Cerebral hemisphere differences reveal in vision processing

Mixing together ideas behind the brain activity which creates face recognition and the left brain/right brain dichotomy has led to some interesting breakthroughs for people with autism.

Ming Meng, an assistant professor in the Department of Psychological and Brain Sciences at Dartmouth College, has developed an approach combining functional magnetic resonance imaging (fMRI), computer vision, and psychophysics to reveal new patterns in brain function. Meng believes that vision is the major domain of perception generally. So his research focuses on vision and the recognition and organization of the information that vision brings to the brain and the way that stimulus activates the brain.

Traditionally, researchers have said that visual recognition starts on the right side of the brain by processing the left visual field and vice versa with the left side of the brain and right field of vision. Later in the process, the hemispheres come together to identify the image. Meng hypothesized that the right and left hemispheres are actually assessing the visual stimulation in different ways.

So Meng put patients in the fMRI to see how their brains functioned while looking at and trying to identify faces. Watching how the brain processed the images – all in different states of identifiability including non-faces – was key to see how each hemisphere of the brain was working the data.

“Our results suggest the left side of the brain is processing the external physical input which resolves into a ‘grey scale’ while the right brain is underlying the final decision of whether or not it is a face,” said Meng. This could provide a template for studying patients with autism where eye contact and facial recognition are challenging. Comparing the process may reveal differences in the autistic brain which could lead to new understandings.

Source: Proceedings of the Royal Society B, MedicalNewsToday