“Improvements in Performance without Nicotine Withdrawal”, 1994 (; backlinks; similar):
Two tests were made of the withdrawal-relief explanation of the improvements in performance obtained with smoking.
Study 1 examined the extent to which abstinence from smoking produced poorer performance in smokers in comparison with non-smokers. No evidence was obtained of differences in performance in smokers who were deprived of cigarettes for 10h and non-smokers.
Study 2 tested smokers with a standard cigarette or sham smoking after one hour and 12h of deprivation. There was no difference in performance for the two deprivation intervals either in the sham smoking condition, or after smoking the lit cigarette.
This study gave no evidence for withdrawal-relief being an explanation of the improvements in performance obtained with smoking.