Understanding How Color Is Perceived in the Brain
Scientists have examined the effects of language on categorical color perception — the idea that color perception is affected by how it is described in language — with behavioral research. Meanwhile, other scholars have looked into this phenomenon using neuroimaging techniques in an attempt to get a better look at the neural processes underlying these results.
In 2009, an international group of researchers replicated one of the first studies to show lateralized Whorfian effects in categorical color perception, with the addition of fMRI data. They predicted that the areas of the brain responsible for processing language (such as the left temporoparietal areas) would be activated during color perception, and that these areas would show increased activation during cross-category distinctions. In addition, they predicted that cortical areas responsible for color perception would be altered by the activation of linguistic areas if those areas are activated in response to, and not simply as a by-product of, color perception.
Results proved the hypotheses correct. Not only were the linguistic areas of the left hemisphere active during color perception, but they were more highly activated when the colors being displayed in the right visual hemifield (which sends information to the left side of the brain) crossed a color category boundary. Contrastingly, between- and within-category stimuli prompted the same hemodynamic responses when they were perceived in the left visual field. Finally, areas of the visual cortex were activated more quickly when cross-category stimuli were displayed.
What does this all mean? First of all, that linguistically-mediated color perception isn’t just a behavioral phenomenon, but a neural one. This means that the language we use has a significant and lasting effect upon the structure of the brain. Second, it means that the left temporoparietal area of the brain may serve as a top-down controller for perceptual processes, an interesting idea for anyone studying the theory of linguistic relativity. Do the linguistic centers of the brain modulate the responses of other portions? Does the processing of language have more global implications? These are things that remain to be seen.
This study is a great example of the use of fMRI in neurolinguistics — as the availability of this neuroimaging technique increases, we are likely to see more studies like this one, where the hemodynamic responses of brain areas are measured and interpreted in the context of specific stimuli.
Gilbert AL, Regier T, Kay P, & Ivry RB (2006). Whorf hypothesis is supported in the right visual field but not the left. Proceedings of the National Academy of Sciences of the United States of America, 103 (2), 489-94 PMID: 16387848
Ting Siok W, Kay P, Wang WS, Chan AH, Chen L, Luke KK, & Hai Tan L (2009). Language regions of brain are operative in color perception. Proceedings of the National Academy of Sciences of the United States of America, 106 (20), 8140-5 PMID: 19416812
- Medical Marijuana – A Magic Bullet for Treating PTSD?