Table 3.
Summary of the unity effect demonstrated in studies of the McGurk effect.
| Study | Origins of the unityassumption | Stimuli | Perception | Effect? |
|---|---|---|---|---|
| Massaro and Cohen, 1993 | Temporal synchrony (±200 ms) | V: /da/; A: /ba/ | /va/ or /ga/ | Yes: /va/ decreased and /ga/ increased when V leading |
| Munhall et al., 1996 | Temporal synchrony (±360 ms) | V: /aga/ or /igi/; A: /aba/ | /ada/ or /idi/ | Yes: -60 to 240 ms for V/aga/ |
| Stimulus congruency (vowel) | No effect for V/igi/ | |||
| van Wassenhove et al., 2007 | Temporal synchrony (±467 ms) | V: /ka/ or /ga/; A: /pa/ or /ba/ | /ta/ or /da/ | Yes: -30 to 170 ms |
| Soto-Faraco and Alsius, 2009 | Temporal synchrony (-640 to 720 ms) | V: /ba/; A:/da/ | /bda/ | Yes: -320 to 480 ms |
| Jones and Munhall, 1997 | Spatial disparity (±90°) | V: /igi/, /IgI/ or /ægæ/ | /idi/, /IdI/ or /ædæ/ | No |
| A: /igi/, /IgI/ or /ægæ/ | ||||
| Jones and Jarick, 2006 | Temporal synchrony (±360 ms) | V: /ava/; A: /aba/ | /ava/ or /aba/ | Yes: -60 to 180 ms |
| Spatial disparity (±90°) | No effect for spatial disparity | |||
| Easton and Basala, 1982 | Congruency (phonetic) | V: lips movements; A: spoken words | Errors in lip-reading | Yes: fewer errors in lip-reading in the higher discrepancy condition |
| Green et al., 1991 | Congruency (gender) | V /ga/ or /gi/; A:/ba/ or /bi/ | /da/, /ða/ or /di/, /ði/ | No |
| Walker et al., 1995 | Familiarity (face and voice from familiar or unfamiliar person) | V /ga/ or /gi/; A:/ba/ or /bi/ | /da/, /ða/ or /di/, /ði/ | Yes: the McGurk effect was larger for familiar face and voice |
| Nahorna et al., 2012 | Context (coherence of audiovisual syllables) | V: /ga/; A:/ba/ | /da/ | Yes: larger McGurk effect in the coherent context |
| Nahorna et al., 2015 | Context (coherence of audiovisual syllables) | V: /ga/; A:/ba/ | /da/ | Yes: smaller McGurk effect when perceiving one incoherent syllable, but recovered after perceiving more coherent syllables |
V: vision; A: audition.
The negative values indicate the auditory leading intervals, whereas the positive values indicate the visual leading intervals; the negative angles indicate that the auditory stimulus was presented on the left, whereas the positive angles indicate that the auditory stimulus was presented on the right.