habituation was more rapid with the short stimulation periods than with the longer ones, although qualitative differences were also found and described. Comparisons of groups E 15 and C 15 showed that repeated daily exposures to the aggression eliciting stimulus were necessary to obtain habituation and that two days of 15 minute stimulation followed by 16 days of no stimulation did not result in response decrement on any of the measures recorded.