Open AccessTopographical gradients of semantics and phonology revealed by temporal lobe stimulation
Author(s) -
Miozzo Michele,
Williams Alicia C.,
McKhann Guy M.,
Hamberger Marla J.
Publication year - 2017
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.23409
Subject(s) - temporal lobe , temporal cortex , middle temporal gyrus , semantic memory , psychology , phonology , semantics (computer science) , inferior temporal gyrus , superior temporal gyrus , neuroscience , cognitive psychology , computer science , epilepsy , cognition , functional magnetic resonance imaging , linguistics , philosophy , programming language
Abstract Word retrieval is a fundamental component of oral communication, and it is well established that this function is supported by left temporal cortex. Nevertheless, the specific temporal areas mediating word retrieval and the particular linguistic processes these regions support have not been well delineated. Toward this end, we analyzed over 1000 naming errors induced by left temporal cortical stimulation in epilepsy surgery patients. Errors were primarily semantic ( lemon → “pear”), phonological ( horn → “corn”), non‐responses, and delayed responses (correct responses after a delay), and each error type appeared predominantly in a specific region: semantic errors in mid‐middle temporal gyrus (TG), phonological errors and delayed responses in middle and posterior superior TG, and non‐responses in anterior inferior TG. To the extent that semantic errors, phonological errors and delayed responses reflect disruptions in different processes, our results imply topographical specialization of semantic and phonological processing. Specifically, results revealed an inferior‐to‐superior gradient, with more superior regions associated with phonological processing. Further, errors were increasingly semantically related to targets toward posterior temporal cortex. We speculate that detailed semantic input is needed to support phonological retrieval, and thus, the specificity of semantic input increases progressively toward posterior temporal regions implicated in phonological processing. Hum Brain Mapp 38:688–703, 2017 . © 2016 Wiley Periodicals, Inc.