A new doctoral thesis from Karolinska Institutet has taken a neuroimaging approach to sleep loss and revealed that sleep deprivation leads us to interpret things negatively.
MRI and PET techniques
Research lead Sandra Tamm and her colleagues used MRI and PET techniques to examine the emotional functions of contagion, empathy, and regulation in a total of 117 participants. The first is our natural tendency to mimic other people’s emotion, the second how we react to other people’s pain and the third how well we control our reactions to emotional images.
The research revealed that sleeplessness not only led to fatigue and an inability to concentrate but also led to negative interpretations and an increased likelihood of losing one's temper. Researchers call this increased negativity a negativity bias.
One good outcome from the study was the revelation that the ability to empathize remained relatively unaffected. So while the rest of your emotional functions may be hindered, at least it's good to know you can still care about your loved ones.
Contributing to psychiatric conditions
“Ultimately, the results can help us understand how chronic sleep problems, sleepiness and tiredness contribute to psychiatric conditions, such as by increasing the risk of depression,” said Sandra who recently defended her doctoral thesis at the Department of Clinical Neuroscience.
This is an important key as sleep has been known for a long time to play a role in depression, anxiety, and other psychological conditions. Understanding this relationship may be crucial to avoiding worsening such conditions.
Unfortunately, the research did not prove beneficial in one area. “Regrettably, we were unable to trace the underlying change mechanisms behind sleep deprivation-induced negativity bias by showing differences in the brain’s emotional system as measured by functional MRI,” said Tamm.
The researchers did, however, look at the rather unusual role allergies may play in sleep deprivation. They found that the participants with a pollen allergy had disrupted sleep both during and outside the pollen season.