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Centroparietal activity mirrors the decision variable when tracking biased and time-varying sensory evidence

Kohl, C., Spieser, L., Forster, B. ORCID: 0000-0001-5126-7854, Bestmann, S. and Yarrow, K. ORCID: 0000-0003-0666-2163 (2020). Centroparietal activity mirrors the decision variable when tracking biased and time-varying sensory evidence. Cognitive Psychology, 122, 101321.. doi: 10.1016/j.cogpsych.2020.101321


Decision-making is a fundamental human activity requiring explanation at the neurocognitive level. Current theoretical frameworks assume that, during sensory-based decision-making, the stimulus is sampled sequentially. The resulting evidence is accumulated over time as a decision variable until a threshold is reached and a response is initiated. Several neural signals, including the centroparietal positivity (CPP) measured from the human electroencephalogram (EEG), appear to display the accumulation-to-bound profile associated with the decision variable. Here, we evaluate the putative computational role of the CPP as a model-derived accumulation-to-bound signal, focussing on point-by-point correspondence between model predictions and data in order to go beyond simple summary measures like average slope. In two experiments, we explored the CPP under two manipulations (namely non-stationary evidence and probabilistic decision biases) that complement one another by targeting the shape and amplitude of accumulation respectively. We fit sequential sampling models to the behavioural data, and used the resulting parameters to simulate the decision variable, before directly comparing the simulated profile to the CPP waveform. In both experiments, model predictions deviated from our naïve expectations, yet showed similarities with the neurodynamic data, illustrating the importance of a formal modelling approach. The CPP appears to arise from brain processes that implement a decision variable (as formalised in sequential-sampling models) and may therefore inform our understanding of decision-making at both the representational and implementational levels of analysis, but at this point it is uncertain whether a single model can explain how the CPP varies across different kinds of task manipulation.

Publication Type: Article
Additional Information: © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license
Publisher Keywords: decision-making, centroparietal positivity, decision bias, non-stationary evidence, accumulator model
Subjects: B Philosophy. Psychology. Religion > BF Psychology
R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry
Departments: School of Arts & Social Sciences > Psychology
Date Deposited: 26 May 2020 14:24
[img] Text - Accepted Version
This document is not freely accessible until 24 June 2021 due to copyright restrictions.
Available under License Creative Commons Attribution Non-commercial No Derivatives.

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