Research assistant Lucy Marlow is a member of Breathe Oxford, a group of researchers investigating breathlessness from a neuroscience perspective. Here she outlines how neuroscientific research could change the way we treat breathlessness…
Breathlessness is a very personal experience, be it a part of illness or health. One of the greatest problems facing respiratory treatments today is the difference in the experience of breathlessness between individuals whose physiological measurements look exactly the same. One patient may be active and get along just fine despite their respiratory disease, whilst another patient with objectively similar lungs may be severely disabled by their breathlessness.
Why is this the case? We have started to consider breathlessness as more than a simple read out of the state of the respiratory system and by doing so we have opened avenues of explanation for these differences. Seeing breathlessness as a perception that is generated by the brain allows us to begin to see how factors beyond the lungs can have a significant impact of breathlessness.
Everything that we experience is a combination of information obtained from the world beyond the brain and the brain’s best guess at what should be happening. Our experiences are generated like this for two key reasons:
- The information the brain receives about the world can be noisy and without further input from the brain, the quality of this information would be insufficient to create the depth of experience we enjoy.
- The brain tries it’s best to be efficient in it’s processing. If it is encountering a similar situation to ones it has previously experienced, it will use these past experiences to inform it’s current perceptions, all in an effort to save energy.
The idea of perception being different between people is a part of our everyday lives in lots of respects, from our likes and dislikes of food flavours to the classic question: “is the blue I see the same as the blue you see?” The basic principles of perception being reliant on a combination of incoming information plus best guesses based on past experiences is formalised in a theory called the Bayesian Brain. This concept has taken the neuroscience world by storm as it is capable of accounting for so many different phenomena and is (it seems) relevant to so many questions neuroscientists consider about how we experience and interact with the world.
By considering breathlessness within the context of the Bayesian Brain, it is possible for us to formulate how past experiences and emotions can have a significant influence on breathlessness. Consider the example often experienced by people with COPD (chronic obstructive pulmonary disease): when approaching a flight of stairs they find that their breathlessness can increase before even beginning to climb. Why is this? Well, within a Bayesian model this would result from past experiences of breathlessness whilst climbing the stairs already biasing the perception of breathing towards one of increased breathlessness. This effect could be further amplified had these experiences been frightening or upsetting with emotions strengthening the importance of these past experiences in their contribution to one’s final experience and perception.
This model provides a guiding light for our search into the depths of the brain to understand where and how breathlessness is processed. Brain imaging and new computational techniques provide opportunity for us to understand how the brain is processing breathlessness, including where and how past experiences and emotions can influence our perceptions. By understanding these processes in greater detail, the door is opened for the development of treatments to improve breathlessness.
Watch our short, fun animation to get an idea of how this work could help in the endeavour to provide personalised treatments to each patient and for a more detailed look at the potential of using the Bayesian Brain model to understand breathlessness click this link to check out our latest review paper.