Sleep, Memory, and Olfactory Cues

Memory is essential for everyday performance and for the advancement of knowledge. An individual normally learns and consolidates memories during sleep, however certain neurodegenerative diseases or altered biological states can vary the efficacy of memory consolidation. Individuals are constantly looking for “the newest memory enhancement drug” that will magically boost their recall of whatever was/is being learned. Through the years, there have been developments in pharmacology which produce medications that increase attention and focus, but do not directly impact the memory retrieval and consolidation pathway. Moreover, these medications are prescribed to individuals with deficits or impairments resulting from injury. The common user looks for something that is more readily accessible.

A study conducted by Jemma McCready and Dr. Mark Moss from the University of North Umbria focused on their previous research focusing on the herb rosemary. In this study, published by the British Psychological Society, rosemary essential oil was diffused into a testing room while another room remained without an olfactory stimulus. Sixty-six participants were randomly assigned a room, scented or not scented, where they would perform a test designed to evaluate prospective memory functions. The participants’ blood was analyzed. The participants in the rosemary filled room contained a higher concentration of (1,8-cineole), a compound present in the rosemary essential oil. This compound has previously been shown to influence the biochemical memory storage system. The study concluded that the rosemary scented room had a higher performance rate than the scentless room on prospective memory tests, therefore associating rosemary scent with enhanced cognitive function.

On December 10^th, Eitan Schechtman-Drayman held a seminar at Loyola University Chicago regarding a clinical review, “State of the art on targeted memory reactivation: Sleep your way to enhanced cognition”, where Drayman elaborated on the benefits of cues during sleep that would enhance memory consolidation during sleep. One of the subtopics noted within the review focuses on the delivery of an olfactory cue during learning and during sleep, where those exposed to the cue performed better in declarative memory upon retrieval in comparison to those exposed to a vehicle.

The seminar held by Drayman ties to the research conducted by McCready and Moss by linking olfactory stimuli and enhanced cognitive recollection/function. Both articles review the benefits of olfactory stimuli, however one focuses on its effect on memory consolidation during sleep and the other on waking performance. Nevertheless, it is important to note that the combination of a rosemary stimulus during learning, as well exposure during sleep, could increase the already-seen memory consolidation and cognitive benefits of both the stimulus and the method of exposure – which holds potential as a possible future direction. Further research is needed to have a clear definition and mechanism towards memory retrieval and consolidation. However, preliminary research demonstrates potential towards a non-pharmacological method of increased memory and cognitive performance.

Works Cited

British Psychological Society (BPS). "Rosemary aroma may help you remember to do things." ScienceDaily. ScienceDaily, 9 April 2013. <www.sciencedaily.com/releases/2013/04/130409091104.htm>.

Schouten, Daphne I., et al. “State of the Art on Targeted Memory Reactivation: Sleep Your Way to Enhanced Cognition.” Sleep Medicine Reviews, vol. 32, 2017, pp. 123–131., doi:10.1016/j.smrv.2016.04.002.