| My oldest recollection referring to music is the metaphoric impression of lower and higher keys fighting each other while listening to the piano-play of my parents in the little one-room-appartment of my earliest childhood. There is nothing frightening to this memory. Apparently, I just tried to make some sense of repeatedly recurring sensory input. We always try to make sense of our experiences, in terms of the most fundamental categories we are aware of. Most (if not all) interesting things can be categorized as higher or lower, stronger or weaker, good or bad. If something new appears on the scene of our internal theatre, our first question is: Is it a threat to us? Or could it be of any advantage? It seems, we always ask the black-or-white questions first, and without clear-cut answer to these first questions, our interest rapidly fades. |
| In a Nature Neuroscience review, Janata & Grafton (2003) draw to our attention the fact that not only we move in order to make music, we also feel the urge to move in response to music. They describe music as an example of a 'perception-action cycle', comparable with the sequence of a serial reaction-time task. In such tasks, response times get shorter if repeated patterns are followed, indicating that the subjects form expectations about the stimulus, facilitating the appropriate motor response. Although we often do move in response to music, sometimes quite vigorously so (as e.g. during dancing), the expression of motor signs is not always appreciated (as e.g. during a classical concert). But it's not only consideration for other listeners that may keep us from moving. Sometimes we may totally forget our environment, drifting away into a Mahler symphony, eyes closed, not even moving the little finger. What's happening in our brains, then? And why? Is there a sense in music, or is it just a useless by-product of our cognitive abilities? |
| The recognition of a melody appears to be reserved for humans only. In behavioral experiments, rhesus monkeys tended to judge two melodies to be the same when they differed by one or even by two octaves. However, they failed to recognize the melody if the key was transposed just slightly, leaving the notes physically even closer to the original (reviewed by Hauser & McDermott 2003). Apparently, only a human-sized brain is able to experience the internal structure of a sequence of tones as a specific quality, with its meaning resulting from the relation of the elements to each other, not from the elements themselves. |
| The benefits of music for hominids may have been manifold. First, the impetus to create sound may have provided a basis for a group to act in synchrony. Second, music offers the mind a unique vehicle for thought, a means to practice the acquisition of expertise in sequencing behaviors (Janata & Grafton 2003). Under the heading 'music', attentional processes are embodied in the brain by resonance, individual elements becoming merged into higher-order concepts. Whereas music itself is mostly devoid of explicit meaning, it is very easy and almost unavoidable to attach meaning to it. But each listener will attach his / her own meaning, and usually it's a meaning without direct verbal correspondence. |
| One notion is that music results in physical entrainment of motor and physiological function, mediated through sensory-motor feedback circuits (Zatorre 2005). We react to music spontaneously, answering to a regular, well timed input with expectations and curiosity. We automatically suppose that events repeated with a certain pattern will continue in that pattern, and focus our attention if the pattern is changed. This pattern may not transport any meaning; it may just tell us that something is happening, something we are able to influence, to cooperate with, by investing our own voice, by moving parts of our own body. This may be the main difference to language: language always claims some meaning, tries to transport some content, some information; music does not. |
| Although often both faculties are affected to a comparable extent, rare examples demonstrate that music is not just some sort of language. Peretz & Coltheart (2003) summarize 24 neurological cases with discordant impairment of either music or language recognition. Music deals with timing, with pitch, with timbre, with repetition, with phenomena language and speech deal as well. Nevertheless, the results are quite different. A sequence of tones may form a melody, and even if you never heard that melody before, it may provoke emotions in your mind. And although a series of words (a sentence) may also be regarded as a sequence of tones, these tones are grouped in syllables and phonems, and we need years of learning to understand their meanings. The information density of a sentence is much higher than that of a melody. In a sentence, the phonems follow each other within a few milliseconds each, i.e. within the shortest time the neurons of our auditory system are able to resolve. In a melody, however, the tones are of standardized convenient length, seldom pushing our information processing abilities to the maximum. |
| Music operates with additional qualities not characteristic for speech. In general, speech is not addressed to us at the same time from several sources (this may rather be disturbing). For music, however, the simultaneous resounding of several different tones is often intended and opens new fields of reception as resonance and harmony, consonance and dissonance. These latter phenomena pertain to the social and communicative appeal of music. Two voices may sound together as harmonic or as disharmonic, without carrying any particular information exceeding this mere fact of fitting or not fitting together. Likewise, a sequence of tones, each of them easy to grasp, draws our attention to the relatedness of these tones in sequence to each other, i.e. the relatedness of the actual tone to the tones still resounding in our short term memory and, after sufficient experience, to the tones expected to come. By that, we train cortical cooperations and the handling of memory contents without the constant pressure of extracting meaning from an auditory input as it is the case with speech. |
| These latter considerations suggest that the reception of and the dealing with music should play an important role for the development of higher cognitive functions. Nevertheless, although subjects born deaf were never able to process auditory information, their cognitive capabilities are in general not inferior to those of hearing subjects. Should we conclude, then, that music is not that important for our brain as suggested above? Or do subjects born deaf experience some other kind of 'music'? Interestingly, several orchestras offer 'music for the deaf' (e.g. the Northern Ballet Theatre), with surprising success. Apparently, even deaf subjects are accessible to acoustic imput, most likely experienced as bodily vibrations in reaction to vibrations of the air or, more likely, of solid materials in contact with the body (Caetano & Jousmäki 2006). That such a rough sensory input should have a chance to elicit impressions qualitatively reaching at auditory input may be explained by the relatively modest complexity of hearing, involving strictly linear processing in just one dimension by a few thousands of sensory cells (in contrast to the several millions dedicated e.g. to vision, Weinberger 2004). This simplicity may also explain why music so easily elicits strong and very personal emotions: music provides only the kick-off and guiding line, enticing a chain of remembrances to rise from forgotten stores, that would be difficult to address by more explicit stimuli. |
| My father has now an electronic piano with earphones. Sometimes when I come for a visit on a sunday afternoon, I can hear him play from the first floor: I can hear his feet tapping, no other sound. No lower and higher keys fighting each other any more. |
| 5/05 < MB 6/05 > 6/05 Music & art |
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P. Janata & S.T. Grafton (2003)
Swinging in the brain: shared neural substrates for behaviors related to
sequencing and music. Nat. Neurosci. 6: 682-687.
M.D. Hauser & J. McDermott (2003) The evolution of the music faculty: a comparative perspective. Nat. Neurosci. 6: 663-668. G. Caetano & V. Jousmäki (2006) Evidence of vibrotactile input to human auditory cortex. NeuroImage 29: 15-28. I. Peretz & M. Coltheart (2003) Modularity of music processing. Nat. Neurosci. 6: 688-691. N.M. Weinberger (2004) Music and the brain. Sci. Am. Nov. 2004; & Spektrum der Wissenschaft Juni 2005: 31-37. R. Zatorre (2005) Music, the food of neuroscience? Nature 434: 312-315. |