Molyneux's question

Frankly I had never heard of either Molyneux or his question before today morning. In brief, Molyneux wondered whether a man who has been born blind and who has learnt to distinguish and name a globe and a cube by touch, would be able to distinguish and name these objects simply by sight, once he had been enabled to see.

The question has been debated by philosophers for 300 years, and lately neuroscientists have become interested in it as well. According to Dr. Pawan Sinha of MIT, the question relates to how perceptions are formed in brain [1].

"Do the different modalities, or senses, build up a common representation, or are these independent representations that one cannot access even though the other modality has built it?"

While there has been some indirect evidence, no one was able to perform a direct test because of lack of test subjects. In rich countries, curable congenital blindness is identified and cured in infancy. Dr. Sinha realized that this was not the case in developing countries. In 2003 he conducted a study in India where he identified 5 young adults with curable blindness. By measuring their ability to discriminate between shapes first using touch and then sight, he was able to experimentally recreate the conditions posed by Molyneux.

The short answer, it turns out, is no. Although after restoration of sight, the subjects could distinguish between objects visually as effectively as they would do by touch alone, they were unable to form the connection between object perceived using the two different senses. So we do not have a central memory where information from all the senses in stored.

This makes me wonder how does brain cross-reference data from different senses in form one coherent version. Maybe the versions are not coherent. What if one version dominates over others and so we end up with a less than true version of reality!


[1] http://www.news.com.au/technology/sci-tech/molyneuxs-question-gets-answered-after-300-years/story-fn5fsgyc-1226037177460
[2] Held, R.; Ostrovsky, Y.; Degelder, B.; Gandhi, T.; Ganesh, S.; Mathur, U.; Sinha, P. (2011). "The newly sighted fail to match seen with felt". Nature Neuroscience. doi:10.1038/nn.2795