Performance on two fixed-interval schedules in the absence of neocortex in rats.
Rats with complete surgical removal of the neocortex (neodecorticates) were trained, with milk as the reinforcer, on a 40-s fixed-interval (FI-40) schedule, then on an FI-120, and finally reexposed to the FI-40. Like controls, neodecorticates developed and appropriately adjusted their postreinforcement pauses and response distributions and showed scallop-type responding on the FI-120 and a positive correlation between running rate and the preceding postreinforcement pause on both FI-40 schedules but not on the FI-120. On some variables neodecorticates reached asymptotic levels of performance more slowly than controls. Extended training on the first FI-40 did not differentially affect neodecorticates' performance. The results suggest that neodecorticates retain a functional timing mechanism.
Jaldow
E J
EJ
Department of Psychology, University College London, United Kingdom.
Oakley
D A
DA
Davey
G C
GC
D000818:Animals; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003216:Conditioning, Operant / Q000502:physiology*; D004193:Discrimination Learning / Q000502:physiology; D004326:Drinking / Q000502:physiology; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009042:Motivation; D009043:Motor Activity / Q000502:physiology; D009474:Neurons / Q000502:physiology; D051381:Rats; D012055:Reinforcement Schedule; D012153:Retention, Psychology / Q000502:physiology; D013998:Time Perception / Q000502:physiology*