Tonotopy in human auditory cortex examined with functional magnetic resonance imaging

Tonotopic organization within the human auditory cortex was investigated with functional magnetic resonance imaging (fMRI) using the blond oxygenation level-dependent (BOLD) contrast mechanism. Single-frequency pulsed tones were alternated with no-tone conditions to elicit stimulus-specific functional activity. Differential frequency-specific activity was imaged within the auditory cortex. Activations for high-frequency tones were located more posteriorly and medially than those for low-frequency tones. Such a pattern is consistent with descriptions of tonotopic organization suggested by other nonneuroimaging methodologies used with human and nonhuman primates. Furthermore, these results demonstrate that fMRI can be used to reliably investigate functional organization of the human auditory cortex.