When we are hungry, we experience cravings for food. Similarly, when we feel lonely, we get cravings to be around people, according to new research published in Nature Neuroscience. When participants spent a day in total isolation, their brains lit up like a Christmas tree when they witnessed social gatherings. So, are human connections as vital to our mental wellbeing as food?
The reason for the research
According to past research, being alone for long periods is harmful to our mental and physical health. Yet, not much is known about how short-term, mandatory seclusion affects a person. [i] [ii]
Meeting with friends and enjoying the company of other people is as important to us as fundamental needs like sleep or food. [iii] Socialising is so hard-wired to our brains that seeing social cues like someone smiling at us is enough to activate the brain’s reward system. [iv]
Researchers were curious to know if being alone would create intense cravings to motivate people to fix the absence of social interaction. Because there is very little research about how our brains respond to unmet social needs, cognitive neuroscientist Livia Tomova decided to set up her own study.
How a hungry brain was tested
40 young adults with healthy social lives took part in the study. Over two days, each participant spent ten hours fasting and avoiding food on the first day. The next day involved social isolation, away from people.
Each volunteer would have their brain activity measured using functional magnetic resonance imaging (fMRI.) The fMRI gave researchers a view into the reward region of the brains of participants.
While strapped up to the fMRI after fasting, volunteers were shown pictures of delicious foods, including pizza and cakes. The scientists saw that the neurons in the reward pathway lit up.
When the volunteers were isolated, pictures were shown of people playing team sports and chatting. Just like the hungry group, the lonely group’s brains lit up when seeing the images. What’s more is that the more hungry or lonely the participants felt, the stronger their brains’ activity.[v]
We crave social interaction as much as food
The reward pathway in the midbrain is crucial for our drive to seek out behaviours that make us feel good and help us survive. So even when we are not lonely or hungry, the midbrain will still react to social signals and food. But when we are lonely or hungry, the reaction from our brains is at its strongest.
The research highlights the vital importance of social interaction in our everyday lives. With lockdowns easing, young people and adults can enjoy the company of others again. To benefit our health and wellbeing, spending time with friends and family is every bit as important as food. Lead researcher Tomova sums it all up with her comment to ScienceNews:
“COVID-19 has left many more socially isolated, putting mental as well as physical health at stake and leaving people with cravings for more than food. So it’s important to look at the social dimension of this kind of crisis.”[vi]
References
- Hawkley LC, Cacioppo JT. Loneliness and pathways to disease. Brain, Behavior, and Immunity [Internet]. 2003 Feb [cited 2021 Jul 23];17(1):98–105. Available from: https://pubmed.ncbi.nlm.nih.gov/12615193/
- Leigh-Hunt N, Bagguley D, Bash K, Turner V, Turnbull S, Valtorta N, et al. An overview of systematic reviews on the public health consequences of social isolation and loneliness. Public Health [Internet]. 2017 Nov [cited 2021 Jul 23];152:157–71. Available from: https://pubmed.ncbi.nlm.nih.gov/28915435/
- Cacioppo JT, Cacioppo S, Boomsma DI. Evolutionary mechanisms for loneliness. Cognition and Emotion [Internet]. 2013 Sep 25 [cited 2021 Jul 23];28(1):3–21. Available from: https://pubmed.ncbi.nlm.nih.gov/24067110/
- Bhanji JP, Delgado MR. The social brain and reward: social information processing in the human striatum. WIREs Cognitive Science [Internet]. 2013 Oct 8 [cited 2021 Jul 23];5(1):61–73. Available from: https://pubmed.ncbi.nlm.nih.gov/24436728/
- Tomova L, Wang KL, Thompson T, Matthews GA, Takahashi A, Tye KM, et al. Acute social isolation evokes midbrain craving responses similar to hunger. Nature Neuroscience [Internet]. 2020 Nov 23 [cited 2021 Jul 23];23(12):1597–605. Available from: https://www.nature.com/articles/s41593-020-00742-z#citeas
Lonely brains crave people like hungry brains crave food [Internet]. Science News. 2020 [cited 2021 Jul 23]. Available from: https://www.sciencenews.org/article/lonely-brains-social-isolation-people-mental-
[i] Hawkley LC, Cacioppo JT. Loneliness and pathways to disease. Brain, Behavior, and Immunity [Internet]. 2003 Feb [cited 2021 Jul 23];17(1):98–105. Available from: https://pubmed.ncbi.nlm.nih.gov/12615193/
[ii] Leigh-Hunt N, Bagguley D, Bash K, Turner V, Turnbull S, Valtorta N, et al. An overview of systematic reviews on the public health consequences of social isolation and loneliness. Public Health [Internet]. 2017 Nov [cited 2021 Jul 23];152:157–71. Available from: https://pubmed.ncbi.nlm.nih.gov/28915435/
[iii] Cacioppo JT, Cacioppo S, Boomsma DI. Evolutionary mechanisms for loneliness. Cognition and Emotion [Internet]. 2013 Sep 25 [cited 2021 Jul 23];28(1):3–21. Available from: https://pubmed.ncbi.nlm.nih.gov/24067110/
[iv] Bhanji JP, Delgado MR. The social brain and reward: social information processing in the human striatum. WIREs Cognitive Science [Internet]. 2013 Oct 8 [cited 2021 Jul 23];5(1):61–73. Available from: https://pubmed.ncbi.nlm.nih.gov/24436728/
[v] Tomova L, Wang KL, Thompson T, Matthews GA, Takahashi A, Tye KM, et al. Acute social isolation evokes midbrain craving responses similar to hunger. Nature Neuroscience [Internet]. 2020 Nov 23 [cited 2021 Jul 23];23(12):1597–605. Available from: https://www.nature.com/articles/s41593-020-00742-z#citeas
[vi] Lonely brains crave people like hungry brains crave food [Internet]. Science News. 2020 [cited 2021 Jul 23]. Available from: https://www.sciencenews.org/article/lonely-brains-social-isolation-people-mental-health
