Preparation Modulation in Timing of Speech-Movement Sequences

Abstract

When timing a fluent sequence of either movement or speech, evidence suggests that people consider the amount of time available during the production of a first unit to prepare a second unit, evident in a reverse length effect for response onset of the sequence (e.g., Griffin, 2003; Ketelaars, Garry, and Franks, 1997). The current study investigated whether such considerations extend to sequences composed of both speech and movement units. Participants named an object and manually traced a course to produce a fluent sequence. Duration of the first production was manipulated. If preparation modulation operates over speech and movement units within the same sequence, sequence onset will be earlier when the first unit is short in production duration as opposed to long. In general, participants began sequences later when production of first unit did not exceed preparation time of the second unit. This finding provides support for preparation.