Examine one interaction between cognition and physiology. Evaluate two studies

How brain damage affects memory processing

Refers to the learning outcome: Explain how biological factors may affect one cognitive process

What is amnesia?• Memory loss (inability to learn new

information or retrieve information)• Two types• I.Retrograde

Memory loss of events BEFORE brain damage

• II. AnterogradeMemory loss of events AFTER brain damage

Info: http://www.tbiguide.com/memory.html

Causes• Developmental issues • Concussion• Migraines• Epilepsy• Electroconvulsive shock therapy• Specific brain lesions (i.e. surgical removal) – HM• Drugs• Infection – Clive Wearing• Psychological (trauma)• Nutritional deficiency• Lack of Sleep!

Famous case: Clive Wearing• Suffers both anterograde and

retrograde• MRI scan shows damage to

the hippocampus and some of the frontal regions

• Episodic memory and some semantic memory are lost cannot put new information in long term memory

• Implicit memory and emotional memory still intact

• Memory span: few seconds

How Clive Wearing percieves it• Not able to remember anything for

more than a blink• Kept a journal• ”I am awake”

”This time finally awake””I was fully conscious at 10.35p.m”

• ”Forever today” Deborah 2005

How it happened?

• In March 1985• In his forties • Brain Infection (Herpes

encephalitis)• Injured hippocampus• Hippocampus - center for long

term memory• Perception was unimpaired but

he could almost not remember anything

• The most devastating case of amnesia ever recorded

CLIP ON CLIVE WEARING!

•http://www.youtube.com/watch?v=WmzU47i2xgw

•http://www.youtube.com/watch?v=Vwigmktix2Y

Case study: HManterograde amnesia• First studied by Milner &

Scoville 1957• Head injury when he was 9• Epileptic seizures• No drug treatment surgey • 27 years old• Removed tissue from the

temporal lobe, including hippocampus, the amygdala

• H.M.'s Brain and the History of Memory by Brian Newhouse:

• http://www.npr.org/player/v2/mediaPlayer.html?action=1&t=1&islist=false&id=7584970&m=7584971

HM after the surgery

• Cured his seizures, gave him amnesia (anterogade)

• Able to: Carry on a conversation• Not able to: Recognize people and

also rereads magazines.• Can remember if rehearsed• MRI scanner in 1997 that

supported what was suspected

• Answer ”ethics in research” on p. 79 and ”understanding research”

Interaction cognition and physiology• HM’s amnesia• Could not memorize

new EXPLICIT (declarative) memories (both semantic and episodic memory)

• Intact procedural memories

• Physiology

• Parts of hippocampus was removed and most of the amygdala

• Cerebellum was not damaged

Critical thinking – the case studies

Strengths Limitations

• Researchers too close to the participants

• Time consuming• Ethical considerations;• Long, intense,

stressful• More difficult to

generalize

• Raise interesting questions for further research

• Could generalize if similar cases

• in depth, rich data through a variety of methods

• High ecological validity• Longitudinal• Ethical if not stressful and

nor forcing

MRI study and Medial Temporal Lobe Amnesia

• Varga-Khadem et al. (1997) performed a study using MRI scanning with three young patients who had brain injuries.

• Aim; investigate the relationship between the brain injury and anterograde amnesia.

• Methods; MRI scanning and memory tests/experiments

• Participants; One child had suffered brain damage at birth, the second by the age of 4 years, and the third one by the age of 9.

• Results;• all three children had damage to the hippocampus. • Amnesia - severe problems with episodic memory, • their cognitive development was within the normal range. • They were low-average to average in language skills, factual

knowledge, and literacy. • Conclusion; the study provides support for the idea that there

are separate episodic and semantic stores in long-term memory.

• Only episodic memory seems to be fully dependent on the hippocampus.

• Critical thinking; a lot of scientific research support this

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CONCLUSION• We have learned a lot about memory and amnesia from

case studies • but individual cases are not as statistically powerful as

group studies

• animal research is needed for in depth analysis

• Animal research show the same thing

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Critical thinking research and theories MLA

• Case studies +/-

• Scanning evidence +/-

• Few cases

• Animal research (cause amnesia in e g monkeys and investigate) +/-

• Applicability Useful and important findings –

• 1) Treat the amnesia • 2) The existence of Multiple memory systems• 3) Localization of cognitive functions

Summary• You can use Clive and H.M as support (how biological factors

may affect one cognitive process: brain damage on memory)• H.M and Clive W can also be used as support for the multi-

store model of memory (since they show that our memory consists of different memory systems)

• Both can be used as support in LO about ethical considerations

• Since you need two biological factors: you can use the study by Martinez and Kesner (1991) Ach in memory formation

• You can also (great isn’t it?) use H.M and Clive for the LO in the biological level of analysis: ”Examine one interaction between cognition and physiology in terms of behaviour”