Do we think about music in terms of space?Metaphoric representation of musical pitch.

Daniel Casasanto (djc@mit.edu)Webb Phillips (webb@mit.edu)Lera Boroditsky (lera@mit.edu)

Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology77 Massachusetts Avenue, NE20-457, Cambridge, MA 02139 USA

IntroductionWe often talk about musical pitch using spatial language. InEnglish, pitches can be high or low, melody lines can rise orfall, and we can sing at the top or the bottom of our range.Are spatial metaphors for pitch merely linguisticconventions, or is it possible that patterns in language revealsomething fundamental about the way we mentallyrepresent pitch?

There are several reasons to suspect that pitch and spaceare importantly related in the brain and mind. Auditorynuclei are organized tonotopically: changes in pitchcorrespond to analogous changes in the localization ofactivity on a neural map (Schreiner & Langer, 1997). PETdata show that the same regions in right prefrontal cortexare engaged during attention to sounds that vary in musicalpitch or spatial location (Zatorre, Mondor & Evans, 1999).Right hemisphere damage that compromises visuospatialmemory also impairs the learning of new melodies (Samson& Zatorre, 1991).

Linguistic metaphors suggest that the relationshipbetween pitch and space may be highly specific. We tend toborrow unidimensional, vertical spatial terms to describepitch (e.g., up, down). Do we think about pitch in terms ofvertical space? A nonlinguistic psychophysical paradigm,used previously to explore the spatialization of temporalrepresentations (Casasanto & Boroditsky, 2002), wasadapted to investigate the spatialization of pitch.

Experiment: Height, Length, and Pitch

Materials and MethodsNative English speaking subjects viewed lines ‘growing’ ona computer monitor, while listening to pitches throughsealed headphones. Eleven Ss viewed lines that grewvertically (bottom to top), and twelve Ss viewed lines thatgrew horizontally (left to right). Nine line displacementsranging from 100-500 pixels in 50-pixel increments werefully crossed with nine pitches, ranging from middle C to G-sharp (an augmented 5th above) in semitone increments. Foreach of 162 trials, Ss reproduced either stimulusdisplacement or stimulus pitch.

It was hypothesized that if we think about pitch in termsof height but not length (i.e., the way we talk about it), thenif any cross-dimensional interference of displacement onpitch estimation were observed, stimulus height wouldinterfere Ss’ pitch estimates more than stimulus length.

ResultsVertical displacement strongly modulated Ss’ estimates ofstimulus pitch (slope=0.37; r2=0.77, p<0.003). For stimuli ofthe same average frequency, lines that grew higher wereestimated to be higher in pitch. Ss incorporated irrelevantspatial information into their pitch estimates, even thoughtask instructions encouraged selective attention to pitch. Incontrast, horizontal displacement did not significantlymodulate pitch estimations (slope=0.09; r2=0.39, ns). Theeffect of length on pitch was significantly weaker than theeffect of height on pitch (difference of slopes=0.28; t=2.68,p<0.02).

It is unlikely that the asymmetric effects of height andlength on pitch estimation are due to some generalperceptual asymmetry. A parallel experiment (report inpreparation) investigated the effects of length and height ontime estimation, and found the opposite pattern of cross-dimensional interference: length modulated durationestimates more than height did, consistent with thepredominance of horizontal metaphors for time in English.

These results suggest that the metaphoric relationshipbetween pitch and height is not only linguistic, it is alsoconceptual. The difference between the effects of heightand length on pitch estimation is consistent with theoccurrence of vertical but not horizontal pitch metaphors inEnglish, though results are agnostic as to the direction ofcausation between language and thought. Ongoing studieswill investigate whether linguistic metaphors merely reflectspatial schemas underlying pitch representations, or whetherthe way we talk about music can shape the way we thinkabout it.

References

Casasanto, D. and L. Boroditsky, Displacement affectsduration estimation, but not the other way around.Proceedings of the 24th Annual Meeting of the CognitiveScience Society, 2002. Fairfax, VA.

Samson, S., & Zatorre, R. J. (1991). Recognition memoryfor text and melody of songs after unilateral temporal lobelesion: evidence for dual encoding. J Exp Psychol LearnMem Cogn, 17(4), 793-804.

Schreiner, C. E., & Langner, G. (1997). Laminar finestructure of frequency organization in auditory midbrain.Nature, 388, 383-386.

Zatorre, R. J., Mondor, T. A., & Evans, A. C. (1999).Auditory attention to space and frequency activatessimilar cerebral systems. Neuroimage, 10(5), 544-554.

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