The McGurk Effect—An Accidental Discovery
Harry McGurk, a cognitive psychologist, came upon this effect while studying infants and their perception of language at various developmental stages. During a phase of his study, he asked his technician to dub a video with a different phoneme or sound from the spoken one. When he sat down to watch the video, he was in for a shock—there was a third phoneme different from the spoken or mouthed one in the video. So, how did the third phoneme become part of the video? Was it by magic or did they stumble upon something new?
The psychologist explained the existence of the third sound by demonstrating the relationship between the visual component and the sound when paired with each other. In order to gain a better understanding, let’s break down to you the three sounds watching the video produced:
- Watching the video with sound and eyes open will produce a “da da da” sound.
- Watching the video with sound and your eyes closed will produce a “ba ba ba” sound.
- Watching the video without sound and your eyes open will produce a “ga ga ga” sound.
In short, the McGurk Effect proved that your senses didn’t evolve in isolation from one and other, but they actually work in union with each other to assist people perceive the world around them. When more than one sense is stimulated at the same time with each other, it enables the brain to learn and remember the information better. However, not everyone is susceptible to the McGurk effect, as different factors such as brain damage and certain disorders can influence a person’s perception.
List of Disorders
People with the following disorders have shown little to zero impact when exposed to the McGurk effect:
- Dyslexia- Cannot perceive and produce consonant clusters
- Language Impairment- Children utilize less visual information in speech perception, but can perceive auditory cues only
- Autism Spectrum Disorder- Cannot identify visual and auditory aspects of speech
- Language Learning Disabilities- People with underdeveloped language skills
- Alzheimer’s Disease- Loss of memory leads to decreased influence on the visual stimulus
- Schizophrenia- Decreases the development of audiovisual integration
- Aphasia- Impaired visual, auditory, and audio with visual condition
Apart from these disorders, other factors that hinder the effect of the McGurk effect include cross-dubbing, mouth visibility, and syllable structure, amongst others. The McGurk effect isn’t magic, but its unearthing led people to discover how people’s senses depend on one another, thus heightening the importance of sight and hearing.