Interaction between grasping and articulation: How vowel and consonant pronunciation influences precision and power grip responses

Abstract

Grasping and mouth movements have been proposed to be integrated anatomically, functionally and evolutionarily. In line with this, we have shown that there is a systematic interaction between particular speech units and grip performance. For example, when the task requires pronouncing a speech unit simultaneously with grasp response, the speech units [i] and [t] are associated with relatively rapid and accurate precision grip responses, while [ɑ] and [k] are associated with power grip responses. This study is aimed at complementing the picture about which vowels and consonants are associated with these grasp types. The study validated our view that the high-front vowels and the alveolar consonants are associated with precision grip responses, while low and high-back vowels as well as velar consonants or those whose articulation involves the lowering of the tongue body are associated with power grip responses. This paper also proposes that one reason why small/large concepts are associated with specific speech sounds in the sound-magnitude symbolism is because articulation of these sounds is programmed within the overlapping mechanisms of precision or power grasping.

Fig 1. Box-plot of reaction times (ms = millisecond) for Experiment 1 (horizontal line inside the box = median; cross inside the box = mean; box = 25–75%; whiskers = scores outside the middle 50%).

The box-plots show the distributions of RT (reaction time) values as a function of Block, Speech unit and Grip. Asterisks indicate statistically significant differences (***p < .001, **p < .01, *p < .05).

Fig 2. Box-plot of reaction times (ms = millisecond) for Experiment 2 (horizontal line inside the box = median; cross inside the box = mean; box = 25–75%; whiskers = scores outside the middle 50%).

It shows the distributions of RT (reaction time) values as a function of Speech unit and Grip. Asterisks indicate statistically significant differences (***p < .001, **p < .01, *p < .05). The upper box-plots (Fig 2a) present the results for vowels and lower box-plots (Fig 2b) present results for consonants.