Nicotine enhances automatic temporal processing as measured by the mismatch negativity waveform.
BACKGROUND
Cholinergic agonists and, more specifically, nicotine, have been found to enhance a number of cognitive processes. The effect of nicotine on temporal processing is not known. The use of behavioral measures of temporal processing to measure its effect could be confounded by the general effects of nicotine on attention. Mismatch negativity (MMN) has been used as a physiological measure of automatic temporal processing to avoid this potential confound.


METHODS
A total of 20 subjects (11 nonsmokers and 9 smokers following 2 hr of abstinence) participated in a two-visit single-blind, placebo-controlled crossover study of the effect of nicotine on MMN indices in response to an interstimulus interval deviant.


RESULTS
Nicotine-enhanced MMN amplitudes from baseline recording to postdrug recording greater than did the placebo condition. This enhancement was seen in both nonsmokers and smokers. Nicotine had no significant effect on MMN latency or N100 amplitude or latency.


CONCLUSIONS
This is the first study to demonstrate a nicotine-related enhancement of MMN amplitude to an interstimulus interval duration deviant and confirms our hypothesis that nicotine enhances preattentive temporal processing. Nicotinic agonists may represent a potential therapeutic option for individuals with abnormalities in early sensory or temporal processing related to cholinergic system abnormalities. Methodologically, our paradigm of nicotine administration in abstinent smokers is important because it resulted in both minimal withdrawal symptoms and meaningful data that are not attributable solely to relief of withdrawal.
Research Service, Denver Veterans Affairs Medical Center, Department of Psychiatry, University of Colorado Health Sciences Center, 4200 East Ninth Avenue, C268-71, Denver, CO 80262, USA. laura.martin@uchsc.edu
Laura F
LF
Martin
Deana B
DB
Davalos
Michael A
MA
Kisley
D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology; D003265:Contingent Negative Variation / Q000187:drug effects* / Q000502:physiology; D018592:Cross-Over Studies; D004569:Electroencephalography / Q000379:methods; D005072:Evoked Potentials, Auditory / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D018722:Nicotinic Agonists / Q000008:administration & dosage*; D011930:Reaction Time / Q000187:drug effects; D016037:Single-Blind Method; D055815:Young Adult
D018722:Nicotinic Agonists; D009538:Nicotine