Episodic-Like Memory in Rats: Is It Based on When or How Long Ago?
William A. Roberts,1*
Miranda C. Feeney,1
Krista MacPherson,1
Mark Petter,2
Neil McMillan,1
Evanya Musolino1
Recent experiments with rats suggest that they show episodic-like or what-where-when memory for a preferred food found on a radial maze. Although memory for when a salient event occurred suggests that rats can mentally travel in time to a moment in the past, an alternative possibility is that they remember how long ago the food was found. Three groups of rats were tested for memory of previously encountered food. The different groups could use only the cues of when, how long ago, or when + how long ago. Only the cue of how long ago food was encountered was used successfully. These results suggest that episodic-like memory in rats is qualitatively different from human episodic memory.
1 Department of Psychology, University of Western Ontario, London, Ontario, N6A 5C2, Canada.
2 Department of Psychology, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada.
* To whom correspondence should be addressed. E-mail: roberts{at}uwo.ca
