This is a guest blog post by Dr Keith Wilson, Postdoctoral Researcher, University of Glasgow ‘Rethinking the Senses: Uniting the Philosophy and Neuroscience of Perception’.

The Glasgow Science Festival showcases some the outstanding contributions made by Glasgow and Glasgow-based researchers to science, technology, engineering, maths and medicine. This year, myself and my colleagues on the Rethinking the Senses and Value of Suffering projects, both of which are hosted at the University of Glasgow’s Centre for the Study of Perceptual Experience (CSPE), took the opportunity to exhibit some of the latest interdisciplinary research in the science and philosophy of perception to a public audience at GSF 2015. The result was a lively and varied mixture of activities, talks, and even a film screening, that invited visitors to explore the strange and often surprising world of multisensory perception and illusions.

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Whilst it might seem unusual for arts and humanities researchers to exhibit at a science festival, as one of the AHRC Science in Culture theme’s large-grant projects, Rethinking the Senses investigates the nature of perceptual experience from the perspectives of science, philosophy and the arts. In particular, we examine how the current trend towards a ‘multisensory’ approach to perception can help us better understand the way in which we experience and interact with the world. This goes beyond the traditional ‘five senses’ of vision, hearing, touch, taste and smell—a division that was familiar to Aristotle—to consider lesser known senses (e.g. proprioception, balance, pain, thermo- and mechanoreception), as well as interactions between and across the senses.

Interactive Activities

To illustrate this, and building upon the success of our earlier ‘Hidden Senses’ event, our team devised a series of fun and interactive activities that challenged the preconceptions of hundreds of visitors to Glasgow’s Kelvingrove Art Gallery and Museum about what they could taste, hear, see and feel as part of a weekend-long event featuring researchers from across the sciences. Amongst other things, we tested

  • visitors’ abilities to identify the ‘taste’ of sweets without using their sense of smell (very difficult since both taste and smell are required to judge flavour)
  • whether or not they were ‘supertasters’ (as recently demonstrated on the BBC’s Masterchef programme by AHRC leadership fellow Barry Smith)
  • if people’s evaluation of ‘good’ and ‘bad’ smells is affected visual imagery (it is!)
  • whether they could hear the difference between hot and cold liquids being poured in to a cup (you can!)

along with a series of visual, auditory and tactile illusions including the waterfall illusion, the McGurk effect, and the rubber hand illusion in which sensations of touch seem to be located in a prosthetic dummy hand rather than one’s own hand, which remains concealed behind a partition. Visitors were invited to record their experiences on an Activity Passport, the results of which will be made available via the CSPE website.

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Multimodal Illusions

Many of the above cases involve information from one sensory modality, e.g. vision or smell, influencing another, e.g. touch or taste, creating a truly multimodal experience. In the McGurk illusion, for example, a heard phoneme /ba/ fuses with a seen lip movement /da/ to produce the experience of a third illusory phoneme /ga/. Whether this illusory sound is heard, seen, or some combination of the two, is an interesting and difficult question to answer since the resulting experience is partly generated by vision, and so changes when you close your eyes.

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Increasingly, scientists and philosophers are realising that such examples are not just isolated curiosities, but illustrate important aspects of how our perceptual and sensory systems combine information from multiple sources into a single conscious experience in which it is no longer apparent which sense, or combination of senses, is operative. Indeed, whether we should think of hearing, vision or taste as discrete senses at all is one of the philosophical questions we hope to shed some light upon during the course of the project.

Science and Philosophy

In addition to the event at Kelvingrove, several of our lead investigators gave talks on the science and philosophy behind our research. These linked in with the Festival’s themes of food, drink, and light, the latter commemorating the 150th anniversary of the ground breaking discoveries of Scottish physicist James Clark Maxwell. These were extremely well attended, with over 150 people signing up for ‘The Perfect Meal’ (Charles Spence) and ‘The Value of Suffering’ (Michael Brady), and over 270 for ‘Vision, Perception and Illusion’ (Fiona Macpherson and Colin Blakemore).

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In his talk ‘Vision Impossible!’, RTS principal investigator Colin Blakemore discussed the magnitude of the problem faced by the brain in turning light falling upon the retinas into the rich and coherent visual experience we normally enjoy, while Fiona Macpherson focused upon the philosophical nature of hallucinations and illusions, and in particular the waterfall illusion in which some subjects report the effect of illusory motion without any change in position—a seeming impossibility. Indeed, this being the Science Festival, Professor Macpherson asked members of the audience to record their experiences of the illusion via a questionnaire designed to test the accuracy of this description.

All in all, GSF 2015 offered a wonderful opportunity to present and communicate our research to a wider audience, and we were delighted with the warm and enthusiastic response received. As philosophers and scientists, we spend many hours debating the finer points of multisensory integration and the nature of experience. However, it’s important not to lose touch with the sense of fascination we all feel when encountering a visual illusion for the first time, or of the surprise and wonder on a child’s face upon realising that what we call ‘taste’ is in fact largely derived from the sense of smell.

To that extent, perceptual experience is not only a problem to be studied by scientists and philosophers, but a shared feature of human experience by which we navigate and discover the world. Events like this give us an important opportunity to share what we’ve learned, stimulate people’s imaginations, and in turn build public understanding of, and support for, the arts and humanities as part of a wider search for knowledge that enriches us all.

The Science in Culture Theme is a key area of AHRC Funding and supports projects committed to developing reciprocal relationships between scientists and arts and humanities researchers. More information about ‘Rethinking the Senses: Uniting the Philosophy and Neuroscience of Perception’ Large Grant is available here. Follow us on Twitter @AHRCSciculture for updates from the Theme.