In the Eye of the Beholder

What happens in our brains while listening to music or deciphering dual optical illusions, like the one illustrated above? Prof. Amiram Grinvald and his research team at the Weizmann Institute’s Neurobiology Department have directly observed the first clues to the neuronal basis of the truism “It’s all in the eye of the beholder.” Sensory perception, the researchers proved, is a dual process. For example, in vision, the image we ultimately perceive is a combination of the external image recorded by the eye and the actively retrieved brain representations or personal memories of the observer.

The researchers’ ability to see the brain in action was made possible by Grinvald’s previous innovations. He developed two high-resolution optical imaging techniques that enable hundreds of laboratories worldwide to peek into the brain and observe it in action as it develops, processes sensory input, or coordinates delicate movements. The inventors of fMRI, a noninvasive method for functional human brain imaging, have reported that their invention was triggered by optical imaging techniques.

In addition, Grinvald’s skilled team of fourteen scientists discovered highly refined geometrical links between groups of cells encoding the various elements of visual scenes: colors, angles, direction of movement, and depth. Direct visualization of cortical dynamics has led to these and other findings that have improved our understanding of visual processing, which engages over 50 percent of the brain cortex.

 

Prof. Grinvald's research is supported by the Horace W. Goldsmith Foundation, Henri and Franeoise Glasberg Foundation, Mrs. Margaret M. Enoch, New York, NY, Carl and Micaela Einhorn-Dominic Brain Research Institute, Murray H. & Meyer Grodetsky Center for Research of Higher Brain Functions, and the Norman and Helen Asher Center for Brain Imaging. He is the incumbent of the Helen and Norman Asher Professorial Chair in Brain Research.