A recent study shows that medical students who had negative dreams about an exam the night before did better than those students who didn't. The results offer support for the Threat Simulation Theory, which suggests we dream as a way to prepare for real-life threats.

This is a very neat study with four primary take-aways:

  • Most medical students dream about an exam before the exam — like, upwards of 60%!
  • Students primarily dream of failure, being late, and being unable to answer the questions
  • Surprisingly, dreaming of an exam predicts higher performance on the exam
  • The dramatization of concerns during dreams may train the brain as per Threat Simulation Theory

The study, which now appears in Consciousness and Cognition, was led by Isabelle Arnulf from Paris-Sorbonne University. The abstract provides a very tidy summary of the results:

We tested whether dreams can anticipate a stressful exam and how failure/success in dreams affect next-day performance. We collected information on students' dreams during the night preceding the medical school entrance exam. Demographic, academic, sleep and dream characteristics were compared to the students' grades on the exam. Of the 719 respondents to the questionnaire (of 2324 total students), 60.4% dreamt of the exam during the night preceding it. Problems with the exam appeared in 78% of dreams and primarily involved being late and forgetting answers. Reporting a dream about the exam on the pre-exam night was associated with better performance on the exam (p = .01). The frequency of dreams concerning the exam during the first term predicted proportionally higher performance on the exam (R = 0.1, p = .01). These results suggest that the negative anticipation of a stressful event in dreams is common and that this episodic simulation provides a cognitive gain.

There is another possibility. Perhaps people who dream about pending exams are more emotionally vested in the result and/or are more serious about studying for it. This could very well explain why they're having dreams about it, and why they fare better than those students who don't dream about it. So the dreams themselves may not be factoring into the result.

For more on these findings, check out BPS Research Digest.

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