Abstract
Abstract
Dreams experienced during rapid eye movement (REM) sleep have emotional features. Intervention methods for dream affectivity have recently garnered interest, and we have demonstrated that negative dreams were induced during REM sleep through exposure to a favorable or familiar odors. Nevertheless, the underlying mechanisms behind this phenomenon remain unclear. To address this gap, we investigated whether more intense odors could induce negative dreams, as odors tend to be perceived as more intense when they are preferred or familiar. Contrary to our hypothesis, the results of our study indicate that subjective intense odors did not induce negative dreams. We initially expected stronger odors to have a greater impact on dream emotionality, as they stimulate the brain more intensely. Notably, during arousal, weak odors tend to evoke a more potent olfactory response, while strong odors tend to produce a weaker response. To investigate whether this difference influenced the effects on dreams, we compared the respiratory activities of the strongly and weakly perceived odor groups but found no significant differences. Our findings suggest that subjectively perceived strong odors are unlikely to affect dream emotionality and may be processed differently than favorable or familiar odors.
Publisher
Research Square Platform LLC
Reference51 articles.
1. Hobson, J. A., Pace-Schott, E. F. & Stickgold, R. Dreaming and the brain: toward a cognitive neuroscience of conscious states. Behav. Brain Sci. 23, 793–842; discussion 904–1121 (2000).
2. Dreaming and the brain: from phenomenology to neurophysiology;Nir Y;Trends Cogn. Sci.,2010
3. Impact of frequency of nightmares comorbid with insomnia on depression in Japanese rural community residents: a cross-sectional study;Nakajima S;Sleep Med.,2014
4. Nightmares, suicide attempts, and melancholic features in patients with unipolar major depression;Agargun MY;J. Affect. Disord.,2007
5. Persistent nightmares are associated with repeat suicide attempt;Sjöström N;Psychiatry Res.,2009