bio psychology- 2 Flashcards
outline the nervous system
made of network of nerve cells
coordinates organisms actions
allows info to be received from outside world
exchanges info between different parts of the body
what are the 2 subsystems of the nervous system
the central nervous system and the peripheral nervous system
what does the brain do
coordinates body’s actions
responds to sensory info and info from within the body
seat of consciousness
what is the spinal cords function
relays info between brain and rest of nervous system
coordinates reflex action
what is the function of the peripheral nervous system
transmit info from the environment to body and coordinate msucles and organs responses
what are the subsections of the peripheral nervous system
somatic nervous system
autonomic nervous system
what are the subsections of the autonomic nervous system
sympathetic nervous system
parasympathetic nervous system
what is the function of the somatic nervous system
receives info from environment
sends info to cns
implements instructions from cns via muscles
what is the function of the sympathetic nervous system
regulating the bodys fight or flight response
how does the fight or flight response happen
the brain perceives a threat- activates the sympathetic nervous system- communicates with adrenal gland to release adrenaline which leads to physiological changes
what happens when the threat has passed
the brain perceives the threat has passed- activates the parasympathetic nervous system takes the body out of fight or flight
what happens if the threat continues
sends signals to release ATCH, which stimulates the release of cortisol, helping the body maintain fight or flight for extended periods
outline examples of psychological changes due to fight or flight response and how they help
increased heart rate- increased oxygenated blood to the body for more energy
increased sweating - cools the body in preparation for exertion
2 examples of hormones- what they do and what gland they are released from
adrenaline- key hormone in fight or flight response- stimulates heart rate contracts blood vessels - adrenal gland
melatonin- key hormone in regulating sleep- inhibited during the day, builds up in response to darkness and promotes sleep- pineal gland
what is localisation of function
theory that different areas of the brain are responsible for different behaviours, processes or activities
what is the motor cortex
in both hemispheres of the frontal lobe
-responsible for voluntary movements
-Different areas of the cortex control different parts of the body, with regions arranged logically next to each other
what is the somatosensory cortex
in the parietal region of both hemispheres
- receives sensory information from various parts of the body and processes this to give the conscious perception of various sensations
what is the visual cortex
in both hemispheres of the occipital lobe
- receives sensory information from the eyes via the optic nerve and processes this so that the person can consciously perceive visual features
what is the auditory cortex
located within the temporal lobes on both sides of the brain
- receives auditory information from the ears and then processes this to give the conscious perception of the different types of acoustic information
what is wernickes area
Located within the left hemisphere’s temporal lobe
-Responsible for language comprehension
what is brocas area
Located within the left hemisphere’s frontal lobe
-Primarily responsible for language production.
llimitation- localisation of function- research support
Sur- “rewired” the brains of ferrets so that signals from their eyes fed into the auditory cortex instead
-auditory cortex was able to process information from the ferret’s eyes
-however- ferret’s auditory cortex didn’t process the visual information nearly as effectively
-visual and auditory cortex have similar functions- both process sensory information- possible that other parts of the brain-Broca’s area- might have been unable to take on the function
strength- localisation of function- evidence from cog neuroscience
PET-Tulving- participants completing semantic memory tasks showed activity in left prefrontal cortex whilst right prefrontal cortex was active in episodic memory tasks.
- show how specific areas of the brain are associated with specific cognitive functions
-strengthened by use of PET- brain scanning technique with high spatial resolution- takes very accurate images of brain activity
what is the connection between plasticity and synaptic plasticity
Plasticity is possible through synaptic plasticity
-when a person experiences something in their environment it causes an activation of relevant synapses in the brain which strengthens the used synapse (synaptic plasticity)
the experience changes the brain (plasticity) through the strengthening of used synapses (synaptic plasticity)
what is plasticity
brain’s ability to change both functionally and physically in response to environmental experiences
-how the brain learns from experience
what is synaptic plasticity
ability of synapses in the brain to strengthen or weaken over time, in response to increases or decreases in their activity
facilitates plasticity and supports functional recovery
what is the use it or lose it principle
synapses that are regularly used will become stronger, whilst less frequent use will result in a weaker synaptic connections
what is the link between plasticity and age
younger brains are more capable of synaptic plasticity than older brains
what is functional recovery
brain’s ability to compensate for a loss of functionality after being damaged
-transfer of functions from a damaged area of the brain after trauma, to undamaged areas
what is neuronal unmasking
synaptic connections which were previously unused become unmasked (active) again
-allows the brain to connect previously disconnected areas of the brain and relocate functions from damaged areas
how does therapy affect functional recovery
new connections are weak, so require lots of use to strengthen them
-Therapy forces the patient to use these new and weaker synaptic connections- thereby strengthening them
strength- plasticity- research support
Draganski- imaged brains of medical students 3 months before and 3 months after exams
- changes in two areas of the brain associated with learning (the posterior hippcocampus and parietal cortex) following exams
-experience of revising for exams physically changed the brains of the students- explained through synaptic plasticity
-revision involved using synapses associated with the information they were revising- strengthened synapses, resulting in the physical changes in the brain
-natural experiment- lacked control over the IV, experimental controls were not possible
- undermines the study’s internal validity and so weakens its credibility as supporting evidence for plasticity
what is the function of the endocrine system
chemical messenger system that works alongside the nervous system
- functions include monitoring the body’s internal environment, and regulating the activity of the body’s organs
what are glands
organs of the endocrine system
- function of glands is to monitor the body’s internal environment and to regulate the action of different organs of the body through the secretion of hormones
what are hormones
chemical messengers of the endocrine system
-They are chemical substances that are secreted by hormones into the bloodstream
- affect any cell in the body that has an appropriate receptor, different hormones have different functions, though they all have powerful effects on the functions of organs, and this has consequences for our behaviour
outline the pituitary gland
master gland- the hormones it releases control the actions of the other glands in the endocrine system
-releases ACTH in response to stress
- It binds with receptors in the adrenal gland, leading to the secretion of stress hormones (cortisol) involved in the fight or flight response
outline the adrenal gland
releases Adrenaline, Cortisol
-Adrenaline is a key hormone in the fight or flight response, interacts with the cardiovascular system, stimulating the heart rate, contracting blood vessels and dilating air passages
- Cortisol is another hormone involved in the fight or flight response, helps maintain the body in fight or flight response for an extended period during times of chronic stress
outline the changes that occur in the fight or flight response
-Increased heart rate, Increased lung action, Constriction of blood vessels leading to higher blood pressure, Increased sweating, Pupils dilate
outline neurones
sensory, relay and motor
-communicate with on another through electrical impulses
-consists of cell body, axon, dendrites, myelin sheath, nodes of renvier, axon terminal
outline sensory neruones
transmit sensory impulses from skin and sensory organs to CNS
- structural differences- specialized dendrites (sensory receptors), long dendrites , short axons
outline motor neurones
transmit impulses from CNS to effects
structural differences- short dendrites and long axons
outline relay neurones
located in CNS, transmit impulses from sensory neurones to motor neurones
- connect together, allowing complex info to exchange within CNS and carry out its higher order thinking
-structural differences- no myelin sheath, short dendrites, short axon
what is synaptic transmission
process through which neurones communicate with one another
-one neurone sends a signal through the release of synaptic transmission to another neurone which receives the signal
why is synaptic transmission needed
the nerve impulse is unable to directly transmit to an adjoining neurone since neurones don’t touch, small gaps called synapses prevent the nerve impulse jumping to the next neurone
outline the process of synaptic transmission
starts when a nerve impulse reaches the axon terminal of presynaptic neurone
- triggers release of neurotransmitter across synaptic cleft from synaptic vesicles
-neurotransmitters diffuse across synaptic cleft
-neurotransmitters bind with receptors on postsynaptic neurones dendrites
- effect of neurotransmitter on postsynaptic neurone depends on the type of neurotransmitter and receptor
outline excitation in synaptic transmission
inside of postsynaptic neurone becomes positively charged, increasing the chance of an action potential, e.g. dopamine in d2 receptors causes excitation
outline inhibition in synaptic transmission
lowers the probability of action potential, as inside of neurone becomes more negatively charged, e.g. serotonin in serotonin receptors causes inhibition
outline reuptake in synaptic transmission
neurotransmitters are taken back up into the presynaptic neurone and stored for later use
- decreases quantity of neurotransmitter in synaptic gap, less likely to bind with and activate receptors
outline hemispheric lateralisation
two halves of the brain are functionally different, so certain mental functions are lateralised to a specific hemisphere
outline what split brain research had revealed about hemispheric lateralisation
some cog functions are lateralised to specific hemispheres, language processing is lateralised to left hemisphere, and visual- motor functions are lateralised to the right
-some functions, like interpretation of visual objects are bilateral
outline split brain research
used to investigate hemispheric lateralisation
- conducted on split brain patients who have had corpus collosum severed due to severe epilepsy
-presentation of visual stimuli to either left or right visual field, patients response can provide evidence as to whether a particular function is lateralised to the relevant hemisphere
strength- split brain research- demonstrates how hemispheric lateralisation occurs
split-brain patients were presented with visual images to the left or right visual field- When presented to the left hemisphere, the patients could describe what they saw, But when visual images were shown to the right hemisphere, the patients could not report what they saw, although they could select an appropriate matching object
-shows different functions are lateralised or lateralised, since patients could only verbally report what they saw with their left hemisphere, this shows language abilities are lateralised to the left
-supports findings from localisation of function- brocas area and wernickes area in left
-sperrys precise control of variables into each visual field gives the research strong internal validity
limitation- split brain research- generalisation
involve small samples of patients who underwent extreme surgical procedure as a last resort for severe epilepsy
-generalising from small samples is difficult, may not tell us how hemispheric lateralisation works in non-split-brain patients
-due to unique nature of split brain condition, researchers don’t have a choice to rely on unrepresentative samples
what are biological rhythms
distinct patterns of change in the body that conform to a cyclical time
what are circadian rhythms
biological rhythms that conform to a free running 24 hour cycle, and can be entrained
what are endogenous pacemakers
bodily processes (often chemical) that take about 24 hours to complete a cycle, they maintain the free-running nature of circadian rhythms
outline entrainment
resetting circadian rhythms by exposure to exogenous zeitgebers which act as cues in to the time in our natural environment
what is the SCN
suprachiasmatic nucleus- body’s master endogenous pacemaker, resets its 24 hour cycle in response to light levels, and communicates with other endogenous pacemakers to synchronise the body’s different circadian rhythms
-bundle of nerves in the brain’s hypothalamus, between the eye and the visual cortex- receives info of light intensity
example of a circadian rhythm
sleep/wake cycle, free running 24 hour cycle, entrained by light
explain jetlag
free-running cycle will remain tied to the day night cycle of the previous location, but light cues from new environment matches a different 24-hour cycle
-free-running sleep/wake cycle will be out of sync with the day/night cycle
-this conflict between the free-running aspect and the entrainable aspect of the circadian rhythm produces jet lag
strength- sleep/wake cycle as circadian rhythm- research support
Siffre- spent two months underground in caves in the alps with a small lamp- he found his sleep/wake cycle increased slightly, to around 25 hours
-demonstrates that the sleep/wake cycle is a circadian rhythm as it is free-running
- sleep wake cycle maintained around 24 hours suggests it is free-running
-brought a lamp with him underground-turning this on when he woke and off when he went to sleep, he introduced an exogenous zeitgeber into his study
- lamp introduced a confounding variable that undermined the internal validity of Siffre’s research
-only on a single person, means generalising to everyone’s circadian rhythms may be difficult
how does the SCN impact the sleep/wake cycle
sends info about light intensity levels to pineal gland- behind the hypothalamus
-pineal gland secretes melatonin when light levels are low- to promote sleep
what are photoreceptor cells
cells that detect light levels in the eyes- can do this even when eyes are closed to spot secretion of melatonin when light levels are higher in the morning
how can social cues act as exogenous zeitgebers
circadian rhythms only start developing at 16 weeks, so bedtimes and feeding routines implemented by parents act as exogenous zeitgebers to entrain their rhythms
strength- research into exogenous zeitgebers and endogenous pace makers on sleep/wake cycle- real life applications
Sleep deprivation is a growing problem- Issues with sleep have been linked with every mental health condition, as well as a huge range of physical health conditions
- Research has helped reveal how features of the modern world, e.g. blue light, are resulting in sleep deprivation
- research can inform guidance on better ‘sleep hygiene’, which may benefit the mental and physical health of modern humans
- research has also led to other interventions, such as the prescribing of melatonin for people who suffer from sleep disorders
- great social value in understanding how exogenous zeitgebers and endogenous pacemakers affect the sleep/wake cycle
strength- SCN impact on sleep/wake cycle- research support
Decorusey- destroyed SCN connections in brains of 30 chipmunks, monitored for 80 days in natural habitat- sleep/wake cycle was severely disrupted and most died during 80 days
-shows SCNs importance, it it wasn’t important we would expect no disruption to sleep/wake cycle
-most died since they were awake when predators were due to disrupted cycle- shows may be evolutionary exp for sleep/wake cycle
-limited for use of chipmunks- biological and social differences to humans means generalising from this research may be difficult
outline fMRI
measures blood flow in the brain when a person performs a task
-neurons in the brain that are the most active during a task use the most energy- explain o2 in blood allows this
-Deoxygenated haemoglobin has a different magnetic quality from oxygenated haemoglobin
- detect these different magnetic qualities creates a dynamic 3D map of the brain, highlighting which areas are involved in different neural activities
outline post-mortem examinations
study the brains of people who have died
-studying the brains of deceased people who presented with unusual mental and/or behavioural conditions and comparing with more neurotypical brains
- Broca- examined the brain of a man who displayed speech problems, was discovered that he had a lesion in the area of the brain important for speech production-Brocas area
outline EEG
electroencephalogram -information is processed in the brain as electrical activity in the form of nerve impulses, transmitted along neurons
-scanners measure this electrical activity through electrodes attached to the scalp
-Small electrical charges detected by the electrodes are graphed over a period of time, indicating the level of activity in the brain
- responsible for developing our understanding of REM sleep
outline ERPs
Event-Related Potentials (similar process to EEGs)
-a stimulus being presented to a participant and the researcher looks for which areas of the brain are active
-Activity would suggest the relevant brain regions play a functional role in the activity connected with the stimulus
- difficult to detect the subtle changes in brain activity when the brain responds to a stimulus, so participants are presented with the stimulus many times, and an average response is graphed
limitation- post mortem examination- causation
study the brain’s of people with unusual behaviours, with the hope of also finding an abnormality in the brain that might explain their behaviour
- correlation does not equal causation- abnormalities detected after death might have been the cause of unusual behavior, but there are other explanations
- a third variable might explain the association
- Unlike brain scanning techniques post-mortem examinations cannot study a live brain, so it is especially problematic to attribute causation
strength- post mortem examination- detailed examination
can access areas -like the hypothalamus and hippocampus- which other scanning techniques cannot easily access without losing spatial resolution
- provide researchers with a tool for forming a detailed picture of all areas of the brain
strength- fMRI- spatial resolution
Spatial resolution-smallest feature that a scanner can detect fMRI scans have approximately 1-2 mm
- significantly greater than the other techniques
- determine the activity of different brain regions with greater accuracy
-using fMRI can specify an exact place in the brain that is active during a particular behaviour
limitation- fMRI -temporal resolution
Temporal resolution- how quickly the scanner can detect changes in brain activity- fMRI scans have resolution of 1-4 seconds
-worse than other techniques
- psychologists are unable to predict with a high degree of accuracy the onset of brain activity- when it happens
strength- EEG and ERPs- temporal resolution
Temporal resolution- how quickly the scanner can detect changes in brain activity- EEG/ERP takes readings of the brain every millisecond
- record the brain’s activity in real time, and are therefore much faster at detecting brain activity than other scanning techniques
- accurate measurement of electrical activity when undertaking a specific task
limitation- EEGs and ERPs- spatial resolution
Spatial resolution- smallest feature that a scanner can detect- EEGs/ERPs have roughly 30 cm
- Compared to the spatial resolutions of other scanning techniques, the EEG/ERP technique is extremely low
- can only detect activity in broad regions of the brain, meaning it cannot pinpoint the exact location of neural activity
what is an infradian rhythm
biological rhythm that runs over 24 hours- e.g. menstural cycle, controlled by oestrogen- promotes ovulation- and progesterone - promotes thickening of womb lining
what is an ultradian rhythm
biological cycle that lasts under 24 hours- e.g. sleep cycle
outline the stages of the sleep cycle
four stages of NREM sleep- sleeper begins in a light sleep, but the brainwaves become increasingly slow, leading to a deeper sleep
- In the fifth stage, the sleeper enters REM sleep- brainwaves speed up, leading to a lighter sleep- REM sleep is highly correlated with the experience of dreaming
menstrual cycle- can be entrained by pheromones- research support
McClintlock -collected daily samples of sweat from 9 women - then applied to upper lips of 20 other female participants- found 68% of the odour recipients experienced changes to their menstrual cycle that brought them closer to the cycle of their odour donor
- menstrual cycle changed in response to an external stimulus suggests that the menstrual cycle can be entrained by exogenous zeitbegers
- at least some infradian rhythms can be entrained, just like circadian rhythms
- findings have proven difficult to replicate by other researchers- reason to doubt the conclusion that the menstrual cycle can be entrained by exogenous zeitgeibers
understanding the sleep cycle- research
Dement and Kleitman- monitored nine sleeping participants Using EEG- identified 5 stages of distinct brain activity
- in one of these stages, the eyes of the patients moved rapidly, so they called this stage REM and the other 4 stages NREM
- Participants woken from REM sleep were much more likely to report dreaming than those in NREM sleep
- pioneering- allowed researchers to identify and understand a new type of ultradian rhythm: the sleep cycle
- use of EEG- high temporal resolution, timings of the different stages of sleep are likely to be very accurate
- weak population validity- small sample size not generalisable
menstural cycles impact on sexual behaviour- research
Penton-Voak - women showed a preference for ‘slightly feminised’ male faces when selecting a long-term partner, but during the ovulation phase they showed a preference for more masculinised faces
- represent a preference for physical attributes associated with kindness and cooperation when looking for a partner who will care for children
- illustrates how infradian rhythms such as the menstrual cycle can have a powerful effect on human behaviour
- socially sensitive- could be used to stigmatise women
limitation- fight or flight- gender bias
research has suggested fight or flight response is a mainly male response
-women are more likely to respond with a tend and befriend- protect their offspring and form alliances with other females
-early research was conducted on males and assumed it could be applied to women, shows beta bias
