Age-related differences for duration discrimination in rats.
The effects of age on duration discrimination were analysed with a symbolic matching-to-sample task, where a compound signal (light and sound) was presented at each trial for a duration of either 2 or 10 s. Four groups of rats (6, 12, 18, and 24 months old) were trained to press one lever if the signal was short and the other if it was long. Results show that, in comparison with younger rats (6 and 12 months), presenescent and senescent rats (18 and 24 months) were slower to reach the acquisition criterion. However, when the performance criterion was met, no age-related difference was found: the percentages of correct responses were equivalent, whatever the duration of the stimulus. These results are in accordance with other data, which have often shown that the cognitive impairment reported in old animals results more from a slowness to learn than from an incapacity to discriminate between different durations.
Leblanc
P
P
Psychobiology Unit, University of Louvain, Louvain-la-Neuve, Belgium.
Weyers
M H
MH
Soffié
M
M
D000375:Aging / Q000523:psychology*; D000818:Animals; D003071:Cognition / Q000502:physiology; D004193:Discrimination Learning / Q000187:drug effects / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013998:Time Perception / Q000502:physiology*