Comparison of McGurk Effect across Three Consonant-Vowel Combinations in Kannada

Abstract

Background and ObjectivesThe influence of visual stimulus on the auditory component in the perception of auditory-visual (AV) consonant-vowel syllables has been demonstrated in different languages. Inherent properties of unimodal stimuli are known to modulate AV integration. The present study investigated how the amount of McGurk effect (an outcome of AV integration) varies across three different consonant combinations in Kannada language. The importance of unimodal syllable identification on the amount of McGurk effect was also seen.Subjects and MethodsTwenty-eight individuals performed an AV identification task with ba/ ga, pa/ka and ma/n· a consonant combinations in AV congruent, AV incongruent (McGurk combination), audio alone and visual alone condition. Cluster analysis was performed using the identification scores for the incongruent stimuli, to classify the individuals into two groups; one with high and the other with low McGurk scores. The differences in the audio alone and visual alone scores between these groups were compared.ResultsThe results showed significantly higher McGurk scores for ma/n· a compared to ba/ga and pa/ka combinations in both high and low McGurk score groups. No significant difference was noted between ba/ga and pa/ka combinations in either group. Identification of /n· a/ presented in the visual alone condition correlated negatively with the higher McGurk scores.ConclusionsThe results suggest that the final percept following the AV integration is not exclusively explained by the unimodal identification of the syllables. But there are other factors which may also contribute to making inferences about the final percept.

Audiovisual incongruence differentially impacts left and right hemisphere sensorimotor oscillations: Potential applications to production

“…In the current study, ~15% of subjects (6/39) were classified as non-perceivers and excluded from further analysis as they did not perceive sensory fusion in at least 15% of McGurk trials [ 49 ]. The proportion of subjects not susceptible to the McGurk illusion is not universally reported in the literature, nor is there a standardized threshold subjects must meet to be considered a ‘perceiver / non-perceiver.’ This consideration notwithstanding, reported ranges for the proportion of non-perceiving subjects range from 0–54% [ 48 , 79 ] with an average of ~25% [ 54 ]. Among the subjects in the current study who reliably perceived the McGurk illusion, sensory fusion was reported in 73.5% of trials.…”