The above-mentioned 'neuromusical research' is one of the disciplines that have experienced a higher development since 1980. Music is one of the activities that has historically been associated with the right side of the brain (because of the trite duality between rationality-left and creativity-right). However, according to several studies, the approach a listener/musician has with the music is what determines which area of the brain is operating more. Analytical views (like focus on the intervallic or harmonies) need a higher participation of the left side, and more 'holistic' perspectives are held by the right side (Altenmüller et al., 2000, p. 99-100).
This lateralization is not strict, because both hemispheres interact constantly. Even the language, an activity mostly produced on the left side, has an element like prosody that belongs to the right. Complex tasks (music is one of them) present an increased interaction (Altenmüller et al., 2000, p. 100).
AN EXPERIMENT ABOUT MUSIC APPROACHES AND BRAIN REGIONS
The advances in neuroscience have given evidence to these conclusions, like in the three experiments held by Dr. E. Altenmüller, M- Bangert, G. Liebert -from the Institut für Musikphysiologie und Musiker-Medizin, Hochschule für Musik und Theater of Hannover, Germany; and Dr. W. Gruhn, from the Hochschule für Musik of Freiburg, Germany; which they collected in the article 'Mozart in Us: How the Brain Processes Music' (2000).
The first little experiment consisted of a small quiz about melodies which aimed to confirm if musicians and non-musicians have the same mental approach to music. With the help of electrodes, they could demonstrate that musicians display a more analytical view (left side) and non-musicians a more encompassing one (right side).
In the second experiment, the following hypotheses were going to be tested: “(1) [...] music learning and acquiring a new mental representation of music change brain activation patterns while listening to music and (2) that different ways of music learning may cause various mental representations that are reflected in different cortical activation patterns" (p. 101).
Regarding the learning, the plan was this: “Subjects were divided into three subgroups: (1) A 'declarative' learner group received traditional instruction about the antecedent and consequent and their tonal relation with respect to the closing on a complete or incomplete cadence. The instruction included verbal explanations, visual aids, notations, verbal rules, and some musical examples, which were played to the subjects, but never sung or performed. (2) A 'procedural' learner group participated in musical experiences for establishing genuine musical representations by singing and playing, improvising with corresponding rhythmic and tonal elements or performing examples from the musical literature. (3) A control group of nonlearners who did not receive any instruction about or in music". The results showed that the declarative group had dominance of the left hemisphere while the procedural group revealed a higher activity of the right frontal and bilateral lobes: a more global way of processing (and visuospatial associations too). See Figure 3.
In a third experiment related to chord identification, almost no generalizations could be made, because the 'auditory biography' of the individuals plays an important role.
SPECIFIC MUSICAL ELEMENTS. Pitch (melodic) and time-based (temporal) relations have often been treated separately, but their independence is questioned, because the perception and memory for pitch relations could be rhythmical, providing then possibly a unified dimension (Peretz and Zatorre, 2005, p. 91). Nevertheless, studies about brain lesions still show a separation between the two elements. The right temporal neocortex is important for pitch relations, whereas the rhythmical parameter is more ambiguous. It might be that the rhythmic patterns are processed by the right hemisphere and the metrical grouping (also the beat) by the left (Ibbotson-Morton, 1981, as cited in Peretz and Zatorre, 2005, p. 94). This could explain the different processing of metrical and nonmetrical rhythms (Sakai, 1999, as cited in Peretz and Zatorre, 2005, p. 94). The right auditory cortex and frontal cortical areas are noteworthy for memory (especially for pitch materials). Sightreading is for instance a distinct ability that takes place mostly in the left hemisphere, even though a keyboard notation could be interpreted in the right occipital-temporal region.
A concept that also battles against the idea of lateralization is the 'neuronal plasticity'. Our brain is exposed to a continuous reorganization process. Specifically, the auditory system has an outstanding ability to adapt to new qualities (Altenmüller et al., 2000, p. 100).