Temporal Aspects of Melodic Contour Processing

Melodic contour information is an important cue for song recognition. When listening to novel melodies, contour information tends to be encoded before exact interval information. Alterations to the precise intervals of the melody are often undetected, provided that they do not change the melodic contour. Prior research has suggested that, while the immediate note-to-note contour is most salient, listeners are also sensitive to changes in non-adjacent contour information. We were interested in the degree to which this pattern of sensitivity is preserved across musical speeds. We tested adult listeners' ability to detect changes to novel six-tone melodic sequences with inter-onset-intervals of 50ms, 100ms, 200ms, and 400ms. Changes either preserved contour or disrupted either adjacent or non-adjacent contour. We found that participants performed at chance in the 50ms condition. Across the other three conditions, the performance pattern was consistent. Adjacent contour violations were best detected, followed by non-adjacent contour violations, with detection of contour preserving alterations generally poor.