Unit 2:Biological Level of

AnalysisSession 2

‘All that is psychological is first physiological’ Session 2: Localisation of Brain Function

What were the there principles of the biological level of analysis?

A recap

1. There are biological correlates of behaviour

2. Animal research can provide insight into behaviour

3. Human behaviour is, to some extent, genetically based

Three Principles of Biological Level of Analysis

Explain one study of localisation of function of the brain

Today’s learning outcome

Explain: give a detailed account including reasons or causes

When a behaviour is localised in the brain, it is possible to trace the origin of a behaviour to a specific part of the brain

Studies in localisation of function led to the desire to map out the brain’s functions

Though localisation does not explain all human behaviour, the mapping out of the brain was an important step forward in brain research

What is localisation of brain function?

Where have we already discussed localisation?

• Iron rod blew threw his skull and he turned into a jerk

• Shows that behavior has a physiological basis (his personality changed)

• Shows there are biological correlates of behavior (after his frontal lobe was damaged he lost his ability to restrain himself)

Phineas Gage

We will focus on brain damage and amnesia

Memory Stores

Amnesia: the inability to learn new information or retrieve information that has already been stored in memory.

Amnesia

Amnesia: the inability to learn new information or retrieve information that has already been stored in memory.

Amnesia

Retrograde Amnesia failure to recall memories that

have been stored before a trauma

Anterograde Amnesiafailure to store new

memories after a trauma

Important in the formation and storage of memories

Case studies of patients with hippocampal damage have shown that they can no longer form new explicit memories

The Hippocampus

Important because it provided evidence that there are different memory systems in the brain

Milner (1957) was first to report case of H.M. and memory function after H.M.

https://www.youtube.com/watch?v=IKP6tBhM2T4

The case study of H.M.

Suffered from epileptic seizures after he fell of his bike aged seven

It was assumed his seizures were related to his accident

He became increasingly incapacitated When he was 27, a neurosurgeon performed

experimental surgery to stop the seizures Tissue from the medial temporal lobe,

including the hippocampus, was removed

The case study of H.M.

After the operation H.M. suffered from amnesia He could recall information acquired in early life, but was

unable to form new memories H.M. suffered from anterograde amnesia (failure to store

memories that happened AFTER a trauma) He was unable to remember the faces of new people he met He could carry out normal conversations, but would not

remember people he met after the operation He could read and re-read the same magazine without

realising that he had read them before

The case study of H.M.

Did an MRI scan* of H.M.’s brain

Brain imaging was used because it allowed researchers to get a precise image of the brain damage

They were then able to identify where the damage was i.e. the removal of the hippocampus

*MRI-Magnetic resonance imaging- a type of brain scanning technique

Corkin et al. (1997)

Only his memory was affected by the removal of the hippocampus

His personality remained unchanged and there was no general intellectual impairment

Suggests hippocampus is not involved in other behavioural processes

What can be learned about localisation of function from H.M?

The hippocampus plays a critical role in converting memories of experiences from short-term to long-term memory

H.M. retained memories of what happened BEFORE the surgery.

Indicates that hippocampus is responsible for storing new explicit memories

H.M. could learn a few new procedural memories which indicates that procedural memories are not stored via the hippocampus

What can be learned about localisation of function from H.M?

The fact that H.M. (and other people with amnesia) had deficits in one part of the memory but not in others is evidence that the brain has several memory systems and that these are supported by distinct brain regions

Shows that memory processes are much more complex than originally believed

Although hippocampus is very important in the storage of new memories it is not the only part of the brain involved in the process

Other parts of brain must be responsible for storage of procedural memories etc.

What can be learned about localisation of function from H.M?

Clive Wearing

In his mid-forties suffered from a brain infection which damaged parts of his brainLeft with a memory span of only a few secondsMost devastating case of amnesia ever recordedSuffers from anterograde and retrograde amnesia

https://www.youtube.com/watch?v=Vwigmktix2Y

Clive Wearing

Wearing’s episodic and some of his semantic memory are lost

He also cannot transfer new information into long term memory

Wearing can still play the piano and conduct music (procedural memories)

He also still demonstrates affection for his wife suggesting his emotional memory is intact

This is evidence of a distributed memory system i.e. different parts of the brain are involved in different parts of memory

Explain one study of localisation of function of the brain (8 marks)

This should include:◦ Definition of localisation of function of brain◦ Description of one study (H.M.)◦ Detailed explanation of what study tells us about

brain

Model SAQ Answer