Spatiotemporal analysis of auditory "what" and "where" working memory

Area of Science:

• Neuroscience
• Cognitive Science
• Auditory Perception

Background:

• Goal-directed attention to sound identity (what) and location (where) is linked to distinct neural activity in ventral and dorsal brain regions, respectively.
• Understanding the temporal dynamics of this neural segregation is crucial for cognitive neuroscience.

Purpose of the Study:

• To determine the precise timing of neural segregation for auditory "what" and "where" information processing.
• To investigate the neural network involved in working memory for sound identity and location.

Main Methods:

• Event-related potentials were measured during an n-back (n=1, 2) working memory task.
• Stimuli varied in semantic category and virtual location.
• Partial least squares analysis was applied to scalp and source waveform data.

Main Results:

• Domain-specific neural activity for "what" and "where" processing began around 200 ms post-stimulus onset.
• This segregation involved activity in Heschl's gyrus, medial frontal and occipital cortex, and right parietal cortex.
• Working memory load effects emerged around 400 ms post-stimulus, primarily in frontocentral regions and right temporal, frontal, and parietal cortices.

Conclusions:

• Top-down effects on processing auditory "what" and "where" information are observable approximately 200 ms after sound onset.
• This processing relies on a widely distributed neural network, with distinct temporal dynamics for information type and working memory load.