Functional Anatomy of Spoken Input
• Note that the low-level
auditory pathway is not
specialized for speech
sounds
– Both speech and non-speech
sounds activate primary
auditory cortex (bilateral
Heschl’s Gyrus) on the top of
the superior temporal gyrus
Functional Anatomy of Spoken Input
• Which parts of the auditory pathway are specialized for
speech?
• Binder et al. (2000)
– fMRI
– Presented several kinds of stimuli:
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•
•
•
•
white noise
These have non-word-like acoustical properties
pure tones
non-words
These have word-like acoustical properties but no
reversed words
lexical associations
real words word-like acoustical properties and lexical associations
Functional Anatomy of Spoken Input
• Relative to “baseline” scanner
noise
– Widespread auditory cortex
activation (bilaterally) for all
stimuli
– Why isn’t this surprising?
Functional Anatomy of Spoken Input
• Statistical contrasts reveal specialization for speech-like
sounds
– superior temporal gyrus
– Somewhat more prominent on left side
Functional Anatomy of Spoken Input
• Further contrasts to identify specialization for words relative
to other speech-like sounds revealed only a few small clusters
of voxels
• Brodmann areas
– Area 39
– 20, 21 and 37
– 46 and 10