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Abstract:
The standard method for mapping critical language areas on
the cortical surface in neurosurgical patients is electrical
disruption of picture naming. The present study contrasted
stimulation disruption of the naming of sounds produced by concrete
entities (domestic and wild animals, machines, and musical
instruments) to pictures of similar entities in seven patients
undergoing excision of brain tumors from the language dominant
hemisphere. After thorough testing of picture naming across the
cortical region exposed for the planned resection, an identical
method was used to identify any areas where sound naming was
blocked. Both sounds and pictures were presented for one second. A
total of 13 sites were identified where picture naming was
consistently disrupted. These sites fell across the range of
cortical regions where such disruption is typically found,
including the superior and middle temporal gyri, the
temporoparietal junction, and the inferior frontal gyrus (see
figure for examples of 2 stereotactically-recorded sites in one
patient). At 12/13 sites, sound naming was similarly disrupted, and
at the single exception (a site in the posterior superior temporal
gyrus), sound naming was still somewhat disrupted, though not
consistently (1/4 trials). Thus far dissociations appear to be
rare, and even when observed, only partial. The overall convergence
of sound and picture naming disruption and activation at the same
sites demonstrate that these are supramodal language areas critical
for lexical access.
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