Inhibitory modulation of speech trajectories: Evidence from a vowel-modified Stroop task

ABSTRACT

How does cognitive inhibition influence speaking? The Stroop effect is a classic demonstration of the interference between reading and color naming. We used a novel variant of the Stroop task to measure whether this interference impacts not only the response speed, but also the acoustic properties of speech. Speakers named the color of words in three categories: congruent (e.g., red written in red), color-incongruent (e.g., green written in red), and vowel-incongruent — those with partial phonological overlap with their color (e.g., rid written in red, grain in green, and blow in blue). Our primary aim was to identify any effect of the distractor vowel on the acoustics of the target vowel. Participants were no slower to respond on vowel-incongruent trials, but formant trajectories tended to show a bias away from the distractor vowel, consistent with a phenomenon of acoustic inhibition that increases contrast between confusable alternatives.

KEYWORDS:

• Speech
• vowels
• inhibition
• competition
• Stroop

Acknowledgements

We thank Swathi Kiran for mentorship and guidance and Ian Quillen for assistance with data collection and processing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Dudley Allen Sargent Research Fund and the National Institute on Deafness and Other Communication Disorders [grant number: R00 DC014520].