Biopsychology

Different parts of the brain are responsible for different functions.
If the area is damaged, the function is damaged.
Broca and Wernicke argues FOR localization.

Localization

We have two symmetrical halves.
Left hemisphere controls right side and vice versa
Thought we have a much more advanced cerebral cortex (putter layer) which is what separates us from animals.

Hemispheres of the brain

Left frontal lobe- language area of the brain.
Responsible for speech.
Damage to this area causes broca's asphasia= slow, laborious speech that lacks fluency.

What is Broca's area?

Left temporal lobe- language area of brain.
Responsible for language comprehension (understanding of words).
Damage to this area causes Wernicke's asphasia= patients have no problem producing language but don't understand it- resulting in nonsense languag

What is Wernicke's area?

Lots of evidence-
Peterson: used brain scans and showed that Wernicke's area was active during a listening task and Broca's area was active during a reading task.
Case study evidence of Phineas Gage who has a steel rod through his face from left cheek to

Strength of localization theory

Motor area= voluntary movement in opposite sides of body. Damage results in loss of control over movements.
Somatosensory= sensory information from the skin is represented. More sensitive the area, the more space is devoted.
Visual area= each eye sends in

Areas of the brain

The brain is like plastic- it can change throughout life.
At ages 2-3 it is thought we have 15,000 synaptic connections as this is the time where we are learning the most about the world. Synaptic connections that we then don't use as an adult are deleted

Brain plasticity

Another example of PLASTICITY.
Unaffected areas of the brain are often able to adapt and compensate for damaged areas.
Healthy brain areas take over the functions of damaged areas of brain.
Can happen quickly/spontaneously after trauma.

Functional recovery of the brain after trauma

Brain forms new synaptic connections close to the area of damage.
Also secondary neural pathways that are not normally used are activated to enable function to continue.
Also structural changes to brain:
-axonal sprouting= nerve endings which attach to ot

How does the brain recover?

Helped in area of neuroehabilitation
Spontaneous recovery slows down after a while so physical therapy may be necessary to continue improvements.
Techniques such as movement therapies and electrical stimulation can be used to counter the deficits in motor

Strengths of plasticity

Negative plasticity: when brain rewires itself it can have negative consequences.
For example, up to 80% of amputees experience phantom limb syndrome- sensations in the missing limb which can be painful.
Thought to be due to cortical reorganization in the

Weakness of plasticity

Different to localization
TWO HEMISPHERES OF THE BRAIN ARE FUNCTIONALLY DIFFERENT.
For example, language controlled by left.

Hemispheric lateralisation

Verbal, motor skills and controls right visual field and right side.

Left side of brain- functions

Holistic perception, non-verbal, motor skills, left visual field and left side.

Right side of brain- functions

Roger Sperry
11 epileptic patients who had surgical separation of two hemispheres. Was done to control epileptic seizures.

Split brain research

Right visual field only= could describe what they saw
Saw nothing in left visual field
Shows language is processed in left hemisphere
Message cannot be conveyed due to removal of corpus collosum.

Describing what they saw

Right hemisphere= could select objects from a bag of various items using left hand
They selected objects that was associated with an object in the left visual field
In right hemisphere= can't verbally say it, only understand it.

Recognition by touch

E.g KEY RING
When two words shown on left and right visual field, they write word using left hand and say word on the right.
Shows right hemisphere is better at drawing tasks.

Composite words

When matching a face from a series of faces, picture in left visual field was consistently selected whereas picture in right visual field was ignored.
When halves of faces shown, left hemisphere better at verbal description and right hemisphere better at

Matching faces

Good methodology- highly controlled, standardized procedures. Patients had to stare at one point with 1 eye blindfolded whilst an image flashes for a 1/10 of a second. This mean Sperry could vary the procedure so only 1 hemisphere was being used at a time

Strength of s.b research

Problems of generalizations- unusual sample= those with history of epileptic seizures so have unique changes in the brain. Not common so cannot generalise.
11 patients is a small sample- inappropriate control group of 11 people with no history of epilepsy

Weakness of s.b research

Distinct patterns of changes in body activity that conform to cyclical time periods. Influenced by endogenous pacemakers and exogenous zeitgebers.

Biological rhythms

Biological rhythm subject to a 24 hour cycle, which regulates a number of body processes such as sleep/wake cycle.

Circadian rhythm

Biological rhythm with a frequency of less than one cycle in 24 hours, such as menstruation.
Longer than 24 hours to complete.

Infradian rhythm

Biological rhythm with frequency of more than one cycle in 24 hours such as stages of sleep.
Less than 24 hours to complete.

Ultradian rhythm

Internal body clocks that regulate many biological rhythms

Endogenous pacemakers

External cues that may affect or entrain our biological rhythms

Exogenous zeitgebers

Seasonal affective disorder:
Happens annually (circannual rhythm)
Persistent low moods, lack of energy, change in eating and sleep patterns
Over production of melatonin.
In winter, lack of light in morning means that the melatonin process continues for lo

Research evidence of infradian rhythms

Stages of sleep-
Stages 1+2= LIGHT SLEEP. Person is easily woken, the beginning of sleep. Brainwave patterns get slower and slower as sleep gets deeper.
Stages 3+4= DEEP SLEEP. even slower patterns and have greater amplitude (electricity). Difficult to ro

Research evidence of ultradian rhythms

Research support:
Sleep patterns of 9 adults
EEG used to record brainwave activity
REM activity highly correlated with dreaming
Brain activity varied according to how vivid the dreams were.
Those who were woken during dreaming reported accurate recall of

Strength of stages of sleep

Practical application: treatment for SAD is phototherapy- where a light box is used to stimulate strong light in morning and evening. It is thought to reset melatonin levels (stops over-production) and relieves symptoms such as persistent low mood.

Strength of Seasonal affective disorder

Suprachiasmatic nucleus= master circadian pacemaker controlling timing of the sleep/wake cycle.
Essential for sleep/wake cycle.
Animal studies and SCN= hamster study: hamsters were bred with cycle of 20 hours. SCN cells removed from unborn hamsters and pu

endogenous pacemakers on sleep/wake cycle

Produces melatonin at night (inducing sleep).

Pineal gland

Light: can reset the SCN whilst also having an indirect effect on hormone secretion and blood circulation.
Campbell+Murphy= people woken at various times during night when light was shone on back of knee. Produced deviation in their usual sleep/wake cycle

Exogenous zeitgebers on sleep/wake cycle

Methodological issues of Campbell and Murphy study: suggest there may have been some limited light exposure to ppts eyes, which is a major confounding variable. Also isolating one zeitgeber doesn't give insight into the other zeitgebers that influence the

Weaknesses:

Interactionist system: pacemakers and zeitgebers interact and it makes little sense to separate them. Always connected to each other making it difficult to measure independently.

Strengths:

A method used to detect changes in blood oxygenation and flow that occur as a result of brain activity in specific part of the brain. When brain area is more active it consumes more oxygen to meet this increased demand. 3D images produced showing activati

fMRI

No radiation unlike PET scans
Non-invasive
Provides clear image of brain localization.
Expensive
Patient has to be still

Strengths and weaknesses of fMRI

A record of tiny electrical impulses in the brain via electrodes that are fixed to the individuals scalp using a skull cap. By measuring brain wave patterns, the EEG can help diagnose certain conditions such as tumours.

EEG

Non invasive
Has contributed to our understanding of ultradian rhythms
Information received is generalised

Strengths and weaknesses of EEG

The brains electrophysiological response to a specific sensory, cognitive or motor event can be isolated through STATISTICAL ANALYSIS OF EEG DATA. It removes all extraneous brain activity from original EEG, leaving only responses that relate the stimulus.

ERPs

Excellent temporal resolution so measured more specifically than EEG
Lack of standardisation in ERP methodology across research studies makes it difficult to confirm findings.

Strengths and weaknesses

Brain is analysed after death to examine damaged areas of the brain to highlight abnormalities. Can compare normal brain to damaged brains.

Post-mortem examinations

Broca's and Wernicke's area relied on post-mortem studies to establish links between language, brain and behaviour decades before brain imaging was possible.
Helps improve medical knowledge
Ethical issues- consent from patient before death causes problem

Strengths and weaknesses of post-mortem examinations