University of Leicester
Perez et al., 2016.pdf (580.99 kB)
Download file

Human instrumental performance in ratio and interval contingencies: A challenge for associative theory.

Download (580.99 kB)
journal contribution
posted on 2017-09-06, 13:41 authored by Omar Pérez-Riveros, Michael R. F. Aitken, Peter Zhukovsky, Fabian A. Soto, Gonzalo P. Urcelay, Anthony Dickinson
Associative learning theories regard the probability of reinforcement as the critical factor determining responding. However, the role of this factor in instrumental conditioning is not completely clear. In fact, free-operant experiments show that participants respond at a higher rate on variable ratio than on variable interval schedules even though the reinforcement probability is matched between the schedules. This difference has been attributed to the differential reinforcement of long inter-response times (IRTs) by interval schedules, which acts to slow responding. In the present study, we used a novel experimental design to investigate human responding under random ratio (RR) and regulated probability interval (RPI) schedules, a type of interval schedule that sets a reinforcement probability independently of the IRT duration. Participants responded on each type of schedule before a final choice test in which they distributed responding between two schedules similar to those experienced during training. Although response rates did not differ during training, the participants responded at a lower rate on the RPI schedule than on the matched RR schedule during the choice test. This preference cannot be attributed to a higher probability of reinforcement for long IRTs and questions the idea that similar associative processes underlie classical and instrumental conditioning.



Quarterly Journal of Experimental Psychology (Hove), 2016, pp. 1-13

Author affiliation

/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/MBSP Non-Medical Departments/Neuroscience, Psychology and Behaviour


  • AM (Accepted Manuscript)

Published in

Quarterly Journal of Experimental Psychology (Hove)


Taylor & Francis (Routledge)





Acceptance date


Copyright date


Available date


Publisher version


The file associated with this record is under embargo until 12 months after publication, in accordance with the publisher's self-archiving policy. The full text may be available through the publisher links provided above.