Tonotopic maps refer to the organization of which sensory modality?

• A. Hearing
• B. Vision
• C. The orderly mapping of sound frequency across the auditory pathway
• D. The mapping of chemoreceptors

Answer: (C)

Tonotopic maps describe how the auditory system is organized by sound frequency. In the cochlea, hair cells are arranged so that the base responds best to high frequencies and the apex to low frequencies, creating a spatial frequency map. This organization is preserved along the auditory pathway up to the cortex, so neighboring neurons respond to neighboring frequencies. That precise frequency-based layout is what tonotopy refers to. The other options don’t fit as well: hearing is the broad sense, but tonotopy is specifically about frequency organization within the auditory system; vision is organized by retinotopy, not by sound frequency; and chemoreceptor mapping pertains to taste or smell, not audition.