Robinson and Solomon (1974)
ROBINSON, George M. and Deborah Jo Solomon. “Rhythm is Processed by the Speech Hemisphere?” Journal of Experimental Psychology 102/3 (1974): 508-11.
Experiments were conducted using a dichotic listening paradigm. Subjects, wearing headphones, listened to two separate stimuli, one in each ear. The stimuli in this case were contrasting rhythmic patterns. Subjects were selected for right-handedness. The investigators sought
to directly investigate the hypothesis that complex nonspeech temporal patterns containing no phonetic information (rhythms) are processed by the speech hemisphere. (509)
They argue that
the results show that rhythmic patterns, unlike other nonspeech auditory stimuli, are processed better by the same hemisphere that is dominant for speech stimuli…
and further that
because rhythm is the only nonspeech auditory feature found to be processed by the speech hemisphere, models of speech cognition based on rhythmic organization are to be encouraged. (509-10)
It should be noted that the long and short durations within the rhythmic patterns of the experiment were specifically selected for being
well within the range of spoken syllable durations. (509)
Arguably, this experiment, rather than establishing speech-hemisphere dominance for rhythm generally, can be viewed as having presented subjects with rhythmic patterns that were processed in ways similar to the processing of speech. It is possible that the perception of rhythmic patterns falling within a range found in normal speech are therefore directed toward neural pathways specializing in speech processing. However, it is not at all certain that this effect is generalizable to all rhythmic patterns. One hypothesis is that certain rhythmic features are cues to the mind that the input is likely human speech. It remains to be seen whether rhythmic patterns outside such circumscribed limits would remain processed by the dominant hemisphere for language.
