Action Planning and the Timescale of Evidence Accumulation.

Perceptual decisions are based on the temporal integration of sensory evidence for different states of the outside world. The timescale of this integration process varies widely across behavioral contexts and individuals, and it is diagnostic for the underlying neural mechanisms. In many situations,...

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Main Authors: Konstantinos Tsetsos, Thomas Pfeffer, Pia Jentgens, Tobias H Donner
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2015-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0129473
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author Konstantinos Tsetsos
Thomas Pfeffer
Pia Jentgens
Tobias H Donner
author_facet Konstantinos Tsetsos
Thomas Pfeffer
Pia Jentgens
Tobias H Donner
author_sort Konstantinos Tsetsos
collection DOAJ
description Perceptual decisions are based on the temporal integration of sensory evidence for different states of the outside world. The timescale of this integration process varies widely across behavioral contexts and individuals, and it is diagnostic for the underlying neural mechanisms. In many situations, the decision-maker knows the required mapping between perceptual evidence and motor response (henceforth termed "sensory-motor contingency") before decision formation. Here, the integrated evidence can be directly translated into a motor plan and, indeed, neural signatures of the integration process are evident as build-up activity in premotor brain regions. In other situations, however, the sensory-motor contingencies are unknown at the time of decision formation. We used behavioral psychophysics and computational modeling to test if knowledge about sensory-motor contingencies affects the timescale of perceptual evidence integration. We asked human observers to perform the same motion discrimination task, with or without trial-to-trial variations of the mapping between perceptual choice and motor response. When the mapping varied, it was either instructed before or after the stimulus presentation. We quantified the timescale of evidence integration under these different sensory-motor mapping conditions by means of two approaches. First, we analyzed subjects' discrimination threshold as a function of stimulus duration. Second, we fitted a dynamical decision-making model to subjects' choice behavior. The results from both approaches indicated that observers (i) integrated motion information for several hundred ms, (ii) used a shorter than optimal integration timescale, and (iii) used the same integration timescale under all sensory-motor mappings. We conclude that the mechanisms limiting the timescale of perceptual decisions are largely independent from long-term learning (under fixed mapping) or rapid acquisition (under variable mapping) of sensory-motor contingencies. This conclusion has implications for neurophysiological and neuroimaging studies of perceptual decision-making.
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spelling doaj.art-838e7ef9250b4a068ddc10ed2b3b42e92022-12-21T19:24:06ZengPublic Library of Science (PLoS)PLoS ONE1932-62032015-01-01106e012947310.1371/journal.pone.0129473Action Planning and the Timescale of Evidence Accumulation.Konstantinos TsetsosThomas PfefferPia JentgensTobias H DonnerPerceptual decisions are based on the temporal integration of sensory evidence for different states of the outside world. The timescale of this integration process varies widely across behavioral contexts and individuals, and it is diagnostic for the underlying neural mechanisms. In many situations, the decision-maker knows the required mapping between perceptual evidence and motor response (henceforth termed "sensory-motor contingency") before decision formation. Here, the integrated evidence can be directly translated into a motor plan and, indeed, neural signatures of the integration process are evident as build-up activity in premotor brain regions. In other situations, however, the sensory-motor contingencies are unknown at the time of decision formation. We used behavioral psychophysics and computational modeling to test if knowledge about sensory-motor contingencies affects the timescale of perceptual evidence integration. We asked human observers to perform the same motion discrimination task, with or without trial-to-trial variations of the mapping between perceptual choice and motor response. When the mapping varied, it was either instructed before or after the stimulus presentation. We quantified the timescale of evidence integration under these different sensory-motor mapping conditions by means of two approaches. First, we analyzed subjects' discrimination threshold as a function of stimulus duration. Second, we fitted a dynamical decision-making model to subjects' choice behavior. The results from both approaches indicated that observers (i) integrated motion information for several hundred ms, (ii) used a shorter than optimal integration timescale, and (iii) used the same integration timescale under all sensory-motor mappings. We conclude that the mechanisms limiting the timescale of perceptual decisions are largely independent from long-term learning (under fixed mapping) or rapid acquisition (under variable mapping) of sensory-motor contingencies. This conclusion has implications for neurophysiological and neuroimaging studies of perceptual decision-making.https://doi.org/10.1371/journal.pone.0129473
spellingShingle Konstantinos Tsetsos
Thomas Pfeffer
Pia Jentgens
Tobias H Donner
Action Planning and the Timescale of Evidence Accumulation.
PLoS ONE
title Action Planning and the Timescale of Evidence Accumulation.
title_full Action Planning and the Timescale of Evidence Accumulation.
title_fullStr Action Planning and the Timescale of Evidence Accumulation.
title_full_unstemmed Action Planning and the Timescale of Evidence Accumulation.
title_short Action Planning and the Timescale of Evidence Accumulation.
title_sort action planning and the timescale of evidence accumulation
url https://doi.org/10.1371/journal.pone.0129473
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