E-Paper
Language can alter the way we see the world
A study has found that the left side of the brain spots different colours faster than it can different shades of the same colour.
A new study by American researchers has found that the left side of the brain can spot different colours faster than it can identify different shades of the same colour. In other words, our perception of colours can depend on whether we view them from the language-loving left hemisphere or the right. This shows how language can alter the way we see the world.
Richard Ivry of the University of California, Berkeley, and colleagues suspected that separating out the effects of visual input to the right and left brain hemispheres might yield some clues. Language is processed mainly in the left hemisphere of the brain, which also deals with signals from the left side of the retinas in both our eyes.
Because light from objects to our right falls mainly into the left-hand area of our retinas, the researchers hypothesized that colours to the right would feel the influence of language more keenly. Conversely, objects on our left side activate the right hemisphere of the brain, so the effect of language would be minimal.
According to Nature, to test their idea, they showed a series of people a picture of green squares arranged in a circle. They measured how long it took each person to pick out a single square of a different colour, which was situated on the right or left side.
The oddball square was either a different shade of green from the rest of the squares, or it was blue. If this square was positioned on the left, people detected both the blue and green square in the same amount of time. But if the square was on the right, the subjects took longer to identify the green square than the blue one.
The bluish square in the lower left can be spotted more quickly thanks to a little help from the language centre of the brain. The researchers say this is because the colour blue has a distinct name, and so the language-loving left hemisphere could perceive the colour difference faster than it could a square with a different shade of green.
The researchers went on to test their theory by asking the subjects to memorize a series of words during the visual tests. With their left brain's language centre otherwise occupied, there would be less opportunity for it to influence visual perception, and so, as expected, the subjects picked out blue or green squares on the right-hand side of the picture in the same time.
