Human auditory cortical responses to pitch and to pitch strength

Pitch is a fundamental auditory sensation, underlying both music and speech perception. This study was designed to explore pitch coding in human auditory cortex by testing whether activity in pitch-responsive regions covaries as a function of pitch salience (pitch strength). A psychophysical paradigm was used to confirm three levels of pitch salience for two different pitch-evoking stimuli. The location and magnitude of the response to these stimuli were measured using functional magnetic resonance imaging. A pitch response was found in planum temporale, close to the posterolateral border of Heschl's gyrus. However, the response was not sensitive to pitch salience. One interpretation is that pitch-sensitive regions are maximally responsive to the presence or absence of pitch and not to pitch salience.