Interaction in planning vocalizations and grasping

ABSTRACT

Previous studies have shown a congruency effect between manual grasping and syllable articulation. For instance, a power grip is associated with syllables whose articulation involves the tongue body and/or large mouth aperture ([kɑ]) whereas a precision grip is associated with articulations that involve the tongue tip and/or small mouth aperture ([ti]). Previously, this effect has been observed in manual reaction times. The primary aim of the current study was to investigate whether this congruency effect also takes place in vocal responses and to investigate involvement of action selection processes in the effect. The congruency effect was found in vocal and manual responses regardless of whether or not the syllable or grip was known a priori, suggesting that the effect operates with minimal or absent action selection processes. In addition, the effect was observed in vocal responses even when the grip was only prepared but not performed, suggesting that merely planning a grip response primes the corresponding articulatory response. These results support the view that articulation and grasping are processed in a partially overlapping network.

KEYWORDS:

• Action planning
• Grasping
• Language evolution
• Speech

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Results when reaction times were trimmed by participant and condition: Manual reaction time grip–syllable interaction F(1, 16) = 19.45, p < .001,  = .55. Vocal reaction time grip–syllable interaction F(1, 16) = 31.90, p < .001,  = .67.

2. Results when reaction times were trimmed by participant and condition: Manual reaction time grip–syllable interaction F(1, 21) = 20.64, p < .001,  = .50. Vocal reaction time grip–syllable interaction F(1, 21) = 16.58, p = .001,  = .44. No-go vocal reaction time syllable–grip interaction F(1, 21) = 8.40, p = .009,  = .29.

3. Results when reaction times were trimmed by participant and condition: Manual reaction time grip–syllable interaction F(1, 21) = 75.02, p < .001,  = .78. Vocal reaction time grip–syllable interaction F(1, 21) = 71.82, p < .001,  = .77. No-go vocal reaction time syllable–grip interaction F(1, 21) = 2.65, p = .118,  = .11.

4. Although the differences were not significant, their reverse directions were the only possible explanation for the interaction. It is possible that the grip response (e.g., the power grip) is initially prepared—to some extent—according to the stimulus colour, even in these no-go conditions. Consequently, the corresponding articulatory representation (i.e., [ka]) is simultaneously partially activated. However, requirement for rapid suppression of the manual activation might lead to simultaneous suppression of the partially activated articulatory representation, resulting in relatively slow vocal responses when the grip and the vocal response are congruent. However, as this interaction was only marginally significant, and not significant with the secondary reaction time trimming, it is not discussed further in this paper.

Additional information

Funding

This work was supported by Suomen Akatemia [grant numbers 265610 and 293348].