GCSE Psychology Brain and Neuropsychology

function of the nervous system

Collects and responds to information in the environment.
Controls working of different organs and cells including the brain.

subdivisions

CNS + PNS
CNS = brain and spinal cord
PNS = ANS + SNS
ANS = sympathetic and parasympathetic

PNS(Peripheral nervous system)

Receives messages from the CNS and sends messages to it.
Messages sent via neurons.

CNS(Central nervous system)

Autonomic nervous system (ANS)

Governs automatic (involuntary) functions.
For example, breathing, heart rate, digestion and the body’s response to stress.

Somatic nervous system (SNS)

Sends information from the brain to muscles, voluntary control of our muscles plus reflex responses.
Takes in information from sensory organs,

Homeostasis

Keeping the body in a constant and balanced internal state.

Sympathetic nervous system

A state of physiological arousal ready for the fight or flight response.

Parasympathetic nervous system

The rest and digest response which returns the body to normal resting state once the threat has gone.

Brain detects threat

The hypothalamus identifies a threatening event
Triggers the sympathetic division of the ANS to act.

Release of adrenaline

The ANS changes from parasympathetic state to a sympathetic state.
adrenaline is released from the adrenal glands into the bloodstream.

Fight or flight response

Immediate and automatic.
Adrenaline targets the cardiovascular system, increasing heart rate and breathing.
Also inhibits digestion and increases saliva production.
Prepares the body to confront the threat (fight) or provide energy to run away (flight).

Once the threat has passed

Parasympathetic division returns body to normal ‘rest and digest’ state.
Digestion and hunger stimulated.

James lange theory

Physiological arousal comes first and emotion after.

An event causes physiological arousal in the following way:Hypothalamus arouses the sympathetic division of the ANS.
Adrenaline is released and creates physiological arousal

If no physiological changes occur then emotions are not experienced.

James lange theory eval- evidence

A strength of the theory is real-life examples.
A fear of public situations (phobia) can develop as a result of the anxiety (emotion) created from falling down in public.
This shows that emotional responses such as fear are a result of physiological arousal like increased heart rate.

James lange theory eval- cannon-bard

A weakness is that the theory is challenged by the Cannon–Bard theory.
We experience some emotions (e.g. embarrassment) at the same time as physiological arousal and not one after the other.
Therefore this theory can explain emotional situations that the James–Lange theory cannot.

James lange theory eval-too simple

A weakness is that the theory is challenged by the two-factor theory.
We need arousal plus social cues to correctly label the emotion we are feeling
Therefore the James–Lange theory does not explain how a person ‘decides’ what emotion they are experiencing.

Synaptic cleft

space between two neurones

Excitation

Excitatory neurotransmitters increase the postsynaptic neuron’s positive charge and make it more likely to fire.

Inhibition

Inhibitory neurotransmitters increase the postsynaptic neuron’s negative charge and make it less likely to fire

Summation

there are more excitatory signals than inhibitory signals

Hebbs theory

brain is plastic- able to change and develop

brain adapts- will change structure and connections in response to learning

Learning produces an engram- a trace that can be made permanent if rehearsed

cell assemblies- groups of neurons that fire together.
The more they fire, the more the synaptic connections grow and strengthen.

Hebbs theory eval-scientific

A strength of Hebb’s theory is that it is scientific.
Hebb explained learning in terms of brain function which provided an objective basis for understanding behaviour.
This shows that learning can be studied through brain processes.

hebbs theory- real world application

A strength of Hebb’s theory is it can be applied to education.
He found that rats raised in stimulating settings were better able to find their way through mazes as adults.
This could be applied to education by creating more stimulating environments to encourage learning.

hebbs theory- reductionist

A weakness with Hebb’s theory is that it reduces learning to a neuronal level.
This means that other levels of understanding are ignored, such as Piaget’s ideas about how accommodation moves learning forwards.
This is an issue as a more complete account of learning would discuss non-biological factors as well.

Parietal lobe

Sensations are processed

Penfield’s study-AM

To investigate patients’ responses when their brain was electrically stimulated.

Penfield operated on people to treat their severe epilepsy.
His technique meant that a conscious patient’s brain was exposed and areas could be electrically stimulated.
Patients could then report their thoughts and sensations.

Penfield’s study-RC

With temporal lobe stimulation, patients recalled experiences or recalled feelings associated with the experiences, including experiences of déjà vu.
The same memory was recalled each time the same area was stimulated.

Suggests that memories of previous experiences are stored in the temporal lobe.
An associated area stores the personal meaning of the experience. Penfield called this the interpretive cortex.

Penfields study eval- method

A strength is that Penfield used a very precise method of studying the brain.
He could stimulate the exact same area of the brain repeatedly and patients could report their experiences.
This enabled him to produce an accurate ‘map’ of brain function.

Penfield’s study eval-sample

A weakness is that the participants in the study made up an unusual sample.
The patients were suffering from severe epilepsy.
This could mean that any results obtained were unusual and not reflective of people with non-epileptic brains.

Penfield’s study-mixed results

A weakness is that Penfield’s later research did not always support his original findings.
In fact only 40 of the 520 patients he studied reported vivid memories when their temporal lobe was stimulated.
This suggests that the interpretive cortex does not always respond in the same way.

Cognitive neuroscience

Scientific study of the influence of brain structures on mental processes.
Aims to create a detailed map of localised functions in the brain.

effects of stroke

When the brain is deprived of oxygen because of disruption to its blood supply, the specific areas affected will die.
The effects may not be permanent if other parts of the brain take over localised functions.

effects of neurological damage on motor ability

Damage to the motor area can lead to the person struggling with fine and complex movements.

effects of neurological damage on behaviour

Brain damage can lead to ‘aphasia’ – an inability to understand and use language.

CT scans

images taken from different angles and combined to make a detailed picture-useful for abnormalities, requires more radiation

PET scan

patient injected with radioactive tracer which shows brain activity-shows localisation of function, expensive and difficult to interpret

fMRI scan

measures changes in blood oxygen levels in the brain- shows brain in action, expensive and person must stay still

Tulvings gold study-AM

To investigate whether episodic memories produced different blood flow from semantic memories.

Six participants were injected with radioactive gold.
Repeated measures design

Blood flow in the brain was monitored on a PET scan.

Tulvings gold study- RC

Different blood flow patterns found in half the participants
Semantic memories created a greater concentration of blood flow in the posterior cortex.
Episodic memories created greater flow in the frontal lobe

Tulvings gold study eval- evidence

A strength is that the study produced scientific evidence.
It used evidence from brain scans that is difficult to fake, unlike other psychological investigations where you can be less sure that participants are behaving genuinely.
This means that Tulving produced unbiased evidence.

Tulvings gold study eval-sample

A weakness is that the sample was restricted.
Only six participants including Tulving were used and differences in blood flow for episodic and semantic memories were seen in only three participants.
This means the results were inconclusive.

Tulvings gold study- memory

A weakness is that episodic and semantic memories are often very similar.
Memories for personal events also contain facts and knowledge about the world so it is difficult to work out which type of memory is being studied.
This may explain why the evidence from Tulving’s study was inconclusive.