UNIT 8.22 Delay Discounting and Impulsive Choice in the Rat

  1. Adam C. Mar,
  2. Trevor W. Robbins

Published Online: 1 APR 2007

DOI: 10.1002/0471142301.ns0822s39

Current Protocols in Neuroscience

Current Protocols in Neuroscience

How to Cite

Mar, A. C. and Robbins, T. W. 2007. Delay Discounting and Impulsive Choice in the Rat. Current Protocols in Neuroscience. 39:8.22:8.22.1–8.22.18.

Author Information

  1. Department of Experimental Psychology and the Behavioural and Clinical Neuroscience Institute University of Cambridge, Cambridge, United Kingdom

Publication History

  1. Published Online: 1 APR 2007
  2. Published Print: APR 2007


Delay discounting refers to the degree to which immediate outcomes exhibit more influence over behavior than outcomes which are delayed. Impulsive choice, in the context of delay discounting, is generally considered as an increased preference for immediate over delayed outcomes, even where the delayed outcomes are more advantageous. In the past decade, there has been increasing use of delay-discounting paradigms to elucidate the physiological, pharmacological, and behavioral aspects of the putative neural circuitry underlying impulsive choice. This unit describes the assessment of impulsive choice in the rat using a delay-discounting procedure involving an operant response choice between a small reinforcer delivered immediately and a larger reinforcer delivered after a delay, which is progressively increased within a session. Variations of some of the main task parameters are also discussed, as well as their significance and interpretation.


  • delay discounting;
  • delayed reward;
  • impulsive choice;
  • impulsivity;
  • temporal discounting;
  • delayed reinforcement;
  • decision making