For most of us bi-directional sleep is a question of sleeping on the left or right side, or on our back or front, head left or right. In immunology bi-directionality of sleep has another meaning. The immune system is linked to sleep in a bi-directional manner. Good sleep enhances the immune response of cells (direction 1) and infected blood cells for example send a signal to the brain to extend sleep. The study by Huynh et al. (2024) in Nature has demonstrated this bi-directional mechanism. It allowed mice who slept well after an imposed heart attack to recover in a better way than those whose sleep got interrupted during the experiment. The most natural response to a heart attack or acute coronary syndrome is more sleep. This is induced by an inflammatory reaction in the brain, which « orders » your body to increase deep sleep. 😴 Sleep is more than just rest, it may be part of healing. ❤️🩹 (people looking at Caspar David Friedrich „Infinite Landscapes“, exhibition Alte Nationalgalerie Berlin 2024)
Weight Stigma
The fashion industry has for a long time produced images of mostly women and men that did not correspond to the normal weight distribution of people. Skinny models were present across all media. The so-called social media of today amplify this trend further. The “Barbie hype” has reinforced the idea of low weight as a socially desirable norm. In scientific research the term coined for this phenomenon is “internalized weight stigma” (IWS). A study shows (Highes et al. 2024) it affects more women than men and more people who are described as socioeconomically disadvantaged adults. Pressure to lose weight originates from multiple sources and social media platforms have given rise to bullying. A major outcome of IWS is eating disorders as eating is often wrongly associated to be the only cause of higher weight. It is not. Many other factors contribute to the actual weight of a person. Even the overuse of the body mass index (BMI) as short hand version to define overweight or obesity is misleading for persons with strong muscles. Just fixing on one parameter of body shape or weight tends to reinforce weight stigma. “Keep walking” and a regular healthy diet, this avoids to internalize a weight stigma. Exercise is fun, the more you do it in a group, the easier it is to get going regularly. We ought to keep trying and eventually it will become a routine.
Sleeping BPS-SPB
Sleeping is a good example of the co-determination of the biological, psychological and societal spheres of life. The environment with the daily cycles of light and dark as well as the social norms of work and rest determine the circadian cycles of hormones. Shift work or otherwise disrupted sleep patterns depend on social norms like regulation of noise or light in cities. Healthy sleep patterns, therefore, depend to a large amount on regulation and implementation of those social norms. Birthday parties are tolerated, but much less the irregular partying in shared housing with lots of neighbours. Reducing social contacts during Covid-19 led to the changes in sleep patterns as well.
The psychological determinants of sleep go well beyond the world of dreams as theorized by Freud. Nowadays, we investigate all sorts of behavioural patterns that have an impact on sleeping like “bedtime technology use” of smartphones or the ability to switch off thinking of problems. Sleeping is a particular functional state of our mind. A lot of sorting of daily impressions into memory occurs during the different phases while sleeping. Persistent disrupted or impeded sleep is recognized as torture in severe cases. Stress at work or working overtime is also a major cause of sleep disorders.
The biological indicators used to investigate sleep have revealed a lot of links of sleep and the hormones of melatonin as well as cortisol. Testing has become more accessible and provides good indicators of how the biological clocks tick within our bodies.
However, we are only at the beginning of the analysis of more complex interactions of the multiple forms of interaction of the bio->psycho->social (BPS) as well as the social->psycho->bio (SPB) co-determination of sleeping. Scientific research is faced with a steep challenge as the direction of causality is not uniform except in very controlled experimental settings. Maybe the arts have coined and popularized a useful term in this respect. “I am in a New York state of mind”.
(Image: extrait of Magritte. La clairvoyance, 1936 and The cultural context of aging, Jay Sokolovsky)