Sleep and its role in Memory

We can’t deny the fact that sleep is a vital component to our normal daily functioning and lack of proper sleep can affect our memory and overall well-being. Several studies have linked a lack of sufficient sleep to dementia and other disorders.

The quantity and quality of sleep that you receive can affect your ability to remember and also consolidate memories.

Lack of sleep can affect your mood, judgment, motivation, and perception of various events. The ability to form memory is critical to the strategic adaptation of human beings and other organisms to the changing environmental needs.

Scientists have conducted various studies that show sleep benefits memory in a wide range of ways. In this article, we discuss the relationship between sleep and memory and how sleep memory health can affect your overall well-being.

Stages of Sleep

Sleep comes into two main stages; the early slow-wave sleep (SWS) commonly referred to as “deep” or non-rapid eye movement sleep (NREM) and the rapid eye movement (REM) sleep.

SWS come during the early stages of sleep while the REM comes during the latter stages of sleep. According to Medical News Today, scientists have also identified four other stages in which sleep occurs. Different brain activities characterize each one of these stages:

Stage one NREM is the first stage of sleep that involves the transition from the state of alertness and wakefulness to the state of sleep. During this time the brain activity tends to slow down and your body transitions into a stage of light sleep that you can quickly come out of if you are disturbed.

Stage two NREM is still a stage of light sleep, but it is slightly deeper than stage one NREM. This stage is still transitional, but this time, you are transitioning from light sleep into a deep sleep. Stage two NREM is characterized by short bursts of electrical activity commonly referred to as sleep spindles.

Stage three NREM is a state of deep sleep in which your brain activity slows down even further. During this stage, your muscles relax fully and your heartbeat and breathing slow down. The moment you enter into this stage, you can be sure that you will be feeling refreshed when you wake up.

Stage four or REM is the final stage of sleep during which dreaming occurs. During REM your brain patterns are quite mixed with the electrical brain waves peaking and slowing down often.

Memory Processes

According to an article published in the American Physiological Society Journal, the memory function comprises of three key sub-processes namely; encoding, consolidation, and retrieval.

1. Encoding or acquisition refers to the process of introducing new information to the brain.
2. Consolidation is the process by which the information becomes stable.
3. Retrieval or recall refers to the ability to access the information whenever you need it.

We can access information consciously or unconsciously once it is stored in your brain.

Memory and Sleep

Memory acquisition and retrieval mostly take place while you are awake, research conducted at Harvard University suggests that memory consolidation usually occurs when someone is asleep.

You can think of consolidation as the process of moving the information acquired from the short-term “buffer-like” memory to the long-term memory that will store it permanently. Memories appear to form in all the four stages of sleep discussed above.

However, some scientists suggest that the kind of memory formation that takes place in stage one and stage two NREM is quite different from the type of memory formation that occurs in REM.

Scientists are also trying to uncover how the memory selects what to remember and what can be retrieved at any given time. Some of them suggest that the neocortex and hippocampus use various methods to store memories.

For instance, the neocortex is used to store different overlapping representations that are useful for understanding patterns while the hippocampus stores unique representations that are useful for episodic memory. – Episodic? Think times, places, people and associated memories.