Response preferences for "what" and "where" in human non-primary auditory cortex.

Area of Science:

• Neuroscience
• Auditory Neuroscience
• Cognitive Neuroscience

Background:

• Primate studies propose distinct ventral ('what') and dorsal ('where') pathways in the auditory cortex.
• These pathways are hypothesized to handle object recognition and localization, respectively.

Purpose of the Study:

• To investigate the neural substrates of spatial and non-spatial auditory information processing in humans.
• To test the validity of the primate auditory cortex model in human listeners using functional magnetic resonance imaging (fMRI).

Main Methods:

• fMRI was employed to examine brain activity in human participants.
• A factorial design manipulated pitch (present/absent, fixed/varying) and spatial (compact/diffuse source, fixed/varying location) information.
• Analysis focused on identifying distinct and overlapping neural responses to these auditory features.

Main Results:

• Spatially distinct activations were observed for spatial and non-spatial temporal information.
• Pitch processing predominantly activated Heschl's gyrus (HG) and planum polare.
• Spatial processing (changing sound location) activated regions posterior to HG, in planum temporale (PT), with overlap in anterior PT.

Conclusions:

• The findings support a segregated 'what' (pitch) and 'where' (spatial location) processing model in the human non-primary auditory cortex.
• Results highlight functional distinctions within the planum temporale (PT), with anterior and posterior fields showing differential sensitivity to non-spatial information.
• Early areas of the spatial processing stream were specified for coding specific types of spatial auditory information.