Attention, memory, and cigarette smoking

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.