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Drawing Activates Visual Cortex in Congenitally Blind Individual – a Case Study

Drawing Activates Visual Cortex in Congenitally Blind Individual – a Case Study

Artists are able to draw what they see. They put the real world into a bunch of lines and curves, abstracting the fact that the real world consists of spaces and surfaces rather than of borders. Moreover, in the moment of producing the artwork, artists are able to use their imagination and draw what they don’t see.

The German physicist Helmholtz was impressed by the artists’ capability. In 1871 he pointed out that artists have not only exceptional observational skills but also a remarkably good visual memory.

During the last century scientists have investigated more and more the idea of visual memory. They explored the existence of a “visuo-spatial sketchpad” in the brain. This is a buffer, keeping ready representations of perceived objects in the brain for a possible goal directed action – like drawing. They also found the location of the sketchpad: the primary visual cortex (V1), being the “largest topographic map” in the brain.

V1 is activated when people draw from memory and it is also activated when the drawer is blindfolded providing the “sketches” from the buffer. The neuroscientist Lora Likova went a step further. She wanted to know what happens with the V1, when a congenitally blind individual (that is an individual who has never experienced a single visual stimulus and therefore possesses no visual sketches at all) draws.

The subject, a 64 years old lady tenderly called CB4 in the description of the experiment, has never drawn a line in her life, thus, she had to learn everything from the beginning. Her task was to explore a certain figure with her left hand and then draw it with her right hand. The brain scanner (fMRI), which was used before and after the two month of drawing training, showed interesting results. In the beginning CB4 was not able to reproduce the figures at all. During these first attempts V1 didn’t show any clear reaction. In the end, however, the drawings resembled the original very much and V1 was fully in action. These results once again prove the possibility of brain plasticity in adults and moreover show that a brain part, which is responsible for visual memory, is able to change its function into tactile memory.

What remains open is how the abstraction from the ‘real world’ (the 3D world) to the lines and curves of a drawing would work for a congenitally blind person.

Likova, L. (2012). Drawing enhances cross-modal memory plasticity in the human brain: a case study in a totally blind adult Frontiers in Human Neuroscience, 6 DOI: 10.3389/fnhum.2012.00044

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