Early-stage chunking of finger tapping sequences by persons who stutter and fluent speakers

Abstract

This research note explored the hypothesis that chunking differences underlie the slow finger-tap sequencing performance reported in the literature for persons who stutter (PWS) relative to fluent speakers (PNS). Early-stage chunking was defined as an immediate and spontaneous tendency to organize a long sequence into pauses, for motor planning, and chunks of fluent motor performance. A previously published study in which 12 PWS and 12 matched PNS practised a 10-item finger tapping sequence 30 times was examined. Both groups significantly decreased the duration of between-chunk intervals (BCIs) and within-chunk intervals (WCIs) over practice. PNS had significantly shorter WCIs relative to PWS, but minimal differences between groups were found for the number of, or duration of, BCI. Results imply that sequencing differences found between PNS and PWS may be due to differences in automatizing movements within chunks or retrieving chunks from memory rather than chunking per se.

Keywords:

• chunking
• sequence
• practise
• stuttering
• finger tapping

Acknowledgments

We acknowledge Whitney Holman for her editorial assistance and the journal reviewers for their knowledgeable statistical advice.

Declaration of Interest: The research reported in this paper was supported in part by a grant from the Toronto Rehabilitation Institute to the first author and a grant from the Natural Sciences and Engineering Research Council of Canada to the second author. A Canadian Institute of Health Research grant to the first author funded the post hoc analyses on the study described herein. The authors report no conflicts of interest.