Resumen de Instrumental Ambiguity in the Discrimination of and Memory for the Duration of a Stimulus
The study of timing in animals has often included instructional ambiguity (or a failure to discriminate), an artifact that has often led to the misinterpretation of results. In the case of the peak procedure, used to determine when animals anticipate the time of reinforcement, the effect of gaps in the to-be-timed stimulus depends importantly on whether the gap appears similar in appearance to the intertrial interval. When the two intervals are similar animals appear to reset their clock ¿as they learned to do between trials. When the two intervals are different the animals appear to pause their clock. In the case of conditional duration discriminations, memory for the durations appears to shorten with the passage of time since their occurrence as indicted by divergent retention intervals, but only when the retention interval is similar to the intertrial interval and the trial appears to occur without a sample. When the retention interval and the intertrial interval are different, parallel functions are often found thus, no such shortening of the interval occurs. Finally two phenomena are examined, (a) the relative categorization of short and long durations depending on what they are being compared with and (b) the subjective passage of time that varies systematically with what the animal is doing while timing.
