A look inwards at the science of interoception
Words By Eleanor Deane, Science and Tech Editor
Have you ever felt an awareness of your heart beating? Our senses help us interpret not only the world around us but also the signals from within us. This sense of the internal state is called interoception. Interoception plays an important role in regulating the body – for example, these internal sensations lead to you feeling hungry or thirsty. It is becoming clear that interoception also has a role to play in emotion.
One theory of emotion suggests that internal sensations can impact our emotional states. It may seem intuitive to think our emotions come first – we feel scared, which leads to our heart beating faster. This theory of emotion suggests that the opposite is important – our hearts beat faster leading us to feel scared. With the development of neuroimaging, it has been proposed that the basis for this linking of internal sensation may lie in an area of the brain known as the insula. This area is involved in both processing internal sensations and emotional processing.
Scientists are becoming increasingly interested in the role this sense plays in mental health. Interoception is thought to play a role in a plethora of conditions including anxiety disorders, mood disorders and eating disorders. The most popular way of investigating interoception in people is to use tasks where people are asked to tune into their heartbeat. One type of heartbeat detection task involves participants counting their heartbeat in a variety of time periods. Their answers can be compared to their actual heartbeats using heartrate monitors. Participants can also be asked how aware they think they are of their internal state. If you think your awareness is high whilst your measured accuracy is low, this can be described as a ‘prediction error’.
During her research at the University of Sussex, Professor Sarah Garfinkel found that participants that had higher ‘prediction error’ also reported greater levels of anxiety. Her results also suggest that ‘prediction error’ is higher in participants with autistic spectrum disorder. Meanwhile, work by psychology researcher Dr Hayley Young suggests interoceptive ‘prediction error’ may be associated with emotional eating. In my own undergraduate research, I measured interoceptive prediction error using heartbeat tasks pre-coronavirus-lockdown and then used questionnaires to monitor emotion during the coronavirus lockdown.
Early in the pandemic, the psychological impact became a concern. A study based in China in March reported that of 1210 respondents, 53.8% rated the psychological impact of the outbreak as moderate or severe. In the covid era, our perception of the internal state had become of heightened importance, due to a heightened awareness of our internal state; a world in which our bodies may be a source of anxiety. In the journal of clinical neuropsychiatry, academics proposed that the pandemic may affect the sense of self and relations to others, which may manifest as heightened anxiety, mediated by interoceptive processing.
With interoception research, the hope is that knowledge gain may inform the development of interventions that target interoceptive processing, with the aim of improving psychological wellbeing.