Visuo-motor adaptation in smokeless tobacco users.
Ten smokeless tobacco (ST) users and 11 non-smokers participated in a visuo-motor adaptation experiment in which the visual feedback of point-to-point horizontal arm movements, displayed in real-time on a computer screen, was rotated by 45 degrees counterclockwise for some trials. Visuo-motor performance between smokers and non-smokers was compared on three occasions, once after at least 8 h of tobacco abstinence (Session 1), a second time following ST intake (Session 2), and a third time 45 min after the original ST intake (Session 3). Non-smokers were tested at the same relative times as the smokers in the absence of any tobacco. Both groups performed the three conditions during each session: baseline (normal visual feedback), rotated visual feedback (45 degrees visual feedback rotation), and post-adaptation (normal visual feedback immediately following feedback rotation). Compared with non-smokers, ST users had significantly larger normalized jerk scores (a measure of movement smoothness) after ST intake during the adaptation and post-adaptation conditions in Sessions 2 and 3, but not during the baseline conditions, implying a differential effect of ST use specific to rotated visual feedback. Movement duration was also longer for smokers than for non-smokers after ST intake, but only in the post-adaptation condition. Overall the results suggest that ST use, and hence nicotine, has a detrimental effect on visuo-motor performance, particularly on movement smoothness.
Contreras-Vidal
J L
JL
Department of Kinesiology, University of Maryland, College Park 20742-2611, USA. je375@umail.und.edu
Van den Heuvel
C E
CE
Teulings
H L
HL
Stelmach
G E
GE
D000222:Adaptation, Physiological; D000328:Adult; D005260:Female; D005731:Ganglionic Stimulants / Q000009:adverse effects*; D006801:Humans; D008297:Male; D009048:Motor Skills / Q000187:drug effects*; D009538:Nicotine / Q000009:adverse effects*; D010947:Plants, Toxic; D011930:Reaction Time; D014030:Tobacco, Smokeless / Q000009:adverse effects*; D014796:Visual Perception
D005731:Ganglionic Stimulants; D009538:Nicotine