The effect of intruded events on peak time: The role of reinforcement history during the intruded event

• Published in: Behavioural processes Vol. 74; no. 2; pp. 187 - 197
• Main Authors: Aum, SangWeon, Brown, Bruce L., Hemmes, Nancy S.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Shannon Elsevier B.V 22.02.2007; Elsevier
• Subjects: Analysis of Variance; Animal ethology; Animal timing; Animals; Association Learning - physiology; Attention - physiology; Biological and medical sciences; Columbidae; Concurrent task; Discrimination Learning - physiology; Extinction, Psychological - physiology; Field Dependence-Independence; Fundamental and applied biological sciences. Psychology; Peak procedure; Pigeons; Postcue effect; Psychology. Psychoanalysis. Psychiatry; Reinforcement (Psychology); Reinforcement Schedule; Set (Psychology); Time Perception - physiology; Postcue effect; Animal timing; Concurrent task; Pigeons; Peak procedure; Columba livia; History; Pigeon; Vertebrata; Animal; Reinforcement; Timing; Aves
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/j.beproc.2006.11.001

Pigeons were studied in an extension of a study by Aum et al. [Aum, S., Brown, B.L., Hemmes, N.S. 2004. The effects of concurrent task and gap events on peak time in the peak procedure. Behav. Process. 65, 43–56] on timing behavior under a discrete-trial fixed-interval (FI) procedure during which 6-s intruded events were superimposed on peak-interval (PI) test trials. In Aum et al., one event consisted in termination of the timing cue (gap trial); the other was a stimulus in the presence of which subjects had been trained to respond under an independent random-interval (RI) schedule of reinforcement (concurrent task trial). Aum et al. found a disruption of timing on concurrent task trials that was greater than that on gap trials. The present study investigated history of reinforcement associated with intruded events as a possible explanation of this earlier finding. After training to peck a side key on a 30-s PI procedure, discrimination training was conducted on the center key in separate sessions; red or green 6-s stimuli were associated with RI 24 s or EXT (extinction) schedules. During testing under the PI procedure, three types of intruded events were presented during probe trials—the stimulus associated with the RI (S+) or EXT (S−) schedule during discrimination training, or a gap (termination of the side-keylight). Intruded events occurred 3, 9, or 15 s after PI trial onset. Effects of reinforcement history were revealed as substantial disruption of timing during the S+ event and relatively little disruption during the S− event. Intermediate effects were found for the gap event. Results indicate that postcue effects are at least partially responsible for the disruptive effects of the S+ event.