Auditory–Visual Speech Integration in Bipolar Disorder: A Preliminary Study

Arzu Yordamlı,Doğu Erdener

doi:10.3390/languages3040038

Abstract

This study aimed to investigate how individuals with bipolar disorder integrate auditory and visual speech information compared to healthy individuals. Furthermore, we wanted to see whether there were any differences between manic and depressive episode bipolar disorder patients with respect to auditory and visual speech integration. It was hypothesized that the bipolar group’s auditory–visual speech integration would be weaker than that of the control group. Further, it was predicted that those in the manic phase of bipolar disorder would integrate visual speech information more robustly than their depressive phase counterparts. To examine these predictions, a McGurk effect paradigm with an identification task was used with typical auditory–visual (AV) speech stimuli. Additionally, auditory-only (AO) and visual-only (VO, lip-reading) speech perceptions were also tested. The dependent variable for the AV stimuli was the amount of visual speech influence. The dependent variables for AO and VO stimuli were accurate modality-based responses. Results showed that the disordered and control groups did not differ in AV speech integration and AO speech perception. However, there was a striking difference in favour of the healthy group with respect to the VO stimuli. The results suggest the need for further research whereby both behavioural and physiological data are collected simultaneously. This will help us understand the full dynamics of how auditory and visual speech information are integrated in people with bipolar disorder.

Highlights

Speech perception is not solely an auditory phenomenon but an auditory–visual (AV) process.This was first empirically demonstrated in noisy listening conditions by Sumby and Pollack (1954), and later in clear listening conditions by what is called the McGurk Effect (McGurk and MacDonald1976)
This study aimed to investigate how individuals with bipolar disorder integrate auditory and visual speech information compared to healthy individuals
It was hypothesized that the bipolar disorder group would be less susceptible to the McGurk effect and to exhibit integration of auditory and visual speech information to a lesser extent compared to the healthy control group

Summary

Introduction

Speech perception is not solely an auditory phenomenon but an auditory–visual (AV) process.This was first empirically demonstrated in noisy listening conditions by Sumby and Pollack (1954), and later in clear listening conditions by what is called the McGurk Effect (McGurk and MacDonald1976). Speech perception is not solely an auditory phenomenon but an auditory–visual (AV) process This was first empirically demonstrated in noisy listening conditions by Sumby and Pollack (1954), and later in clear listening conditions by what is called the McGurk Effect In a typical demonstration of the McGurk effect, the auditory syllable /ba/ dubbed onto the lip movements for /ga/ is often perceived as /da/ or /tha/ by most native English speakers. This illusory effect unequivocally shows that speech perception involves the processing of visual speech information in the form of orofacial (lip and mouth) movements. Most, if not all, cross-language research in auditory–visual speech perception

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