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Sci Tech
Seeing colours in numbers
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A faulty gene allows leakage of information between the two adjacent areas responsible for seeing colours and identifying numbers. This aberration makes some people see colours in numbers.
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RAINBOWS ARE not the only phenomena that exhibit colours. For some people who are otherwise normal, seeing colours in things as mundane as numbers or even particular tunes is not new. For instance, these people see the number two as a particular colour, say green and number three as red. The same is the case with different tones. Brand them as crazy, as they were generally called, but that cannot wish away the fact that these people do indeed see colours when none exists.
This bizarre ability was known as early as in the 19th Century when Francis Galton, cousin of Charles Darwin, first noticed this in some individuals. Unfortunately these people were labelled as crazy and not much was done to medically investigate the issue. But according to V.S. Ramachandran, Director of Centre for Brain and Cognition at the University of California at San Diego, the experience of seeing colours in numbers or tones can be explained medically. Called Synesthesia, the abnormal ability can be explained in terms of neuro connections in the brain.
The brain has a map of the whole body clearly laid out with every part of the body being represented by a particular point or area in the brain. And the area responsible for seeing colours, called the fusiform gyres is adjacent to the area responsible for identifying numbers. In the case of people with synesthesia, a faulty gene allows leakage of information between the two areas resulting in a cross talk between the areas responsible for seeing colours and identifying numbers. This gives them the (dis)ability to see numbers as colours. As is the case with many genetic disorders, synesthesia also runs in the family.
A normal foetus has an excess of connectivity between different parts of the brain. "The connections are selectively pruned to create the specialisation that we see in an adult brain," Mr. Ramachandran explained. The selective pruning continues for a few months after birth. The presence of a faulty or mutated gene at the time of selective pruning results in cross wiring to happen. And the result is synesthesia. This is not an isolated case. For instance, in individuals with hands amputated, any touching of the amputated hand triggers a touch sensation in the face. This is because the hand and the face are mapped next one another in the brain.
Although branded as `crazy' people, these individuals are harmless. At times they use the faulty gene and hence their abnormal condition to their advantage. "Synesthesia is seven times more common in artists, poets, novelists and those in the creative fields," he noted. It gives them the capability of using and seeing metaphors where none exists or when other people are unable to see a connection between different ideas or themes.
Ability to see metaphors is strong when such faulty genes are present in more areas of the brain.
Being aware of awareness
Mr. Ramachandran has worked in another interesting area that seems to go against the general perception. According to him, humans, unlike animals, are aware of awareness. This he calls as meta-awareness. "When a person sees an object different parts of the brain get fired and finally he becomes aware of seeing the object or is just aware of his awareness," he elucidated.
This can be best explained in the case of people suffering from blind sight syndrome.
In these people, the visual cortex is damaged and hence the faculty to see an object is destroyed. But the interesting part is the person's ability to physically touch the object despite not being able to see it. For instance, when a light is turned on people with the syndrome are unable to see the light but are able to touch it. But the interesting point is that they never know that they have touched it right. "They are basically not aware of awareness," he said. These people do not see things in the human sense.They are able to see the object but are not conscious of seeing or perceiving it.
According to him seeing an object and recognising it is not a one-way process. On the other hand this happens due to two pathways of vision — the brain stem pathway that basically involves the eye sight but does not involve the awareness of seeing the object. And the other pathway goes into the brain's cortex and is the one responsible for creating meta-awareness.
He refutes the well-accepted notion of seeing being a single process. "If that be so, then how is it that these people are able to correctly touch the object though they are unable to see in the human sense?" he questioned.
On the other hand of the spectrum are those suffering from schizophrenia. This strengthens his theory. Here the person's meta-awareness is hyperactive even when the object is really non-existent.
This leads to hearing or seeing things even if they are non-existent. In a nutshell, such people suffer from hallucination and inability to distinguish reality from unreality.
R. Prasad
in Chennai
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