Music perception and octave generalization in rhesus monkeys.

Abstract

Two rhesus monkeys were tested for octave generalization in 8 experiments by transposing 6-and 7-note musical passages by an octave and requiring same or different judgments. The monkeys showed no octave generalization to random-synthetic melodies, atonal melodies, or individual notes. They did show complete octave generalization to childhood songs (e.g., "Happy Birthday") and tonal melodies (from a tonality algorithm). Octave generalization was equally strong for 2-octave transpositions but not for 0.5or l.S-octave transpositions of childhood songs. These results combine to show that tonal melodies form musical gestalts for monkeys, as they do for humans, and retain their identity when transposed with whole octaves so that chroma (key) is preserved. This conclusion implicates similar transduction, storage, processing, and relational memory of musical passages in monkeys and humans and has implications for nature-nurture origins of music perception. Music is considered among cultures' highest achievements. Nevertheless, music from different cultures shares many characteristics. Among these common characteristics is that all music uses a limited number of possible notes. A limited number of possible notes helps to make songs memorable and reproducible. Other factors contribute to their memorability, reproducibility, and general appeal. Take, for example, the familiar tune "Happy Birthday." There is no doubt about its memorability. The first four notes readily identify it. Furthermore, different sets of four notes separated by whole octaves suffice equally well to identify "Happy Birthday." Preverbal infants as well as adults can identify a transposed melody as the same melody while at the same time recognizing that the notes are different, that is, different pitch heights (e.g.,

The capacity for music: What is it, and what’s special about it?

“…He finds that they make their choices not on the basis of melodic contour, but rather on the basis of one or two distinctive points within the contour. By contrast, Wright, Rivera, Hulse, Shyan, and Neiworth (2000) find that rhesus monkeys can make reliable same-different judgments on 6-note melodies. Moreover, they find that judgments are significantly more reliable when the melodies conform to a diatonic pitch space than when they do not.…”

Cortical representations of pitch in monkeys and humans

“…The ability to perceive this missing fundamental is not unique to primates, and has also been shown in several other animal species including birds [16] and cats [17]. In addition, monkeys have been shown to be capable of spectral pitch discrimination [18], melody recognition [19][20] and octave generalization [21], each of which requires the perception of pitch. One important difference between humans and some animal species is the size of their cochlea.…”

The biology and evolution of music: A comparative perspective

“…The same is true of speech (although pitches are not discrete in speech): a sentence spoken by a woman is ''the same'' as one spoken by a man an octave lower. This free transposability may represent a key difference between human and animal melody perception (DÕAmato, 1988;Hauser & McDermott, 2003) (but see Wright, Rivera, Hulse, Shyan, & Neiworth, 2000). It is less clear that innate calls possess transposability: is high-pitched tittering laughter the same as a similar signal at a lower pitch?…”

“…Another source of useful and important data on animal musical abilities comes from laboratory studies examining animalsÕ perception of human music, e.g., the finding that goldfish and pigeons can distinguish between and generalize about musical styles (Chase, 2001;Porter & Neuringer, 1984), or the difficulties monkeys have in generalizing about melody transpositions other than the octave (DÕAmato, 1988;Wright et al, 2000). However, there are several comprehensive reviews of this topic already in the literature (Carterette & Kendall, 1999;McDermott & Hauser, 2005), so I will focus here on studies of animalÕs spontaneous production of ''song'' or drumming.…”