The temporal structure of reinforcement: VI. Local determinants of response topography as determined by analysis of interresponse times.
Rats chronically exposed to intracranial reinforcement tend to respond in brief, well-organized response episodes. In these studies, rats implanted with electrodes aimed at the medial forebrain bundle were permitted sufficient stimulation access to allow the generation of episodic patterns. Interresponse times (IRTs) were collected and examined for indications of systematic trends within individual episodes. Analysis within and between subjects suggested three trends. First, intervals between successive responses within episodes declined for the initial 10-15 responses, at which point they reached a stable asymptote. Second, the degree of this trend varied with the length of time separating successive episodes. At very short times between episodes, little declining trend in initial IRTs was evident. Third, IRTs systematically increased prior to episode termination. These findings suggest that local response topography in spontaneously initiated and organized episodes may reflect the cumulating and subsequently dissipating influence of a priming process. The organizing properties of the priming process suggest that it is a significant motivational influence.
D000818:Animals; D001931:Brain Mapping; D005108:Extinction, Psychological / Q000502:physiology; D008297:Male; D008474:Medial Forebrain Bundle / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012055:Reinforcement Schedule; D012653:Self Stimulation / Q000502:physiology*