Description: You may recall from a section in one of your psychology courses that the early part of a night’s sleep is typically referred to as restorative sleep. This involves deep sleep. In the latter half of a night’s sleep we typically engage in more rapid eye movements or REM state sleep. Do you recall any statements being made in that same course section regarding the relationship, if any, between REM state sleep and memory? Research into this question has been mixed. The article linked below however describes a carefully designed study out of McGill University’s Douglas Mental Health University Institute that seems to point fairly strongly towards a role for REM state sleep in memory processing.
Source: Rapid eye movement sleep: Keystone memory formation, Science Daily.
Date: May 13, 2016
Photo Credit: Anton Maltsev / Fotolia
Links: Article Link — https://www.sciencedaily.com/releases/2016/05/160513130241.htm
In their research, the McGill researchers trained mice to identify which of two objects placed in a simple environment was the novel or new one. They did this by exposing the mice to one of the objects day before they were assessed. The next day the mice were provided with a novel object and one that they’d seen the day before. Mice spend more time exploring novel objects than familiar objects. In the critical part of the experiment the researchers used pulses of light to turn off the activity of neurons in the hippocampal area of the brain that were suspected of being involved in processing or consolidating new memories. The researchers used this light mechanism either when the mice were or were not in REM state sleep. Basically they found that the mice had these memory – associated neurons shut down during REM state sleep seemed not to be able to recognize objects that they’d seen the previous day when given an opportunity to choose between the familiar previewed object and a novel object. The researchers suggest that they’ve identified neuronal activity that is a specific requirement of memory consolidation which must occur during REM state sleep. This finding supports other findings indicating that dream state or REM state sleep may have an important role to play in memory consolidation and learning, or other in the processing of new information into memory.
Questions for Discussion:
- How did the researchers set about to create long-term memories in mice that they could try and manipulate?
- How did the researchers test their hypothesis that the effects of memory consolidation only occur during REM state sleep in mice?
- What are some of the possible applications and implications of this finding if it should turn out to be generalizable to human beings and more specifically to university students preparing for midterms and finals?
References (Read Further):
- Boyce, S. D. Glasgow, S. Williams, A. Adamantidis. Causal evidence for the role of REM sleep theta rhythm in contextual memory consolidation. Science, 2016; 352 (6287): 812 DOI: 10.1126/science.aad5252
Genzel, L., Spoormaker, V. I., Konrad, B. N., & Dresler, M. (2015). The role of rapid eye movement sleep for amygdala-related memory processing. Neurobiology of learning and memory, 122, 110-121.
Ravassard, P., Hamieh, A. M., Joseph, M. A., Fraize, N., Libourel, P. A., Lebarillier, L., … & Salin, P. A. (2015). REM sleep-dependent bidirectional regulation of hippocampal-based emotional memory and LTP. Cerebral Cortex, bhu310. https://cercor.oxfordjournals.org/content/early/2015/01/13/cercor.bhu310.full