Memory

An Overview Memory refers to the processes that are

used to acquire, store, retain and later retrieve information.

There are three major processes involved in memory: encoding, storage and retrieval.

“Without encoding, the brain has nothing to process for storage. Without storage, the brain would always live in the present. Without retrieval, memories stored in the brain would remain there to no practical purpose.” (Sweeney, 2008, pp239)

There are three stages of memory: sensory memory, short-term (working) memory and long-term memory.

Cherry, 2010; Sweeney, 2009.

Three Stages of Memory

Stage 1: Sensory Storethis is the earliest stage of memory. During this stage,

sensory information from the environment is stored for a very brief period of time, generally for no longer than a half-second for visual information and 3 or 4 seconds for auditory information. We attend to only certain aspects of this sensory memory, allowing some of this information to pass into the next stage - short-term memory.

Einstein, 2004

Three Stages of Memory (cont.)Stage 2: Short-term memory

also known as active memory or the “conscious mind”, this is the information we are currently aware of or thinking about. Paying attention to sensory memories generates the information in short-term memory. Most of the information stored in active memory will be stored for approximately 20 to 30 seconds. While many of our short-term memories are quickly forgotten, attending to this information allows it to continue on the next stage - long-term memory.

Einstein, 2004

Three Stages of Memory (cont.)Stage 3: Long-term memory

refers to the continuing storage of information. This information is largely outside of our awareness, but can be called into working memory to be used when needed. Long term memory is divided into expicit or implicit types which are then divided into more specific memory forms.

Einstein, 2004

Memory Classification

Eichenbaum, 2002; Universe-review.ca

• The concept of explicit and implicit memory refers to whether or not the recollection is produced consciously and intentionally.

• There are many ways to classify memory.

• While the scheme of declarative and non declarative memory depend on the retrieval that can be declared verbally or not.

• Associative memory is triggered by clues; non associative memory can be habitual or sensitive.

Functions in the Brain

Memory is created by association between a group of neurons such that when one fires, they all fire, producing a specific pattern.

Thought, sensory perceptions, ideas, and hallucinations - any brain function is made up of this same thing. For example, a group of neighbouring neurons firing together in the auditory cortex would bring about the experience of a certain note of music.

A memory is a pattern like these. The only difference is that it remains encoded in the brain after the stimulation that originally gave rise to it has ceased.

Universe-review.ca

Functions in the Brain (cont.)

Memories form when a pattern is repeated frequently, or in circumstances that encourage it to be encoded. This is because each time a group of neurons fires together the tendency to do so again is increased.

Once the neighbour has been triggered to fire a chemical change takes place on its surface which leaves it more sensitive to stimulation from that same neighbour. This process is called long-term potentiation (LTP). If the neighbour cell is not stimulated again it will stay in this state of readiness for hours, maybe days.

Universe-review.ca

Functions in the Brain (cont.)

If the first cell fires again during this period, the neighbour may respond even if the firing rate of cell number one relatively slow. A second firing makes it even more receptive and so on.

Eventually, repeated synchronous firing binds neurons together so that the slightest activity in one will trigger all those that have become associated with it to fire, too. A memory has been formed.

Universe-review.ca

Why do we forget?

The major reasons why are:Retrieval failure

○ why retrieval fails is known as decay theory. Decay theory suggests that over time, these memory traces begin to fade and disappear. If information is not retrieved and rehearsed, it will eventually be lost.

Interference○ suggests that some memories compete and interfere with other

memories. When information is very similar to other information that was previously stored in memory, interference is more likely to occur.

Failure to store○ information failed to store because it never actually made it into long-term

memory. Encoding failures sometimes prevent information from entering long-term memory.

Motivated forgetting○ Sometimes, we actively work to forget memories, especially those of

traumatic or disturbing events or experiences. The two basic forms of motivated forgetting are: suppression, a conscious form of forgetting, and repression, an unconscious form of forgetting.

Cherry, 2010

How does Aging Affect Memory?

As we age, the brain loses cells that are essential in the encoding and retrieval processes of memory. Overall brain weight decreases, and among the cells lost are those that produce neurotransmitters, including acetylcholine, causing the connections between the synapses to weaken.

The hippocampus loses 5%of its neurons every decade, with 20-30% being lost by the age of 80.

Aging also causes changes in white matter, the part of the brain that contains the nerve cell fibers involved in relaying information.

In addition, continued mental stimulation is vital; reading, drawing, and doing puzzles can stimulate the growth of dendrites that maintain strong connections between neurons.

Giovanello, 2010; Yurkiewicz, 2008

Ways to Improve Memory

Stay mentally active Just as physical activity helps keep your body in shape, mentally stimulating

activities help keep your brain in shape – the brain is just like a muscle so “use it or lose it”. Some suggestions are - do crossword puzzles, read the newspaper, learn to play a musical instrument.

Socialize regularly Social interaction helps ward off depression and stress, both of which can

contribute to memory loss. Look for opportunities to get together with loved ones, friends and others

Be organized Jot down tasks, appointments and other events. It might even help to repeat

each entry out loud as you jot it down to help cement it in your memory. Set aside a certain place for your wallet, keys and other essentials.

Focus Limit distractions, and don't try to do too many things at once. If you focus

on the information that you're trying to remember, you'll be more likely to recall it later. It might also help to connect what you're trying to remember to a favorite song or another familiar concept.

Einstein, 2004; Kenneth, 2010

Ways to Improve Memory (cont.) Eat a healthy diet

Eat breakfast! Some types of foods that enhance memory includes: Omega 3 fatty acids, (flaxseed, walnuts, cold-water fish, tuna) antioxidants (blueberries, sweet potatoes, red tomatoes, nuts and seeds, green tea), vitamins in particular vitamin B (dark leafy greens, asparagus, broccoli, citrus fruits, straberries and soy beans).

Exercise regulary Physical activity increases blood flow to your whole body,

including the brain, which helps keep your memory sharp. For most healthy adults, at least 150 minutes a week of moderate aerobic activity or 75 minutes a week of vigorous aerobic activity, preferably spread throughout the week, is reccommended.

Manage chronic conditions Follow the doctor's treatment recommendations for any

chronic conditions, such as diabetes, high blood pressure and depression. The better you take care of yourself, the better your memory is likely to be

Einstein, 2004; Kenneth, 2010

Annotated Bibliography Unknown, Nervous System: A Review of the Universe, http://universe-

review.ca/R10-16-ANS.htm; this article was extremely interesting as it gave very informative details of the different parts of the Nervous System and including an overview and functions of memory in the brain.

Cherry, K, “Overview of Memory”, http://psychology.about.com/, July 2010, Web, 10 August 2011; this website covered a great introduction to memory including the processes, types, and stages of memory.

Eichenbaum, Howard, The Cognitive Neuroscience of Memory, Oxford University Press, 2002; from this text, I was able to retrieve information about the memory systems as well as specific details about the typesa dn classifications of memories.

Einstein, Gilles O, Memory Fitness: A Guide for Successful Aging, Yale University Press, 2004; this book was extremely useful when reading about the techniques to improve memory and information related to aid and enhance memory.

Annotated Bibliography Giovanello, Kelly.S., “Age related Neural Changes During Memory

Conjunction Errors”, Journal of Cognitive Neuroscience, 22.7,p1348-1361, July 1, 2010, Ebsco.Web; This was a great article that portrayed the specific affects of memory with age.

Kenneth, Berge, “Memory Loss: Tips to Improve”, http://www.mayoclinic.com/health/memory-loss/HA00001, April 30 2010, Web, August 12 2011; this article encompassed some ways to improve one’s level of memory through a various number of techniques.

Sweeney, Michael S, Brain: The Complete Mind. Washington D.C, National Geographic Society, 2009, pg. 239; this small section from the text was used to enhance the understanding of the major processes of memory.

Yurkiewicz, Ilana, “How Aging Affect Memory”, http://ysm.research.yale.edu/article.jsp?articleID=676, February 2009; this was a very interesting article which gave a brief insight of the effects to the brain as you age.