Famous face identification in temporal lobe epilepsy: Support for a multimodal integration model of semantic memory

• Type of Material: Article
• Authors: Daniel L Drane, Emory University; Jeffrey G. Ojemann, University of Washington; Vaishali Phatak, University of Washington; David W Loring, Emory University; Robert Gross, Emory University; Adam O. Hebb, University of Washington; Daniel L. Silbergeld, University of Washington; John W. Miller, University of Washington; Natalie L. Voets, University of Oxford; Amit Manohar Saindane, Emory University; Lawrence Barsalou, Emory University; Kim J Meador, Emory University; George A. Ojemann, University of Washington; Daniel Tranel, University of Iowa
• Language: English
• Date: 2013-06
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2012 Elsevier Ltd. All rights reserved.
• License: Creative Commons Attribution-NonCommerical-NoDerivs 3.0 Unported
• Final Published Version (URL): http://dx.doi.org/10.1016/j.cortex.2012.08.009
• Title of Journal or Parent Work: Cortex
• ISSN: 0010-9452
• Volume: 49
• Issue: 6
• Start Page: 1648
• End Page: 1667
• Grant/Funding Information: This research was supported by the National Institute of Neurological Disorders and Stroke (NINDS) of the National Institute of Health (NIH) (Grant Numbers: K23 NSO49100, K02 NS070960, and NS19632).; Dr Tranel is also supported by the National Institute of Drug Abuse (Grant Number: DA022549).
• Keywords: Epilepsy surgery; Models of semantic memory; Famous face naming and recognition
• Research Categories: Health Sciences, Medicine and Surgery; Health Sciences, Radiology; Psychology, Cognitive

Abstract

This study aims to demonstrate that the left and right anterior temporal lobes (ATLs) perform critical but unique roles in famous face identification, with damage to either leading to differing deficit patterns reflecting decreased access to lexical or semantic concepts but not their degradation. Famous face identification was studied in 22 presurgical and 14 postsurgical temporal lobe epilepsy (TLE) patients and 20 healthy comparison subjects using free recall and multiple choice (MC) paradigms. Right TLE patients exhibited presurgical deficits in famous face recognition, and postsurgical deficits in both famous face recognition and familiarity judgments. However, they did not exhibit any problems with naming before or after surgery. In contrast, left TLE patients demonstrated both pre-and postsurgical deficits in famous face naming but no significant deficits in recognition or familiarity. Double dissociations in performance between groups were alleviated by altering task demands. Postsurgical right TLE patients provided with MC options correctly identified greater than 70% of famous faces they initially rated as unfamiliar. Left TLE patients accurately chose the name for nearly all famous faces they recognized (based on their verbal description) but initially failed to name, although they tended to rapidly lose access to this name. We believe alterations in task demands activate alternative routes to semantic and lexical networks, demonstrating that unique pathways to such stored information exist, and suggesting a different role for each ATL in identifying visually presented famous faces. The right ATL appears to play a fundamental role in accessing semantic information from a visual route, with the left ATL serving to link semantic information to the language system to produce a specific name. These findings challenge several assumptions underlying amodal models of semantic memory, and provide support for the integrated multimodal theories of semantic memory and a distributed representation of concepts.