Inner speech sustains predictable task switching: direct evidence in adults

ABSTRACT

It has been proposed that inner speech supports task selection in task-switching studies, especially when the need for endogenous control is increased. This has been established through the suppression of inner speech in cognitive-flexibility tasks that leads to poorer performance. The aim of this study is to quantify the role of inner speech in a flexibility task by using surface laryngeal electromyography, which, contrary to previous studies, enables participants to freely verbalise the tasks. We manipulated endogenous and exogenous flexibility in a mathematical switching task paradigm. Experiment 1 shows that inner speech acts as a support for switching and is recruited more often when the tasks are of an endogenous type. The main result of Experiment 2 that language is recruited more for the mixing cost than for the switch cost (regardless of the endogenous factor) extends past findings obtained through articulatory suppression.

KEYWORDS:

• Task switching
• cognitive control
• inner speech
• language
• electromyography

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

¹The RT measures cannot however be easily compared because completion times were recorded by the experimenter with a stopwatch in this previous study.