In order for you to complete pretty much every bodily function you can think of, your brain must continuously communicate with every single part of your body. This communication is co-ordinated via your nervous system, a highly complex network which connects your brain to your muscles, and allows you to physically respond and adapt to changes in your surroundings. At the WIMM, David Beeson’s group are interested in how genetic mutations affect the communication between nerves and muscles, but researchers in other departments within the Medical Sciences Division are working on the other end of the system – how we perceive the sense of touch. In this post, guest blogger Harriet Dempsey-Jones (a DPhil student in the Nuffield Department of Clinical Neurosciences) explains more about her own research into how our sense of touch can actually be heightened by training, and the context in which this could be an enormously valuable skill.
Compared to our other primary senses (such as sight and hearing), we take our sense of touch largely for granted. For this reason, considerably less is known about the processes in our body and brain that allow us to feel the huge variety of sensations we encounter every day.
What is exceptionally interesting about our sense of touch is that, in the same way we train other skills (like learning a sport), it is actually possible to train your sense of touch to become more acute. That is, to enhance your sensory perception, allowing you a more accurate and sensitive sense of touch.
So how do you train a super-sense?
Neuropsychological research from a field called ‘perceptual learning’ is helping to uncover how this can be achieved.
In a typical perceptual learning experiment, a scientist would present different kinds of tactile stimuli (e.g. surfaces with raised patterns or grooves) to their participants’ skin, usually the fingers.
The participant will receive some kind of feedback about what they are touching, allowing them to match the sensation with the stimuli: for example, when touching a stimulus with raised grooves on it – you might be asked to determine whether the grooves are oriented vertically or horizontally. Once you have made your judgement, the feedback will tell you whether you were correct or incorrect in your assessment. Following this process of exposure and feedback, subsequently it has been shown that perception improves!
It may seem logical that improving sensation in the fingers would be caused by a change in the sensory receptors in the fingers themselves. But contrary to what one might expect, this does not appear to be the case.
In fact, this touch learning occurs rather higher up the neural hierarchy. Studies suggest that perception improves because systems of neurons in the brain get better at tuning in to the stimuli being presented to your skin. Therefore, while all the same information is being provided to the system, your brain is better able to tune into the signal and ignore the noise – leading to enhanced sensory perception.
Another unexpected outcome of this training is that not only the trained finger learns, but certain other fingers also show learning even though they have never been exposed to the training…
New research suggests that this spread of learning occurs because of links in the brain between particular pairs of fingers – such as directly neighbouring fingers and same fingers on opposite hands.
These findings have very interesting applications, which are already being exploited by savvy neuroscientists and tech developers.
Following on from the huge popularity of brain training apps that attempt to improve cognitive power and working memory, there is a new series of apps that employ principles of perceptual learning to maximise the power of our senses.
One recent example is the UltimEyes app recently developed by Professor Aaron Seitz from the University of California Riverside. This app allows the user to play a series of simple games with visual stimuli that allow significant enhancements to your visual acuity – which are also due to changes in your brain, not your eyes, as described above.
While not yet developed, similar apps for touch perception are likely to be just around the corner, allowing a finer level of touch perception for people who might find this useful from surgeons to seamstresses.
With these developments in the field of perceptual learning, we move towards fantastic opportunities to maximise our sensory perception, aid rehabilitation after sensory loss, and just generally become more awesome.
Post edited by Bryony Graham.