1. How Biological Factors May Affect Memory
By Mr Daniel Hansson

2. Question for Discussion
Identify factors that affect the body and may indirectly have a negative effect on memory
How much sleep per night do you think a teenager need on average?
Calculate how much you sleep on average per night on a regular week
What can you do to prevent memory impairment?
What can you do to improve your memory?

3. Important Concepts
Dementia: A gradual decline in cognitive function due to damage or disease in the body beyond what might be expected from normal aging
Amnesia: Partial or total loss of memory
What is the main difference between dementia and amnesia?

4. Biological factors That May Impair Memory
Alzheimers´ disease
Brain damage
Sleep deprivation

5. Important Concepts: Alzheimers Disease
Semantic memory: Memory for meaning, facts, words, knowledge
Procedural memory: Memory for skills
Neuroplasticity: The ability of the brain to change with learning. This ability is believed to decrease with age.

6. Alzheimers Disease
A brain disease that starts with amnesia and gradually leads to dementia
The brain activity is initially lowered in the back part of the brain (important for forming procedural memories), before it gradually moves forward

7. Alzheimers’ disease
In the early stages, the most commonly recognized symptom is partial loss of the semantic memory
In the middle stages, the individual has problems with her short term memory
In the later stages, the individuals’ long term memory is severely impaired

8. Possible Cause of Alzheimers
Possible Cause of Alzheimers?: Attack of the Cholesterol Metabolism on Neuroplastic Processes
Cholesterol metabolism may lead to amyloidosis

9. Amyloidosis
The amyloid protein is accumulated in the brain and impairs communication between brain cells

10. Destabilization of Brain Cells by the Tau Protein
Once a critical point of amyloidosis is reached, invidual brain cells are destabilized by the Tau protein

11. Acetylcholine
Acetylcholine, a chemical substance (neurotransmitter) in the brain that encourages learning may inhibit the attack on the brain’s neuroplastic processes

12. Other possible factors on Alzheimers disease
Positive emotions
Language ability
Sleep deprivation
Genetic factors
Strokes

13. Important Concepts: Brain Damage
Localization of function in the brain: The idea that different parts in the brain carry out different functions
Hippocampus: Is found in the limbic system of the brain. Is important for long term memory, short term memory and spatial orientation
Anterograde amnesia: Inability to form new memories
Retrograde amnesia: Inability to remember past events

14. Amnesia through Brain Damage: What Type(s) of Amnesia?
H.M.: Had two thirds of his hippocampus removed due to surgery. He lost 11 years of his past memories prior to the surgery. Was unable to form new memories

15. Amnesia through Brain Damage: What Type of Amnesia?
Clive Wearing: Contracted a virus (Herpes simplex encephalitis) that attacked his brain. He has lost most of his past memories and is unable to form new memories.

16. Sleep Deprivation
The average adult requires 8 hours of sleep per night. If she has less, she may suffer from sleep deprivation
Sleep deprivation may lead to impaired learning, memory loss and an increased risk of developing Alzheimers disease (e.g. Kang et al. 2009; Holzman et al. 2009)
It is possible to catch up on lost sleep (sleep debt), but if severe it can take months

17. Sleep and memory consolidation
The younger you are, the more sleep you need. The average teenager requires 9.5 hours of sleep per night
Procedural skills (e.g. talking, driving, playing music) are improved by sleep
Studies on rats demonstrate that memory consolidation is most important within five hours of learning

18. Task
Find and summarize one study that demonstrates the effect of biological factors on memory.
Use the study summary worksheet and Summarize aim, research method, procedure, findings and conclusion
Examples of biological factors include sleep, Alzheimers disease, insulin, hormones
Brain damage or the H.M. case study is not allowed

19. Links to Suggested Studies