Specifying the role of the left prefrontal cortex in word selection.
Word selection allows us to choose words during language production. This is often viewed as a competitive process wherein a lexical representation is retrieved among semantically-related alternatives. The left prefrontal cortex (LPFC) is thought to help overcome competition for word selection through top-down control. However, whether the LPFC is always necessary for word selection remains unclear. We tested 6 LPFC-injured patients and controls in two picture naming paradigms varying in terms of item repetition. Both paradigms elicited the expected semantic interference effects (SIE), reflecting interference caused by semantically-related representations in word selection. However, LPFC patients as a group showed a larger SIE than controls only in the paradigm involving item repetition. We argue that item repetition increases interference caused by semantically-related alternatives, resulting in increased LPFC-dependent cognitive control demands. The remaining network of brain regions associated with word selection appears to be sufficient when items are not repeated.
Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, USA; Veterans Affairs Northern California Health Care System, Martinez, USA. Electronic address: stephanie.ries@berkeley.edu.
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Riès
Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, USA.
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Karzmark
Dipartimento di Psicologia dello Sviluppo e della Socializzazione, Università di Padova, Italy.
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Navarrete
Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, USA.
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Knight
Veterans Affairs Northern California Health Care System, Martinez, USA; University of California, Davis, USA; National Research University Higher School of Economics, Russian Federation.
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Dronkers
D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000473:pathology / Q000502:physiology* / Q000503:physiopathology; D011930:Reaction Time; D060865:Repetition Priming; D012660:Semantics; D020521:Stroke / Q000503:physiopathology / Q000523:psychology; D014705:Verbal Behavior / Q000502:physiology*
Chronic stroke patients; Language production; Left prefrontal cortex; Proactive control; Semantic interference; Word selection