title: Contextual response time adaptation in the countermanding performance of rats.
abstract: Humans and non-human primates are known to lengthen their response time (RT) to a go signal when they occasionally must cancel their responses following a stop signal in a countermanding task as well as to adjust their RT adaptively on a trial-by-trial basis. Less is clear regarding the adaptive RT adjustments in the countermanding performance of rodents. To investigate this question, male Wistar rats (N=12) were trained with food reward to press a lever directly below an illuminated light (go signal), but to countermand the lever press subsequent to a tone (stop signal) presented infrequently (25% of trials) at variable delays. Rats were then tested in a standard responding task (0% stop trials) or a countermanding task with a 10-s or 1-s TO interval following errors. Rats exhibited significant RT lengthening in the countermanding task, compared with the standard responding task, and RT shortening following consecutive correct go trials. They also show RT lengthening following both error trials in the standard responding task and unrewarded, non-canceled stop trials in the countermanding task. RT lengthening following erroneous stop trials was observed in sessions with a 10-s TO interval, but not with a 1-s TO interval. Analyses of RT distributions suggest that RT lengthening results largely from reduced sensitivity to the go signal, but also from reduced readiness. These findings indicate that rats exert control in the countermanding task by lengthening RT in anticipation of stop trials to avoid long, unrewarded TO intervals.
authors.affiliation: Centre for Neuroscience Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Beuk
authors.affiliation: Centre for Neuroscience Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Beninger
authors.affiliation: Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada.
authors.forename: Elysia
authors.initials: E
authors.lastname: Mechefske
authors.affiliation: Centre for Neuroscience Studies, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Psychology, Queen's University, Kingston, Ontario K7L 3N6, Canada; Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada. Electronic address: martin.pare@queensu.ca.
authors.forename: Martin
authors.initials: M
authors.lastname: Paré
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal; D005403:Fixation, Ocular / Q000502:physiology; D007266:Inhibition, Psychological; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology*; D012438:Saccades / Q000502:physiology
keywords: performance monitoring; post-error slowing; proactive slowing; response adjustment; stop-signal; timeout interval