The octave illusion revisited: Performance measurements for handedness categorization

Abstract

An extended replication study of the octave illusion (Deutsch 1974, 1983) is presented. Since the first description of the octave illusion in 1974, several studies showed that the perception of the two-tone patterns depends on subjects' handedness. Partially almost 90% of the right-handed subjects reported to hear the high tone of the octave at the right ear. In all related studies the handedness categorization was done by means of a questionnaire, e.g., the handedness inventory of Varney and Benton (1975). Several current studies (e.g., Kopiez, Galley, Lehmann, 2010), however, showed that objective non-right-handed persons cannot be identified by handedness inventories. In concordance with Annett's “right shift theory” (2002), performance measurements as speed tapping seem to be a much more reliable handedness predictor. Therefore in the replication study (N=158) Varney and Benton's inventory as well as a speed tapping task were used to categorize left- and right-handed subjects. The results of Deutsch's study could be replicated when using the same handedness inventory. The performance measurement task, however, led to a significantly clearer distinction between the left- and right-handed subjects (w=0.39 in contrast to w=0.26 in the replication) and more structured perception patterns could be observed within the left-handed group.