Disruption of temporal discrimination and the choose-short effect (original) (raw)
Related papers
1998
Abstract In conditional discriminations, when samples differ only in duration, pigeons typically show a choose-short effect (ie, higher matching accuracy on short-duration-sample than on long-durationsample trials with increasing delay between sample and comparison stimuli). That this effect depends on the similarity of retention interval (RI) and intertrial interval (ITI) houselight illumination conditions has been taken as evidence that pigeons judge duration relative to a temporal background.
Learning and Motivation, 2011
To better understand short-term memory for temporal intervals, we re-examined the choose-short effect. In Experiment 1, to contrast the predictions of two models of this effect, the subjective shortening and the coding models, pigeons were exposed to a delayed matching-to-sample task with three sample durations (2, 6 and 18 s) and retention intervals ranging from 0 to 20 s. Consistent with the coding model, the results suggested a sudden forgetting of memories for duration. In Experiment 2, to test the confusion hypothesis, the characteristics of the ITI and the retention interval differed. Contrary to the confusion hypothesis, a choose-short effect was obtained. In both experiments, a test with only two of the three comparison keys was performed. The results suggest three effects that may be controlling the birds' responses: stimulus generalization when no retention interval is present; an increase in random responding at longer retention intervals; and, similarly, an increase in preference for the "short-sample" key at longer retention intervals.
Waiting in pigeons: the effects of daily intercalation on temporal discrimination
1992
Pigeons trained on cyclic-interval schedules adjust their postfood pause from interval to interval within each experimental session. But on regular fixed-interval schedules, many sessions at a given parameter value are usually necessary before the typical fixed-interval "scallop" appears. In the first case, temporal control appears to act from one interfood interval to the next; in the second, it appears to act over hundreds of interfood intervals. The present experiments look at the intermediate case: daily variation in schedule parameters. In Experiments 1 and 2 we show that pauses proportional to interfood interval develop on short-valued response-initiated-delay schedules when parameters are changed daily, that additional experience under this regimen leads to little further improvement, and that pauses usually change as soon as the schedule parameter is changed. Experiment 3 demonstrates identical waiting behavior on fixed-interval and response-initiated-delay schedules when the food delays are short (<20 s) and conditions are changed daily. In Experiment 4 we show that daily intercalation prevents temporal control when interfood intervals are longer (25 to 60 s). The results of Experiment 5 suggest that downshifts in interfood interval produce more rapid waiting-time adjustments than upshifts. These and other results suggest that the effects of short interfood intervals seem to be more persistent than those of long intervals. Key words: linear waiting, timing, fixed-interval schedules, response-initiated delay schedules, key peck, pigeons One of the most reliable aspects of performance on any reinforcement schedule is the postreinforcement pausing observed when reinforcers are delivered at regular time intervals. Independent of any response-reinforcer contingency, birds and mammals (including humans, under some conditions) learn to postpone food-related responses after each food delivery for a time proportional to the typical interfood interval (temporal control: Chung &
Biasing temporal judgments in rats, pigeons, and humans
Models of interval timing typically include a response threshold to account for temporal production. The present study sought to evaluate the dependent concurrent fixed-interval fixed-interval schedule of reinforcement as a tool for selectively isolating the response threshold in rats, pigeons, and humans. In this task, reinforcement is available either at one location after a short delay or at another location at a longer delay. Because the reinforced location is not signaled, subjects normally respond on the first location and, if reinforcement is not delivered, then switch to the second location. The latency to switch between locations served as the primary dependent measure. After training rats, pigeons, and humans with equal reinforcement magnitudes in the short and long delays, the magnitude of reinforcement was increased threefold on the long-delay location. Consistent with model predictions, this biasing procedure decreased estimates of the response threshold of rats and pigeons, but also reduced temporal control in these species and increased response-threshold estimates in humans. Human and pigeon performance also suggested a magnitude-induced increase in the speed of the internal clock. Collectively, these results suggest that differences in reinforcement magnitude between response alternatives appear to modulate the response threshold, but not selectively, and may provide guidance for better isolating response threshold effects in humans.
Behavioural Processes, 2006
This experiment investigated the effects of nonpharmacological disruption on temporal discrimination. Pigeons responded on a multiple schedule composed of fixed interval, color-matching, and temporal-discrimination components. The effects of three different disruptors (prefeeding, intercomponent-interval food, and extinction) were assessed. All disruptors decreased response rates during the fixed interval. Prefeeding and intercomponent-interval food had unsystematic effects on response patterning during the fixed interval, whereas extinction increased the relative response rate in the initial portions of the fixed interval. Accuracy of color matching was decreased by prefeeding and was not systematically affected by intercomponent-interval food and extinction. In the temporal-discrimination component, all disruptors flattened the psychophysical functions relating proportion long responses to sample duration. This result indicates a general disruption of temporal discrimination. In addition, parameter estimates derived from the behavioral theory of timing indicated all disruptors decreased pacemaker rate, a result consistent with the predictions of the theory. These results highlight the similarities between disruption of temporal discrimination by pharmacological and nonpharmacological manipulations.
Journal of the Experimental Analysis of Behavior, 1967
Pigeons were exposed to a cyclic schedule in which each cycle was composed of twelve 1-min fixed intervals followed by four 3-min fixed intervals; four such cycles comprised an experimental session. The pigeons responded at a much higher average rate during the 3-min intervals than during the 1-min intervals. Other effects were a depression of responding during the first short interval of each cycle and a shortening of postreinforcement pause during the second short interval. The main effect is attributable to a relatively fixed pattern of responding after reinforcement; this pattern consisted in a pause of approximately constant duration followed by responding at an approximately constant rate until the next reinforcement, resulting in much higher average response rates during the longer interreinforcement intervals. The other effects seem attributable to relatively slight differences between the pattern of responding characteristic of later long intervals and the pattern during later short intervals of each cycle. A major implication is that the pigeon is largely insensitive to the sequential properties of many interval-reinforcement schedules. A description of intervalschedule "frustration" phenomena in terms of the inhibitory effects of reinforcement is discussed in relation to these results.
Journal of the Experimental Analysis of Behavior, 1992
Killeen and Fetterman's (1988) behavioral theory of animal timing predicts that decreases in the rate of reinforcement should produce decreases in the sensitivity (A') of temporal discriminations and a decrease in miss and correct rejection rates (decrease in bias toward "long" responses). Eight rats were trained on a 10-versus 0.1-s temporal discrimination with an intertrial interval of 5 s and were subsequently tested on probe days on the same discrimination with intertrial intervals of 1, 2.5, 5, 10, or 20 s. The rate of reinforcement declined for all animals as intertrial interval increased. Although sensitivity (A') decreased with increasing intertrial interval, all rats showed an increase in bias to make long responses.