The brain before the body

Dr Anna Sedda, Assistant Professor in our Psychology Department, recently published a paper on the importance of working with the mind as well as the body when managing recovery from spinal cord injury. Here she talks through the role of the brain in our perceptions of the body and its abilities.

You are your body. What a silly sentence, right? Of course we have a physical body that belongs to us and we use to drink coffee or, if you are not as lazy as myself, to go for a walk. The interesting thing is that our body is not only “physical”: we do also have a mental representation of it. This cognitive function is called body representation, and is ruled by our brain activity. Even more importantly, this body representation contributes to a great deal to our self-identity.

Dr Anna Sedda, Heriot-Watt Psychology

Like a spouse of 20 years or more; we take our bodies for granted. Most people, when waking in the morning, rush for a cup of coffee, rather than counting their limbs and verifying the numbers of fingers on each hand. But if that body is damaged in a sudden accident – everything changes. Imagine you are involved in a car crash, and that as a consequence you lose the ability to walk. This condition – named paraplegia – is a serious physical disability that affects the spinal cord and impacts on our ability to use the lower limbs. Interestingly enough, you can still move the upper limbs. Your arms and hands works perfectly, you assume. Are you sure? When trying to grasp your cup of coffee…the movement is not so precise, you might miss the target and spill your coffee. But how is this possible?

Everything goes back to body representation. Even if an accident only causes physical damage to the lower limbs; in your brain, body parts are connected, and they are represented in conjunction with the environment. This means that once you are not able to walk, you are also unable to use the same actions to interact with objects on a table in front of you – you can’t get up and reach them as you used to. But your brain does not know, and it is still using the same old schemas to move. Or maybe he is confused as the cup is not where it was expected to be if you were standing or if you could move your back. This scenario is what we studied in our paper Affordances After Spinal Cord Injury. Our research established that when a spinal cord injury occurs, it changes all perception of the world – not only our ability to walk. The implications of this are huge: requiring a rethink of how we approach rehabilitation of spinal cord injuries.

Together with physical exercises, we also need to have people re-train their brain and their mind, so that their body representation can adapt to their physical status.

Body representation is so important that we are equipped with an alarm system that causes us to react with disgust at the mere idea of damaging our bodies. Could you imagine cutting part of your leg? Or maybe removing your left arm? No? This is a natural reaction that we have to protect our bodies. Spinal cord injuries are abrupt accidents that take something away from us. But there are other instances, ones that are a bit counterintuitive, where the problem is that sensation of having something ‘too much’. Individuals with this condition would like to have only three limbs, or maybe even to be paraplegic. This may seem shocking, but is a genuine condition and is not due to a psychiatric disturbance (i.e. they are not hallucinating) or to a physical impairment (i.e. they can’t feel their legs).

Again, it all comes back to body representation. We are still investigating the cause, but what we know for sure is that as this desire is so alien to most people, these individuals suffer from stigma and are rarely able to get help. Sometimes they are so desperate to reach their desired body state that they even try and get rid of the “wrong” body part themselves.

So yes: body representation and disgust have a great deal in common.

If you want to find out more, Anna will be appearing at the Cabaret of Dangerous Ideas in the Edinburgh Fringe Festival with her show “Disgust for Dummies” on 14 August 2018.

CODI-NTT Disgust for Dummies – 2018 Flyer

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