Category: Posts

The senses and the relationship between them – the scientific approach

tgraven/ / Scientific Approach

It all started with Molyneux asking Locke about seeing after “recovery from blindness”:

“Suppose a man born blind, and now adult, and taught by his touch to distinguish between a cube and a sphere of the same metal. Suppose then the cube and sphere were placed on a table, and the blind man made to see: query, whether by his sight, before he touched them, could he distinguish and tell which was the globe and which the cube?”

And the scientific study of S.B. who, after more than fifty years of blindness, regained vision1. (See our blog for the philosophical approach.)

So, do people who are born blind and who gain vision later in life recognise the world around them?

Yes and no. Gregory and Wallace found that S.B. recognised simple shapes, like circles and squares, as well as ordinary objects, such as chairs and tables, and their size. S.B. read print numbers, print capital letters, and the time on a large clock hanging on the wall. He struggled with complex information: for example, faces and facial expressions meant nothing to him if he did not hear the person’s voice. S.B. could not read the small print letters, and he did not recognise depth and movement. In traffic, he closed his eyes and functioned as if he were still blind; he was surprised by how the moon looked, and he was fascinated by reflections.

It was known long before S.B. that correspondences between the senses exist, but not that information transfers between them in shape and object recognition2.

Gregory and Wallace found that S.B. recognised by vision information that he already knew by touch – indeed, for the first time, demonstrating that information transfers from touch to vision.

Following Gregory and Wallace’s first scientific study on crossmodal recognition, researchers continue to investigate what information is and is not transferred and between which senses. Revisiting Molyneux, they typically measure with what accuracy, speed, or both people recognise information already familiar by touch and now explored by vision. An example of information that transfers between the senses is shape however information that is retained in one sense only is colour. Researchers are also investigating crossmodal plasticity in the brain. They typically scan what brain areas are active in people with one sense missing and people with all senses intact. An example of brain plasticity in people who are born blind is auditory information that activates both the auditory and visual areas (compared with only the auditory in the fully sighted).

When Gregory revisited the historical cases of people who have gained vision, he found that all, perhaps except one, had sad endings3. However, our knowledge from scientific studies allows us to change all that: for example, for people who lose vision later in life and who do not have the same option as S.B. – to function in traffic as if they were still fully sighted. To ensure that people who are partially sighted successfully combine information from low vision and touch. And to ensure that children with and without sensory disabilities learn well together. For an example of sharing sensory experiences in art, please see “Shaping Shapes” and “Please Touch the Art“.

See our blog for Activities; especially 4-6.

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1Gregory, R. L., & Wallace, J. G. (1969). Recovery from Early Blindness A Case Study. Experimental Psychology Society Monograph, No. 2. See: https://www.richardgregory.org/papers/recovery_blind/recovery-from-early-blindness.pdf

2An example of a correspondence between the senses is the sound of spoken words and visualshapes: later known as the “bouba/kiki-effect”.

3Gregory, R. L. (2003). Seeing after blindness. Nature Neuroscience, 6(9), 909-910. See:  https://faculty.washington.edu/gboynton/publications/gregory-newsandviews03.pdf

The senses and the relationship between them – the philosophical approach

tgraven/ / Philosophical Approach

The relationship between the senses has been of interest to philosophers for centuries: with Empiricists such as Berkley and Locke focusing on how the individual sensory (e.g., visual and tactile) experiences contribute to people’s knowledge about the world around them. And in contrast, Phenomenologists such as Merleau-Ponty arguing that there is no visual and no tactile experience, but rather a total sensory experience from which it is impossible to single out individual visual and/or tactile contributions. Essential to the first philosophers was the understanding of extremes in sensory perception, comparing “the blind” with “the sighted”.

I have invited Reader Simon Hayhoe, University of Bath to write this very first blog post. Simon Hayhoe has written numerous books and articles on visual impairment and the arts, public spaces, and the philosophy of social research.

The study of the relationship between the senses is central to our understanding of a philosophy of mind. This relationship is essential not just to our understanding of the physical interface between human consciousness and our external reality, but also to topics such as scientific methodology, communication, language, creativity and imagination. At the centre of this philosophical understanding of the relationship between the senses is the philosophical conjecture on blindness as a means of unbalancing or changing our comprehension of this relationship. And, at the root of this conjecture is the belief that studying what “the blind” can or cannot do in comparison to the sighted will help philosophy recognise what are the most significant extremes of our conceptualisation of an existent or non-existent outside world to sensory perception.

Philosophical conjectures on lacking sensory perception began in the ancient world, when blind figures often became linked to a heightened spiritual ability and a potentially heightened sense of intellect or morality, or with a lack of understanding and an implicit immorality. For instance, in Ancient Egypt the figure of the blind harpist and in ancient Greece the mythological figure of the blind seer were felt to have superior inner vision as a result of their “outer blindness.” By contrast, the Old Testament often presented people who were blind as sinners and incapable of worshipping God as a person with perfect vision would do. Unfortunately, research has shown that a belief in the deficit of people who are blind can often be traced back to these negative religious beliefs. As a result, children who were born blind or those who became blind in early childhood in particular were raised with a belief in their own intellectual and moral inadequacy for hundreds of years.

Philosophical conjecture on the blind was elevated to another level during the renaissance and then became central the enlightenment, when a new curious and fictious figure appeared in the literature. In histories of Western blindness this philosophy was described variously as the cult of the man born blind (by me) or the figure became the mythological born totally blind man (by the writer Georgina Kleege). This philosophical cult or mythology became so influential in the philosophy of mind that a single question by William Molyneux to John Locke on the ability of a fictional born blind man was described by the historian Michel Foucault as the founding myth of the enlightenment. Unfortunately, this fictional figure and the literature that followed his birth subsequently reinforced traditional notions of the intellectual and moral deficit of blindness in the public consciousness under the guise of liberal intellect.

It was not until the twentieth century when empirical studies were able to correct this notion of the relationship between the senses and blindness. In particular, work such as John Kennedy’s theory that all humans have the ability to interpret and create images and Richard Gregory’s study of cross modal transfer, which is the ability of the mind to recognise an object through one sense via another sense that was alluded to in Molyneux’s question, showed what was possible through the quality of perception and language. As a result, we now have the power to change the narrative on blindness, as well consciousness, language, perception and imagination – and even of scientific methodology. We can now also stand back and possibly reappraise the harm that has been done by some philosophies on the lives of the many.

Simon has also very kindly suggested some very interesting books for us to read:

Hayhoe, S. (2015). Philosophy as Disability & Exclusion: The development of theories on blindness, touch and the arts in England, 1688-2010. Charlotte, NC: Information Age Publishing.

Hull, J. (1991). Touching the Rock: An Experience of Blindness. London: Arrow Books.

Magee, B., & Milligan, M. (1996). On Blindness: Letters between Bryan Magee and Martin Milligan. Oxford: Oxford University Press.

Sacks, O. (1995). An Anthropologist on Mars: seven paradoxical tales. London: Picador.

See our blog for Activities; especially 1-3.