By Aleksandra Herman

Have you ever gone grocery shopping to get some bread and milk, and you found yourself leaving the shop with a bag full of items that you never intended (and needed) to buy? Or maybe you’ve committed to keeping a diet, but found it impossible to resist another helping of that delicious chocolate cake? Or perhaps instead of analysing all available information before making an important decision, you tend to make a choice on impulse?

We all behave impulsively, to some extent, on a daily basis. Sometimes, acting impulsively is harmless or even advantageous, for example when there is little time to react, or when the matter is of little importance (e.g. ‘what am I having for dinner tonight?’). Keeping a healthy balance is important though: Too much impulsivity leads to negative consequences and has been associated, among other things, with alcohol abuse, addictions, overeating or dangerous sexual behaviours (e.g. unprotected sex). Increased levels of impulsivity are also characteristic features of certain neuropsychiatric conditions such as attention-deficit hyperactivity disorder (ADHD), bipolar disorder or obsessive-compulsive disorder (OCD). 

Given that impulsivity plays such a vital role both in daily life and in clinical practice, it is crucial to understand this phenomenon better. What interests me the most, are those brief moments when the impulse-control mechanisms fail, particularly in healthy and highly functioning individuals. What drives impulsive behaviours? How is it that, despite a strong motivation to keep a diet, a piece of chocolate cake is just irresistible? Why do we often forgo our long-term goals for immediate pleasures?

My research focuses on identifying factors which influence how impulsively we behave and to uncover the neural mechanisms responsible for those momentary self-control failures. One of the factors which seems to play a role here is our current mood state. Take ‘comfort eating’: We may be inclined to help ourselves to some extra snack when we feel blue. Similarly, when angry or frustrated, we may sometimes not think things through and reply to someone’s email in an impolite fashion.

What might be the mechanism responsible for these impulse-control failures? Well, the key brain regions in charge of emotional processes are also vital for behavioural control and decision-making. Therefore, it seems likely that when the brain is busy dealing with strong emotions, such as sadness or anger, they might be less ‘brain power’ left for overcoming immediate pleasures (chocolate cake) over long-term goals (losing weight).

The matter may be even more complicated when we consider individual differences. It seems that some individuals may be more likely to stay cool while facing negative emotions, while some are particularly vulnerable to impulsive behaviours while experiencing intense emotions. Why is that the case? And if we unlucky to belong to the latter group, is there anything we can do to mitigate the impact of emotional states on our actions and decisions? These are some of the questions I ask during my PhD. To better understand the relationship between emotions and impulsive behaviours, I combine behavioural approach with neuroimaging techniques and pharmacological manipulations. By studying situations when self-control processes fail and the underlying neural mechanisms, we may be able to develop strategies that target affected networks and exercise self-control abilities. This way we could prevent some of the negative consequences linked to various impulsive actions, as well as help individuals make more future-oriented decisions on a daily basis.

You can read more about impulsivity and emotions here:

Herman, A. M., Critchley, H. D., & Duka, T. (2018). The role of emotions and physiological arousal in modulating impulsive behaviour. Biological Psychology, 133, 30–43. https://doi.org/10.1016/j.biopsycho.2018.01.014

Contact:

a.herman@sussex.ac.uk

@AleksHerm

Aleksandra Herman is a student of the Sussex Neuroscience 4-year PhD Programme, working with Professor Theodora Duka and Professor Hugo Critchley to investigate the factors that drive impulsive behaviour.

Find out more about our research on Behavioural and Clinical Neuroscience.