KSR Kumar

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Purves himself is trying to understand why and how the appeal of music is embedded in our biology. In a key study published in 2007, he and his colleagues began their research based on the fact that music is created using subgroups of the same 12 notes—the chromatic scale—irrespective of geography and culture (Ross et al, 2007).

The team recorded and analysed spoken vowels in English and Mandarin—in human speech, the vibration of the vocal cords that occurs during vowel vocalization is responsible for the tonal quality, or periodicity, of speech. Each vowel is characterized by several formants, which are peaks of intensity in the sound spectrum; although the absolute frequency values of formants varies from speaker to speaker, the ratio between the first two formants is characteristic for each pronounced vowel and the basis of vowel identification.

The scientists found that the frequency relationships of these formants in vowel sounds in both English and Mandarin specifically represent all 12 intervals of the chromatic scale. Thus, the way we make and appreciate music is apparently rooted in the nature of periodic sounds that our own body creates and that form the basis of speech. “The significance of this work and more recent studies we have done on scale preferences and the different emotional impact of major and minor music is that many aspects of tonal music appear to be based on the spectral characteristics of speech,” Purves commented. “We are exposed to these characteristics on a daily basis, but in contrast to tempo, intensity, timbre and pitch, spectral relationships as such do not enter consciousness. This fact has made it more difficult to recognize that our appreciation of musical tones comes from the biological importance of social communication by vocal means.”

Additional comparative studies are generating evidence that challenges the traditional view that music and language are two largely independent neurocognitive systems (Johansson, 2008; Patel 2008). Indeed, although music and language have common features—such as basic sound elements and a syntactic structure—researchers had long believed that they resulted from essentially different processes in the brain.

Instead, the newly evolving scenario reveals two overlapping cognitive and neural systems that share brain structures and are more closely related to each other than previously thought. Aniruddh Patel, from the Neurosciences Institute in San Diego (CA, USA), has proposed that, “linguistic and musical syntax share certain syntactic processes—instantiated in overlapping frontal brain areas—that apply over different domain-specific syntactic representations in posterior brain regions” (Patel, 2003).

Put another way, although words and their syntactic features in language and chords and their harmonic relations in music are stored in distinct brain networks, the networks that provide the neural resources for the activation of stored syntactic representations overlap.

Other theories have been proposed in recent years—both on the basis of new experimental observations and existing evidence—that attempt to reconcile, or at least to reconnect music and language and to explain the nature of music itself.

“According to my theory, music is a super-stimulus for the perception of ‘musicality’ in normal speech,” commented Philip Dorrell (Wellington, New Zealand), who developed a hypothesis, which matches the findings of Purves and others, that music is a form of speech that has retained many traces of its origins from language (Dorrell, 2005). “The perception of musicality is a hidden aspect of speech perception. It is hidden because it acts gradually and in the long-term, to alter the listener's perception of reality, but it does not have any immediate effect on the perception or understanding of any particular speech utterance,” he said.

“Music itself can be regarded as an artificially contrived form of speech, contrived so as to have an exaggerated musicality (sufficiently exaggerated that it is no longer so hidden).”

Dorrell is indeed hinting at a crucial question that has generated intense debate: is music related to language in evolutionary terms and if so, how? More specifically, does—or did—our ability to perceive and create music serve any adaptive and/or survival purpose and did this intersect with speech? “There has been discussion about common roots of music and language in human evolution.

We think that music is preserved in human evolution as it is a tool to communicate even without words. Music is unique in its ability to evoke a wide spectrum of emotions,” Järvelä commented. “Music is social communication between individuals.

Darwin proposed that singing is used to attract the opposite sex. Furthermore, lullabies are implied to attach [an] infant to a parent and singing or playing music together [might increase] group cohesion.” As such, Järvelä thinks that it is justifiable to hypothesize a link between musical perception and/or creativity in music and the same phenotypic spectrum of human cognitive social skills that include human bonding and altruism, both of which have been reported to be associated with AVPR1A.

“We hypothesized that humans are social animals that need each other and here music is a tool for social communication between individuals”

“If we can show that music dissociates from language at the brain and genetic level, it constitutes the clearest path to demonstrating a separate faculty of music and perhaps support[s] Steven Mithen's [an archaeologist and anthropologist at the University of Reading, UK] hypothesis that pitch could have preceded rhythm (and speech) in evolution, and that pitch and rhythm could have independent evolutionary forces,” Peretz said. “Being in-tune could be one force behind sexual selection and being in-time could be a group cohesive force.

According to Barbro Johansson, a neuroscientist at the Wallenberg Neuroscience Center in Lund, Sweden, the linkage between music and language might also play a role in the development of the latter during childhood. “From an evolutionary perspective, studies on the early development of language and music abilities in children are particularly interesting and have so far indicated some overlapping and possibly shared neural resources,” he said. “Musical training facilitates pitch processing in both music and language, and children with specific language impairment also show impairment in music-syntactic processing.”

Given that it requires a higher precision of pitch and rhythm to appreciate music than to understand speech, Dorrell believes that the only reason humans are so good at perceiving pitch is to appreciate music.

“[This] strongly suggests that our ability to appreciate music has some biological purpose, since the mechanism of precise pitch perception presumably has a non-trivial implementation cost in terms of brain growth and operation, and wouldn't exist if it didn't have some value.