Brain + Neuropsychology

• Decision making + rational thinking
• Impulse control
• Emotional processing
• Problem solving
• Damage – short attention span, can’t solve problems, impulsive behaviour

Parietal lobe

• Perception
• Recognition of faces
• Sensory perception
• Damage – inability to recognise faces

Temporal lobe

• Auditory processing
• Speech
• Memory
• Damage – problems producing speech

Occipital lobe

• Visual processing
• Damage – problems with sight

Cerebellum

• Balance, coordination, movement
• Struggling to walk and move

Referring to the idea that the two hemispheres have different specialist functions that they perform

• Control of right hand and visual field
• Logical thinking
• Speech
• Ability to write and understand written language
• Broca’s area – control production of speech

Right hemisphere

• Control of left hand and visual field
• Spatial awareness
• Emotional processing
• Creativity and musical ability

Corpus callosum – thick bundle of nerve fibres, connecting the hemispheres and allowing them to communicate and interact

• Thought that females better at language skills (left-brain tasks)
• Thought that males better at spatial skills (right-brain tasks
• suggested females have a thicker corpus callosum, meaning they often use both hemispheres for some tasks
• males tend to show dominance for one hemisphere in the same tasks

• Harasty et al – found that specifically Wernicke’s Area and Broca’s Area (parts that process and produce language) of left hemisphere tend to be bigger in females
• Rilea et al – found that men were better at spatial tasks, using right hemisphere as men outperformed women in ‘water-level task’ requiring a lot of spatial ability

Refuting

• Rilea et al – males did not always do better at spatial tasks; for example, no difference in male and female performance in the ‘paper folding task’ using spatial ability
• Sommer et al – no strong evidence suggesting that females used both hemispheres – so not good explanation for girls being better at language skills than boys

• Electrical impulse triggered in soma of neuron
• Impulse passed along axon
• Reaching terminal buttons
• Triggering release of neurotransmitters from vesicles
• Neurotransmitters travel into synaptic gap, binding to receptors on dendrites of adjacent neuron

When brain is affected by an impairment to an area or transmission process

• Can’t recognise everyday objects, symbols, music or words
• able to see and describe but can’t recognise whole object
• using colours, textures, components of objects and other senses to figure out object
• occipital lobe damaged

Prosopagnosia

• can’t recognise faces (of loved ones)
• can recognise height, hair, clothes, features like glasses
• fusiform face area near back of temporal lobe damaged
• 1 out of 50 suffer from prosopagnosia

aims –

• To identify location of Phineas Gage’s damage using modern neuroimaging techniques
• To see if proposed location of damage and his reported behavioural changes were similar to other case studies of brain damaged individuals

• Taking x-rays and precise measurements of skull
• Deform 3D construction of human skull to match Gage’s
• Using co-ordination system to map out both skulls, determining trajectory and entry points or iron rod

Results

• Ventromedial region of both frontal lobes damaged
• Dorsolateral areas, Broca’s area and motor cortex’s undamaged
• 12 of other patients studied with brain damage in same are had similar impairments in function to Phineas Gage

Conclusions

• Patients and Gage had problems making rational decisions about personal and social matters and in processing of emotions
• Abilities to perform calculations, tackle abstract problems and recall remained intact

• Practical applications

Can now make predictions of what behavioural changes someone  with the same damage as Gage might experience

• Objective findings

Findings are factual, not opinion – based, as modern computer based techniques and x rays were used, so more scientific

Weaknesses

• Lacking reliability

Info from accident (like reports on Gage’s behavioural changes) based on reports gathered 150 years ago

Info may not be accurate

• Not generalisable

Case unique to Gage, so unlikely someone would experience exact same damage

Sample size – 11 split-brain patients

• When word ‘KEY’ flashed into left visual field, unable to verbalise and describe it but could pick out a key from range of objects with left hand
• When a nude presented to right hemisphere, giggled and blushed but couldn’t describe what they had seen

Conclusions

• Left hemisphere – responsible for processing language and producing speech
• Right hemisphere – responsible for emotional processing and spatial skills

• High reliability

Standardised procedure used; procedure kept same for each patient so data collected in reliable, consistent way

Weaknesses

• Lacks mundane realism

Activities were artificial and unlike activities they would complete in everyday life

So not reflective of how brain works in everyday life

• Not generalisable

Small sample size – difficult to generalise findings to wider population

Very few people have split-brain surgery so research not useful in explaining how ‘normal’ brains work

Old methods –

• Limited to post-mortem examinations
• Had to wait till person died

Strengths

• Only way to study brain at individual cellular level
• Brain damage caused by Alzheimer’s only visible through post-mortems

Weaknesses

• Knowledge gained can’t be used to help individuals while alive

EEG (electroencephalograph)

• Developed in 1920s
• Measures electrical and brainwave activity
• Electrodes placed on scalp to pick up levels of activity in different sections of brains when carrying out activities
• Used to diagnose epilepsy and sleep disorders

PET (positron emission tomography)

• Developed in 1970s
• Helps us see how drugs affect the brain and allows doctors to check for diseases
• Allows doctors see how well body is working
• Special dye with radioactive tracer injected and absorbed by tissues and organs – highlighted under PET scanner

fMRI (functional magnetic resonance imaging)

• developed in 1990s
• helps identify which parts of brain are being used while completing set task
• detects changes in oxygenation and blood flow as result of more activity in specific parts of brain

• allow for opportunity to study living brain (with high-powered resolutions and intricacy) and thus help people currently living with brain damage
• can now study specific areas of brain with a lot of new knowledge provided as a result
• Phineas Gage
• originally little insight due to using post-mortem examination
• to CT scans and 3D computer modelling (Damasio 1994), illustrating trajectory or tamping iron, areas affected, and their perceived functions based of Gage’s reported behavioural changes
• Prosopagnosia
• fMRI scanning identifying fusiform face area of temporal lobes as responsible for facial recognition
• whereas Bodamer in 1940s unable to carry out more scientific research into the neurological causes of his discovery and identification of prosopagnosia conditions, due to limitations of methods of studying brain

Weaknesses

• providing reductionist explanation for human behaviour due to focusing on increasingly small areas of brain
• therefore, disregarding other causes of behaviour, such as another area of brain or nervous system or external factors (e.g., environmental factors or stressful life events)
• still unable to study brain at individual cellular level