12 May 2003

Time Perception Goes Up In Smoke

by Kate Melville

Not being able to estimate accurately how long something is taking may contribute to the performance declines and discomfort smokers typically experience while trying to quit, say Penn State researchers.

In a recent study, 20 daily smokers, who went without a cigarette for 24 hours, overestimated the duration of a 45 second interval. To the abstaining smokers, the interval felt approximately 50 percent longer than 45 seconds or more than one minute.

Dr. Laura Cousino Klein, assistant professor of biobehavioral health and co-director of the study, says, "The time perception impairment that we observed in the abstaining smokers may be part of the reason they also reported feeling more stressed and unable to focus or be attentive. Time estimation is used as an index of attention processes"

The Penn State team detailed their results in a paper, "Smoking Abstinence Impairs Time Estimation Accuracy in Cigarette Smokers," published in the current issue of the journal, Psychopharmacology Bulletin. The authors are Klein; Dr. Elizabeth J. Corwin, assistant professor in the Penn State Intercollege Physiology Program and the School of Nursing; and Michell McClellan Stine, doctoral candidate in biobehavioral health.

In the study, 22 nonsmokers (12 male and 10 female), and 20 daily smokers (12 male and 8 female), ages 18 to 41, were asked to estimate the duration of a 45 second period of time in a laboratory setting. The smokers were asked to participate in two sessions, once while smoking as usual and once after having stopped for 24 hours.

During each session, the participants were given these instructions: "In a moment, I'm going to say 'start' and then I will say 'stop.' When I say 'stop,' please tell me how much time you think has gone by in seconds. Please try not to count, but just tell me how much time you feel has gone by. Do you have any questions? Ready? Start. [45 second elapse] Stop."

The time estimates made by the nonsmokers and the smokers before the abstinence period were similar and fairly accurate. However, after 24 hours without a cigarette, the smoker's accuracy declined significantly compared to both the nonsmokers and their own estimates before the abstinence period. There were no gender differences in any of the outcomes.

The researchers conclude, "That 24-hour cigarette smoking abstinence can alter perceptions of time in a healthy, young, non-clinical population of smokers emphasizes the need for future research to delineate the attention -altering effects of nicotine and nicotine withdrawal on addiction processes."