This video is recently getting a lot of shares and exclamations on Facebook. The face on the left side of the video seems to be saying “Bar” while the right is saying “far”. However, if you close your eyes and listen to it, you will realize they are both saying the same thing -” Bar”. This happens due to an unique phenomenon called McGurk Illusion, first documented in McGurk and McDonald (1976). Let’s take a closer look at why we always hear “far” on the right side of the video.
We process information from multiple sensory organs. These multisensory information then gets integrated into one experience. This is one of our unique capabilities that scientists, working on artificial intelligence, are trying to replicate in a computer. McGurk illusion provides support to multisensory integration of information processing.
By the laws of physics, we see before we hear (Recall how you see a lightning before hearing the thunder). When you are concentrating on the face on the right, your visual experience is preparing you to hear the word “far”. So when you are hearing something similar (bar), you are adapting your auditory perception to what you are supposed to hear. In essence, what you see is modifying what you hear to give an altered perception. Some brain areas have also been identified as places where the visual and auditory stimulus merge to form a overall sensation. This amount of neural processes devoted to audio-visual integration is perhaps the reason for our increasing obsession with technology. On the brighter side, implementing audio-visual aid in schools should also enhance learning experience.
The great thing about science is all claims are testable. The validity of the phenomenon discussed above can be easily tested if we can find subjects that lack multisensory integration and see what they make of this facebook puzzle. (Un)fortunately, patients with Asperger Syndrome match this description. Asperger is a milder form of Autism with similar problems with social interaction. Subjects with severe asperger symptoms are thought to lack audio-visual integration and hence have impaired social interactions. If tested on this “Bar-far” video, it is likely that a person with severe Asperger will hear both as “Bar”. There is nothing wrong with the person’s vision. He/she is unable to modify their auditory perception based on visual cue.
Now that I have somewhat demystified the Bar-Far video, hopefully Sean Kingston (this video appeared first in his page) will get a good night’s sleep 😉
Some sources consulted:
Salasti et. al (2012), Sams et.al (1991), Tippana (2014)