Autonomic Arousal During Speech Production and Sensorimotor Adaptation

Autonomic arousal impacts speech; however, it is unclear how it affects speech motor control mechanisms. The purpose of this study was to delineate the role of autonomic arousal during typical lower order speech output and higher order sensorimotor adaptation.

Cognitive load was modulated to induce autonomic arousal in two experiments in a group of adults with typical speech (N = 30). Experiment 1 involved producing sentences with embedded Stroop stimuli. Experiment 2 consisted of an altered auditory feedback paradigm in which participants received predictable changes of F₁ of single Stroop words. Autonomic activity (cardiovascular and electrodermal) was collected in both experiments. Acoustic measures of articulation (F₂ slope, vowel articulatory index, and percent pause time) were collected from Experiment 1, and adaptive responses (% change in F₁) to manipulations of feedback were collected from Experiment 2. Mixed linear effect models were used to assess cognitive load and autonomic arousal on acoustic responses from both experiments.

Increased autonomic arousal was related to decreased F₂ slope in Experiment 1. Increased autonomic arousal was related to greater adaptation in Experiment 2. Cognitive load did not significantly affect acoustic metrics in Experiment 1 or adaptation in Experiment 2.

These findings suggest that the physiological state of the body not only plays a role in typical speech production but could also be important for sensorimotor adaptation.