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Memory
Week 3
Biological Approach
Biological
• Biological Psychology is the study of the biological
basis of behaviour and suggests that it is our
physiology and our genetics that cause us to think,
feel and behave as we do.
• Areas of the brain associated with STM & LTM
• MRI scans show that when a person is doing
immediate memory tasks the prefrontal cortex is
active BUT
• When doing LTM task the hippocampus is active
• Clinical evidence (patients like HM & Clive Wearing
etc) supports distinction between STM & LTM
How is memory stored?
Memory and the Brain
• Hebb (1949) proposed that during
the process of learning, we form an
‘engram’ which is a wordused for
‘memory trace’
• Initially this is a fragile, ‘active trace’,
but it is formed into a permanent
‘structural trace’
• Engrams are means by which
memory is stored in the brain
• An Engram is the hypothesized
physical memory trace, that that is
produced when information is
stored in the brain
• Although the actual existence of
memory "engrams" is still unproven
Trace Decay
Engrams & The Brain
• In 1931 Lashley (a neuroscientist) attempted to
identify the location of the engram in rats using a
maze task
• He trained rats to learn mazes and then remove
sections of their brains
• Findings???
• there was a relationship between the amount of
material removed and the amount of forgetting
that happened
• Can it be generalised to humans?
The Brain
• The brain is divided into two
halves called hemispheres.
• An outer layer called the cortex
covers the hemispheres.
• The cortex has many folds and
convolutions thereby increasing
the overall surface area of the
brain.
• The cortex can be divided into
areas (or lobes) according to their
functions.
Parietal
Frontal
Occipital
Temporal
The brain
• Frontal Lobe involved in planning, initiative and
voluntary motor control
• Parietal Lobe is involved in sensing and
monitoring of body parts. Integrates information
from different sensory areas; for example pairing
up the sight and sound of an object
• Occipital lobe is involved in sight. Damage to the
occipital lobe may cause a variety of visual
disturbances, depending on where damage
occurred.
The Brain
• Temporal lobe is involved in hearing, language and memory.
Damage to the temporal lobe may cause impairment of any of
these functions
• The temporal lobe also contains the Hippocampus. Research
suggests that the hippocampus is vital for long-term memory. It is
also vial for spatial memory.
• Spatial memory allows the individual to move within their
environment, know where they are located and remember where
things are.
• The temporal lobe contains the amygdala which is involved in the
consolidation of long-term memories. Damage to the hippocampus
may prevent the individual from being able to store new
information
Temporal Lobe – Hippocampus – Amygdala
STM/LTM – Different areas of the brain?
• One way to demonstrate the existence of two
separate stores in memory is to link STM and LTM to
specific areas of the brain
• MRI scans take images of the active brain and help
us to see what region is active when a person is
doing a task
• Research found that the prefrontal cortex is active
when individuals are working on STM tasks
(Beardsley, 1997)
• Where as the hippocampus is active when LTM is
engaged (Squire et al, 1992)
Support for Multi-store model
Internet research activity
• Scoville and Milner (1957) A study of HM
• Hippocampus and Memory
Greek name for
Seahorse is
hippocampus
Scoville and Milner (1957)
Study of HM
• 1953, HM had the hippocampus removed from both sides of the
brain to control severe epilepsy
• Result: personality & intellect remained but memory affected
– Lost his memory of 10 years prior to operation
– Lost his ability to store new information
– He had a 90 second memory span – effectively waking up every 90
seconds not knowing where he was
– Procedural memory was fine (doing things) as was his semantic
memory (knowing that)
– For many years he said he was 27 and the year was 1953, but started
to realise this was wrong – he re-read magazines/books with no loss
of interest
• Conclusion: Demonstrates the importance of Hippocampus in
LTM
Scoville & Milner - Evaluation
• Was it the loss of hippocampus or trauma of
brain surgery that led to his subsequent
behaviour?
• Ethics – informed consent?
• Evidence for MSM?
How does the study of HM demonstrate
evidence for separate STM and LTM stores?
• Star study: A case study of HM by Scoville & Milner (1957)
p.35/36
• STM intact but could not form new long-term memories
– Could memorise a number & recall it 15 mins later, but if given
another task during that time, he wouldn’t remember the
number
• He could still talk and show previous skills (procedural
memory)
• But his episodic memory (for past events) and semantic
memory (e.g. word meanings) was affected more than the
procedural memory
• Evidence for different stores for STM & LTM
Hippocampus & Spatial Memory
• Maguire et al (2000) Navigation-related structural
changes in the hippocampi of taxi drivers
• Research Question: Can changes in the brain be
detected in those with extensive navigation
experience?
• Remember that the hippocampus is vital for LTM
and spatial memory
• The hypothesis: That the hippocampi in London Taxi
drivers will be structurally different to the
hippocampi in non-taxi drivers
Maguire et al, 2000
• London Taxi Drivers ‘the knowledge’.
• It takes two years to train to become a London Taxi driver
and they must memorise thousands of routes
• They are tested by police before a license is issued
• Method: Natural experiment
• 2 groups of 16 participants (their brain)
– All right handed – matched for age (av. 44years)
• IV: London Taxi driver brain (av. 14.3 years experience)
Non taxi driver brain
Comparison
• DV: Structure & volume of hippocampi
of analysis
of MRI scans
Maguire et al (2000)
Procedure
• Firstly: MRI scans of brains of 50 healthy, right
handed, male, non taxi drivers aged 33 - 61 were
analysed to establish a comparison data base of
‘average hippocampi’
• MRI scans of brains of 16 taxi drivers and of 16
matched controls were analysed and compared to
the data base of images
• CONTROL: the expert conducting the analysis did not
know whether MRI scan was taxi driver brain or
not….why?
– To reduce bias of those assessing the scans
Maguire et al (2000)
Findings / Conclusion
• Increased volume of grey matter in both the right
& left hippocampi in taxi driver brains
• Volume (size) of right posteria (back part)
hippocampus increased as length of time as taxi
driver increased
• Conclusion:
– That the structure of the brain changes in response to
environmental demand
– That the mental map of the city of London is stored in
the posteria hippocampi
The Case of KF (Shallice and
Warrington, 1970)
• In the 1970s, KF was in a motorcycle
accident, resulting in brain damage to
his left occipital lobe (pictured right).
• STM was damaged but LTM was
normal
• He remembered words better if
presented visually as opposed to
auditorally.
• Therefore, impairment was mainly for
verbal information - his memory for
visual information was largely
unaffected.
• This case study suggests separate
visual and spatial systems thus
supporting the existence of the visuospatial sketchpad in working memory.
Evidence that the Occipital
Lobe is important for visual
memory
Neuropsychological evidence
•Some of the strongest evidence to prove that STM and LTM
are separate stores comes from the study of people who have
suffered brain damage.
•Loss of memory is usually selective – it affects one type of
memory but not another.
• Clive Wearing
The case of Clive Wearing
• https://www.youtube.com/
watch?v=OmkiMlvLKto
• http://www.youtube.com/
watch?v=WmzU47i2xgw
Clive Wearing
• Temporal and frontal lobes were damaged by viral encephalitis.
• He remembers nothing at all; his entire experience is restricted to the
minute or two available through working memory
• Every time Mr. Wearing is distracted, he awakens to an entirely new
and unfamiliar reality.
• For years, Mr. Wearing has kept a diary. Each entry contains the
current time and a record of the profound realization that he is now, for
the first time, alive and conscious. He then notices the previous
entries. Pages of them. All making the same claim. All in his own
familiar handwriting. All written by some unremembered stranger. He
goes back, systematically crosses out these false entries, and
underlines the current entry. The first true entry. He sets the diary
down, glances out the window, and awakens for the first time.
What a story – website link
Group Work: How does this show there are different memory
stores?
• Evidence of LTM: Procedural memory (play piano) &
Semantic memory (knows his wife)
• No STM – continually thinks he’s is waking up for the first
time
• Cannot retain new information and pass it on to LTM
through rehearsal
• Good evidence for STM and LTM being different stores
Link to Models of Memory?
• Biological Approach worksheet
Practice Essay – group plan
• Explain the topic of Memory using two
psychological approaches and/or theories
– 14 Marks