How embodied is perceptual decision making? Evidence for separate processing of perceptual and motor decisions

Filimon, F., Philiastides, M.G. , Nelson, J.D., Kloosterman, N.A. and Heekeren, H.R. (2013) How embodied is perceptual decision making? Evidence for separate processing of perceptual and motor decisions. Journal of Neuroscience, 33(5), pp. 2121-2136. (doi: 10.1523/JNEUROSCI.2334-12.2013)

Abstract

The extent to which different cognitive processes are “embodied” is widely debated. Previous studies have implicated sensorimotor regions such as lateral intraparietal (LIP) area in perceptual decision making. This has led to the view that perceptual decisions are embodied in the same sensorimotor networks that guide body movements. We use event-related fMRI and effective connectivity analysis to investigate whether the human sensorimotor system implements perceptual decisions. We show that when eye and hand motor preparation is disentangled from perceptual decisions, sensorimotor areas are not involved in accumulating sensory evidence toward a perceptual decision. Instead, inferior frontal cortex increases its effective connectivity with sensory regions representing the evidence, is modulated by the amount of evidence, and shows greater task-positive BOLD responses during the perceptual decision stage. Once eye movement planning can begin, however, an intraparietal sulcus (IPS) area, putative LIP, participates in motor decisions. Moreover, sensory evidence levels modulate decision and motor preparation stages differently in different IPS regions, suggesting functional heterogeneity of the IPS. This suggests that different systems implement perceptual versus motor decisions, using different neural signatures.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Philiastides, Professor Marios
• Authors: Filimon, F., Philiastides, M.G., Nelson, J.D., Kloosterman, N.A., and Heekeren, H.R.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Journal of Neuroscience
• Publisher: The Society for Neuroscience
• ISSN: 0270-6474
• Copyright Holders: Copyright © 2013 The Authors
• First Published: First published in Journal of Neuroscience 33(5):2121-2136
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher