The Neurophysiology Of Memories

WRITTEN BY RASHA AMEERA MISKIN CLASS OF 2028

This article includes concepts of memories, how brain is able to preserve and recover information and past experiences, how memories are formed, stored and recalled, and what this means for understanding conditions like Alzheimer's disease and Dementia.

INTRODUCTION

What are memories?

Memories form an important aspect of human life. It plays a huge role in our day-to-day activities, including learning, development and survival. If we do not have memories of the past, carrying out daily activities in the present and future would be a very difficult task. Not only does memories recall certain incidents and people, it also links various other emotions that were attached to it in the past. Memories and emotions are strongly bound together, and positive memories produce a sense of joy and happiness. Scientifically, ‘memory” refers to the psychological process of acquiring, storing, retaining, and later retrieving information. Human memory is the power of the brain, which involves the ability to both preserve and recover information and past experiences.

THE DIFFERENT TYPES OF MEMORIES

Think about this? Why s it that we can remember the birthdays of our loved ones, but don’t remember all the ingredients of a bag of chips we read some time back? This is because different types of memories are stored by the human brain for different spans of time.

Memory can be classified into 3 separate types:

·         Short term memory

·         Long term memory and

·         Sensory memory.

Short term memory: Involves the information that we are currently thinking about, and it generally lasts for about 20 to 30 seconds. and most of these memories are forgotten after this time period.

Long-term memory. refers to the type of memory that is constantly stored in the brain. For example, the birthdays of our dear ones, and the road to our house. Long term memory is also called unconscious memory because memory can be retieved at any tme when required.

Sensory memoty: stores the information gathered by the human senses. Seeing a STOP sign while driving or hearing a bell ring at school are both instances of sensory memory. They typically last only for less than a few seconds.

 THE FORMATION OF MEMORIES IN THE BRAIN

The reason why we cross the road when the traffic light is green and stop when it tums red. is because this memory has been stored in our brains and recalled when needed. So the question arises- how do these memories even form in the first place? When we leam something or gain an understanding of something, we form connections between neurons (brain cells) in the brain. This occurs due to the work of the synapses present in between the neurons. These small gaps between the neurons play an important role in the process of memory formation. When a change in the electrical charge of one neuron occurs, it activates the release of certain chemicals called neurotransmitters across these synapses. These chemicals are then absorbed by the neurons on the other side of the synapse, which then generate an electrical charge in that cell.

This process forms ‘circuits’ in the brain, and this process is repeated whenever a memory is synthesized. Ultimately, the human brain modifies itself with each new memory. When neurons constantly stimulate other neurons, they form stronger interconnections, therefore it becomes easier for them to stimulate each other with time. During the time in which neurons rarely communicate, their connections decrease, and communication between neurons may come to a halt.

 WHERE ARE MEMORIES STORED?

 Memories are stored in different areas of the brain. Explicit/definite memories and facts and information are stored in the hippocampus, neocortex and amygdala. Hippocampi are paired areas of the brain that are necessary for the transfer of memories from short term to long term. On the other hand, the amygdala applies emotions to memories, particularly the emotion of fear. For instance, the reason why a person with a fear of dogs would run away from a dog upon seeing one, is all because of this tiny, almond shaped structure- the amygdala. It triggers a person’s ‘fight or flight response’. Implicit memories such as playing a guitar or riding a bike are stored in the basal ganglia and cerebellum.

HOW ARE MEMORIES RECALLED?

The retrieval of memory refers to our ability to access information and extract it from our stored memory. Have you ever wondered why we are taken back to a past memory upon smelling or tasting something familiar? For instance, eating something delicious, similar to our grandma's cooking? Hasn't that ever reminded you of your grandma? This stimulus such as a smell or taste is called a refrieval cue, and that is what stimulates the recall of a memory. There are 4 types of retrieval that activates memory. ‘Recall’- where memory is retrieved without a cue to stimulate its presence. ‘Recollection’- recalling various pieces of memory and reassembling them into a united sequence of memory. ‘Recognition’-the process of identifying information after repeating it. ‘Relearning’- happens when previously leamed data is releamed at another time.

THE ROLE OF MEMORY IN DEMENTIA AND ALZHEIMER'S DISEASE

Dementia is a neurological disorder that is characterized by the loss of memory, reasoning and other thinking skills. It is caused by damage to neurons that affect their ability to interact with each other. As a result, new memories may not be made and will not be able to be recalled later. People may also take a long time to recall whatever information that they had stored before. Dementia exists in many different forms which are caused by many conditions. As per research, Alzheimer's disease is the most common cause of dementia resulting in 60-80% of dementia cases. Alzheimer’s is a degenerative brain disease that is caused by complex brain changes due to neuron damage. It causes symptoms of dementia that eventually get worse with time, and may deteriorate further, resulting in confusion, disorientation and unusual behavior. As per research, most people with Alzheimer's develop the disease when they are 65 years or older. This suggests that memories have been a part of us in every step of life and that is what gives us our sense of identity and who we are.

CONCLUSION

In conclusion, it has been proven that some of the activities to improve brain functioning and memory are learning a new skill. getting plenty of sleep, meditation and stress management. It is vital for humans to preserve memories, as without memories it would be very difficult to carry out routine activities and live an untroubled life.