Biopsychology Flashcards
The human nervous system is divided into…?
The central nervous system and the peripheral nervous system
The central nervous system is made up of…?
The brain and spinal cord
What is the autonomic nervous system made up of?
Sympathetic nervous system and parasympathetic nervous system
What is the peripheral nervous system made up of?
The somatic nervous system and the autonomic nervous system
The brain is the centre of all…?
Conscious awareness
Describe the role of the spinal cord in the central nervous system
It’s responsible for reflex actions (involuntary)
Passes messages to and from the brain
Connects the nerves to the peripheral nervous system
What is the Peripheral nervous system made up of?
It’s made up of nerves that are outside of the central nervous system
When the peripheral nervous system gets information from the outside world, it sends it to…?
The central nervous system
When the PNS gets information from the CNS, it sends the info to…?
Muscles and glands in the body
The somatic nervous system responds to info from…?
Sensory receptors
How does the SNS transmits info to the CNS?
Using sensory neurons, it transmits info from. Receptor cells in the sense organs towards the CNS
Where does the SNS receive info and for what?
From the CNS
To direct muscles to act using motor neurons - muscle movement
State 2 differences between the CNS and the PNS
1a) CNS = origin of all complex demands + decisions
1b) PNS = Receives and sends messages to the CNS
2a) Entire CNS = encased in bone
2b) PNS = connects the CNS to the organs in the body
State all the glands in the endocrine system
Hypothalamus Pituitary Thyroid Adrenals Pancreas Ovaries Testes
How do hormones work?
Hormones are secreted by glands into the blood stream and affect any cell in the body that has a receptor for that hormone
Describe the autonomic nervous system
It is automatic and involuntary
Why is the ANS important in homeostasis?
It controls automatic redness and vital functions e,g breathing/ heartbeat
What other system does the ANS work with in the fight or flight response?
The endocrine system
What happens during fight or flight?
Stressor is perceived
Hypothalamus activates pituitary gland
Pituitary gland triggers activity in sympathetic nervous system in ANS
Physiological changes = adrenaline leads to heart rate increase
Parasympathetic = when threat is over
Define the sympathetic state
This is when the body is involved with fight or flight in repose to a stressful event
The sympathetic nervous system gets the body ready by increasing heart/ breathing rates
Describe the parasympathetic state
This is the normal resting state of the body.
What is a neuron?
They are nerve cells that process and transmit messages through electrical and chemical signals.
There is 100 billion in the human nervous system = 80% of them is in the brain
What are sensory neurons?
Carry messages from the PNS to the CNS. They have long dendrites and short axons.
What are motor neurons?
These connect to the CNS to effectors e.g muscles and glands. They have short dendrites and long axons
What are dendrites?
They carry nerve impulses from neighbouring neurons towards the cell body
What is the function of the relay neuron?
To allow the sensory and motor neurons communicate
What are relay neurons?
These connect the sensory neurons to the motor/ other relay neurons.
They have short dendrites and axons.
What is the axon?
This carries impulses from the cell body along the length of the neuron. This is covered by the myelin sheath.
What is the myelin sheath?
This protects the axon and speeds up transmission of electrical impulse
What is the node of ranvier?
This is gaps in the myelin sheath which speed up the transmission of impulse by forcing it to ‘jump’ across the gap
What is the Schwann cell
This forms the myelin sheath
Where can the sensory neuron be found?
Receptors outside the CNS e.g eyes, ears
Where can motor neurons be found?
CNS = dendrites and cell body is in the spinal cord, Axon is outside the spinal cord
What is the axon terminal?
Terminal buttons at the end communicate with the next neuron across the synapse
What is the function of motor neurons?
To carry messages to organs and muscles
What is the function of sensory neurons?
To send info to the brain about the internal and external environment through our senses.
Some sensory neurons stop at the spine = allow for reflexes
What happens inside a neuron?
Electrical transmission
1) resting state = inside of cell is negative compared to the outside
2) neuron when activated by stimulus = positively charged for a split second.
3) Action Potential produced
What is action potential?
This causes an electrical impulse that travels down the axons towards the end of the neuron
Where can the relay neuron be found?
Makes up 97% of all neurons and most are found in the brain and spine, in the visual system
What is synaptic transmission
This is how neighbouring neurons communicate with each other by sending chemical messages across the synapse
What happens in synaptic transmission?
1) electrical impulse in presynaptic nerve terminal triggers the release of neurotransmitters from synaptic vesicles
2) neurotransmitters = chemicals that diffuse across synapse to reach impulses to the next neuron
3) Absorbed by the post synaptic receptor sites on the dendrites of the other neuron = lock and key
What happens if a neurotransmitter has an inhibitor effect on the neighbouring neuron?
It will increase its negative charge and make it less likely to fire
E.g serotonin causes inhibition
What is summation?
This is the overall effect on the post synaptic neuron. Once the electrical impulse is created, it travels down the neuron
What is an early theory of the brain?
Before 19th century belief.
Scientists believed that all parts of the brain were involved in all thoughts and actions.
What happened to Phineas Gage (case study)?
In 1848 1m iron rod went through Gage’s left cheek, behind left eye and through his frontal lobe and out of his head.
What was the aftermath of the work accident for Gage?
Gage survived and was able to function the same.
H/E = frontal lobe is in charge of higher mental functions e.g social interactions and planning. So Gage was seen to now rude and impatient - what we know as Frontal Lobe Disorder.
Why is Phineas Gage important as a case study?
Challenged the holistic view as suggested by previous scientists.
Contributed to modern neurology = supported location of the brain. Specific parts of the brain have different functions.
Who did Broca and Wernicke study?
People with language problems
How did Broca and Wernicke study this sample?
By looking at their brains post-mortem
What did Broca and Wernicke find from the post-mortems of brains?
Found anatomical differences and damage to to people with language problems.
This enabled them to identify specific brain areas are associated with specific language functions.
What is another modern example that supports localisation of function (Sz)?
Sz = low levels in the ventral stratum is linked with negative symptoms.
The brain is divided into two…?
Hemispheres
The two hemispheres in our brain is joined by the…?
Corpus Callosum
What is the Corpus Callosum made up of?
Bundles of nerve fibres
What does the Corpus Callosum do?
All communication between the hemipsheres of the brain.
What does contralateral mean?
When the function of the body on one side is controlled by the opposite hemisphere of the brain.
E.g = Movment of the left hand is controlled by the right hemisphere of the brain.
What does localisation mean?
Different areas of the brain is repsonsible for specific bhvrs, processes or activities. E.g Broca’s area is in charge for speech production whereas Wernicke’s = understanding what people say.
What is lateralisation?
The two hemispheres of the brain fucntion differently and different processes are mainly controlled by the hemisphere (which is lateralised and localised)
What covers the cerebral cortex?
It is an outer layer (3mm thick) that covers the two hemispheres. It is grey matter and more developed compared to animals.
What are the names lobes that the cortex of the two hemispheres are divided in?
Frontal lobe
Parietal Lobe
Occipital Lobe
Temporal Lobe
Where is the motor centre found?
In both hemispheres
Back of the frontal lobe
What does the motor centre do?
Controls voluntary movement in the body
What happens when the motor centre is damaged?
Loss of control of fine moments
Where is the somatosensory centre found?
Frontal lobe = separated from the motor centre by a valley = central sulcus
What does the somatosensory centre do?
Process sensory info (e.g heat)
The more devoted the centre is to a specific area, the more sensitive the area will be. E.g hands and face = over half of the somatosensory area.
Where is the Borca’s area found?
Left hemisphere, frontal lobe
What does the Broca’s area do?
Speech production
What happens if the Broca’s area is damaged?
Broca’s aphasia
What is Broca’s aphasia?
Speech becomes slow, labourious for the person and lacks fluency.
They also find prepositions and conjunctions hard.
Example patient = Tan
Where is the visual centre ?
Occipital Lobe
What does the visual centre do?
Process visual info
What happens if the visual centre is damaged?
Blindess
Where is the Wernicke’s area found?
LH, temporal lobe
What does Wernicke’s centre do?
Language comprehension
What happens if Wernicke’s centre is damaged?
Wernicke’s aphasia
what is Wernicke’s aphrasia
Part of a person’s speech has nonsense words in them.
Where is the auditory centre?
Temproal lobe in both hemispheres
What does the auditory centre do?
Process speech-based info
What happens if the auditory centre gets damaged?
Hearing loss and if there is damage in the Wernicke’s area, language comprehension.
How does neurosurgery support the localisation of function of the brain?
Cingulotomy = isolates the cingulate gyrus.
Dougherty et al (2002) = reported 44 people with OCD and used this procedure.
After 32 weeks = 30% success and 14% were partial responses.
This increases the validity and application of localisation of function in the brain.
How does brain scans support localisation of function in the brain?
Brain scans = objective and scientific.
Tulving et al (1994) = episodic and semantic memory are different areas in the prefrontal cortex.
This increases the internal validity of the theory. Supports biological determinism.
What is a counterpoint from Lashely that discredits the validity of localisation?
Lashley (1950) = removed areas from the cortex (10-50%) in rats who were learning routes through a maze.
No area was found to have a specific effect on the rats’ learning ability.
How are case studies a weakness of localisation of function?
Has a low generalisability. Conclusions could be subjective because they depend on the interpretation of the researcher.
Evidence supporting localisation may lack validity, oversimplifying brain processes and undermine theory. Early studies of brain damage = poorly controlled and lacked objectivity compared to brain scans.
What does LLLL stand for?
Langauge centres are
Localised and
Lateralised to the
Left
What is lateralisation?
The concept that the two hemispheres of the brain have different functionality.
What is split brain procedure?
Research on people who have had their hemispheres separated by severing the corpus callosum
If information comes from the LEFT visual field, where is it processed?
RIGHT hemisphere because it is contralateral
If information comes from the RIGHT visual field, where is it processed?
LEFT hemisphere
How is the processing of vidual info processed across hemispheres?
Uses the corpus callosum
Who carried Split brain research?
Sperry (1968)
Why did people choose to have split brain procedures?
To control severe epileptic seizures
What did Sperry (1968) do?
Aim = to show that the hemispheres of the brain had specific functions
Sample = 11 split brain participants.
Procedure = participants look at a screen with a dot in the middle. Other eye is blindfolded. An object is shown to the left or right visual field for 1/10th of a second. Participants are asked what it is.
This made sure only one hemisphere was getting info at a time.
In relation to language, what were Sperry’s findings?
Image shown in the RVF (LH) = participants could say what they saw.
Image shows in the LVF (RH) = participants couldn’t say what they saw. They can draw it instead. Bc there were no language centres in the RH.
In relation to recognition tasks, what were Sperry’s findings?
Ps can recognise and choose items presented to their LVF even if they couldn’t name the object.
Shows the right hemisphere = understand what the object was.
In relation to facial recognition, what were Sperry’s findings?
Facial recognition happened in the RH
How does supporting evidence a strength of lateralisation?
Fink et al (1996) = used PET scans to identify which brain areas were active during visual processing tasks.
Normal brain Ps = asked to looked at global elements of an image (pic of a whole forest) –> regions of RH was more active.
Then asked to focus on the finer detail (e.g individual trees) –> specific ares of LH dominate activity.
Findings and Conclusions = hemispheric lateralisation is a feature of the normal brain.
How is lateralisation and the immune system linked and how does it support the lateralisation theory?
Architects and mathematically gifted people = more likely to have higher right hemispheric skills + left-handed + suffer higher rates of allergies and problems with the immune system.
Supported by Tonnessen et al (1993)
APPLICATION and INTERNAL VALIDITY
How does changes in age negatively affect lateralisation?
Szaflarski et al (2006) = language is more increasingly lateralised in the LH with under 25s. But after 25 = every decade lateralisation decreases.
We don’t know why, possibility = compensate for age-related decline in function. Link to plasticity.
How does research support increase the validity of split-brain research?
Luck et al 1989 - split-brain participants performed better than normal controls on specific tasks e.g they were faster identifying the odd one out in a group of similar objects.
This supports Sperry’s early findings that the left and right brain are distinct.
How is split-brain research ethically wrong?
Trauma of the operation on Ps = not fully understand the situation and implication when they consented. They were subjected to repeated testing over long periods of time (some years) which may have been stressful.
How was Sperry’s control group a weakness of split-brain research?
Participants were compared to neurotypical control group. H/E confounding variable = none of the CG had epilepsy.
Differences found = may be bc of epilepsy rather than split-brain. Thus the generalisability of the research is low because of the methodology.
What is plasticity?
The brain changes or adapts functionally and physically.
This is because of experience and new learning.
What is functional recovery (a form of plasticity)?
The brain changes, redistributes or transfers functions from one area to another.
This is a result of damage (e.g stroke( and trauma.
What does Gopnick et al (1999) argue about plasticity?
Connections in babies’ brains show rapid growth int synaptic connection.
At age 2-3 years old = peaks at 15,000
This 2x as many compared to an adult brain.
What is synaptic pruning?
When synaptic connection that we don’t use very much are deleted and what we use are made stronger.
Recent research = neural connections can be changed/ formed at any stage in our life.
What does Maguire et al (2000) research about plasticity?
Studied brains of London taxi drivers
Found increased grey matter in the posterior hippocampus which is linked to development of spatial and navigational skills and in humans and animals.
The more time spent in job = greater structural difference (positive correlation)
What does Draganski et al (2006) research about plasticity?
Imaged brains of medical students 3 months before and after final exams.
Findings = learning-induced changes in the posterior hippocampus and parietal cortex
What does functional recovery refer to?
When unaffected areas of the brain adapt and compensate for damaged areas.
What is spontaneous recovery?
When there is quick recovery after the trauma but after several weeks/months it slows down.
Rehab may be needed to used for further recovery when it slows down.
What happens in the brain during recovery of function?
The brain forms new synaptic connections near the area damaged
Doidge (2007) = secondary neural pathways are activated or unmasked so functioning can be continued.
What are secondary neural pathways?
They are dormant synapses
What is axonal sprouting as a structural change in the brain during recovery?
Axonal sprouting = growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways. It can also reconnect with neutrons whose links have been damaged or severed.
What is the recruitment of homologous areas a structural change in the brain during recovery?
Similar areas in the hemisphere that is opposite the damaged one, carries out the function.
E.g Broca’s area damaged LH, RH equivalent would carry out its functions.
What is denervation supersensitivity as a structural change in the brain during recovery?
Axons that do a similar job to the ones damaged, becomes more aroused to a higher level to compensate.
Can lead to problems = oversensitivity to pain.
What are the 3 main phases of plasticity in functional recovery of the brain?
- Immediately after injury
- After few days
- After few weeks
What happens immediately after the injury?
Neurons begin to die + secondary neural networks that haven’t been/rarely used are uncovered/activated.
This phase lasts 1-2 days
What happens after few days of injury?
New synapses are formed; both neutrons + other cells are recruited to replace damaged/ dead cells + facilitate healing
What happens after a few weeks after the injury?
New synapses continue to appear and “remodelling” of the brain continues = when therapy can help the brain learn new pathways
How is it a strength that neural plasticity can continue throughout the lifespan?
Bezzola et al (2012) = 40 hrs of golf training produced changes in the neural representations of movement in participants aged 40-60. Using fMRI = found increased motor cortex activity in novice golfers compared to control group. This shows there was more efficient neural representations in the experimental group than CG. APPLICATION
How does plasticity have negative effects and why is this a weakness?
Medina et al (2007) = prolonged drug use could cause ⬇️ cognitive functioning and ⬆️ risk of dementia.
This Qs the validity of the theory bc it doesn’t explain why there are negative changes to individuals and their differences
What happens if a neurotransmitter has an excitatory effect on a neighbouring neuron?
It will increase it’s positive charge and make it more likely to fire
E.g adrenaline
What does fMRI stand for ?
Functional magnetic resonance imaging
How does the fMRI machine work?
Detects changes in blood oxygenation and blood flow as a result of neural brain activity = more active, more consumption of O2
Name strengths and weaknesses of fMRIs
Good - non evasive and has a very high spatial resolution (1-2mm)
Bad - expensive and poor temporal resolution bc 5 second time lag
What does EEG stand for?
Electroencephalogram
How does EEGs work?
Electrodes are attached to the brain and measures the brain wave patterns made by millions of neurons
What are the strengths and weaknesses of EEGs
Good - useful in studying stages sleep and diagnosing epilepsy + high temporal resolution (1-10 milliseconds)
Bad - overall account of brain activity = can’t pinpoint which neuron
What does ERP stand for?
Event related potentials
What is ERPS?
Puts electrodes on the scalp (uses EEG), but isolate specific responses they are interested in. This lets them look at even re,aged potentials - the brain wave triggered by a particular event or cognitive task
Strengths and weaknesses of ERPs
Good - good temporal resolution (1-10 milliseconds) and good for measuring cognitive function = helped identify tiff aspects important with working memory
Bad - evasive + cannot eliminate the extraneous variables
