Narinesingh Cindy, Wan Michael, Goltz Herbert C, Chandrakumar Manokaraananthan, Wong Agnes M F
Program in Neuroscience and Mental Health, The Hospital for Sick Children, Toronto, Canada.
Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Canada.
Invest Ophthalmol Vis Sci. 2014 Apr 24;55(5):3158-64. doi: 10.1167/iovs.14-14140.
The effects on multisensory integration have rarely been examined in amblyopia. The McGurk effect is a well-established audiovisual illusion that is manifested when an auditory phoneme is presented concurrently with an incongruent visual phoneme. Visually healthy viewers will hear a phoneme that does not match the actual auditory stimulus, having been perceptually influenced by the visual phoneme. This study examines audiovisual integration in adults with amblyopia.
Twenty-two subjects with amblyopia and 25 visually healthy controls participated. Participants viewed videos of combinations of visual and auditory phonemes, and were asked to report what they heard. Some videos had congruent video and audio (control), whereas others had incongruent video and audio (McGurk). The McGurk effect is strongest when the visual phoneme dominates over the audio phoneme, resulting in low auditory accuracy on the task.
Adults with amblyopia demonstrated a weaker McGurk effect than visually healthy controls (P = 0.01). The difference was greatest when viewing monocularly with the amblyopic eye, and it was also evident when viewing binocularly or monocularly with the fellow eye. No correlations were found between the strength of the McGurk effect and either visual acuity or stereoacuity in subjects with amblyopia. Subjects with amblyopia and controls showed a similar response pattern to different speakers and syllables, and subjects with amblyopia consistently demonstrated a weaker effect than controls.
Abnormal visual experience early in life can have negative consequences for audiovisual integration that persists into adulthood in people with amblyopia.
弱视对多感官整合的影响鲜有研究。麦格克效应是一种公认的视听错觉，当一个听觉音素与一个不一致的视觉音素同时呈现时就会出现。视力正常的观察者会听到一个与实际听觉刺激不匹配的音素，这是受到了视觉音素的感知影响。本研究考察弱视成年人的视听整合情况。
22名弱视受试者和25名视力正常的对照者参与研究。参与者观看视觉和听觉音素组合的视频，并被要求报告他们听到的内容。一些视频的视频和音频是一致的（对照），而另一些视频的视频和音频是不一致的（麦格克）。当视觉音素比听觉音素占主导时，麦格克效应最强，导致该任务的听觉准确性较低。
弱视成年人表现出比视力正常的对照者更弱的麦格克效应（P = 0.01）。在用弱视眼单眼观看时差异最大，在用健眼单眼或双眼观看时也很明显。在弱视受试者中，未发现麦格克效应的强度与视力或立体视锐度之间存在相关性。弱视受试者和对照者对不同的说话者和音节表现出相似的反应模式，且弱视受试者始终表现出比对照者更弱的效应。
生命早期的异常视觉体验会对视听整合产生负面影响，这种影响在弱视患者成年后依然存在。
