Pitch is coded by firing rate constancy, not spike phase

Evidence

Finally, entracking is invariably accompanied by exquisite phase-locking. One could debate whether it fundamentally is a temporal or rate code. The temporal aspects of the response are disregarded here in the sense that it is the constancy in rate, within and across neurons and stimuli, that codes for pitch, while the phase of spiking is surmised to be irrelevant. — Dijk, Pim van, Physiology, Psychoacoustics and…, 4523

Various schemes and neural mechanisms have been proposed for the encoding of pitch-related periodicity based on the temporal information carried by peripheral neurons. They have in common that they predict tuning in which a neuron is optimally responsive to a certain periodicity. Sounds that differ in pitch would activate different neurons; different sounds with the same pitch would activate the same neurons. Such schemes are referred to as vector codes (Churchland and Sejnowski 1992 ). … The scheme proposed here dispenses with delays and suggests a scalar code, based on a property which is physiologically well documented. We surmise that entracking neurons at the brain stem level are not tuned to a particular periodicity but all code for a range of periodicities by their monotonic relationship between average firing rate and pitch-related period. — Dijk, Pim van, Physiology, Psychoacoustics and…, 4494

The temporal aspects of the response are disregarded here in the sense that it is the constancy in rate, within and across neurons and stimuli, that codes for pitch, while the phase of spiking is surmised to be irrelevant. — Dijk, Pim van, Physiology, Psychoacoustics and…, 4525

Categorization

• DEFINE: Clarifies the key conceptual claim distinguishing the butte/rate code from temporal phase codes for pitch.
• XREF: Connects to earlier material on phase-locking and temporal vs rate coding debates in auditory neuroscience.
• QUESTION: Whether pitch works via scalar firing rate rather than a tuned filter bank is the open empirical question driving this hypothesis.
• corroborated: 4 independent passages support this claim — Dijk, Pim van, Physiology, Psychoacoustics and…, 4523; Dijk, Pim van, Physiology, Psychoacoustics and…, 4494; Dijk, Pim van, Physiology, Psychoacoustics and…, 4525