biopsych Flashcards
Describe the structure and function of a neuron.
Neurons enable communication within the nervous system
Cell body (soma) contains the genetic material
Dendrites extend from the cell body (often with dendritic spines), carry functional information towards the cell body and can receive information from other neurons
Axons carry messages away from the cell body, can be myelinated to increase speed of nerve transmission
Terminal boutons are at the end of axons, these make synaptic connections with other cells
Axon terminals contain neurotransmitters
Outline the difference in function between Broca’s area and Wernicke’s area.
Broca’s area is responsible for speech production whereas Wernicke’s area is responsible for
language comprehension
Broca’s area enables speech to be fluent whereas Wernicke’s area enables speech to be meaningful.
Ways of studying the brain.
- post-mortem examinations study the brain after death to try and correlate structural
abnormalities to behavioral changes - EEGs use electrodes fixed to a participant’s scalp which detect neuronal activity directly below
where they are placed - ERPs use electrodes fixed to a participant’s scalp to detect neuronal activity in response to a
stimulus introduced by the researcher - fMRI use magnetic field and radio waves to detect changes in blood oxygenation and flow as a
result of neural activity. It gives a moving picture of the brain; activity in regions of interest can
be compared between a specific activity and a baseline task.
Discuss ways of studying the brain.
- fMRI data is complex and can be affected by the baseline task used and how the data is
interpreted - fMRIs have low temporal resolution and research is expensive leading to low sample sizes
which can reduce the validity of studies - post-mortem examinations require special permission to be conducted which often leads to
small sample sizes - post-mortem examinations can be affected by changes which occur during/after death
- post-mortem examinations enable deeper regions of the brain to be investigated than
non-invasive techniques - EEGs and ERPs are cheaper than fMRIs so enable larger sample sizes which can increase the
validity of the data obtained - EEGs and ERPs have poorer spatial resolution than fMRIs
- unlike post-mortem examinations, neuroimaging techniques allow the active brain to be
investigated during specific tasks/activities - research studies used to evaluate techniques described.
Explain the difference between infradian rhythms and ultradian rhythms.
the rhythms have different durations: infradian rhythms have a duration of over 24hrs whereas
ultradian rhythms are cycles that last less than 24hrs.
Explain one limitation of asking hospital patients to self-report the effectiveness of
Zapurpain.
- social desirability, patients may feel obliged to say the drug is effective at reducing their pain
- pain is subjective, a participant who has a higher pain threshold may report Zapurpain to be more
effective for example.
Explain how Zapurpain might affect the process of synaptic transmission through
inhibition.
- Zapurpain mimics the effect of inhibitory neurotransmitters, stimulation of postsynaptic receptors by an
inhibitory neurotransmitter result in inhibition (hyperpolarisation) of the postsynaptic membrane - when an inhibitory neurotransmitter binds to the post-synaptic receptors it makes the post-synaptic cell
less likely to fire (IPSP) - Summation – if inhibitory inputs are higher than excitatory they can cancel out excitation and inhibit an
action potential occurring/Zapurpain would decrease the overall activity - Zapurpain would make the post-synaptic cell less likely to fire
- reducing brain activity may lead to reduced pain.
Explain one difference and one similarity between Functional Magnetic Resonance
Imaging (fMRI) and Event-Related Potentials (ERPs) as ways of studying the brain.
- fMRIs have poor temporal resolution whereas ERPs have good temporal resolution
- fMRIs have good spatial resolution whereas ERPs have poor spatial resolution
- fMRIs provide indirect measure of neural activity whereas ERPs offer a direct measure of neural
activity - different methodology - fMRIs work by measuring changes in blood oxygenation as a measure of
neural activity whereas ERPs measure electrical activity via electrodes to detect brainwaves triggered
by certain events - fMRIs are more expensive than ERPs
Outline split-brain research.
- ‘split-brain’ patients have had their corpus callosum severed
- Sperry’s methodology
- Sperry’s key visual/tactile findings
- case of Karen Bryne – Alien Hand Syndrome
evaluate split-brain research.
- ‘split-brain’ research has enabled discoveries of lateralisation of function
- experiments on split-brain patients were scientific
- research has added to the unity of consciousness debate
- lack of controls: extent of disconnection between hemispheres varied, lack of valid control groups,
may be additional effects of surgery other than just procedure, some patients had experienced drug
therapy for much longer than others - artificial data – in real life severed corpus callosum can be compensated for by unrestricted use of two
eyes - ‘split-brain’ patients may initially suffer from hemispheres acting independently but in an adaptive
process one tends to dominate - issue of generalisability – research relates to small sample sizes, Andrewes (2001) and patients are
atypical - research oversimplifies hemispheric lateralisation – usually hemispheres are constantly
communicating, and plasticity allows for compensation across hemispheres - contradictory findings casting doubt over discoveries made, eg Gazzaniga (1998), patient JW in Turk
et al. (2002).
Which method of studying the brain would most accurately identify specific brain areas
activated during a cognitive task?
Functional magnetic resonance imaging (fMRI)
Using an example of a gland and hormone, outline the function of the endocrine
system. Do not use the adrenal gland/adrenaline as your example.
- the endocrine system helps to regulate the activity of cells and organs in the body
- the endocrine system communicates chemical messages to the organs of the body
- the thyroid gland produces thyroxine, which increases heart rate and metabolic rates
- the pineal gland produces melatonin, which may help regulate the wake-sleep cycle
- the anterior pituitary gland secretes Luteinizing hormone (LH) & Follicle-stimulating hormone (FSH),
which stimulate ovaries to produce oestrogen & progesterone - the anterior pituitary gland secretes LH & FSH, which stimulate the testes to produce testosterone &
sperm - the posterior pituitary releases oxytocin, which stimulates the uterus to contract during labour and also
plays a role in bonding - the pancreas secretes insulin and glucagon, which help regulate blood sugar levels.
Discuss research into localisation of function in the brain and/or hemispheric
lateralisation.
- localisation of functions in the brain such as the somatosensory cortex, motor cortex, primary visual
cortex, primary auditory cortex, Broca’s area and Wernicke’s area and research supporting these
functional divisions.
Note – examiners should be aware that candidates may refer to other specific areas such as the
hippocampus and amygdala which would be creditworthy - hemispheric lateralisation refers to the notion that certain functions are principally governed by one
side of the brain - case studies, eg Phineas Gage, Leborgne (Tan), Lelong, etc., or imaging studies suggesting particular
functions are dealt with by one hemisphere, eg Fink, Hallingan et al, 1996, Clarke, Assal & de Tribolet,
1993, etc. - Sperry’s (1968) split brain research studies
- case studies involving damage to the corpus callosum, eg Kim Peek
- Broca’s discovery that the speech production area was in the left hemisphere
- Wernicke’s discovery that the area for understanding language was in the left hemisphere.
Evaluate research into localisation of function in the brain and/or hemispheric
lateralisation.
- gender differences, eg Harast et al (1997)
- lateralisation patterns shift with age, eg Szaflarski et al 2006, with most tasks generally becoming less
lateralised in healthy adulthood - functions such as language are too complex to be assigned to just one area and instead involve
networks of brain regions - support for functional differentiation from aphasia cases used as a counter-argument
- equipotentiality theory – Lashley 1930
- issues with generalising from non-human animals to humans in lesion studies
- findings from plasticity studies that show compensation by undamaged regions on the opposite
hemisphere, eg Danelli et al 2013 - issues generalising from case studies or from ‘abnormal’ patients, eg participants in the split brain
research - discussion of patient J.W. who could speak about information presented to the left or right brain (Turk
et al, 2002) - issues with generalising from studies with small participant numbers.
Give one difference between the autonomic nervous system and the somatic nervous
system.
- the autonomic nervous system is involuntary whereas the somatic nervous system is under
conscious control. - ANS controls smooth muscles and glands whereas the SNS controls skeletal muscles.
