Debates surrounding the evolution of language often hinge upon its relationship to cognition more generally and many investigations have attempted to demark the boundary between the two. Though results from these studies suggest that language may recruit domain-general mechanisms during certain types of complex processing, the domain-generality of basic combinatorial mechanisms that lie at the core of linguistic processing is still unknown. Our previous work (Bemis and Pylkkänen, 2011, 2012) used magnetoencephalography to isolate neural activity associated with the simple composition of an adjective and a noun (“red boat”) and found increased activity during this processing localized to the left anterior temporal lobe (lATL), ventro-medial prefrontal cortex (vmPFC), and left angular gyrus (lAG). The present study explores the domain-generality of these effects and their associated combinatorial mechanisms through two parallel non-linguistic combinatorial tasks designed to be as minimal and natural as the linguistic paradigm. In the first task, we used pictures of colored shapes to elicit combinatorial conceptual processing similar to that evoked by the linguistic expressions and find increased activity again localized to the vmPFC during combinatorial processing. This result suggests that a domain-general semantic combinatorial mechanism operates during basic linguistic composition, and that activity generated by its processing localizes to the vmPFC. In the second task, we recorded neural activity as subjects performed simple addition between two small numerals. Consistent with a wide array of recent results, we find no effects related to basic addition that coincide with our linguistic effects and instead find increased activity localized to the intraparietal sulcus. This result suggests that the scope of the previously identified linguistic effects is restricted to compositional operations and does not extend generally to all tasks that are merely similar in form.
Keywords: language, cognitive neuroscience, temporal lobe, domain-generality, combinatorics
Citation: Bemis DK and Pylkkänen L (2013) Combination across domains: an MEG investigation into the relationship between mathematical, pictorial, and linguistic processing. Front. Psychology 3:583. doi: 10.3389/fpsyg.2012.00583
Received: 31 July 2012; Accepted: 11 December 2012;
Published online: 03 January 2013.
Edited by:Gina Kuperberg, Tufts University, USA
Reviewed by:Evelina Fedorenko, Massachusetts Institute of Technology, USA
Copyright: © 2013 Bemis and Pylkkänen. 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: Douglas K. Bemis, CEA-INSERM, NeuroSpin Center, Bât 145, Point Courier 156, F-91191 Gif-sur-Yvette Cedex, France. e-mail: firstname.lastname@example.org