Auditory cortex layers divide pitch extraction from pattern synthesis

Evidence

The auditory cortex stands between the ear and the seat of consciousness. It is divided into three parts with different function. The tertiary cortex apparently synthesizes the aural experience before sending it on, and the secondary cortex apparently processes harmonic, melodic, and rhythmic patterns. The primary cortex extracts pitch and loudness data, and is tonotopically organized (different frequency zones in physically different places). Brain scans show that the primary cortex is not involved when imagining music, but it is active when schizophrenics have auditory hallucinations. — Eric J. Heller, Why You Hear What You Hear- An…, 2287

Categorization

• QUESTION: The claim that primary cortex is inactive during imagined music but active in schizophrenic hallucinations suggests hallucinations recruit perceptual circuitry imagination does not - worth chasing the imaging literature.
• DEEPTHINKING: The dissociation between imagined music (no primary cortex) and schizophrenic auditory hallucinations (primary cortex active) is a striking lever on the boundary between perception, imagination, and hallucination.
• SEED: The primary-cortex-activity difference between imagination and hallucination is a strong hook for a piece on how hearing, imagining, and hallucinating differ in the brain.