Temporal Encoding: Relative and absolute representations of time guide behavior

Abstract

Temporal information-processing is critical for adaptive behavior and goal-directed action. It is thus crucial to understand how the temporal distance between behaviorally relevant events is encoded to guide behavior. However, research on temporal representations has yielded mixed findings as to whether organisms utilize relative versus absolute judgments of time intervals. To address this fundamental question about the timing mechanism, we tested mice in a duration discrimination procedure in which they learned to correctly categorize tones of different durations as short or long. After being trained on a pair of target intervals the mice transferred to conditions in which cue durations and corresponding response locations were systematically manipulated. Specifically, responses and/or durations of cues were switched in different experimental phases so that either the relative or absolute mapping remained constant. The findings indicate that the transfer occurred most readily when relative relationships of durations and response locations were preserved. In contrast, when the animals had to re-map these relative relations, their temporal discrimination ability was impaired, and they required extensive training to re-establish temporal control. However, preserving the response location of one of the cue durations in such conditions was found to help with initial transfer. These results demonstrate that mice can represent experienced durations both as having a certain magnitude (absolute representation) and as being shorter or longer of the two durations (an ordinal relation to other cue durations), with relational control having a greater influence in temporal discriminations.

Slow motion bias: Exploring the relation between time overestimation and increased perceived intentionality

“…An additional observation pointing towards two dissociable systems was the missing association between these (relative) measures and absolute time estimation (see also, Caruso et al, 2016). For animals, a dissociation between relative and absolute time representations was already demonstrated (Akdoğan et al, 2020). Hence, it seems plausible that relative and absolute time representations in humans are similarly based on different mechanisms (for a review on the neural basis of different time processing systems including both human and animals studies, see Ivry & Spencer, 2004).…”

Temporal scaling and computing time in neural circuits: Should we stop watching the clock and look for its gears?

“…During this task, subjects are presented with a cue that lasts either a short or long duration and, once it terminates, are trained to map each duration to a distinct response-option. To use a concrete example, in Akdoğan et al ( 2020 ), we recently trained mice to press a left lever if a cue lasted 2-s and a right lever if it lasted 6-s ( Figure 10A ; 2-s = left/6-s = right). Consider how two brains would solve this task–one that exclusively represents absolute time and another that represents relative time.…”

“…(A) Temporal discrimination task-design. (B) Task-designs for the three groups included in Akdoğan et al ( 2020 ) at the top. Mean accuracy during phase 2 across all trial types are plotted in the middle.…”