which is experienced as a jump in the movement. ERPs recorded from reading subjects
showed that ‘jumps’elicited a large centrally negative response resembling the MMN. This
suggests that expectation about the source location of the next sound was automatically
formed (for related data about automatic sound source discrimination, see Refs 53–55).
Chord cadences
How syntactic rules of major-minor tonal music are represented in the brain has been
addressed by a chord-cadence paradigm.^56 Cadences offive chords (first four chords
600 ms,fifth chord 1200 ms in duration) were continuously presented at several randomly
varying frequency levels. The majority of the chords were presented with synthesized piano
timbre, the task of the subject being to detect the chords presented with a different timbre
(e.g. celesta, marimba). The study was conducted to reveal whether chords violating musi-
cal regularities would elicit differential ERPs compared to ‘music-syntactically’appropriate
chords, although the subject’s attention was directed away from these regularity-violating
chords.
The ERPs, recorded from subjects without any formal training in music, were found to
differ at two latencies between harmonically appropriate chords and Neapolitan chords vio-
lating the context established by the previous chords. The first difference was labelled as the
early right anterior negativity (ERAN) according to its relatively early peak latency at around
200 ms, right preponderant distribution, and negative polarity (its linguistic counterpart
being termed as the left anterior negativity, ELAN^57 ). (See also Ref. 58 for previous related
data in music neurocognition.) The second difference was called the N5 (negative polarity
and peak latency at around 500 ms; without hemispheric dominance in distribution). The
authors concluded that musically untrained subjects may have several neural mechanisms
activated for extrapolating the tonal harmony and musical regularities of musical sequences,
and, further, that this may occur despite the direction of their conscious attention. In fact,
the second argument was confirmed in a subsequent experiment. There, the subjects were
reading a book during the stimulation (Reading condition) or listening to the cadences and
indicating the presence of a Neapolitan chord (Attend condition).^59 The ERAN did not dif-
fer between these two conditions. MEG evidence suggests that the ERAN is generated in the
inferior fronto-lateral cortex (in the left hemisphere known as Broca’s area), suggesting the
involvement of the language areas in music-syntactic processing.^60
Taken together, the auditory system appears to be able to encode automatically regular-
ity of the sound environment. For this regularity extraction, acoustic repetitiveness of the
sound material is not necessary; instead, also more abstract sound relations (direction of
the sound change, interval size, chord progression) are encoded.
Musical expertise
Pitch encoding
Musical expertise is reflected in early auditory ERPs even 100 ms after the sound onset, at
least when the attention of the subject is not directed away from the sounds.^61 Likewise, it
is reflected in the cognitive late-latency ERPs such as P3 and LPC when the subjects are
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