Language And Color Perception Linked In Human Brain

The idea that language may affect thought and perception was first put forward by Benjamin Lee Whorf in a book entitled "Language, Thought, and Reality", published in 1956. Much research has been done on the "Whorfian Hypothesis" in the last fifty years, but so far little hard evidence is available either in support of or against the hypothesis.

For example, the Pirahãs, a small community of some 200 hunter-gatherers in the Amazon jungle, speak a language that has no words for numbers beyond two. Researchers have found their ability to conceptualize numbers to be limited, possibly by their language. This work is very suggestive, but it is not based on direct neuro-physiological evidence.

In a series of experiments, the HKU researchers investigated the relationship between language and colour perception, using new neuro-imaging techniques. "By using neural imaging, we have succeeded in showing that brain regions mediating language processes participate in neural networks activated by perceptual decision," explained Dr Luke.

In their experiments, seventeen subjects were asked during neuro-imaging sessions to decide whether two squares were of the same colour. Some of the squares were filled with easy-to-name colours (such as 'red' or 'blue'); others with hard-to-name colours. The result shows that the perception of both kinds of colours involved the same cortical regions which have long been known to be associated with colour vision. However, in comparison with the hard-to-name colours, perception of the easy-to-name colours evoked significantly stronger activation in two additional brain areas that have been found independently to be responsible for word searching suggesting that with colours that have names in a language, there is a close link between language processing and colour perception .

"These findings represent a major break-through on this research topic by providing neuro-physiological evidence in support of the Whorfian hypothesis," said Professor Tan Li-Hai, professor in linguistics of HKU and a member of the research team.

"This work also serves as a demonstration of a new method for the study of the age-old question of how people's experience might be shaped by their language," explained Dr Luke.

Thinkers since antiquity have pondered about the nature of the relationship between language and perception: to what extent are the mental categories that we use to classify objects and their qualities determined by our language? The new findings have opened up new opportunities for the study of the human mind, Dr Luke elaborated.

He said a deeper understanding of the universal basis of language on the one hand, and how different languages may vary in their conceptual bases, should be of direct relevance to language teaching. Further research on the relationship between language and perception may uncover principles that would enhance the effectiveness of people's learning of second and foreign languages.

The research was conducted with the new 3T GE MRI scanner at Queen Mary Hospital, and in collaboration with Professor Paul Kay of the Department of Linguistics at the University of California, Berkeley, a world authority on the Whorfian Hypothesis, and known internationally for his research on the relationship between language and colour perception.

The research was supported by grants from China's National Strategic Basic Research Programme ("973" Programme), the National Institutes of Health (NIH) of the USA, and HKU.

Journal reference: "Language affects patterns of brain activation associated with perceptual decision", by Li Hai Tan, Alice H.D. Chan, Paul Kay, Pek-Lan Khong, Lawrence K.C. Yip, and Kang-kwong Luke.  Proceedings of the National Academy of Sciences (PNAS), March 2008.