A dual task study of the effects of increased cognitive load on speech motor control

Abstract

Research has shown that behavioral task performance suffers when cognitive load is increased. One method for observing this phenomenon is the so-called dual task paradigm, which has been applied in previous research manipulating the motor, linguistic, and cognitive demands of speech tasks [Dromey & Benson, JSLHR, 46(5), 1234–1246 (2003)]. Trade-offs between (and within) domains necessary to maintain task performance probe sensitivity to increased load and the nature of variability in speech (i.e., does speech become more or less variable in increased load situations). In the current study, cognitive load on a speech motor task (mono- and di-syllable repetition) is manipulated using simple, competing memory, visual attention, and inhibition tasks, with concurrent recording of speech acoustics and kinematics. A preliminary analysis of acoustic data from five participants measured duration, amplitude and F0 of utterances during the single and dual task conditions. Results from the dual task conditions suggest a complex trade-off between the amplitude, duration and F0 measures, which differed systematically among the memory, attention, and inhibition tasks. In contrast, the baseline speech measures varied idiosyncratically among participants. Analysis of kinematic data should assist in clarifying how the interactions among these variables are affected by the different types of cognitive load.