The Cognitive Neuroscience of Music

A

B

C

D

E

01020304050

D 3

A 3

Post-stimulus time

Voltage

ISI 1

ISI 2

ISI 3

ISIall (ms)

Perfect 5th

Perfect 4th

Minor 2nd

Tritone

Number of occurrences of each ISI

all

Figure 9.4Interspike interval (ISI) distributions embedded in the responses of axons throughout the auditory
nerve during stimulation with four musical intervals. (A) Schematic of a train of action potentials (or ‘spikes’,ver-
tical lines) fired by an auditory nerve fibre when a musical interval is played.Double arrowsdemarcate some of the
ISIs between pairs of spikes in the spike train.ISI 1 refers to the first-order ISI,ISI 2 and ISI 3 to higher-order ISIs.
All possible ISIs are in ‘all-order’ISI histograms. (B–E) All-order ISI histograms showing ISIs embedded in the
responses of 50 auditory nerve fibers to musical intervals composed of two complex tones (Figure 9.1E–H and
Figure 9.3E–H).Arrowsmark peaks in the ISI pattern that correspond to the missing F 0 of the interval. If the peak
corresponds to a note on the scale, the name of the note is given.