Biopsychology Flashcards
What is the nervous system split up into?
- central nervous system
- peripheral nervous system
What is the human nervous system?
A body wide system of nerve cells that collects and processes information and then directs organs and muscles via electro chemical messages
What is the function of the CNS and what 2 parts of the body do they contain?
- complex processing
- the brain (all conscious and most unconscious processing)
- the spinal cord (receives and transmits information, also is responsible for some simple reflexes)
What is the peripheral nervous system?
A body wide network of messenger neurons. Sensory neurons deliver information to the CNS and motor neurons transmit information away from the CNS
What is the PNS split into and what are they?
- somatic nervous system (controls skeletal muscles and is a voluntary system)
- autonomic nervous system (controls actions of internal organs and glands and is an involuntary system)
What does the sympathetic branch (ANS) do?
Increases bodily activities and releases noradrenaline in a stress response (fight or flight)
-heart rate increase
-sweat increase
-breathing rate increase
-dilates pupils
-inhibits digestion
What does the parasympathetic branch do?
Decreases bodily activities and releases acetylcholine. Activates in rest (rest and digest)
-heart rate decrease
-sweat decrease
-breathing rate decrease
-constricts pupils
-stimulates digestion
What is the motor cortex responsible for?
Responsible for voluntary motor movements
Where is the motor cortex found?
Found in BOTH frontal lobes of the brain
What is the function of the somatic nervous system?
Transmits information from receptor cells to the CNS
Also receives information from the CNS that directs muscles on how to act
What is the function of the autonomic nervous system?
Responsible for unconscious bodily functions
What is the autonomic nervous system split into?
The parasympathetic nervous system / the sympathetic nervous system
What is the function of the sympathetic nervous system?
Co-ordinates organs when in situations when the individual needs to be aroused / when our muscles need oxygen
Signals to our hearts,lungs and liver when to work harder
What is the function of the parasympathetic nervous system?
Co-ordinates to our organs when we can relax and conserve energy
Rest + digest
What happens to the eye, heart and saliva glands in the SNS
Pupil dilates
Heart rate increases
Inhibited saliva production
What happens to the eye, heart and saliva glands in the PSNS?
Constricts pupil
Heart rate decreases
Stimulated saliva production
What are the 6 parts of a neuron?
- Cell body / soma
- Nucleus
- Dendrites
- Axon
- Myelin sheeth
- Axon terminal
What is the function of the soma?
Control centre of the neuron and includes the nucleus
What is the function of the nucleus?
Contains genetic material of the cell
What is the function of the dendrites in a neuron?
Dendrites recieve signals from other neurons or from sensory receptor cells. Typically connected to cell body
What is the function of the axon in a neuron?
Long slender fibre that carries nerve impulses in the form of an electrical impulse, action potential.
What is the function of the myelin sheath in the neuron?
Insulates axon so impulses travel faster and preserves the signal
What is the function of the axon terminal in a neuron?
Connects the neuron to other neurons using a process called synaptic transmission
What is unique about a relay neuron?
A relay neuron has no myelin sheath
What is unique about a sensory neuron?
In a sensory neuron the cell body sticks out
What is the function of a sensory neuron?
Sensory neurons transmit nerve impulses from sensory receptors to the brain and spinal cord
Impulses begin as sensory receptors and are translated into sensations at the brain which allows for reflex actions
What is the function of a motor neuron?
Carry impulses from the CNS to other areas of the body
Releases neurotransmitters which bind to muscle receptors and trigger muscles movement
Muscle relaxation is caused by the inhibition of the motor neuron
What is the function of a relay neuron?
Connect sensory and motor neurons allowing for communication
Located in brain and spinal cord
What neurons are uni/multipolar?
Unipolar- sensory neurons
Multipolar- motor and relay neurons
What was the aim of Sperry and Gazzanigas study?
To investigate the effects of hemispheric reconnection and to show that each hemisphere has different functions
What was the method of sperrys split brain study?
Comparing performance of 11 split brain patients, who had undergone surgery for their epilepsy to people with no connection
In lab conditions, participants were asked to fixate on a dot in centre of screen while a word or picture was flashed to the left or right visual field for 1/10 of a second
They would then make responses verbally or using left/right hand without being able to see their hands
What were the results of the split brain study?
- When object was shown to right visual field the patient could easily say what was seen but if object was shown to left visual field they reported nothing was there - although could identify object from a grab bag using their left hand
- If two words were simultaneously on their side of the visual field the patient would write the word on the left with their left hand and say the word on the right
- When asked to match a face from a series of faces, picture processed from right hemisphere was consistently selected whereas left hemisphere was consistently igored
What are the evaluation points of split brain research? AO3
+ quasi experiment / high control
+ pioneering research
- population validity
- individual differences - lateralisation not fixed
How does split brain research have high control? AO3
P: Sperry and Gazzanigas research is a quasi experiment we they were able to take advantage of the naturally occurring variable as the epileptic patients had experienced hemisphere deconnection
E: able to have high control over the experimental environment and so demonstrate the effect that hemisphere disconnection has on brain function
E: since hemisphere deconnection was regarded as the only significant difference between the two groups, the observed difference in performance was seen as having been caused by this deconnection so providing support for the theory of hemispheric lateralisation
L: consequently it can the argued that this study has high internal validity
How is Sperrys split brain research pioneering research? AO3
P: this research had a huge impact on our understanding of how different hemispheres of the brain work
E: Sperry and Gazzanigas work into split brain has produced an impressive sizeable body of research that suggests that the left hemisphere of the brain is more analytical and verbal and the right is more adept to spatial tasks and music
E: this is a strength as the research has enabled scientific progress
How does Sperry and Gazzanigas split brain research have low population validity? AO3
P: research has low population validity
E: sample consists of only 11 split brain patients which is a small sample size which may not be representative. In addition, participants epilepsy may of caused changes in the brain which are not present in the brains of others - another reason why the sample may be unrepresentative
E: consequently, it can be argued that this study lacks external validity
How are individual differences a limitation of Sperrys split brain research? AO3
P: lateralisation appears to change with age and for many types of task
E: patterns in younger individuals tend to switch to bilateral pattern in health older adults. For example, Szaflarski found that language becomes more lateralised in the left hemisphere with increasing age, but after the age of 25 lateralisation decreased with each decade of life. This suggests that older people’s brains recruit both hemisphere to increase their processing power, perhaps to compensate for age related cognitive decline
E: this is a limitation of hemispheric lateralisation theory because these findings suggest that the theory might not be completely correct
What does plasticity refer to?
The brains tendency to change or adapt
What age did Gopnik find to have the most synaptic connections?
2-3 years old with 15,000 connections
What is synaptic pruning?
When neurons that are rarely used die
How does the brain constantly adapt to a changing environment?
By developing new pathways and pruning away weak ones
What does synaptic pruning enable?
Lifelong plasticity because new neuronal connections are formed in response to new demands on the brain
What was Boyke et als plasticity study?
60 year olds taught new skill - juggling
What did teaching 60 year olds juggling result in (Boyke et als study)
Increases in grey matter in the visual cortex, although when practicing stopped these changes reversed
What was the aim of Maguire et als plasticity study? AO1
To investigate whether changes in the brain could be detected because of extensive experience of spatial recognition
What was the sample of Maguire et als taxi study?
16 male London taxi drivers
50 males who didn’t drive taxis
What did Maguire et al use to measure the ammount of grey matter in taxi drivers and control groups brains
MRI scanner
What did Maguire et al use to measure the ammount of grey matter in taxi drivers and control groups brains
MRI scanner
What were the findings of Maguire et als plasticity study? AO1
The posterior hippocampus ( spatial and navigational skills) was larger than those of control group.
Posterior hippocampus volume was positively correlated with the ammount of time they had been a taxi driver
What are the evaluation points of Maguire et als plasticity study? AO3
+ highly empirical
- population validity
- evidence is correlations
How is it a strength that Maguire et als study is highly empirical? AO3
P: Maguire research is highly empirical
E: brain scans provide objective evidence to show that cab drivers she studied did have a significantly greater volume of grey matter in the posterior hippocampus than a matched control group
E: this is a strength as these findings provide verifiable evidence for brain plasticity and so suggests that the conclusions drawn about brain plasticity are valid
How does Maguire et als study have low population validity? AO3
P: she only used a small sample of 16 London male taxi drivers
E: it is possible that the group of participants are not representative of the population
E: this means that maguires conclusion that the brain physically changes as a result of experience may not be valid. However, there is no evidence to suggest that her sample size was unrepresentative which suggests that a lack of population validity is not really an issue. However, since the sample only consisted of males it is possible that her findings are not applicable to females
How is it an issue that Maguire et als plasticity study produced correlations evidence? AO3
P: an issue is that the evidence is correlational
E: this means that she has not proven that the taxi drivers brains have changed as a direct result of their experience - might be due to another factor
E: however, the correlation between their occupation and enhanced grey matter was very clear, which suggest that, despite being correlational, maguires evidence is valid
What evidence is there to support the claim that plasticity does not decline sharply with age? AO3
P: there is evidence that plasticity does not decline sharply with age
E: bezzola et al demonstrated how 40 hours of golf training produced changes in neural representations of movement in participants aged 40-60, using FMRI scans. Researchers observed increased motor cortex activity in novice golfers compared to control group suggesting more efficient neural representations after training
E: this demonstrates that neural plasticity can continue throughout the lifespan
What is a limitation of plasticity of the brain? AO3
P: a limitation of plasticity is that it may have negative behavioural consequences
E: for example, 60-80% of amputees develop phantom limb syndrome. The continued experience of sensations in the missing limb as if it were still there, these sensations are usually unpleasant. They are thought to be due to cortical reorganisation in the somatosensory cortex
E: this suggests that the brains ability to adapt to damage is not always beneficial
What does functional recovery refer to?
Functional recovery refers to a form of plasticity following trauma where the brain redistributes or transfers functions from damaged areas to undamaged areas
Neuroscientists suggest at first this can occur quickly following trauma but ___ ____ after several months. At this point the individual may require _____
- Slow down
- Rehabilitation
What happens to the brain during recovery?
The brain rewires itself by forming new synaptic connections close to area of damage and secondary pathways are unmasked to enable functioning to continue
What are the 3 structural changes in the brain which support recovery?
- Zonal spouting
- Denervation super sensitivity
- Recruitment of homologous area on the opposite side of the brain
Define Axonal spouting
The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
Define denervation super sensitivity
Axons that do a similar job to the damaged areas are armoured to a higher level to compensate. However this can have unfortunate consequence of over sensitivity