What’s love got to do with it? Tina Turner doesn’t necessarily have the eyes in mind when she belts out that tune, but neuroscientists do. Trolling for something else this morning, I came across a a great viewpoint piece I had forgotten about, with the provocative title of EMOTIONAL VISION – Nature Neuroscience 2004 It’s written by Ralph Adolphs, a social scientist who hangs his hat at Cal Tech in Pasadena and his coat at the University of Iowa’s Department of Neurology.
The gist of the article is that emotions can directly influence sensory processing, and can do so at surprisingly early stages. Surprising, that is, only if one is not familiar with the concepts of behavioral and developmental optometry. In this diagram, the components of the amygdala, the major brain structure involved in emotions, can be seen to modulate key visual regions of the brain that follows a ventral stream of information which helps us in recognition objects and form.
A dramatic example of emotions affecting visual processing is the Streff Syndrome, in which patients exhibits constriction of their visual field and reduced visual acuity unrelated to structural damage of the eyes. Other manifestations of visual stress include the cognitive imbalances seen in patients with acquired brain injury and strabismus.
It is still not known precisely how visual information from the retina reaches the amygdala, but as neuroscience learns more about about these connections we will have an even better model for understanding the power of optometric vision therapy that complements, but goes well beyond the kinematics of eye movement or the optical power of the eye’s structures. Our good colleague Dr. Bob Sanet is fond of quoting Dr. Lawrence Macdonald as saying: Eyes don’t tell brains what to see; brains tell eyes what to look for, and the amygdala connection provides further evidence of this.
Another intriguing concept cited in this article is that abnormal activation of the fusiform gyrus and amygdala observed in people with autism when viewing faces may result from impairments in the same mechanism. Ralph Adolphs speculates that dsyfunctional modulation of visual cortices early in life might contribute to the development of abnormal social perception in persons with autism. This theory is consistent with an article I co-authored with my mentor and colleague, Dr. Jack Richman, on Optometry’s role in the early detection of Autism Specturm Disorders, in a theme issue on Autism for the journal Optometry and Vision Development.
– Leonard J. Press, O.D., FCOVD, FAAO