“Exploring the Musical Brain”

Source: Scientific American, “Exploring the Musical Brain” By Kristin Leutwyler. January 22, 2001. Retrieved from http://www.scientificamerican.com/article.cfm?id=exploring-the-musical-bra

Summary:

It is accepted that the human brain processes music much in the way it processes language, in terms of the wide-spread neural engagement that occurs when either entity is perceived by the brain. This wide-spread engagement occurs also in areas that are also used for other for other brain activities. It is for this reason that Tramo recently suggested in Science that rather than having a specific music centre, there are pockets of specificity that are spread throughout the brain. For example, Tramo suggests that the brain’s left planum temporale is responsible for the gift of perfect pitch. This same left planum temporale also, however, plays an important role in processing language.

Such patterns as described by Tramo have been confirmed by other neuroimaging studies, such as those done in the 1990’s, by Peretz and Ligeois-Chauvel. They experimented on patients who had sections of either temporal lobes removed due to epilepsy. According to the results of these tests, musicality rested primarily in the right hemisphere of the brain. Peretz and Ligeois-Chauvel’s experiments consisted of playing the different songs to each patient twice. The researches would switch certain elements of the song. These elements were termed “dimensions”, and included pitch, rhythm, tempo, contour, key, timbre, loudness, and spatial location. It was discovered that those with damage to the left temporal lobe had difficulty primarily with recognizing changes in key, while those with damage to the right had difficulties in recognizing key and contour. Although further imaging studies showed a similar bias to the right hemisphere, such discussions of a music hemisphere have been called into question by studies showing the way the brain discriminates in different regions between such distinctions as note and metre separation and duration.

As more studies are being performed, it has become apparent that areas of the brain which are considered unsophisticated do have a big role to play in interpreting, writing, and performing music. An example of this is the study done by Baron, who discovered through positron emission tomography (PET) scans that even the visual cortex becomes quite active when exposed to music. The reason why this is surprising is because the visual cortex is where make-believe pictures begin. This has led Baron to suggest that “the brain may create a symbolic image to help it decipher changes in pitch”. Music also effects the brain and body on a deeply emotional level, as its responses can be measured through the limbic system which controls our emotions. The physiological changes that are associated with specific emotions such as happiness and sadness also occur as a result of being exposed to music. For instance, music with a quick tempo in a major key brought forth all of the physiological responses of happiness – that is, breathing faster. Further experiments conducted at McGill University using PET imaging patterns which showed that dissonant melodies made the areas of the limbic system which are associated with displeasure light up, while the “consonant melodies stimulated limbic structures associated with pleasure.”

The question of how humans process music, of whether or not the appreciation of music is a uniquely human attribute, and the possibilities of music being an evolutionary advantage, are of enduring interest and much scientific testing has been done to try and get to the bottom of this question. The important and enduring position which music occupies in the history of human existence is undoubtable: recently, flutes made out of animal bones were discovered in France and Slovania in Neanderthal dwellings, and are estimated to be about 53,000 years old. There have even been postulations that music developed before humans did. In a paper published in Scientific, Gray proposed that although our evolutionary paths have not crossed with those of whales for 60 million years, our music and that of whales have much in common. To Gray this suggests that rather than inventing music, we are rather latecomers onto the scene. Some of the similarities in composition between humpback whales and human composers include: using similar ryththms, keeping musical phrases to a few seconds, typically follow an ABA form, and singing in key and spreading single notes over a range no greater than a scale. Such similarities are also found in birds. The canyon wren, for example, sings in the chromatic scale. Such examples beg the question of whether or not there is a “universal music” that awaits discovery, and fires the debate over what is the true meaning of music. While some, such as Stephen Pinker, argue that music is an accidental (albeit pleasant) aspect of evolution and that there is no profound purpose to music. Others such as have refuted this charge by pointing to the fact that listening to music can activate “neural structures deep in the ancient primitive regions of the brain”, and that this points to the profundity and ancient origins of music. Obvious evolutionary benefits include mating and helping us establish patterns and order in our environments, thereby exercising our brains and making sense of our world.

Response:

Leutwyler’s article raises some very interesting questions about music’s purpose and origins. The studies that she cites are illuminating in the way that they attack very different aspects of music’s functions. Her descriptions of the analyses done on the musical “output” of whales and birds is fascinating. The parallels drawn between the musical world of humans and of animals have striking and sophisticated parallels. It is obvious that there is an element of universality and innateness in music – if this were not the case, it would be difficult to account for the physiological responses that our bodies and brains have in response to music, as well as for the affinity and familiarity felt when hearing birds “sing”. What is obvious is that music is closely related to our evolutionary development and that it deeply buried in our primal and instinctual natures. The emerging field of biomusicology offers many interesting venues for deeper investigations into these questions.