The effects of individual differences on multimodal speech perception were investigated using the McGurk effect paradigm. Two successive experiments were conducted with an interval of three weeks. Two hundred and twenty undergraduate students participated in the experiments, which were carried out under conditions similar to a daily-life audiovisual environment. The experiments examined the amount of visual influence on the perception of audiovisually incompatible syllables and consistency of judgments. The results showed that the distribution of judgments of the participants is wide-ranging from the participants who were strongly influenced to those who were not at all-and that judgment tendencies were consistent. This suggests that factors such as individual differences are very important when conducting McGurk effect experiments and interpreting the results.
Sumi Shigeno (Fri,) studied this question.