Watching the clock

Abstract

Four rats and four pigeons were monitored while performing retrospective timing tasks. All animals displayed collateral behaviors which could have mediated their temporal judgements. Statistical analysis made a good case for such mediation in the case of two pigeons performing on a spatially-differentiated response, but not for the two responding on a color-differentiated response. For the rats, all of which performed on a spatially-differentiated task, prediction of their temporal judgements was always better if based on collateral activity than if based on the passage of time.

Fig. 1

The probability of engaging in a collateral behavior as a function of time through the trial for four rats, trained to discriminate 6 from 12 s.

Fig. 2

The probability of engaging in a collateral behavior as a function of time through the trial for two pigeons, trained to discriminate 6 from 12 s (top row) and 6 from 9 s (bottom row). The discriminating response was to the left or right response key.

Fig. 3

The distribution of collateral behaviors (head-bobbing in the corner for Bird 12, pecking the houselight for Bird 54) on trials in which the subject subsequently pecked the ‘short’ key (disks) or the ‘long’ key (circles).