Article

Despite accumulating evidence that cortical motor areas, particularly the lateral
premotor cortex, are activated during language comprehension, the question of
whether motor processes help mediate the semantic encoding of language remains
controversial. To address this issue, we examined whether low frequency (1 Hz)
repetitive transcranial magnetic stimulation (rTMS) of the left ventral premotor
cortex (PMv) can interfere with the comprehension of sentences describing manual
actions, visual properties of manipulable and non-manipulable objects, and
actions of the lips and mouth. Using a primed semantic decision task, sixteen
participants were asked to determine for a given sentence whether or not an
auditorily presented target word was congruent with the sentence. We hypothesized
that if the left PMv is contributing semantic information that is used to
comprehend action and object related sentences, then TMS applied over PMv should
result in a disruption of semantic priming. Our results show that TMS reduces
semantic priming, induces a shift in response bias, and increases response
sensitivity, but does so only during the processing of manual action sentences.
This suggests a preferential contribution of PMv to the processing of sentences
describing manual actions compared to other types of sentences.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

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