Visual Cortex Processes Auditory Information Too, Study Finds
Seeing is believing, but it also involves a bit of hearing. Visual cortex also uses information gleaned from the ears as well as the eyes when viewing, according to a new study.
The auditory input enables the visual system to predict incoming information and could confer a survival advantage, the study suggested.
"Sounds create visual imagery, mental images, and automatic projections," said professor Lars Muckli, of the Institute of Neuroscience and Psychology at the University of Glasgow, who led the research, in a press release.
"So, for example, if you are in a street and you hear the sound of an approaching motorbike, you expect to see a motorbike coming around the corner. If it turned out to be a horse, you'd be very surprised."
The study involves conducting five different experiments using functional Magnetic Resonance Imaging (fMRI) that examined the activity in the early visual cortex in 10 volunteer subjects.
"This research enhances our basic understanding of how interconnected different regions of the brain are. The early visual cortex hasn't previously been known to process auditory information, and while there is some anatomical evidence of interconnectedness in monkeys, our study is the first to clearly show a relationship in humans," Muckli added in the press release.
"In future we will test how this auditory information supports visual processing, but the assumption is it provides predictions to help the visual system to focus on surprising events which would confer a survival advantage.This might provide insights into mental health conditions such as schizophrenia or autism and help us understand how sensory perceptions differ in these individuals."
The study has been published in the journal Current Biology.