7. Análisis de datos
7.9 Las representaciones sobre la Justicia y ciudadanía: ¿Qué cambió?
In this section, the results of chapters 2, 3 and 5 are summarised and placed in the context of previous research on music reading. A cognitive model of music reading is proposed, based on past and present empirical work. The findings are proposed to bridge the gap in knowledge between the existing understanding of expertise in music reading and the understanding of the fundamental transcription processes involved in music reading. The limitations of the experiments are described and studies designed to address them are presented. Finally, plans for future experiments to address new questions regarding the cognitive and neural bases of music reading are outlined.
6.1 INTRO DUCTIO N_____________________________________________________
The invention o f written notation has enabled ideas to be preserved and
disseminated without the loss o f information. This is just as true for music as it is for
language. The introduction o f musical notation in the tenth century has shaped the
development o f musical history, changing the way music is created, preserved, learned and
performed.
The skill o f music reading is a feat o f cognition at least equivalent to that o f
language reading. The visual appearance o f symbols on a stave bear as little resemblance to
their musical realization as the written word does to its spoken output. However, research
into the cognitive and neurobiological basis o f music reading has lagged far behind that o f
language reading, even though an understanding o f the psychological processes involved in
music reading can help to understand how the brain processes information in the external
world.
Music reading is at once uniquely human and considerably complex, yet reducible
research (visual processing, m otor behaviour, visuo-m otor integration). It therefore
constitutes a behavioural system which can serve as a model o f how basic well understood
psychological processes are integrated into real world behaviour. The introduction to this
thesis revealed that research has largely used music reading as a m odel o f expertise
(Sloboda, 1974), investigating the factors which distinguish good readers from poor
readers, when performance is equated. Although early studies were designed to investigate
the encoding o f musical notation, (Sloboda, 1976; Halpem et al., 1982), the nature o f the
representations remained elusive and further work on the basic psychological processes
involved in music reading was not forthcoming. This thesis aimed to partially redresses the
balance between the relatively good level o f understanding o f musical expertise and the
relatively poor level o f understanding o f the fundamental transcription processes involved
in converting musical symbols into their musical response. In addition, this thesis has
delineated the brain changes that are associated with becoming musically literate. Together,
the findings provide a starting point for the development o f a neuro-cognitive model o f
music reading (section 6.1.1.5).
6.1.1 SUMMARY OF FINDINGS
6.1.1.1
Music Reading is Automatic
The experiments described in Chapter 2 were motivated by the Stroop paradigm
(Stroop, 1935), which has had a long and productive history in the study o f w ord reading.
In particular, this paradigm has elucidated the automatic nature o f w ord reading. Those
who can read, can’t help but read; they do it automatically, even when reading is not
required and is detrimental to performance. In this thesis, the Stroop paradigm was
The hypothesis tested was that music reading, like language reading, is obligatory for those
who are musically Hterate.
The presence o f irrelevant musical notation affected performance o f expert pianists
on a task which required a simple num ber to finger mapping. Performance was slower and
less accurate when the information from the musical notation conflicted with the
information from the numbers but faster and more accurate when the information from
the two sources coincided. Like the language Stroop task, the effect was uni-directional:
when the task was instead to play the musical notes, ignoring the numbers, performance
was not influenced by the congruence o f the note/num ber pairing. This is evidence that
the acquisition o f music reading skill has profound and pervasive effects on information
processing. Furthermore, these effects were shown to develop early in skill acquisition: a
version o f the musical Stroop task in a group o f novice pianists demonstrated some
evidence o f automaticity, after three m onths o f musical training.
6.1.1.2
Musical Notation is Represented Visuo-spatially
Representations are inner, mental events, distinct from the behaviours in which
they play a role. They do not yield easily to observation or study. Nevertheless, by
hypothesis-driven manipulation o f certain task variables and measurement o f the
concomitant effect on behaviour, it is possible to make inferences about the nature o f
these representations. The musical Stroop effect, described above, provided the
foundation for the hypothesis-driven manipulation o f task variables in an endeavour to
determine how musical notation is represented. The hypothesis that musical notation for
melody is represented visuo-spatially was tested by stripping the musical Stroop task o f its
Again, a musical Stroop effect was obtained, which did not differ significandy from that
elicited by the full musical Stroop stimulus; evidence that visuo-spatial information plays a
major role in the representation o f musical notation.
The experiments described in Chapter 3 were designed to characterize the role o f
visuo-spatial information in the realization o f musical symbols into their musical response.
A consideration o f stimulus-response compatibility in musical notation motivated the
design o f a non-musical interference paradigm that would test the hypothesis that music
reading, for keyboard performance, can be envisaged as a set o f vertical to horizontal
stimulus-response transformations. Expert pianists were found to be equally sensitive to
spatial stimulus-response compatibility when the stimulus varied vertically, as when it
varied horizontally (stimuli were always mapped to a horizontally organized response).
Non-musicians showed considerably less sensitivity to violations o f vertical, as opposed to
horizontal stimulus-response compatibility. Evidence for the development o f vertical to
horizontal mappings over a three m onth period o f musical training was found, as indicated
by a relative increase in sensitivity to violations o f vertical to horizontal stimulus-response
compatibility.
A n early experiment (Sloboda, 1976), which investigated encoding o f musical
notation in musicians, concluded that:
"musicians have overleamed mechanisms for immediate transcription....ln general it seems that automated and overleamed tasks are less susceptible to interference than novel tasks".
The musical and non-musical Stroop experiments described in Chapters 2 and 3
refute this idea, showing that overleamed processes in musician can indeed be disrupted by
encoding is that the copying recall tasks did not adequately capture the kind o f processing
that occurs during music reading. It is rare for musicians to simply encode musical
notation, as if it were written text. Almost without exception, musical notation is
intimately linked to musical production.
6.1.1.3
The Acquisition of Musical Literacy Changes the Brain
Music reading is well suited for asking questions concerning how the acquisition o f
a notational system affects brain function. While m ost people in the developed world are
literate in language reading, only a small percentage are musically literate. However, many
people are keen to learn to read and play music and a basic standard can be reached in a
relatively short time. Thus the acquisition o f music reading skill is particularly amenable to
longitudinal neuroimaging studies such as that described in Chapter 5.
Participants were scanned, using fMRI, before and after three m onths o f musical
training. The tasks which they performed in the scanner were designed to separately probe
the learning-related changes associated with reading music for melody and rhythm. A third
task was designed to establish whether learning-related changes would be seen in response
to the mere presence o f musical notation even when music reading was not involved.
Consistent with the prediction that music reading for melody would activate
structures in the dorsal visual stream, this condition was associated with activation in
bilateral superior parietal cortex. Superior parietal cortex has been implicated in other
studies such as m irror reading (Poldrack et al., 1998; Poldrack et al., 2001; Goebel et al.,
1998; Alivisatos et al., 1997) which require sensori-motor transformations based upon the
notation was present but irrelevant, activated the same area o f superior parietal cortex that
was observed in the melody reading condition. Just as Price et al.(1996) report that the
mere presence o f word stimuli in a visual task evokes activation in areas associated with
language processing, the present experiment shows that the mere presence o f musical
stimuH in a visual task evokes activation in areas associated with the explicit processing o f
musical notation and its realization as a musical response. Whilst the participants in the
Price et al. study had at least twenty years experience in word reading, the participants in
the present study had just three m onths experience in the processing o f musical notation.
The musical Stroop experiments described in Chapter 2 provide parallel behavioural
evidence o f the development o f automaticity in music reading after three m onths o f
training.
I f the superior parietal activation seen in the melody reflects a spatial sensori-motor
transformation o f the musical stimulus into its response, the activation o f this same area in
the implicit music reading condition, in which no musical response was made, suggests that
the brain processes the musical notation as if a musical response is about to be made but
terminates processing before the level o f response execution. The additional activation o f
left supramarginal gyms in the same condition is also consistent with the hypothesis that
musical notation is processed as if it prescribed a musical response. The hypothesised
functional roles o f supramarginal gyms and superior parietal cortex suggest a processing
hierarchy, whereby activation o f supramarginal gyms may be involved in the initial
automatic evaluation o f the musical notation as prescribing a learned m otor response (in
general), while the superior parietal cortex computes the sensori-m otor computation which