Original Research ARTICLE
Electrophysiological potentials reveal cortical mechanisms for mental imagery, mental simulation, and grounded (embodied) cognition
- 1School of Psychology, University of Plymouth, Plymouth, Devon, UK
- 2Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA
- 3Department of Radiology, Harvard Medical School, Boston, MA, USA
Grounded cognition theory proposes that cognition, including meaning, is grounded in sensorimotor processing. The mechanism for grounding cognition is mental simulation, which is a type of mental imagery that re-enacts modal processing. To reveal top-down, cortical mechanisms for mental simulation of shape, event-related potentials were recorded to face and object pictures preceded by mental imagery. Mental imagery of the identical face or object picture (congruous condition) facilitated not only categorical perception (VPP/N170) but also later visual knowledge [N3(00) complex] and linguistic knowledge (N400) for faces more than objects, and strategic semantic analysis (late positive complex) between 200 and 700 ms. The later effects resembled semantic congruity effects with pictures. Mental imagery also facilitated category decisions, as a P3 peaked earlier for congruous than incongruous (other category) pictures, resembling the case when identical pictures repeat immediately. Thus mental imagery mimics semantic congruity and immediate repetition priming processes with pictures. Perception control results showed the opposite for faces and were in the same direction for objects: Perceptual repetition adapts (and so impairs) processing of perceived faces from categorical perception onward, but primes processing of objects during categorical perception, visual knowledge processes, and strategic semantic analysis. For both imagery and perception, differences between faces and objects support domain-specificity and indicate that cognition is grounded in modal processing. Altogether, this direct neural evidence reveals that top-down processes of mental imagery sustain an imagistic representation that mimics perception well enough to prime subsequent perception and cognition. Findings also suggest that automatic mental simulation of the visual shape of faces and objects operates between 200 and 400 ms, and strategic mental simulation operates between 400 and 700 ms.
Keywords: mental imagery, visual shape perception, object categorization, face identification, semantic memory priming, visual knowledge, embodiment and grounded cognition, event-related potential
Citation: Schendan HE and Ganis G (2012) Electrophysiological potentials reveal cortical mechanisms for mental imagery, mental simulation, and grounded (embodied) cognition. Front. Psychology 3:329. doi: 10.3389/fpsyg.2012.00329
Received: 07 May 2012; Accepted: 17 August 2012;
Published online: 14 September 2012.
Edited by:Joel Pearson, The University of New South Wales, Australia
Reviewed by:Fred Mast, Universität Bern, Switzerland
Karla K. Evans, Harvard Medical School, USA
Adam Reeves, Northeastern University, USA
Copyright: © 2012 Schendan and Ganis. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: Haline E. Schendan, School of Psychology, University of Plymouth, Drake Circus, Plymouth, Devon, PL4 8AA, UK. e-mail: email@example.com