The Brain and Neuropsychology

Brain diagram

Temporal lobe function

• Hear and understand speech

• Create speech

• Damage: Understand and process speech

Occipital lobe function

• Processes visual information

• Our ability to see

• Damage: Vision. Understanding surroundings

Frontal lobe function

• Decision making

• Impulse control

• Problem solving

• Concentration

• Damage: Memory and problem solving

Parietal lobe function

• Facial recognition

• Sense of touch

• Damage: Facial recognition

Cerebellum function

• Movement and coordination

• Balance

• Information from senses

• Damage: Balance, coordination

Broca and Wernicke’s area

• Broca: Responsible for speech

• Wernicke: Responsible for comprehension

Hemisphere dominates

• Left: Language, logic and math skills

• Right: Dominates emotion, creativity and music

Sex differences in brain

• Size: Male brain is 10% larger than female brain

• Hemisphere: Men are left dominant, woman are equally balanced

• Language: Women process in both hemispheres. Men only process in one

• Emotion: Women have larger limbic so are more emotional. They are more likely to experience depression and other disorders

Sex differences strengths

• Haresty et al found language part is bigger in females than in males

• Rilea et al found males are better at spacial tasks than females

Sex differences weaknesses

• Sommar et al found no strong evidence that women use both sides for language

• Most tasks focused on the left brain so can’t explain spacial tasks

Central Nervous System

• Made of brain and spinal cord

• Brain sends messages to the body

• Messages are carried through the spinal cord

• The spinal cord can activate the Peripheral Nervous System

Peripheral Nervous System

• Connects the CNS to the muscle, skin and organs

• Carries out the action required by the message sent from the brain

Neurone

Synapse

Dendrite

Receives messages through receptors from other cells

Axon

Passes messages from the cell body to other neurones, muscles or glands via terminal buttons that hold neurotransmitters

Nerve impulse

An electrical signal that travels down the axon from the cell body to the terminal buttons so it releases a neurotransmitters

Synaptic transmission

• An electrical impulse is triggered inside the neurone

• A small impulse is passed along the axon towards the end of the nerve

• It arrives at the terminal buttons which are filled with vesicles

• These contain neurotransmitters

• When the impulse reaches here, the vesicles release their chemical into the synaptic gap

• These chemicals are grabbed by the receptors on the next nerve cell, which passes the message on.

Dopamine

• Plays a role in attention and learning

• Not enough dopamine makes it difficult to concentrate

Seratonin

• Plays a role in our mood

• Too little serotonin can make people depressed

GABA

• Plays a role in calming us down

• Not enough BAGA causes us to feel stressed

Neurological damage

• Damage to the body’s central and peripheral nervous system

• Messages can be interrupted

• Neurons might not be working

• Normal functions of the brain not possible

• Behaviour can be affected

Visual agnosia

• The inability to recognise things that can be seen

• Affected by parietal lobe

Prosopagnosia

• Patient is unable to recognise faces of people

• Affected by temporal lobe

What happened to Gage

• 1848 – railway line worker

• Explosion forced iron rod through his head

• Before: calm and well liked

• After: irresponsible and rude

• Died 12 years later – epilepsy

Demasio 1994 Aim

• To investigate the brain damage to Phineas Gage using his skull

• Determine functions of the frontal lobe

Demasio 1994 Procedure

• Took photos and measurements of Gage’s skull

• Built a 3D replica of skull

• Measured iron rod and compared it to damaged areas of skull

• Mapped 20 entry and 16 exit points

• Narrowed this to 5 paths

Demasio 1994 Results

• Damage to both the left and right hemisphere.

• Extreme damage to the frontal lobe

• Damage to white matter (where neurones pass their message along)

• Damage was worse in the ventro medial region

• Broca’s area was undamaged

Demasio 1994 Conclusion

Ventromedial region of the frontal lobe responsible for sensible decisions

Evaluating Demasio

• Generalisable: No, brain damage is unique to Gage.

• Reliable: No, the reports of the damage are over 150 years old

• Validity: The study is based on a real life case

• Used modern day technology making the study scientific.

• We can make predictions about damage to the frontal lobes.

• We can now treat people who have similar brain damage based on what happened to Gage.

Sperry 1968 Aim

• How the split brain works

• Examine the extent of which the 2 hemispheres are specialised

Sperry 1969 Procedure

• Studied 11 patients who had their corpus callosum cut

• Had them complete 2 tasks

• Visual: Word or picture was shown for 1/10th of a second. They had to recall the picture

• Tactile: Had to close eyes and name the object that was placed in their left or right hand

Sperry 1968 Results

• Information sent to the right field could be described in speech

• Objects placed in the right hand could be named

Sperry 1968 Conclusion

• Hemispheres can function without each other but the information can’t be shared

• The left hemisphere= language abilities

• The right hemisphere = spatial abilities

Sperry Strengths

• Reliability: Sperry gathered a lot of consistent information

• Reliability: The procedure was kept the same for each participant, keeping it standardised.

• Real world application: The study tells us a lot about the lateralisation of the brain so strategies can be put in place to support individuals with damage to one side of their brain.

Sperry Weaknesses

• Generalisability: It is hard to generalise findings from the study because the sample size is small and so specific.

• Validity: The study was a lab experiment which is an artificial setting which means it lacks ecological validity

• Validity: The task is not something we would naturally do and so it lacks mundane realism.