biopsychology - everything Flashcards
what is the function of the central nervous system
receives information from the senses and controls behaviour and regulation of the body’s psychological processes
what is the central nervous system composed of
the brain and spinal cord
what is the function of the hypothalamus
controls basic functions such as hunger, thirst, sexual behaviour and also controls the pituitary gland
what is the peripheral nervous system
part of the nervous system that is outside the brain and spinal cord, connects the brain and spinal cord to the rest of the body and external environment
what is the peripheral nervous system made up of
autonomic and somatic
what is the somatic nervous system
controls voluntary movements
what is the autonomic nervous system
regulates involuntary actions such as body temperature, homeostasis, heart rate, digestion, blood pressure
what are the two divisions of the autonomic nervous system
sympathetic and parasympathetic nervous system
what is the sympathetic nervous system
involved in responses which help to deal with emergencies e.g fight or flight
what is the parasympathetic nervous system
relaxes an individual once an emergency has passes
what do the brain and spinal cord do
brain makes decisions and the spinal cord helps the brain communicate with the body
what is a sensory neurone
convey informations about sensory stimuli e.g vision, taste, touch
what is a motor neurone
conveys instructions for physical operations e.g muscle movement
what is a relay neurone
connects different parts of the central nervous system (in the brain)
what is an excitatory synapse
makes nerve impulse more likely to be triggered
what is an inhibitory synapse
makes nerve impulses less likely to be triggered
what are hormones
chemical messengers secreted from structures (glands) in the body which pass through the bloodstream to cause changes in our body or behaviour
how are hormone levels controlled
by the endocrine system
what is the adrenal medulla
hormone = adrenaline and noradrenaline
fight or flight response, increase heart rate and blood pressure
testes
hormone = testosterone
male sex characteristics
ovaries
hormone = oestrogen
female sex characteristics, the menstrual cycle and pregnancy
pineal gland
hormone : melatonin
sleep wake cycle
what is the pituitary gland
the master gland that controls the release of hormones from the other glands
what is a threat recognised by
the amygdala
what is the amygdala
almond shaped structure in the brain, responsible for emotional responses and communicates with the hypothalamus
what is an acute stressor
short term stressors e.g chased by a lion
what is a chronic stressor
long term stressor e.g stressful job
what is the sympthatho-medulla pathway
amygdala informs the hypothalamus of the danger and arouses the sympathetic nervous system. The hypothalamus alerts the adrenal medulla to release either adrenaline or noradrenaline
what effects do the fight or flight response have on the body
saliva flow decreases
pupils dilate
digestion slows down
deep quick breathing
heart beats faster
chills and sweating
what happens once a acute stressor has passed
the parasympathetic nervous system kicks in, balances and reverse the excitation
what happens if the stress does not pass
the body cannot survive in fight or flight mode so the Hypothalamic-Pituitary-Adrenocortical Axis
what is the process of a chronic stressor
the hypothalamus activates the HPA by releasing CRH, the pituitary gland releases ACTH, the adrenal cortex releases cortisol, stored glucose is turned into glycogen giving the body more energy and the immune system is repressed
what is localisation of function
the theory that different areas of the brain are responsible for different behaviours, processes or activates
what is the motor cortex
responsible for voluntary motor movements
where is the motor cortex
at the rear of the frontal lobe along a bumpy region known as the pre central gyrus, both hemispheres have a motor cortex with the motor cortex on one side of the brain controlling the opposite side of the body
what is the somatosensory cortex
detects sensory events from different areas of the body e.g touch, pressure, pain and temperature
where is the somatosensory cortex
in the parietal lobe along a region known as the postcentral gyrus, both hemispheres have one
what are the visual centres
visual processing actually begins in the retina, where light enters and strikes the photoreceptors, nerve impulses from the retina are than transmitted to the brain via the optic nerve, some nerve impulses are involved in the coordination of circadian rhythms but most terminate in an area of the brain called the thalamus which acts as a relay station, passing information on to the visual cortex
where is the visual centres
at the back of the brain
what are the language centres
Broca’s area and Wernickes area
what is Broca’s area
responsible for language production
where is Broca’s area
in the posterior portion of the frontal lobe of the left hemisphere
what is Wernickes area
responsible for understanding language
where is Wernickes area
posterior portion of the left temporal lobe
what supports language centres
aphasia studies
what are aphasia studies and how do they support language centres
aphasia refers to an ability (or impaired ability) to understand or produce speech as a result of brain damage, expressive aphasia is an impaired ability to produce language caused by brain damage in Broca’s area, receptive aphasia is an impaired ability to understand language, an inability to extract meaning from spoken or written words resulting from brain damage in Wernickes area
what is a limitation to localisation
communication may be more important, areas of the brain are interdependent in the sense that in order to work they must interact with each other, therefore damage to the connection results in impairments that resemble damage to the localise brain region associated with that specific function
what is the equipotentiality theory (Lashley, 1930)
basic motor and sensory functions are localised but higher mental functions are not, Lashley removed areas of cortex in rats that were learning a maze, no area was found to be more important than another in solving the puzzle therefore learning seems to require all areas
limitation to localisation involving plasticity
brain damage patients who have lost a specific function can regain functions through cognitive remapping or plasticity
what is an fmri
functional magnetic resonance imaging, has a very strong magnetic field and tracks the flow of oxygenated and deoxygenated blood
how do fMRIs work
when a part of the brain is being used the fmri shows the rush of blood towards that part of the brain which means we can identify which brain areas are active due to the on-rush of oxygenated blood
what is the evaluation of fMRIs - strengths
non invasive
what is an eeg
electroencephalogram, measures patterns of electrical activity
how does an eeg work
placing small electrodes on the scalp which are able to detect electrical impulses by nerve cell activity, the frequency and amplitude of the waves shown tell us about brain activity, most often used in sleep research
evaluation of an eeg
non invasive, good temporal resolution so brain activity represented quickly but it is unreliable spatial resolution
what is an erp
event related potentials, same process as eeg but looks at a stimulus response relationship, looking for action potential caused by a specific event
evaluation of an erp
useful for showing cause and effect between stimulus and response but unreliable spatial resolution
what is a post mortem
physical examination of brain after death, looking for abnormalities e.g tumour, relative size of the area, chemical analysis
evaluation of post mortems
useful for unique cases of brain damage, gives information brain scans can’t but can’t be used to infer cause and effect, has to be dead
evaluation of an fmri - limitations
has poor temporal resolution so there is a short delay between activity and representation on the scan, the patient must be very still for an accurate measure so not suitable for children or patients who cannot stay still,
what is plasticity
the brains tendency to change as a result of experience and new learning
what is functional recovery
when the brain looses ability such as language it is able to recover that ability over time, an example of plasticity
what is bridging or synaptogenesis
new synapses are made as neurons grow new axons to connect to other neurons. The more connections, the more abilities the brain has.
what is pruning or apoptosis
synaptic connection that are not used are destroyed to make the brain more efficient
what is neuronal unmasking
after damage to an area, the function may be regained by activating a previously dormant area. For example, recruitment of homologous areas in the opposite hemisphere, meaning that the undamaged equivalent in the other half of the brain becomes activated.
what are stem cells
a medical treatment where unspecialised cells can be transplanted to the area and become the type of cell needed (e.g. brain cell)
strengths for bp and fr
- Maguire – London black cab drivers had significantly greater density in their posterior hippocampus, compared to non-taxi driver controls. Thought to be due to their practice with spatial navigation and memory.
- Patient JW – a split-brain patient who was able to gain the ability to speak from his right hemisphere. Supports plasticity and demonstrates recruitment of homologous areas in the opposite hemisphere.
limitations of bp and fr
- Individual differences – Schneider found that participants with university-level education were significantly more likely (7x) to experience functional recovery than participants with high school-level education. Suggests functional recovery doesn’t work the same for everybody.
- Difficult to establish causality – for example, in Maguire’s taxi driver study. For example, perhaps their greater posterior hippocampus volume (and associated benefit to their spatial navigation) is what made them well-suited to be taxi drivers.
what are fMRIs
Measures blood flow using magnets. More activity in a brain area will lead to reduction in oxygen, so more oxygen will be transported to that area. Can ask person to do certain tasks whilst being monitored, and oxygenated blood flow is tracked.
strengths of fMRIs
High spatial resolution – is able to establish localisation of function in a living person
limitations of fMRIs
Not a direct measure so lacks temporal resolution – there will be a delay between the brain activity and the rush of oxygenated blood response
what are eegs
Measures electrical activity using electrodes on the scalp. Can tell a lot from the frequency (speed) and amplitude (size) of the waves produced (alpha, beta, theta, delta). Often used for sleep research.
strengths of eegs
Can test in real time (high temporal resolution), as it is a direct measure of neural activity
what are limitations of eegs
Poor spatial resolution – the scalp is a good conductor, so it is not clear exactly where the brain activity is happening
what are ERPs
Similar to EEG, but focuses on one small electrical change in the brain. Person is asked to complete the same task over and over again, and researchers identify the recurring brain activity – this helps to reduce the ‘noise’ of other activity
strengths of ERPs
Very specific measure and is direct – has excellent temporal resolution and can establish stimulus-response
limitations of ERPs
Needs lots of trials, which limits the type of task being asked – for example, would be difficult to present ‘funny’ or ‘scary’ stimulus dozens of times with the same effect
what are post mortems
Thorough examination of the brain after death. Can then correspond the features of the brain with different traits of the person during their lifetime.
strengths of post mortems
Detailed analysis, can be more thorough, e.g. weighing areas
limitations of post mortems
Retrospective. Can’t see cause and effect – for example, the cause of death could affect the brain
