Biopsychology Flashcards
(83 cards)
1
Q
What is the response to acute stress?
A
Amygdala (sends a message)—– Hypothalamus (causes the)——— Adrenal medulla (to release; adrenaline & noradrenaline)——– adrenaline.
2
Q
Difference between chronic and acute stressors
A
Acute- something small and temporary such as a spider
Chronic- something long term and ongoing such as a stressful job.
3
Q
What is the response to chronic stress?
A
- Hypothalamus detects stress
- This stimulates corticotrophin releasing hormone (CRH)
- Released into the blood stream
- CRH causes pituitary gland to release ACTH
- Adrenal gland releases cortisol (good for quick bursts if energy but bad for cognitive performance and the immune system)
- ACTH transported to bloodstream, target site adrenal glands
- ACTH stimulates adrenal cortex.
4
Q
Describe divisions of nervous system.
A
- made up of several divisions
- largest divisions being central nervous system (CNS) and the peripheral nervous system (PNS)
- CNS made of brain and spinal cord (connected by complex web of neurons)
- PNS divided into somatic and autonomic
Somatic; consists of sensory and motor neurones, enables reflex actions - Autonomic; largely unconscious and involuntary. Divided into parasympathetic (PS) and sympathetic (SS) NS.
- PS regulated body functions during non stressful situations
- SS prepares us for fight or flight.
5
Q
Structure and function of a sensory neurone
A
- long dendrites and short axons.
- Carry impulses from sensory receptors to the spinal cord & the brain
- convert info from receptors into neural impulses, when reaches the brain a sensation is felt.
6
Q
Structure and function of a relay neurone
A
- lots of short dendrites, cell body and short axon
- allows sensory and motor neurones to communicate with each other and brain and spinal cord.
7
Q
Structure and function of a motor neurone
A
- short dendrites & long axon
- controls muscle movements
- when stimulated they release a neurotransmitter which triggers a response.
8
Q
What is a neurotransmitter?
A
- brain chemicals released from synaptic vessels
- bind to receptors on a post-synaptic cell. Create an inhibitory or excitatory action.
9
Q
What is synaptic transmission?
A
- process in which a nerve impulse passes the synaptic cleft from a pre to post synaptic neurone.
10
Q
Describe the process of synaptic transmission (6 marks)
A
- an action arrives at the terminal button at the end of the axon, this needs to be transferred to another neurone or tissue
- must cross the synaptic gap
- at the axon of a nerve, synaptic vesicles (sacs containing neurotransmitters) are stimulated by the action. This process causes the vesicles to release their contents (exocytosis)
- the released contents diffuses across the synaptic gap and binds to specialised receptor cells on the surface of the post-synaptic neurone.
- this activates the cell, producing either excitatory or inhibitory effects on the post synaptic neurone.
11
Q
Explain excitatory effect
A
- occurs when receptor stimulation results in an increase in the positive charge of of the post- SN & increases the likelihood of the neurone firing and passing on the impulse.
12
Q
Explain inhibitory effect
A
- receptor stimulation increases the negative charge of the receiving neurone & decreases the likelihood of the neurone firing and passing on the impulse.
13
Q
What is summation?
A
- addition of positive and negative postsynaptic potentials. Can receive pos and neg simultaneously. Overall is summed, excitatory or inhibitory is produced.
14
Q
What is the endocrine system?
A
- network of glands throughout the body
- works very closely with nervous systems
- releases hormones into the bloodstream to regulate physiological processes
15
Q
What’s a gland?
A
- they produce and secrete hormones.
- main glands; pituitary, adrenal, ovaries, testes.
- regulates the activity of organs & tissues.
16
Q
What’s a hormone?
A
- chemicals that circulate the body and are carried to target sites
- target cells only respond to specific hormones (specialised).
17
Q
Hormone & function of pituitary gland.
A
- ACTH
- stimulates the adrenal cortex during the stress response
18
Q
Hormone & function of Adrenal cortex.
A
- Cortisol
- stimulates the body to release glucose to provide energy for the flight-or-fight response
19
Q
Hormone & function of Adrenal medulla
A
- Adrenaline
- Triggers physiological changes; increased heart rate, which creates arousal needed for fight-or-flight
20
Q
Hormone & function of Pineal gland
A
- Melatonin
- responsible for biological rhythms; sleep-wake cycle
21
Q
Hormone & function of Thyroid gland
A
- thyroxine
- increases metabolic rates
22
Q
Hormone & function of Ovaries
A
- oestrogen
- regulation of female reproductive system
23
Q
Hormone & function of Testes
A
- testosterone
- development of male sexual characteristics during puberty, promotes muscle growth
24
Q
Explain the flight or fight response (include reference to adrenaline)
A
When something is perceived as a stressor or threat, the amygdala is activated which sends a distress signal to the hypothalamus. This then activates the sympathetic medullary pathway (SAM). This activates the adrenal medulla, which then releases adrenaline and noradrenaline into the blood stream. Adrenaline triggers physiological changes within the body (increased heart rate, breathing rate, pressure) which creates the arousal needed to either fight or flight.
25
Evaluation of flight or fight response.
limitation; The fight-or-flight response is not the only reaction by humans facing dangerous situations. Gray suggests that the first response to danger is to avoid the confrontation, which is demonstrated by the freeze response. During this, individuals are hypervigilant while they assess the situation and work out what to do. An example of this is victims of sexual crimes. TMB the freeze reaction is not a recognised trauma response, this sometimes means that prosecutors are not table to help the victim or convict the criminal. Thus, lacking validity.
limitation; The fight-or-flight response is typically a male response to danger. Taylor et al. (2002) suggests that females adopt a 'tend or befriend' response in a stressful/dangerous situation. This is because women are more likely to protect their offspring (tending) and form alliances with other women (befriend), rather than fight or run away. The focus on the fight-or-flight response arose due to research being conducted on males and assuming the findings could be generalised to females (beta bias). Thus limiting fight or flight response
limitation; Flight or fight response is maladaptive. It aided survival in our evolutionary past, but it can have a negative effect on health, especially in modern-day life. Modern-day stressors tend to be non-life-threatening. However, they still trigger the release of adrenaline and other stress hormones which, over time, can have devastating consequences on health. This suggests it is a maladaptive response in modern life. Thus limiting fight or flight response.
26
What is localisation?
idea that specific locations of the brain have specific functions in the body/ behaviour.
27
Motor cortex
- generation of voluntary motor movements
- in frontal lobe along the bumpy region
- both hemispheres
- arranged logically (in order of the way our bodies look in terms of what it controls)
28
Somatosensory cortex
- detects sensory events
- in parietal lobe
- processing info from touch, produces sensations
- both hemispheres
29
Visual cortex
- occipital lobe
- both hemispheres
- contains different areas that process different info (colour/shape)
30
Auditory center
- hearing
- temporal lobe
- both hemispheres
- inner ear, sounds waves converted to nerve impulses
- travels to thalamus then brain stem to be decoded, then back to auditory cortex where response.
31
Language centres- Broca's area
- in the back of portion of the frontal lobe
- critical for speech production
- Broca's aphasia- damage to Broca's area causing inability to produce speech.
- left hemisphere only
32
Language centres- Wernicke's area
- back portion of left temporal lobe
- deals with understanding of language
- if damaged the indiviudal is able to talk but unable to understand language
33
Evaluation of localisation of function?
strength; has research support of localisation in the brain. For example, Broca's aphasia is an impaired ability to produce speech, this comes from damage to the Broca's area in the back portion of the frontal lobe in the left hemisphere. TMB, shows that some parts of the brain have specialised functions, such as being part of
the language centre. Thus strengthening localisation of function.
limitation; individual in language areas of the brain. Harasty found that women have larger language centres than men, this may be because they talk more and use language to express themselves. TMB, cannot apply localisation of brain function in the same way to everyone as there may be individual variations in how brains are structured,. Thus limiting loc of function.
limitation; loc of function may not be as important as intercommunication. Dejerine argued that Wernicke’s
aphasia was due more to damage to the
pathway between the visual cortex and Wernicke’s area than damage to the area itself. TMB, shows that the neural pathways between the areas are more vital than the actual areas themselves. Thus limiting loc of function to explain human behaviour.
limitation; Evidence that challenges localisation. For example, Lashley claimed that higher
mental functions were not localised, only basic
ones were. This means when one part
of the brain is damaged, other intact areas are
often able to adapt to take on the function it used
to perform. TMB, suggests that the extent of the damage is more important than its actual location, and that
the brain has the ability to adapt when there is
damage in order to maintain key functions, which is
known as functional recovery. Thus limiting importance of loc of function
34
What is lateralisation?
- idea that two halves of the brain are functionally different
- right hemisphere processes info from the left half of the body (visa versa)
- two hemispheres are connected by a bundle of nerves (corpus collusom)
35
Left hemisphere specialisation?
language
36
Right hemisphere specialisation?
- facial recognition
- drawing ability
- spatial tasks
37
What is a split brain patient?
- had corpus collusom severed, stops connection between hemispheres
- often used to control severe epileptic fits
38
KEY STUDY (split brain patients)- Sperry and Gazzaniga (1968)
Aim- investigate what functions of the brain are lateralised
Procedure- compared split brain patients with a control group
- different activities (touch of objects & visual presentation of stimuli).
Findings-
- Drawings; better with left hand as controlled by right hemisphere (specialises in drawing) this is despite patient being right handed
- Face recognition; split face shown (woman on the left- man on the right). Ppt's recalled seeing a woman. Left VF goes to RH (specialised in facial recognition)
Conclusions- hemispheres process info separately
- split brain patients have 2 separate streams of consciousness.
39
Evaluation of Sperry & Gazzaniga.
- limitation; disproved that language processing is restricted to the left hemisphere. Case study; patient with lesion to left hem, founded ability to speak out of right hem when info was presented to right VF.
-limitation; limited sample size as split brain patients are not very common.
-strength; high levels of control, provides validity to the study
40
Evaluation of Lateralisation.
- strength; advantages to having a split brain, allows us to perform two tasks simultaneously, humans having enhanced abilities.
- limitation; lateralisation decreases with age, not as essential to brain function as originally suggested (after age of 25)
- limitation; opposing research, case study where a man was able to develop the ability to talk out of the right hemisphere. Disproves that right hemisphere cannot process or produce language. Challenges lateralisation explanation.
41
What is neural plasticity?
structure of brain can change as we experience new things- new neurons and synapses created & old ones discarded.
42
What is pruning and bridging?
study that supports this
pruning- neural connections lost due to a lack of use.
bridging- new neural connections created due to use and new stimulus.
Kuhn- playing a computer game for 30 mins a day for two months showed increased neural connections- gaming is good for you
43
Research into plasticity?
- Maguire (2000) looked at brains of black taxi drivers in London, found more grey matter in posterior hippocampus than control group
- this part of brain is associated with spatial and navigational skills
- spatial learning they have to complete (learning whole map of London) alters the structure of the brain.
44
Functional recovery of the brain?
- after injury of the brain, non-damaged areas can take over their functions
45
Mechanisms for recovery (axonal sprouting/ homologous areas)
axonal sprouting- growth of new nerve endings which connect to undamaged to form new neural pathways
homologous areas- similar areas of the brain in the opposite hemisphere used to perform specific task.
46
Evaluation of plasticity?
(discussion points)
strength; research support from animal studies, enriched environments can encourage neural pathways to form. shows brain has ability to adapt based on conditions, supporting plasticity.
strength; research support from human studies (Maguire, taxi drivers). Increased grey matter supports that the brain can adapt and change with experience.
47
Evaluation of recovery?
(discussion points)
strength; research support from animal studies, rats given stem cells injections after injury compared to rats who weren't, showed a clear improvement. Highlights importance of mechanisms of recovery (stem cells)
limitation; differences in functional recovery with age. When you are at your youngest, neural capacity is at it's greatest. Doesn't ever stop but is harder to recover as you get older. Limits importance of functional recovery.
limitation; individual differences, educational attainment plays a key role in functional recovery. those with a higher education are more likely to recover and quicker from an injury.
48
Ways of investigating the brain- Post mortem.
- study of the physical brain to look at behaviours displayed whilst patient was alive, see if there was possible brain damage
- example; discovery of Broca's area. Patient had lesions on the left hemisphere, displayed speech problems when alive.
- invasive, poor temporal resolution, retrospective.
49
Ways of investigating the brain- fMRI's.
- functional magnetic resonance imaging
- brain scanning technique, measures blood flow in brain when person performs a task.
-fMRI can detect magnetic qualities of haemoglobin, creates a dynamic map of brain.
- temporal res: 1.4 secs (poor)
- spatial res: 1-2mm (good)
- non-invasive, high spatial res, poor temporal res, non-retrospective.
50
Ways of studying the brain- ERP's
- event related potentials
- same equipment as EEG'S (electrode cap)
- stimulus is presented whilst scanning is happening, look for activity related to the stimulus
- lots of data recorded & average is made.
- non-invasive, good temporal res, poor spatial res
51
Ways of investigating the brain- EEG.
-electroencephalogram
- uses electrode cap
-measures electrical activity in the brain, created into a graph over a period of time, detecting active areas of the brain.
-can be used to detect health issues (insomnia and epilepsy)
-non-invasive, good temporal res, poor spatial res
52
What is temporal resolution?
how quickly we can get the info from the scan (no lagging) (basically instant).
53
What is spatial resolution?
shows exactly where the activity is happening.
54
What is an invasive/ non-invasive procedure?
how intrusive/ non-intrusive a procedure (going into the brain or not).
55
What is reterospective?
looking back at something that's already happened.
56
Evaluation of fMRI's.
strength; non-invasive (more ethical than other procedures such as post-mortems)
strength; high spatial res (1-2mm) unlike an EEG, allows us to see exactly where the activity is happening.
limitation; poor temporal res, there's a lag between activity in the brain and in the scan, in contrast to EEGs who have very high temporal res. Cannot fully see the extent of what effect the stimulus
limitation; not always practical, expensive compared to others ways of investigation. Person is required to stay still and can be uncomfortable. May cause a reduced sample size , lacing pop validity.
57
Evaluation of EEG's (can be used for EP'S)
strength; provides an image of the brain in real time (high temporal res) than fMRI's. Accurate at detecting brain activity.
strength; cost effective, much more than an fMRI. Easier to carry out research, increasing pop validity.
limitation; poor spatial res in comparison to fMRI's. Difficult to pinpoint location of activity, cannot help with localisation of function, not useful for all research
limitation; cannot reveal activity in deeper regions of the brain such as hypothalamus or hippocampus, TMB it's limited to what it can be used for in research
58
Evaluation of ERP's (only one that cannot be use for EEG)
strength; able to measure reaction to stimuli without patient having to give response. Reduces social desirability bias, therefore cannot censor their responses due to no conscious control.
59
Evaluation of Post-mortems.
strength; allow for detailed analysis of brain that any other methods cannot provide.
strength; allows researchers to see specific neural circuits, not possible through other methods. fMRI's still only give general rea of activity. High spatial res.
limitation; cofounding variables can influence results of post mortems. Length of time between death and post-mortem exam and treatments given before death. Any comparison to controls may not be valid.
limitation; a problem with establishing causation. Due to it being retrospective it's impossible to follow up on anything that arises. Damage may not be a result of suspected cause. Difficult to draw any conclusions from research.
60
What is a biological rhythm?
cyclical patterns with a biological system that have evolved in response to environmental responses. Governed by internal clocks and external cues.
61
What is a circadian rhythm?
a biological rhythm that occurs over a 24 hour cycle
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What is an ultradian rhythm?
a biological rhythm that occurs under (less than) 24 hours. (occurs more than once in 24hrs)
63
What is an infradian rhythm?
a biological rhythm that lasts longer than 24hrs. (weekly/monthly/annually)
64
What is an endogenous pacemaker?
internal body clocks that regulate biological rhythms.
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What is an exogenous zeitgeber?
external cues that influence our biological rhythms.
66
Circadian rhythms (SCN & sleep wake cycle)
SCN- suprachiasmatic nucleus
-located in hypothalamus
- regulates sleep-wake cycle
-uses light info to regulate release of melatonin
Cycle- SCN triggers the release of melatonin by signalling the pineal gland to make us sleepy. When light increases, SCN supresses melatonin production to wake us up.
SCN also regulates body temp, digestion/feeding patterns.
Light info- detected by receptors in the Retina, info sent to hypothalamus, communicates to SCN, regulates rhythm, signals pineal gland, melatonin produces or supressed.
67
KEY STUDY- for circadian rhythms- Siffre (1962)
- case study
- Aim; to see if circadian rhythms/ internal body clocks reset themselves without external cues.
- Procedure; lived in a cave for a few months, no daylight info.
- Findings; SCN followed the circadian rhythm with wake and sleep time (slightly longer than 24hrs)
Provides evidence that endogenous pacemakers can be free running as well as entrained.
entrained (syncs to available external cues to regulate itself)
68
Evaluation of circadian rhythms.
(discussion points)
strength; has research support for effect of light. Stationed in Antarctic (deprived of daylight for 3 months), circadian rhythms had changed. Evidences daylight is responsible for variations in hormone release. Supports external stimuli (exogenous zeitgebers) has effect. Usefulness of conducting research.
strength; has real life, useful applications. For example, the use of chronotherapeutics in drug therapy, this means administering the drug at a specific time in order to achieve greatest effect, helping people to return to normal functioning. Thus supporting research into biological rhythms due to it's real life applications.
limitations; individual differences, cycles can differ between 13-65 hrs, suggests why some people prefer getting up earlier. Suggests that not only affected by external factors, but innate behaviours. thus researchers should consider this when discussing biological rhythms on human behaviour.
limitations; opposing research, temp may be more important than light. Buhr found that light is only a trigger for body clocks, SCN transforms light signals into thermal messages to set body temp, for organs to become inactive to prepare for sleep. Thus more research needs to be done on the effect of temp to understand biological rhythms.
69
What is an ultradian rhythm and the main rhythm?
- A cycle that lasts less than 24 hours (repeats more than once in the 24hr period)
- Sleep cycle (including REM sleep) (rapid eye movement)
- found by looking at EEG's
70
What is the sleep cycle and the 5 stages of sleep?
- a cycle that reoccurs during sleeping (lats around 90 mins for one full cycle to complete)
1-2; 'light sleep' brain waves slow and rhythmic. Alpha waves to theta waves.
3-4; 'deep sleep' slow waves- difficult to wake someone up. slow delta waves (this is the stage used for the body carry out growth & repair)
5; REM sleep (dream). Body is paralysed. Brain activity/waves resemble that of an awake person.
71
What is the ultradian rhythm BRAC?
- Kleitman (1969) suggests that this cycle continues during the day when we are not asleep.
- rather than moving through stages of sleep we move through stages of alertness into a state of fatigue every 90 mins.
72
What is an infradian rhythm and what is the main one?
- a cycle that lasts longer than 24hrs (weekly/ monthly/annually)
- menstrual cycle
73
Weekly rhythms?
- 7 day rhythms of heart rate and blood pressure
- sex drive reportedly higher on the weekend
- not much evidence to support weekly rhythms
74
Monthly rhythms- menstrual cycle?
- cycle length varies from 26-35 days (average being 28)
- regulated by hormone that promote ovulation or stimulate fertilization
- ovulation occurs around 14 days, oestrogen levels peak (lasts for about 16hrs)
- progestogen levels increase in prep for implantation of an embryo in the uterus
75
Annual rhythms- SAD?
- most annual rhythms governed by seasons (migration & hibernation)
Magnusson (2000)
- some people depressed in winter (seasonal affective disorder)
- less light means more melatonin, an increase in melatonin causes a decrease in serotonin which is linked to depression.
76
Evaluation of Infradian rhythms-
(discussion points)
strength; research support for exogenous factors on menstrual cycle. Women can synchronise their cycles to other women. TMB emphasises role of exogenous zeitgebers. Supporting understanding of infradian rhythms
strength; research support for mate choice in cycle. Women's mate choices change during cycle, ovulation period- look for more masculine mates. Enhances chances of reproducing . Highlights how infradian rhythms affect human behaviour.
strength; useful and practical applications from research into SAD. Development of phototherapy, 60% patients relieved of symptoms using treatment, only 30% relieved using placebo. Supports that it works, improves quality of life for individuals suffering.
Counter- effect of light on our mood may not be as significant as we originally thought, limiting use of phototherapy.
77
Evaluation of ultradian rhythms- sleep cycle.
(discussion points)
strength; research support for distinct stages of sleep. Measured sleep activity, ptps able to recall dreams more if awoken just after REM sleep rather than any of the other stages, supports different phases in sleep.
limitations; individual differences, found differences for the length of each stage between ptps (particularly in stage 3 & 4). this needs to be taken into consideration and investigated more when researching sleep as an ultradian rhythm.
Limitation; somewhat invasive, ptps made to sleek with monitors in them in a controlled lab setting. Observed results may not be representative of their actual sleep. Invalidating the results, ultradian rhythms may lack ecological validity.
78
Endogenous pacemakers (SCN)
suprachiasmatic nucleus
- located in hypothalamus
- acts as master clock, regulates circadian rhythms
- SCN has own built in circadian rhythm, only needs resetting by light.
- regulates production of melatonin in pineal gland via interconnecting neural pathways.E
79
Endogenous pacemakers (Pineal gland)
- SCN sends signals to pineal glad- increasing production of melatonin at light- decrease of melatonin in morning.
- SCN & Pineal gland work as one endogenous pacemaker.
- synchronised with light signals
- melatonin induces sleep by inhibiting the mechanisms that promote wakefulness
80
Exogenous Zeitgebers (light)
- cones and rods in the Retina detect light, send signal to SCN which has receptors that are sensitive light
- protein- melanopsin is sensitive to natural light (proves we can distinguish between diff types of light)
- light resets SCN
81
Exogenous Zeitgebers (social cues)
- social stimuli such as meal times
Wegman (1974) (jet lag
- circadian rhythms of air travellers adjusted quicker if they went outside more at their destination. Due to being exposed to the environment of the new time zone, they received social cues- acted as a Zeitgeber
- made no differnce if person was blind or not
82
Evaluation of Endogenous Pacemakers.
(discussion points)
strength; has research support from animal studies. Morgan (1955) found that if you implanted a regular SCN neuron (24hrs circadian rhythm) into an abnormal hamster (20hr circadian rhythm), it then formed a normal circadian rhythm. Shows that SCN is an endogenous pacemaker that sets and regulates a rhythm, regardless of other factors (other than light)
limitation; research shows that exogenous zeitgebers can have a neg impact on our endogenous. Touitou (2017), found neg impact of blue LED light (from phones etc) on the production of melatonin, especially in teens. TMB, SCN can be disrupted by exogeneous zeitgebers such as light, which can lead to health issues. Limiting the role of endogenous pacemakers in regulating biological rhythms.
83
Evaluation of Exogenous Zeitgebers.
(discussion point)
strength; research support for light being important as an exogenous zeitgeber. Skene & Arenat (2007) claimed that the majority of blind people who still have some perception of light have normal circadian rhythms. TMB it provides evidence to support that light is a powerful exogenous factor which affects our circadian rhythms. Validates role of external factors (light).
strength; Practical applications. Brugess (2003) used light exposure to counter jet lag. Allows travellers to arrive with their circadian rhythms partially entrained to local time. TMB it provides a way to help those who travel a lot to different time zones (for example travelling for work). This overall benefits those who suffer from jet lag and potentially improves quality of life by maintaining a stable circadian rhythm.
