Fractionating the left frontal response to tools: dissociable effects of motor experience and lexical competition.
A number of theories about the evolution of language posit a close (and perhaps causal) relationship between tool use and speech. Consistent with this idea, neuroimaging studies have found that tool knowledge retrieval activates not only a region of the left premotor cortex involved in hand action, but also an adjacent region that is typically described as a language center. We examined whether this pattern of activation is best described as the result of a single process, related to both action and language, or the result of two independent processes. We identified two distinct neural components that jointly contribute to this response: a posterior region centered in the premotor cortex, which responds to motor knowledge retrieval, and an anterior region centered in the left frontal operculum, which responds to lexical competition. Crucial to the interpretation of the premotor response, individual variation in motor experience was highly correlated with the magnitude of the response in the premotor cortex, but not in the prefrontal cortex.
University of Pennsylvania, PA, USA. ikan@bu.edu
Irene P
IP
Kan
Joseph W
JW
Kable
Amanda
A
Van Scoyoc
Anjan
A
Chatterjee
Sharon L
SL
Thompson-Schill
D000293:Adolescent; D000328:Adult; D001931:Brain Mapping; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D019359:Knowledge; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009044:Motor Cortex / Q000502:physiology; D010100:Oxygen / Q000097:blood; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D017397:Prefrontal Cortex / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012660:Semantics
D010100:Oxygen