The main purpose of this study is to investigate the effects of partial sleep deprivation (PSD) on resting state brain connectivity, emotional contagion, empathy, and emotional regulation.

Inclusion Criteria:

• 20-30 years of age, inclusive OR 65-75 years of age, inclusive

• Able to understand spoken and written Swedish (in order to understand instructions)

• Normal or corrected-to-normal vision not using glasses

• Not colour blind

• Right-handed

• Free from ferromagnetic objects in body

• No history of any neurologic or psychiatric illness including drug abuse

• No history of diabetes nor hypertension

  • No depression according to ratings using the Hospital Anxiety and Depression scale (HAD)
  • No insomnia according to ratings using the Insomnia Severity Index (ISI) and Karolinska Sleep Questionnaire (KSQ)

• No use of psychotropic drugs

• Not studying or working in medicine, psychology, nor behavioural science

• Not suffering from severe seasonal allergy

• No use of cortisone, anti-histamines, nor any other immune-modulating drugs

• Habitual intake of no more than 4 cups of coffee per day or the equivalent in terms of caffeine

• No daily use of nicotine

Exclusion Criteria:

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De-identified individual participant data will be shared through the openfmri.org data repository.