Effects of Negative Emotions and Personality Traits on Laryngeal and Speech Motor Control

The purpose of this study was to identify the effects of negative affective stimuli on oral and laryngeal motor control. It was also aimed to examine the role of personality traits in emotion-motor interaction.

Thirty-five female volunteers (age range: 18-25) were included in the study. Affective stimuli were selected from within the Nencki Affective Picture System (70 pictures with neutral affective valence and 70 with negative affective valence). Participants' personality traits were assessed using the five-factor personality inventory (FFPI). Skin conductance response and heart rate variability assessments were made simultaneously with the presentation of affective pictures. Oral and laryngeal motor skills were assessed via seven vocal tasks: one task was based on electroglottographic analysis (fundamental frequency-F₀, vocal fold contact quotient-CQ, and EGG-jitter), and the remaining six tasks were based on acoustic analyses and included oral and laryngeal diadochokinesis (O-DDK and L-DDK), syllabic rate, and second formant transition rate (F2 rate) assessments.

The abductor L-DDK rate, adductor L-DDK rate, syllabic rate, and EGG-CQ values obtained in the presence of negative affective stimuli were statistically significantly higher than those obtained in the presence of neutral affective stimuli (P < 0.05). There was no statistically significant difference between the two stimulus types in terms of their F2rate and O-DDK rate values (P > 0.05). Moreover, neuroticism and extraversion as personality traits were significantly correlated with the F₀, EGG-CQ, and EGG-jitter values obtained in the presence of negative affective stimuli.

Negative affective stimuli led to an increase in oral and laryngeal motor movement speed by likely activating the sympathetic nervous system. There was also an increase in the CQ of the vocal folds. Furthermore, participants who scored higher on the FFPI personality trait of "extraversion" had lower EGG-CQ scores, while those who scored higher on the personality trait of "neuroticism" had higher EGG average jitter and F₀ scores.