To miss a few night’s sleep seems like no big deal, but to have a long pattern of sleep deprivation in your life can be very serious business. The long term effects of sleep deprivation on the brain are just beginning to be understood. As science begins to learn more about how the brain works, it is becoming apparent that your sleep patterns are the key to maintaining healthy brain function.
How long do you have to be sleep deprived before there are problems?
Most people think of sleep deprivation as being a solid block of time in which you get no sleep or little sleep. While that is one extreme example of what is considered sleep deprivation, it occurs in many other instances as well. You are considered to be sleep deprived if you –
- Cannot fall asleep easily
- Cannot stay asleep
- Have difficulty waking up
- Spend too much time in REM, or not enough
- Fail to move sequentially through the brainwave stages
Sleep deprivation isn’t about how many days you go without sleep, but how consistently inadequate your sleep patterns are to what your brain and body needs.
Diminished Temporal Lobe Functioning
The temporal lobe is affected by sleep deprivation immediately. This is why when you do not get a good night’s sleep you feel easily confused, groggy and detached from your surroundings. The temporal lobe is the area of the brain that controls how we process language, memories and experiences. It takes in stimulus and places it within the context framework we have learned to form our understanding of the world. This is a highly complex process that is dependent on the appropriate behavior of brain chemicals and neuron states. These are two of the things that require sleep to restore and rebalance within the brain, without sleep there is a deficient amount held in the brain and the temporal lobe will begin to malfunction, or it can even shut down.
The main issue with sleep deprivation that effects the entire brain is that science knows that moving through the appropriate sleep stages so the brain experiences different patterns of brain waves is necessary to regenerate the neurons in the brain. The neurons are the core tool that the brain uses to send and receive impulses that then carry direction and orders to the body. Without regenerated neurons, different parts of the brain begin to lose their ability to function well – if at all. The major part of the brain that is affected by sleep deprivation, the temporal lobe, is often covered by the increase of activity of the parietal lobe and cerebral cortex as they try to replace what is now missing.
Increased activity in the Parietal Lobe and Cerebral Cortex
The good news is that one of the long term effects of sleep deprivation on the brain includes an increase in activity in the parietal lobe and cerebral cortex; the bad news is that this is called an adaptive activity and is not the activity that these areas of the brain are meant to do. In studies that compared rested and sleep deprived subjects reactions to manual tasks, the rested subjects primarily used their temporal lobes to process information, stimulus and to form appropriate physical responses.
In the sleep deprived subjects the activity in the temporal lobe was greatly diminished, but the parietal lobe and cerebral cortex increased their activity to try and replace the functioning of the temporal lobe. This is great news for anyone who has suffered trauma to their temporal lobe as it allows them to “rewire” their brain to take over learned physical actions and reflexes; however it does not allow them to learn to do these things as well or as fast as they could with the temporal lobe. This is why sleep deprived persons have much slower reflexes than their rested partners. It is also why there are so many cautions against operating machinery when you are experiencing sleep deprivation.
Prefrontal Lobe Impairment and the I-function
One of the most important of the long term effects of sleep deprivation on the brain is the way that it impairs the activity of the prefrontal lobe, which has then been shown to disrupt how the I-function of the brain works. The prefrontal lobe and the I-function, to put it simply, are how the brain works together to process information, compare it to experience and to form judgment. The I-function is active during dreams and hallucinations, but it is also active in your day to day life. Scientists believe that it is the I-function that allows us to creatively imagine cause and effect in order to make decisions that we base our judgments on.
When your brain is sleep deprived the activity in both of these areas becomes erratic and over stimulated. The I-function becomes more prominent during waking hours which can lead to an increase in anxiety, paranoia and hallucinations. The prefrontal lobe shows a more consistent level of activity, but not as much activity in response to stimulus as it would in a rested brain. This has led to an assumption that is currently being studied that the prefrontal lobe recovers and repairs itself during the first stages of sleep. If the first stages of sleep are missed or interrupted, the chemical process the lobe uses to manage and regulate the I-function is disrupted too.
Sleep deprivation and Alzheimer’s
There is more work being done to examine the potential link between long term effects of sleep deprivation on the brain and the development of Alzheimer’s and other dementias. Initially, it was thought that dementia and Alzheimer’s raised the risk for sleep deprivation but new studies are looking at the sleep habits of subjects before they developed any type of dementia to see if there is a connection. It is not known whether the changes to the brain caused by long term sleep deprivation are a part of the cause of Alzheimer’s, or if they make a person less resistant to Alzheimer’s and allow for a faster onset of the disease and its advanced symptoms.