Introduction: What is memory and how does it work?
Memory is crucial for our identity and for daily life. It makes us who we are and enables us to function.
So, what is memory, how does it work and what does memory have to do with sea slugs? Memory is the acquisition, storage, retention, and subsequent retrieval of information. Nobel-prize-winning neuroscientist, Eric Kandel, has been studying memory for many decades, and the sea slug is the animal model he uses in his research. We now know a great deal about how memories are formed, both the psychology of memory formation and the neurobiology of making memories.
Involves information input from the 5 senses and awareness of the environment. Registration has subcategories – attention and concentration. Memories can be explicit/declarative (or made consciously, such as memorizing a grocery list), or implicit (learning something, but doing it without much mentation, such as learning how to ride a bike).
There are three types of memory storage: sensory memory, short-term memory (the duration of which is up to one minute), and long-term memory.
Once a memory’s registration and storage have occurred, retrieval can follow.
In the language of neurobiology, memory is the reactivation of a group or assembly of brain cells of brain cells or neurons that were “wired together” when the memory was initially formed. Neurons are connected to each other via long protrusions called axons that nearly touch the neuron they are interacting with. The gap between the first neuron’s axon and the second neuron’s cell body is called a synapse. When a person takes in information from the environment the connections between activated neurons at the synapses are strengthened or new axonal/synaptic connections are formed between neurons (scientists use the phrase “neurons that fire together wire together”). Neurotransmitters such as serotonin and dopamine are chemicals made by the first neuron that cross the synapse and cause changes in the second neuron. The strengthening of the connection between two neurons at a synapse is called long-term potentiation and probably underlies memory. The more you use the connection between the neurons, the stronger that memory becomes. Thus, repetition of a task or of material to be learned enhances memory.
Neuroplasticity is the brain’s ability to strengthen connections between neurons at synapses or form new connections between neurons. It is central to the process of memory formation and learning and is also important for healing the brain after a concussion.
Memories are stored in four different brain regions: the hippocampus, the prefrontal cortex, the amygdala and the cerebellum, which store short-term memories, long-term memories, memories of emotions, and motor memories, respectively.
Short-term memories are formed in the hippocampus, and “consolidated” (turned into long-term memories) in the neocortex. Short-term memory is also known as working memory. When reinforced, the short- term memory is changed into a long-term memory in the cortex. The location in the neocortex where the memory is stored depends upon the nature of the memory. Thus, visual memories are stored in the visual cortex and sound memories in the auditory cortex.
Sleep and Memory Formation
As we sleep, the brain undergoes two types of patterns of electrical activity: slow-wave sleep and rapid eye movement (REM) stage sleep. We experience slow-wave sleep at first, and REM-stage sleep later. During slow-wave sleep, the brain probably sifts through declarative memories (memories of what you have consciously experienced), stores the memories that are important, and discards unimportant memories. On the other hand, during the REM stage of sleep, we might be dealing with emotional memories or procedural memory (implicit memory of skills like riding a bike).
Sleep is very important for memory because the hippocampus talks to the neocortex while we sleep. The hippocampal assembly of neurons that have a trace of memory are reactivated many times when we experience slow-wave sleep, and this helps to consolidate the memory in the neocortex. In other words, while we sleep, memories are “rewound” and “replayed” in the hippocampus and this is a way of consolidating memories.
Sleep is also important for clearing toxins from the brain. In general, getting enough sleep is crucial for being attentive and assimilating new information.
How a Concussion Affects Memory
Memory problems, including problems with working memory (short-term memory), are common after a concussion and vary from person to person. In some cases, memory deficits persist long after a concussion, as a symptom of post-concussion syndrome. Post-concussion memory problems range from not being able to recall events (problems with episodic memory) and digest new information to general forgetfulness. These problems occur since the injury has prevented the brain from encoding information properly. The ability to pay attention, to organize information, to not easily tire during memorization and motivation are all factors that influence memory, and these factors may also have been affected by the brain injury.
How long can memory problems last after a concussion?
Memory problems can last seven to ten days after a concussion, or for months or even years.
What can be done to improve memory after a concussion?
1. Rest your brain in the first week or two after the concussion.
You must rest your mind for the first three days after the concussion to enable the brain to heal. Otherwise, recovery might be delayed. Get lots of sleep and don’t engage in activities that require concentration, like reading or watching TV, until you feel better.
2. Get 7 to 8 hours of sound sleep.
Sleep is extremely important for a healthy brain. The brain consolidates short-term memory into long-term memory, removes toxins and repairs itself while we are asleep.
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3. Eat healthy foods.
Your brain needs nutrients so that it can function effectively. It is extremely important to have an anti-inflammatory diet that allows the brain to heal, eliminating refined sugar, corn syrup, and any grains that can be fermented or distilled. Foods that contain omega-3 fatty acids, including fatty fish, flaxseeds, and walnuts, can improve memory and mental acumen (see point number 14, regarding nootropics). Eat plenty of spinach and other vegetables rich in antioxidants to help improve your memory. Coconut, olive oil, and avocado are good sources of fats that help the brain heal and enhance your storage and retrieval capabilities. Avocados, blueberries, and dark chocolate are also considered to be good for the brain. Drinking water helps the brain, too.
Exercise benefits your overall health and is good for the brain as well. It can increase blood flow to the brain, encourage neurogenesis (growth of new neurons), and help repair damaged tissue. It can also reduce inflammation in the brain and lead to the production of “happiness hormones” or endorphins (natural brain chemicals that enhance mood and reduce stress – they are endogenous opioid neuropeptides that activate the body’s opiate receptors). In addition, exercise leads to the production of endocannabinoids (brain chemicals that also improve mood) and brain-derived neurotrophic factor (or BDNF, which fosters survival and increase in the number of neurons, and is involved in neuroplasticity, and therefore, in learning and memory). It also enhances neuronal fiber integrity. Research has revealed that exercise improves memory and in older people in general and specifically in older people with mild cognitive impairment. It has also been shown to increase the size of the hippocampus and improve memory in healthy older adults. You should get at least thirty minutes of moderate-intensity exercise nearly every day. Engage in low-impact exercises (walking or swimming, for instance).
5. Avoid drinking alcohol or taking drugs.
Alcohol and drugs can have a detrimental effect on memory and cognition. Avoid these two things to improve your memory.
6. Decrease Stress
Stress management is very important, as stress can have a negative effect on memory. Chronic stress is particularly detrimental to memory, as it keeps the level of the stress hormone cortisol high. Healthy ways for stress management include yoga, exercise, stress reducing products, and meditation.
7. Use Memory Aids
You can improve your efficiency by means of memory aids such as calendars, to-do lists and sticky notes.
8. Stimulate your mind and use brain training software with memory exercises
Mental stimulation after the first few weeks, after your initial symptoms have resolved is important. Reading, solving puzzles, playing games and in general engaging in activities that challenge the brain with new and diverse tasks can improve memory. Engage in activities that are not frustrating, as being frustrated can worsen symptoms.
Practice memorization by repeating lists of words or numbers. Or memorize a poem or song. There are a many other exercises for training your brain.
Playing memory games is useful too. There are numerous software programs for improving the ability to recall. They strengthen attention and problem-solving as well. The software programs are based on scientific research and can be effective in improving memory for adults of all ages. These programs can keep your mind sharp but will not make you a genius overnight. Also, note that different people might achieve different results with the software, the benefits they confer vary from individual to individual.
Memory-enhancing software includes:
9. Cognitive Rehabilitation
Cognitive rehabilitation can help you improve memory and cognition. You can do rehab as an individual or as part of a group. Neuroplasticity plays a key role in cognitive rehab. Hypnosis, cognitive therapy and neurofeedback all enhance neuroplasticity. Learn more about Dr. Diane’s holistic and integrative 5-prong approach to helping with mild traumatic brain injury, including concussion.
10. See a speech and language therapist.
A speech and language therapist can assist with word-finding issues and with memory problems in general.
12. Support Groups
Support groups enable you to connect with others who are going through the same experience. They can offer support, encouragement, and motivation.
13. Get treatment for depression, if depressed
Depression is associated with memory problems, so people with depression should seek professional help.
Nootropics such as DHA and EPA (docosahexaenoic acid and eicosapentaenoic acid, omega-3 fatty acids found in fish oil) might help. Some studies with rats have shown DHA to be beneficial in alleviating memory problems after concussion. It is important to consult with your doctor before taking supplements, to ensure safety and efficacy.
15. And more…
Dr. Diane’s 5-prong approach to healing brain trauma addresses the mental, physical, psychological, emotional, spiritual, and energy aspects of a person.
It can take time and effort to heal from a concussion, but there are things you can do to improve your memory and cognitive function, such as exercise, eating the right foods (including intake of foods with omega-3 fatty acids), staying generally healthy, getting enough sleep, stimulating your brain with mental exercises and brain-training software, getting cognitive rehab, and joining a support group. Innumerable resources are available to help you recover from concussion and improve your memory. Dr. Diane can direct you to them. If you have memory problems after a concussion, it is important to discuss it with your doctor. Dr. Diane® has many specialists on her team who can help you to regain memory function.