Averaging of temporal memories by rats

J Exp Psychol Anim Behav Process. 2009 Jul;35(3):434-9. doi: 10.1037/a0014021.


Rats were trained on a mixed fixed-interval schedule in which stimulus A (tone or light) indicated food availability after 10 s and stimulus B (the other stimulus) indicated food availability after 20 s. Testing consisted of nonreinforced probe trials in which the stimulus was A, B, or the compound AB. On single-stimulus trials, rats responded with a peak of activity around the programmed reinforced time. On compound-stimulus trials, rats showed a single scalar peak of responding at a time midway between those for stimulus A and B. These results suggest that when provided with discrepant information regarding the temporal predictability of reinforcement, rats compute an average of the scheduled reinforcement times for the A and B stimuli and use this average to generate an expectation of reward for the compound stimuli.

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Association Learning
  • Conditioning, Operant*
  • Conflict, Psychological
  • Cues
  • Discrimination Learning*
  • Male
  • Mental Recall*
  • Photic Stimulation
  • Problem Solving*
  • Rats
  • Rats, Sprague-Dawley
  • Reinforcement Schedule*
  • Time Perception*