The study I analyzed presented an investigation of sleep’s ability to consolidate memory for long-term storage. Several theories of what contributes to the assimilation and structuring of memories during sleep are discussed in the scientific community. There is a theory that certain stimuli received during wakefulness and repeated during sleep can help refresh memories. This hypothesis is promising, as sleep’s memory consolidation abilities are entirely unexplored and of great scientific interest. The study’s primary goal presented in the article was to investigate the consolidation of hippocampus-dependent memories during sleep through stimulation by smell. The smell was chosen because it was not necessary to interrupt the integrity of the subjects’ sleep to introduce it into the experiment.
The preliminary study was conducted on volunteers who were asked to remember the order of things in a two-dimensional task. This task was chosen because it involved hippocampal function. The participants were exposed to the smell of a rose at varying intervals. Then the subjects slept, during which they were also introduced to the scent of a rose. The morning after they slept, they were asked to take a test to see how well they remembered the order of the objects. The study also included a control group that was not stimulated by the scent while memorizing the location of the objects. As a result, those participants for whom smell was used remembered 97.2 ± 4.1% of the information, while the control group remembered only 85.8 ± 3.8% (Rasch et al., 2007). The researchers concluded that once an odor became associated with the context of memorized object locations, repeated exposure to an odor during sleep reactivated new memories and thereby accelerated their consolidation.
Indeed, exposure of the hippocampus to an odor helps to refresh memory and better assimilate necessary images. However, it has also been concluded that such a procedure is ineffective when it affects other parts of the brain or when it is only performed in the waking state. This statement narrows the results base but also makes it more delineated. I think this study is very revealing and essential for the development of modern somnology. People have been struggling to expand memory capabilities for many decades (Cleary & Schwartz, 2020). Therefore, I would like to suggest several experiments that could open up new frontiers for research. For example, one could test stimuli that disrupt sleep – sound, and light – and compare their results. It may turn out that the consolidation of memories occurs only during uninterrupted sleep. This could significantly change the idea of memory consolidation during sleep and expand the boundaries for research.
In addition, one could investigate the reactivation of memories obtained several days before the experiment rather than a day before. With this, it will be possible to see if the information obtained less recently could be fitted into long-term memory. Less recent information tends to be stored in short-term memory and forgotten (Cleary & Schwartz, 2020). The experiment I am proposing will test whether these memories can be recovered. The technique of recovering older memories is undiscovered in modern science, and such a study could give it a fresh impetus. In this way, it will be possible to narrow the evidence base even more and derive a clear theory about memory consolidation in dreams under different conditions.
References
Cleary, A. M., & Schwartz, B. L. (Eds.). (2020). Memory quirks: The study of odd phenomena in memory. Routledge. Web.
Rasch, B., Buchel, C., Gais, S., & Born, J. (2007). Odor cues during slow-wave sleep prompt declarative memory consolidation. Science, 315(1), 1426-1429.