Stimulus probability effects on temporal bisection performance of mice (Mus musculus)

Abstract

In the temporal bisection task, participants classify experienced stimulus durations as short or long based on their temporal similarity to previously learned reference durations. Temporal decision making in this task should be influenced by the experienced probabilities of the reference durations for adaptiveness. In this study, we tested the temporal bisection performance of mice (Mus musculus) under different short and long reference duration probability conditions implemented across two experimental phases. In Phase 1, the proportion of reference durations (compared to probe durations) was 0.5, whereas in Phase 2 it was increased to 0.8 to further examine the adjustment of choice behavior with more frequent reference duration presentations (under higher reinforcement rate). Our findings suggest that mice developed adaptive biases in their choice behaviors. These adjustments in choice behavior were nearly optimal as the mice maximized their gain to a great extent which required them to monitor stimulus probabilities as well as the level of variability in their temporal judgments. We further found that short but not long categorization response times were sensitive to stimulus probability manipulations, which in turn suggests an asymmetry between short and long categorizations. Finally, we investigated the latent decision processes underlying the bias manifested in subjects' choice behavior within the diffusion model framework. Our results revealed that probabilistic information influenced the starting point and the rate of evidence accumulation process. Overall, the stimulus probability effects on choice behavior were modulated by the reinforcement rate. Our findings illustrate that mice can adapt their temporal behaviors with respect to the probabilistic contingencies in the environment.

Temporal Encoding: Relative and absolute representations of time guide behavior

“…At first glance, these findings might seem at odds with previous studies providing evidence for mainly one type of time encoding in humans and nonhuman animals (e.g., Carvalho & Machado, 2012;Tomaschke et al, 2014;Zentall et al, 2004). However, we think that our evidence for the use of both types of temporal representations is not surprising, as it is wellestablished that organisms can process, learn, and adapt to varying temporal and stimulus contexts (e.g., Akdoğan & Balcı, 2016;Avlar et al, 2015;De Corte et al, 2018;Jazayeri & Shadlen, 2010). Even though our findings indicate that categorizations heavily rely on relational control of timing behavior, they also provide clear evidence that animals also utilize absolute temporal information.…”

“…One of the main underlying assumptions about this switch-like response strategy is that with elapsing time, individuals can become more confident that the timed stimulus is subjectively more similar to the long duration and thus might move to the long response location prior to the end of cue presentation (Balcı et al, 2011;Balcı & Simen, 2014). When the response keys are made available, subjects can report their long decisions right away, resulting in shorter response times (RTs) on the long location (Akdoğan & Balcı, 2016;Balcı & Simen, 2014;Klapproth & Wearden, 2011). We therefore first tested this explanation by analyzing short and long lever response latencies in the last two pre-transfer sessions (data aggregated across groups and days).…”

Duration Bisection: A User’s Guide

“…In animal studies, the anchor durations typically comprise 50% of the trials (25% each for short and long), whereas in human studies all durations, whether anchor or intermediate, are usually presented an equal number of times. Notably, the presentation probability of the anchor durations does affect stimulus classification (Akdoğan & Balcı, 2016). For example, when fewer short than long anchor stimuli are presented in the test phase, mice are more likely to classify a given probe duration as long as compared to when the short and long anchors are presented with equal frequency during the test session.…”

Clock Speed as a Window into Dopaminergic Control of Emotion and Time Perception

“…These proportional effects were indexed using the point of subjective equality (PSE = 0.5 proportion 'long' response) of the observed sigmoidal functions as illustrated in Fig. 1 (see Akdoğan & Balcı, 2016, Allan & Gibbon, 1991, Kopec & Brody, 2010, and Penney et al, 2008 for theoretical discussions of how participants determine the PSE in duration bisection procedures). As one can see, the PSE was lower for the electric shock trials than for the no-shock trials, consistent with higher clock readings.…”