This could be the strangest advice you have heard lately. However, it is true and is backed by science. After a stressful day or after a long learning session, you may feel like you simply cannot learn one thing more. But the next day, when you are well rested, you resume learning new things. Research suggests that there is an important connection between sleep and improved memory, both before and after a learning session. It is suggested that your body strengthens learning and memory pathways in your brain, making it easier for you to learn new things.
The process of learning and forming memory consists of three functions: acquisition, consolidations, and recall.
The introduction of new information into the brain is considered acquisition, whereas consolidation refers to the processes by which a memory becomes stable. This stage is further divided into two specific processes, synaptic consolidation and system consolidation.
Synaptic consolidation occurring within the first few hours of learning takes only minutes or a few hours to assimilate new information into memory. Whereas system consolidation is a slow, dynamic process which can take years to be fully formed in the human brain. Memories from the hippocampal region, where memories are first encoded, are moved to the neo-cortex in a more permanent form of storage. Lastly, recall is the process of accessing information after it has been stored.
For proper memory function, all three steps are important. Scientists suggest that memory consolidation takes place during sleep in which strengthening of the neural connections that form our memories takes place, whereas acquisition and recall occur when the person is awake.
Now the question arises, how does the brain consolidate memory during sleep?
To answer this, let’s see what happens inside the human brain during sleep. In the consolidation stage, the reorganization and pruning of synapses happens.
The central nervous system consists of a network of approximately 1011 (one hundred billion) neurons. Each neuron has, on average, 7,000 synaptic connections to other neurons. A neuron processes and transmits information through synapses using electrical and chemical signals. Although the function of neurons is more important, still the cells in the central nervous system mostly consists of glia. Glia are non-neuronal cells that provide support and protection for neurons in the central nervous system. Four main types of glia exist: astrocytes, oligodendrocytes, ependymal cells, and microglia. Microglia are the key cells responsible for brain maintenance. To prune away the damaged or unwanted neurons and synapses, they are constantly scanning the central nervous system.
Here's the best part: You can actually control what your brain decides to delete while you sleep!
The things you spend most of your time thinking about are stored and strengthened during sleep, while the synaptic connections that get used less are marked. Microglial cells then detect that mark and deletes them. For example, when you run out of storage in your laptop’s hard drive what will you do? You probably just delete files you don't use anymore.
Similarly, during the synaptic pruning process, the brain sheds old, weak connections to makes room for new ones. This process of pruning is important for learning. This is how the human brain makes the physical space for new and stronger connections.
At times, you must have woken up from a good night’s sleep with a good feeling and the verve to think clearly and do things quickly. This happens because all the pruning that took place while you were sleeping has left you with lots of space in your brain to take in new information.
Hence, sleep matters. Next time you are feeling sleepy, don’t force yourself to work longer hours. Instead, take advantage of your brain's pruning process. Think how much more you can achieve when you are well rested. Think about the things that are important to you. Think about the new things you can learn after some restful sleep.
It’s time to reclaim your sleep and improve your learning!
Do you have tips to share on how to make learning easier? We are all ears.