MEMORY AND THE
BRAIN
LEARNING OUTCOME:
EXPLAIN HOW BIOLOGICAL FACTORS MAY
AFFECT ONE COGNITIVE PROCESS.
The human brain
- important parts to know of-
Methods studying the brain to
gain more information about
memory
Experiments – using leisioning - on animals.
Case studies, studying people who already
have brain damage.
Observational techniques using scanning.
THE LEISIONING TECHNIQUE
A technique used to find out about the
importance of different parts of the brain. In
this case which parts are responsible for
different tasks important for memory.
The researchers test an ability, then cut away brain
tissue and test again to see if there are changes
in the particular ability tested.
Example: Thomson
An example – investigating
Alzheimers
http://www.learner.org/discoveringpsychology/09/e09expand.html?pop=yes&pid=1528#
Thomson – using classical conditioning together with lesioning to investigate what areas are active when
forming memories. Goal: to come up with new methods and techniques to deal with memory
disorders.
Woodruff – pioneered using tests of eye-blink classical conditioning on humans to identify early onset of
Alzheimers.
Theory: Alzheimers impairs the transmission of acetylcholine which is the memory transmitter responsible for
forming new memories.
Case: A 89 years old woman who came in as a good conditioner with 50% conditioned responses – a couple
of years later a serious drop of conditioned responses 25% was seen. All neuropsychological tests were
still normal though and continued to be so for 5 years but then there was a rapid deterioration in the
neuropsychological abilities. So these tests show impairment 5 years before the actual onset.
Implications: Because Alzheimer's disease kills cells and its pathology is irreversible, early detection is the only hope for
a cure or prevention.Doctors and researchers are working to develop a vaccine for Alzheimer's disease. The
vaccine would block the toxins that accumulate in the brain and preserve the acetylcholine connection that is
so vital to memory.
Thanks to case studies and
lesioning we now know that:
Our memory system is a distributed one. Brain
damage(lesioning or naturally occuring) show
that implicit memories rarely are affected while
semantic and episodic memory can be so.
The long-term memory system
Long term memory
Explicit/declarative
memories
Semantic
memories (memory
of facts)
Episodic memories
(memories of
events)
Implicit
memories/nondeclarative
memories
Procedural
memories
(memoryof how to
do things)
Emotional
memories (memory
of how - emotional
states)
Clive Wearing
MRI scanning of Clive Wearing’s
brain shows damage to the
hippocampus and some of the
frontal regions. He is suffering
from both anterograde and
retrograde amnesia.
This give insight into the biological
foundation of different memory
systems. His episodic and some of
his semantic memory are lost. But
his implicit memory is intact. This
is evidence of a distributed
memory system.
H.M
To stop severe epilepsy
brain tissue, including the
hippocampus and
amygdala, was removed
from H.M.
H.M. Could recall early
memories but could not
form new ones. H.M.
Suffers mainly from
antereograde amnesia.
http://www.youtube.com/
watch?v=LBsW5qz5sDU
Hippocampus and amygdala –
important for episodic and
semantic memory.
For the future:
Let’s be optimistic and beleive that this will change future:
http://www.pbs.org/wgbh/nova/sciencenow/0301/02.ht
ml
Homework:
Read O.R.G on intrusive techniques. Prepare a discussion about
ethics. We will discuss ethical considerations and dilemmas
when using:
-
Cases in research.
-
Lesioning in research.
Write an extended essay response:
Discuss how and why lesioning and cases are used by cognitive
researchers. See CC 385-387 for essay writing help.