How Biological Factors May
Affect Memory
By Mr Daniel Hansson
Question for Discussion
1. Identify factors that affect the body and may
indirectly have a negative effect on memory
2. How much sleep per night do you think a
teenager need on average?
3. Calculate how much you sleep on average per
night on a regular week
4. What can you do to prevent memory
impairment?
5. What can you do to improve your memory?
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?
Biological factors That May Impair
Memory
 Alzheimers´ disease
 Brain damage
 Sleep deprivation
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.
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
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
Possible Cause of Alzheimers?:
Attack of the Cholesterol Metabolism
on Neuroplastic Processes

Cholesterol
metabolism may
lead to amyloidosis
Amyloidosis
 The amyloid protein is
accumulated in the
brain and impairs
communication
between brain cells
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
Acetylcholine
 Acetylcholine, a
chemical substance
(neurotransmitter) in
the brain that
encourages learning
may inhibit the attack
on the brain’s
neuroplastic processes
Other possible factors on Alzheimers
disease





Positive emotions
Language ability
Sleep deprivation
Genetic factors
Strokes
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
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
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.
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
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
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
Links to Suggested Studies
 http://www.sciencedaily.com/releases/2005/
06/050629070337.htm
 http://www.sciencedaily.com/releases/2003/
07/030709064042.htm
 http://www.nytimes.com/2001/05/07/health/07
NUNS.html?pagewanted=all