MEMORY FORMATION

Dot Point #1- Consolidation Theory– Amnesia resulting from brain trauma and neurodegenerative diseases including dementia and Alzheimer’s disease - Memory decline over the lifespan

Consolidation TheoryConsolidation is when memories become solid (fixed and firm). In order for new information to be transferred effectively from Short Term Memory (STM) to Long Term Memory (LTM), physical changes need to occur to the neurons in the brain when something new is being learned & immediately following learning. As such, there needs to be a finite time period in which these memories are able to fortify or stabilise without being disrupted.

Consolidation Theoryhttp://www.youtube.com/watch?v=bwYzvKUbfJM It is thought that a period of approximately 30 minutes on

average is needed for consolidation and information can be altered or lost during this period when interference or interruptions occur. In other words, the memory will never form. However, after this period, neurological changes have occurred and the information stored in LTM is considered to be relatively permanent.

Consolidation theory explains why people may not recall recent events following a head injury, or after electroconvulsive ‘shock’ therapy (ECT). The lost information had not yet been consolidated. Think of the process like setting concrete, initially it is fluid and can be disturbed easily, but once it sets it is rock hard and relatively permanent.

LA 6.29 Page 342 Qs 2,3,4 (exam style question)

Amnesia resulting from brain trauma

Amnesia is loss of memory, either partial or complete, temporary or permanent.

brain trauma (any type of brain damage) neurodegenerative disease (characterised

by a progressive decline in the structure, activity and function of brain tissue).

AMNESIAAmnesia caused by an inflicted brain injury:

Caused by brain damage due to an intentional blow to the head or by violent shaking of the head sufficient to rupture veins or cause some other kind of injury.

http://www.youtube.com/watch?v=KQ7_q5NgIgg

Amnesia caused by an acquired brain injury:

Caused by brain damage at some time after birth due to an accident, a stroke, brain infection, long-term alcoholism, drug abuse, brain surgery, or by a neurodegenerative disease of the brain such as Alzheimer’s disease.

Anterograde vs Retrograde Amnesia

http://www.youtube.com/watch?v=Omphbdtaw3s

ANTEROGRADE: Old memories remain ; New memories after brain damage cannot be formed

RETROGRADE: Old memories that occurred before the brain damage are lost ; New memories can be formed

Types of AmnesiaAnterograde amnesia: loss of memory only for information or events occurring after the trauma causing amnesia.  Memory of experiences and events from before the brain damage remain intact and can still be remembered. E.g. People with anterograde amnesia can tell you things about their childhood before the brain damage was sustained, but they have difficulty in remembering what has happened since the brain damage; they might find it hard to remember the names of people they meet, regardless of how frequently they see them. Anterograde amnesia is one of the symptoms experienced by people who have Alzheimer’s   disease or Korsakoff’s syndrome.

Retrograde amnesia: loss of memory only for information or events occurring before the trauma causing amnesia. However, retrograde amnesias are usually of a temporary nature; and are often caused by a stroke, brain tumour or a blow to the head, such as one received in a boxing match.  Retrograde amnesia is also experienced by people who have been treated with electroconvulsive therapy (ECT) for severe depression  When this amnesia is caused by head injury, such as trauma or stroke, some memories might eventually return, with the older memories generally returning first  It is unlikely however, that memories just prior to the brain damage would be recovered, as these memories would have not had enough time to consolidate or set in to the memory

Learning Activity 6.31

LA 6.31 Questions: 1-6 Next Lesson: Read the following Pages-Dementia and Alzeimer’s Disease (347-350)-Memory Decline over the lifespan (351-354)

Dementia and Alzheimer’s Disease Alzheimer’s Disease:

http://www.youtube.com/watch?v=7-P9lbTJ9Hw

Dementia is a general term used for a variety of symptoms of a large group of illnesses or neurodegenerative diseases that cause a progressive decline in mental functioning,

Alzheimer’s DiseaseAlzheimer’s disease is

a neurodegenerative disease characterised by the gradual widespread degeneration of brain neurons, causing memory loss, a decline in cognitive and social skills, and personality changes.

Symptoms include:

- memory loss

- confusion

- unusual irritability

- impaired decision-making

- decline in cognitive and social skills

- personality changes.

Memory decline over the lifespan

There may be some naturally occurring decline in some aspects of memory as people get older, however memory decline does not occur for everyone. It is not an inevitable part of growing old.It depends on how the memory decline is measured, the level of motivation of the individuals being tested, and on their level of self-confidence. In many cases a lack of self-belief in learning new things can become a self-fulfilling prophecy.The meaningfulness and how well the original material was first learned can impact the rate of forgetting.Research shows that although recall declines as people get older, recognition does not appear to deteriorate with age.http://www.youtube.com/watch?v=qpMtzwrymsM

This trend is thought to occur due to cognitive slowing, that is, aged subjects demonstrate a slowing of neural processes. They take longer to encode information for storage and consolidate material into their long-term memory.

Decline is more likely to be experienced in working memory and declarative memory. For example, episodic memories a form of declarative memory, appear to be the worst affected by ageing. These memories are less well learned and more context-dependent and state-dependent in nature.

Procedural memories may be limited by physical factors but recall of the processes remains strong.

Semantic memories which are more easily accessed seem to remain as strongly as ever. In contrast

People who continue to use their memory for thinking and problem solving well into old age, tend to suffer less memory loss than those who occupy their old age with less mentally challenging pursuits. IE Use it or Lose it!