Neuroscience
Painting By Touch
Blindness allows ‘visual’ brain areas to enhance the sense of touch.
Posted February 17, 2010
John Bramblitt didn’t start painting until he lost his sight. It was a difficult time. Bramblitt was in his late 20’s and unaware that his sight was seriously degrading until he was sideswiped by an unseen car. He was also worried about having the severe epileptic seizures that had already taken their toll on his vision. And he was angry. In fact, he believes that taking up painting after losing his sight was mostly an act of defiance.
While Bramblitt’s twenty-five years of visual experience provided him with mental images of what he wanted to paint, he was uncertain how to render these images on a canvas he couldn’t see. Then he discovered ‘puffy paint’. Puffy paint is typically used for decorating fabric and leaves a thin raised line, a line Bramblitt can touch. Using puffy paint allows Bramblitt to produce an initial outline of his subject on the canvas. He then feels his way across the raised lines with his left hand, as he fills-in the colors using a brush held in his right.
For color, Bramblitt uses oil paint, which has proven critical to the process. While oil paint is messier, more pungent, and dries much slower than acrylics, it offers something that no other paint can: idiosyncratic viscosity. According to Bramblitt, “White feels thicker on my fingers, almost like toothpaste, and black feels slicker and thinner. To mix a gray, I’ll try to get the paint to have a feel of medium viscosity”. In fact, he has learned to recognize and mix all the colors he uses by his sense of touch. And the colors are the first thing one notices about Bramblitt’s work (www.Bramblitt.net). While the subjects of his paintings are immediately recognizable, proportioned, and smartly stylized, the colors are supremely vibrant, and nearly psychedelic in their rendering.
John Bramblitt has developed his touch skills in particularly impressive ways. But the enhancement of the touch sense is known to generally occur for blind individuals. Research has shown that regardless of training in Braille, the blind have better touch skills than the sighted, especially when it comes to touching complex spatial patterns. This cross-modal plasticity is thought to be a result of the blind’s visual cortex being reassigned to other senses. Brain imaging shows that when touching complex patterns, the visual cortex of blind, but not sighted individuals is activated in systematic ways. Moreover, inducing a transient brain lesion (using transcranial magnetic stimulation) in visual cortex will disrupt some of the tactile skills of blind, but not sighted subjects.
Similar enhancements in auditory and even smell skills have been observed for blind individuals, especially those blind at an early age. Reciprocally, deaf individuals show some enhancement of visual skills, particulary those used to attend to objects in the visual periphery – objects that might typically be detected by hearing.
Perhaps some of the most surprising findings from the cross-modal plasticity research is just how quickly the phenomenon occurs. It turns out that relatively short periods of blindfolding (five days or even 90 minutes, depending on the test) is enough for enhancement of touch skills. And this enhancement can occur without touch training of any kind. While blindfold induced tactile enhancement is short-lived (it recedes within 24 hours of blindfold removal), it seems based on recruitment of similar visual brain areas as those involved for the blind. These findings have led many scientists to believe that cross-modal plasticity is a general strategy of all brains, regardless of the sensory ability of the owner.
These days John Bramblitt is a much happier person. He has married a fellow artist and has a young child. His art is selling well, both from his web site (www.Bramblitt.net) and gallery exhibitions. He gets great pleasure from sharing his techniques and experience with others, and plans to get a masters degree to teach art at the college level. And he continues to get tremendous satisfaction from the eight hours a day he devotes to his unique style of painting.
Lawrence Rosenblum is a Professor of Psychology at the University of California, Riverside. He studies multimodal speech perception and general auditory perception. His book on our implicit perceptual skills, “See What I’m Saying: The Extraordinary Powers of Our Five Senses” (www.lawrencerosenblum.com) will be published by Norton Press in March.
References
Amedi, A., Merabet, L. B., Bermpohl, F., & Pascual-Leone, A. (2005). The occipital cortex in the blind: Lessons about plasticity and vision. Current Directions in Psychological Science, 14, 306–311.
Bavelier, D., Dye, M. W., & Hauser, P. C. (2006). Do deaf individuals see better? Trends in Cognitive Sciences, 10, 512–518.Facchini, S., & Aglioti, S. M. (2003). Short- term light deprivation increases tactile spatial acuity in humans. Neurology, 60, 1998–1999.
Cuevas, I., Plaza, P., Rombaux. P, De Volder, A.G., & Renier, L. (2009). Odour discrimination and identification are improved in early blindness.Neuropsychologia 47, 3079–3083.
Pascual-Leone, A., & Hamilton, R. (2001). The metamodal organization of the brain. In C. Casanova & M. Ptito (Eds.) Progress in brain research (Vol. 134, pp. 1–19).
Weisser, V., Stilla, R., Peltier, S., Hu, X., & Sathian, K. (2005). Short-term visual deprivation alters neural processing of tactile form. Experimental Brain Research, 166, 572–582.