Face configuration affects speech perception: Evidence from a McGurk mismatch negativity study

We found that Thatcherization disrupted a strong McGurk illusion and a correspondingly strong McGurk-MMN only for upright faces. This confirms that facial configuration can be important for audiovisual speech perception. For inverted faces we found a weaker McGurk illusion but, surprisingly, no MMN. We also found no correlation between the strength of the McGurk illusion and the amplitude of the McGurk-MMN. We suggest that this may be due to a threshold effect so that a strong McGurk illusion is required to elicit the McGurk-MMN.