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the brain processes
||Visual processing begins in the retina where light is
transformed into nerve signals which are sent to the visual cortex at the
back of the brain. Information then travels to other parts of the brain
where specific functions (facial recognition, spatial processing, emotional
response, etc.) are performed. The motor cortex then plans and controls
movements which the hand implements.
||Brain imaging was first developed for clinical studies of brain damage.
The fMRI (functional magnetic resonance imaging) technique uses a powerful
magnetic field to detect increased blood flow in specific areas of the
brain while the subject is performing a particular task. Could an artist
at work be observed in this way? The question had never been addressed
||While lying inside the scanner, Humphrey drew from photographs in small
sketchbooks. He had 30 seconds or 1 minute to copy each portrait
photograph or abstract design. By comparing the brain activity when copying
the designs to that when drawing portraits, the processes exclusive to
drawing a face could be seen. Non-artists were also submitted to the same
||The images of increased blood flow measured along near
horizontal slices were mapped onto an image of the brain.
John: You don't usually draw that way!
Humphrey: Not in as cramped conditions, but I'm used to drawing in
unusual conditions and quite quickly... With the 30 seconds drawings I
was really on the spot I had to catch the thing on the wing
and that's where I had a bit of practice.
|Test 1: Areas of brain activation (red & yellow) during the drawing
of faces. The lowest brain slice (at about eye-level) is top left, the
highest is bottom right. Abstract designs were geometric figures.
||Test 2: Middle scanned slice. Abstract designs were Korean letters.
More tests are required to understand differences with previous scan.
||Humphrey showed no activation in the visual cortex, but
in more frontal regions, suggesting that he was relying on an abstracted
representation of each photograph. He was 'thinking' the portraits.
||In contrast, the non-artists showed most activation in the posterior
region of the visual cortex, indicating that they were 'slavishly copying'
|Comparison of Humphrey and a non-artist for the same task.
Abstract designs were geometric figures.
||With these exploratory results, we now know that central questions
about the production of art can be addressed.
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