Context effect in a temporal bisection task with the choice keys available during the sample (original) (raw)

What do humans learn in a double, temporal bisection task: Absolute or relative stimulus durations?

Behavioural Processes, 2013

The relative-coding hypothesis of temporal discrimination asserts that humans learn to respond to the relative duration of stimuli ("short" and "long"). The most frequently used procedure to test the hypothesis is the double bisection task. In one task, participants learn that red and green are the correct comparisons following 2 s (short) and 5 s (long) samples respectively. In another task, participants learn that triangle and circle are the correct comparisons following 3.5 s (short) and 6.5 s (long) samples, respectively. Later the samples of one task are tested with the comparisons of the other task, and vice versa. According to the hypothesis, participants will choose red following a 3.5 s sample because that sample is short and red is the comparison that goes with short. Similarly, they will choose circle following 5 s samples because that sample is long and circle goes with long. We replicated this procedure and improved it by introducing several sample durations during testing to obtain the whole psychometric function of each task. Results from Experiment 1 only partially corroborated the relative-coding hypothesis. Results from Experiment 2 did not corroborate the hypothesis. The combined data from Experiments 1 and 2 partially corroborate the hypothesis. Alternatively, we present an explanation of relative-coding-like results that posits exclusively absolute coding of temporal stimuli. This article is part of a Special Issue entitled: SQAB 2012.

Relative Versus Absolute Stimulus Control in the Temporal Bisection Task

Journal of the Experimental Analysis of Behavior, 2012

When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s, or 4 s and 16 s. Across phases, we varied the mapping between the samples and the keys. For group Relative, short and long samples were always associated with the same keys (e.g., Phase A: '1s Left, 4s Right'; Phase B: '4s Left, 16s Right'); for group Absolute, the 4-s sample was associated always with the same key (e.g., Phase A: '1s Left, 4s Right'; Phase B: '16s Left, 4s Right'). If temporal control is relational, group Relative should learn the new task faster than group Absolute, but if temporal control is absolute, the opposite should occur. We compared the results with the predictions of the Learning-to-Time (LeT) model, which accounts for temporal discrimination in terms of absolute stimulus control and stimulus generalization. The acquisition curves of the two groups were generally consistent with LeT and therefore more consistent with the absolute than the relative hypothesis.

Learning in the temporal bisection task: Relative or absolute?

Journal of experimental psychology. Animal learning and cognition, 2016

We examined whether temporal learning in a bisection task is absolute or relational. Eight pigeons learned to choose a red key after a t-seconds sample and a green key after a 3t-seconds sample. To determine whether they had learned a relative mapping (short→Red, long→Green) or an absolute mapping (t-seconds→Red, 3t-seconds→Green), the pigeons then learned a series of new discriminations in which either the relative or the absolute mapping was maintained. Results showed that the generalization gradient obtained at the end of a discrimination predicted the pattern of choices made during the first session of a new discrimination. Moreover, most acquisition curves and generalization gradients were consistent with the predictions of the learning-to-time model, a Spencean model that instantiates absolute learning with temporal generalization. In the bisection task, the basis of temporal discrimination seems to be absolute, not relational. (PsycINFO Database Record

Biasing Performance Through Differential Payoff in a Temporal Bisection Task

Journal of Experimental Psychology: Animal Learning and Cognition, 2019

We investigated how differential payoffs affect temporal discrimination. In a temporal bisection task, pigeons learned to choose one key after a short sample and another key after a long sample. When presented with a range of intermediate samples they produced a Gaussian psychometric function characterized by a location (bias) parameter and a scale (sensitivity) parameter. When one key yielded more reinforcers than the other, the location parameter changed, with the pigeons biasing their choices toward the richer key. We then reproduced the bisection task in a long operant chamber, with choice keys far apart, and tracked the pigeons' motion patterns during the sample. These patterns were highly stereotypical-on the long sample trials, the pigeons approached the short key at sample onset, stayed there for a while, and then departed to the long key. The distribution of departure times also was biased when the payoff probabilities differed. Moreover, it is likely that temporal control decreased while control by location increased. No evidence was found of changes in temporal sensitivity. The results are consistent with models of timing that take into account bias effects and competition of stimulus control.

Trial frequency effects in human temporal bisection: Implications for theories of timing

Behavioural Processes, 2014

To contrast the classic version of the Scalar Expectancy Theory (SET) with the Behavioral Economic Model (BEM), we examined the effects of trial frequency on human temporal judgments. Mathematical analysis showed that, in a temporal bisection task, SET predicts that participants should show almost exclusive preference for the response associated with the most frequent duration, whereas BEM predicts that, even though participants will be biased, they will still display temporal control. Participants learned to emit one response (R[S]) after a 1.0-s stimulus and another (R[L]) after a 1.5-s stimulus. Then the effects of varying the frequencies of the 1.0-s and 1.5-s stimuli were assessed. Results were more consistent with BEM than with SET. Overall, this research illustrates how the impact of nontemporal factors on temporal discrimination may help us to contrast associative models such as BEM with cognitive models such as SET. Deciding between these two classes of models has important implications regarding the relations between associative learning and timing.