Effect of stimulus probability on anti-saccade error rates.
Subjects sometimes fail to suppress a reflexive saccade towards the flashed stimulus in an anti-saccade task. Here, we studied how error rates in the anti-saccade task varied as a function of saccadic probability. Ten subjects performed 200 anti-saccade trials for each of three saccade-direction probability conditions (20%, 50%, and 80%). We found that as the likelihood of a saccade in a given direction increased, the percentage of pro-saccade errors also increased for stimulus presentations in this direction. These results provide support for the hypothesis that errors in the anti-saccade task are the result of an increased level of motor preparation.
Koval
Michael J
MJ
Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, N6A 5C1, Canada.
Ford
Kristen A
KA
Everling
Stefan
S
D000328:Adult; D003071:Cognition / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology*; D009483:Neuropsychological Tests; D015588:Observer Variation; D010775:Photic Stimulation; D011336:Probability; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology*; D014836:Volition / Q000502:physiology*