title: Degree of dependence influences the effects of smoking on psychomotor performance and working memory capacity.
abstract: OBJECTIVE
  Exploration of the variable effect of the degree of smoking dependence on psychomotor performance and working memory capacity.
  
  
  METHODS
  This is a randomized, controlled, prospective study conducted in the Department of Pharmacology, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq from 15 January 2011 to 25 February 2011. After third stage male medical students completed the Fagerstrom Test for Nicotine Dependence questionnaire, we randomly selected a sample of 32 students and divided them into 3 groups: 10 participants with zero score (non-smokers), 11 participants with a score of 5 or less (light smokers), and 11 participants with a score of 6 or more (heavy smokers). Choice reaction time and flicker fusion were measured by the Leeds psychomotor performance test battery, and working memory capacity was measured by the N-back working memory test.
  
  
  RESULTS
  We found significant improvement in ascending flicker fusion test in heavy smokers in comparison with non-smokers (p=0.005, confidence interval [CI] 0.99-6), and light smokers (p=0.053, CI 0.39-4.5). Heavy smokers significantly deteriorated in the 3-back task in comparison with non-smokers (p=0.006, CI 4-25.8), and light smokers (p=0.009, CI 3-24.4). No significant changes were seen between groups in the descending critical flicker fusion, the components of choice reaction time, and in 1-, 2- back working memory tests.
  
  
  CONCLUSIONS
  Heavy smoking (high nicotine) enhances arousal, but impairs working memory capacity.
authors: Department of Pharmacology, College of Medicine, Al-Mustansiriya University, Baghdad, Iraq. ammar_w_78@yahoo.com
authors: Ammar W
authors: AW
authors: Ashor
mesh_terms: D003072:Cognition Disorders / Q000139:chemically induced / Q000175:diagnosis* / Q000523:psychology; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects* / Q000502:physiology; D011597:Psychomotor Performance / Q000187:drug effects* / Q000502:physiology; D012907:Smoking / Q000009:adverse effects*; D014029:Tobacco Use Disorder / Q000145:classification / Q000209:etiology* / Q000523:psychology; D055815:Young Adult