Biopsychology Flashcards
1
Q
Hemispheric Lateralisation
A
idea that the 2 hemispheres are functionally different + certain mental processes are mainly controlled by 1 hemisphere
2
Q
Right Hemisphere important for…
A
orientating & navigating
recognizing faces
recognizing music
3
Q
Left Hemisphere important for…
A
producing & comprehending language
maths solving
logical thinking
4
Q
Hemispheric Lateralisation & Split-Brain Research: Sperry & Gazzanigna split brain patients
A
split brain patients are people who undergone surgical procedure where corpus callosum connecting the 2 hemispheres is cut
5
Q
Hemispheric Lateralisation & Split-Brain Research: Sperry & Gazzanigna (aim)
A
investigate the function of each hemisphere of the brain
6
Q
Hemispheric Lateralisation & Split-Brain Research: Sperry & Gazzanigna (procedure)
A
studied a small number of split brain patients using a visual task. PPs presented images to the left and/or right visual fields
7
Q
Hemispheric Lateralisation & Split-Brain Research: Sperry & Gazzanigna (findings)
A
PPs only able to name objects presented in right visual field, when asked what they saw in left field said ‘nothing’
8
Q
Hemispheric Lateralisation & Split-Brain Research: Sperry & Gazzanigna (conclusions)
A
cannot articulate what is in the right hemisphere unless hemispheres are connected
language is in the left hemisphere only
9
Q
Hemispheric Lateralisation & Split-Brain Research: Sperry & Gazzanigna Evaluation (strengths)
A
methodology: standardised which increases the internal validity of the procedure
10
Q
Hemispheric Lateralisation & Split-Brain Research: Sperry & Gazzanigna Evaluation (weaknesses)
A
generalisability: only people with epilepsy - seizures may have changed brain activity so can’t
sample: very selective small sample decreases external validity
other research (Turk et al: patient damage to L hem but developed capacity to speak in R leading to ability to speak about info presented to either side of brain) (Szaflarski et al: in childhood, language is lateralised (in L hem). As we age, the R hem starts to take on some of language functions)
11
Q
Brain plasticity
A
Brains ability to change and adapt as a result of experience
12
Q
Research support for plasticity
A
Having skilled job: London taxi drivers have significantly large hippocampus
Playing video games: 30’ a day increases grey matter
Meditation: monks have more brain activity than visitors
13
Q
Animal research for plasticity
A
Kempermann et a: 1 group of rats complex & enriching houses and another standard lab cages
Rats with complex environment had larger hippocampus
14
Q
Functional Recovery
A
Regaining of abilities that have been damaged/lost as result of brain injury/disease
15
Q
How is functional recovery achieved?
A
Neural masking
Neural recognition
Axonal sprouting
16
Q
How is functional recovery achieved? Neural unmasking
A
Signals can be rerouted through dominant synapses TMT neural communication can continue + abilities recovered
17
Q
How is functional recovery achieved? Neural reorganisation
A
Brain gets other locations to perform damaged function thereby recognising itself. It ca ‘recruit’ similar (homologous) regions on the opposite side of the brain to take on lost function called ‘laterality shift’
18
Q
How is functional recovery achieved? Axonal Sprounting
A
growth of new nerve endings connecting with other undamaging nerve cells to form new neuronal pathways
19
Q
Functional Recovery: Stem Cells
A
- implanting to directly replace damaged/missing cells
- implanting next to damaged areas so growth factor they secret can help nearby cells repair themselves
- using them to create pathways around damaged area, by rerouting communication to a new area which could take over function
20
Q
Functional Recovery: Evaluation
A
+ real world application: neurorehabilitation: constraint-induced movement therapy used with stroke patients whereby they practice using the affected parts of their body
21
Q
Ways of Investigating the Brain: Functional magnetic resonance imaging (fMRI)
A
Enables researchers to detect which regions are rich in oxygen/active by detecting changes in blood oxygenation + flow that occurs as result of neural (brain) activity
haemodynamic response (when brain area more active consumes more O2 to meet increased demand blood flow directly to active area)
produces 3-dimensional images (activation map) showing which parts of brain involved in particular mental processes (understanding localisation of function)
22
Q
Ways of Investigating the Brain: Electroencephalogram (EEG)
A
measure electrical activity within brain via electrodes fixed to individuals scalp using skull cap to indicate neurological abnormalities e.g. epilepsy, tumours, disorders of sleep
23
Q
Ways of Investigating the Brain: Event-related potentials (ERPs)
A
brain’s electrophysiological response to specific sensory/cognitive/motor event can be isolated through statistical analysis of EEG data
24
Q
Ways of Investigating the Brain: Post-mortem Examination
A
brain analysed after death to determine whether certain observed behaviours during patients life can be linked to abnormalities in brain
25
Ways of Investigating the Brain: Evaluation - fMRI
+ doesn't rely on use of radiation
+ risk-free, non-invasive, straightforward
+ very high spatial resolution proving clear picture of how brain activity localised
- expensive + only clear if still
- poor temporal resolution
- only measure blood flow in brain so difficult to tell what kind of brain activity
26
Ways of Investigating the Brain: Evaluation - EEG
+ invaluable in diagnosis of conditions
+ contributed to understanding of stages involved in sleep
+ extremely high temporal resolution
- signal not useful for pinpointing exact source of neural activity
27
Ways of Investigating the Brain: Evaluation - ERPs
+ excellent temporal resolution, led to widespread use
+ able to identity many types + describe precise role
- lack of standardisation, difficult to confirm findings
28
Ways of Investigating the Brain: Evaluation - Post-mortems
+ vital in providing foundation for early understanding of key processes in brain (Broca & Wernick relied on studies in establishing links between language, brain, behaviour)
+ improve medical knowledge + help generate hypothesis
- observed damage may not be linked to deficits
- ethical issues of consent
29
endogenous pacemakers
internal body clocks regulate biological rhythms
e.g. influence of suprachiasmatic nucleus on sleep/wake cycle
30
endogenous pacemakers - suprachiasmatic nucleus
bundle of nerve cells located in hypothalamus in each hem
one of primary EPs in mammalian species + influential in maintaining circadian rhythms
receives information about light directly from this structure - continues when eyes closed, enabling biological clock to adjust to changing patterns of daylight whilst we asleep
master clock
31
endogenous pacemakers - animal studies and the suprachiasmatic nucleus
DeCoursey et al: destroyed SCN connections in brains of 30 chipmunks - returned to natural habitat + observed for 80 days - sleep/wake cycle disappeared + significant proportion had been killed
Ralph et al: 'mutant' hamsters with 20-hour sleep/wake cycle - SCN cells of mutant transplanted into brains of normal, cycles of 2nd group defaulted to 20 hours
32
endogenous pacemakers - pineal gland & melatonin
receives information on day length & light from SCN - during night (dark) increases melatonin (chemical that induces sleep)
33
exogenous zeitgebers
external cues that affect (entrain) biological rhythms
e.g. light
34
sleep / wake cycle
daily cycle of biological activity based on 24-hour period (circadian rhythm) influenced by regular variations in environment
governed by EPs and EZs
two dips between 2-4am + between 1-3pm
in absence of EZs a free running circadian rhythm runs 25 hours
35
exogenous zeitgebers - light
reset body's main EP (SCN)
indirect influence on key processes in body that control functions (hormone secretion & blood circulation)
Campbell & Murphy
36
exogenous zeitgebers - light (Campbell & Murphy)
light may be detected by skin receptor sites on body even when same information not received by eyes
15 PPs woken various times + light pad shone on back of knees
deviation in usual cycle of up to 3 hours
37
exogenous zeitgebers - social cues
at 6 weeks old, circadian rhythms begin + about 16 weeks most babies entrained - schedules imposed by parents likely to be key influence, including times for eating & sleeping
38
strengths for exogenous zeitgebers
research revealed numerous circadian rhythms in many organ/cells in body called peripheral oscillators
although peripheral clocks highly influenced by actions of SCN they can act independently - Damiola et al demonstrated ow changing feeding patterns in mice could alter circadian rhythms of cells in liver by up to 12 hours whilst leaving rhythm of SCN unaffected suggests there are other complex influenced in sleep/wake cycle
phototherapy for jet-lag: Burgess et al used bright vs intermittent vs dim light on passengers after flight - bright sifted rhythms by 2.1 hours, intermittent 1.5 hours, dim 0.6 hours - PPs in bright group felt sleepier 2 hours earlier in evening + woke up 2 hours earlier
39
order of the three neurons
sensory, relay, motor
40
sensory neuron
carry messages from sensory receptors via peripheral NS and CNS
convert info from sensory receptors into neural impulses
long dendrites + short axons
41
how do reflex actions occur
some of sensory neurons terminate in spinal cord allowing reflex actions to occur quickly without delay of sending impulses to the brain
42
relay neurons
when impulses reach brain, info analysed + translated into sensations of visual input, heat, pain meaning so that organism can decide how to respond appropriately
connect with other neurons e.g. allows sensory + motor neurons to communicate
short dendrites + short axons
found within brain + spinal cord only (CNS)
43
motor neuron
send messages via long axons from brain to muscles/effectors
when axon of neuron fires, muscles with which it forms synapses contracts - when neuron inhibited muscle relaxes
located in CNS + project their axons outside of CNS to directly/indirectly control muscles
form synapses with muscles + control contractions - when stimulated, bind to receptors on muscle and trigger a response which leads to muscle movement
short dendrites + long axons
44
types of neurotransmitter
1. excitatory (noradrenaline) - excitatory NT bind with postsynaptic receptor + produces excitatory postsynaptic potential TMT postsynaptic cell more likely to fire impulse
2. inhibitory (GABA/serotonin) - responsible for relaxation and sleep - inhibitory NT binds with postsynaptic receptor + produces inhibitory postsynaptic potential TMT postsynaptic cell less likely to fire
45
synaptic transmission
when action potential reaches presynaptic terminal triggers synaptic vesicles to release NT into synaptic gap
NT diffuse across gap between pre and post-synaptic cells
NT bind to post-synaptic receptor sites on membrane of post-synaptic neuron's dendrite
stimulation of post-synaptic receptors converts the chemical message back to electrical impulse + process of transmission begins again in post-synaptic neuron
effects are terminated by reuptake - NT taken up by pre-synaptic neuron where they are stored in synaptic vesicles ready for later release
46
endocrine system
network of glands throughout body that manufacture/secrete hormones
provides chemical system of communication for body via bloodstream - specific hormone release from endocrine gland
works closely with nervous system to regulate these physiological processes, but uses blood vessels to deliver hormones to target sites in the body rather than neuron
47
endocrine glands
group of cells within endocrine system
produce + secrete hormones - each gland produces different hormones which regulate activity of tissues/organs
major endocrine glands: pituitary gland, adrenal glands, reproductive organs
48
endocrine glands - pituitary glands & hormones
produce hormones which release hormones from other glands to regulate body's functioning
hypothalamus collects information about what's required to maintain homeostasis, which triggers pituitary gland to make changes to return body to correct state
front (anterior) associated with ACTH (triggers release cortisol in response to stress) - associated with hormones relating to reproduction
back (posterior) release 'love hormone' oxytocin
49
endocrine system - adrenal gland and hormones
top of kidneys
2 parts: adrenal cortex + adrenal medulla
adrenal cortex: produce hormones related to cardiovascular regulation + anti-inflammatory functions, releases cortisol + controls hormones that regulate blood thickness + volume
adrenal medulla produces adrenaline + noradrenaline
50
endocrine system - fight of flight response to acute stress
SAM
1. amygdala & hypothalamus - A associates sensory signals with emotions associated with fight or flight - sends distress signal to H which communicates with SNS
2. SNS preps body for fight or flight - sends signal through to adrenal medulla which releases adrenaline into bloodstream
3. adrenaline circulates through body + causes physiological changes
4. PNS - once threat passes, this dampens down stress response
51
endocrine system - response to chronic (ongoing) stressors
Hypothalamus (CRH)
Pituitary Gland (ACTH)
Adrenal Cortex (cortieosteroids)
hypo releases CRH into bloodstream
CRH causes pituitary to produce + release ACTH - ACTH transported into bloodstream to adrenal glands
ACTH stimulates adrenal cortex to release cortisol (responsible to positive effects)
52
localisation of functions in the brain
different areas of brain responsible for different behaviours, cognitive processes or activities associated with different parts of body
human brain viewed being formed of 3 concentric layers: central core, limbic system, cerebrum
53
localisation of function - cerebral cortex
divided into 2 hemispheres
some functions dominated by 1 hem (lateralisation)
activity of left side of body controlled by right hem
outer layer of hems called cerebral cortex - each hem made up of 4 sections called lobes
3 mm thick
54
localisation of function - visual cortex
in occipital lobe
both hems have it, each receiving input from opposite side of visual field
different parts specialised for colour, shape, movement, pattern, recognition, faces
55
localisation of function - auditory cortex
in temporal lobe
responsible for sound processing
56
localisation of function - motor cortex
governs voluntary movement
posterior of frontal lobe
both hems have 1
specialised areas which control different parts e.g. fingers
57
localisation of function - somatosensory cortex
detects sensory events
anterior of parietal lobe
both hems have 1 + they process touch, pain, pressure, heat from opposite side of body
produces sensation in relevant location
58
localisation of function - the language centres: Broca's area
identified by Broca in 1880s
most famous patient was Tan
involved in cognitive tasks + considered vital for language production
Broca's aphasia characterised by every limited + clumsy speech/writing
frontal lobe in left hemisphere
59
localisation of function - the language centres: Wernicke's area
identified by Wernicke
patients could speak (nonsense words) but couldn't understand
responsible for language comprehension
Wernicke's aphasia characterised by very limited understanding of language + inability to form coherent speech
temporal lobe in left hem
60
localisation of function - Phineas Gage
worked construction of US railroads
explosives ignited in rock + rod propelled through Skull
Gage survived + John Harlow treated him and wrote report on recovery & life
Gage became impulsive, rude + incapable of reason - lost his friends + alienated those close to him
conc: frontal lobes responsible for personality + reason
- case studies can't be replicated
- can't generalise (very unique)
- case studies no inter-observer reality + subjective (researcher bias)
+ allows us to study behaviours that may not be ethical
61
localisation vs holistic theory
19th century Broca & Wernicke discovered specific areas associated with particular physical & psychological functions
before supported holistic (all parts involved in processing of thought & action)
Broca & Wernicke argued localisation of function - if certain area of brain damaged, function associated with that area will also be affected
62
evaluation - supporting evidence for localisation of function
Dougherty et al: neurosurgery (damage to areas of brain linked to mental disorders) (neurosurgery last resort for treating mental disorders targeting specific areas of brain which may be involved e.g. cingulotomy involved isolation region called cingulate gyrus which has been implicated in OCD)
Buckner & Peterson: used brain scans to demonstrate how Wernicke's area was active during a listening task + Broca's area during reading task - semantic & episodic memories reside in different parts of prefrontal cortex
63
evaluation - contradictory evidence for localisation of function
Lashley: removed areas of cortex (10-50%) in rats that were learning a maze - no areas were proven more important than any other area in terms of rat's ability to learn maze
Dick & Tremblay: only 2% modern researchers think language in brain completely controlled by B&W areas - fMRI mean neural processes in brain studied (language function distributed more holistically)
64
weakness of exogenous zeitgebers
ethics in animal studies - DeCoursey et al: animals exposed to considerable harm & risk when returned to natural environment
influence of EZ overstated: Miles et al (recount story of man, blind with circadian rhythm of 24.9 hours despite exposure to social cues - studies of indiv who live in Arctic regions show normal sleep patterns (both examples suggests there are occasion when EZ little bearing on internal rhythm)
65
the different biological rhythms
infradian - more than 24 hours (menstrual cycle, SAD)
circadian - 24 hours (core body temp, sleep/wake cycle)
ultradian - less than 24 hours (stages of sleep)
66
biological rhythms - SCN
night (less light) - eyes (photoreceptors send message through optic chiasm) - message sent to SCN - SCN sends message to pineal gland - pineal gland produces melatonin
67
EPs & EZs
interaction of these produce biological rhythms (circadian)
photoreceptor cells sensitive to changes in light levels so sun rising resets SCN TMT internal & external factors combine to enable us to keep rhythm + adjust to changes
68
strengths of endogenous pacemakers
teenagers & phones: Touitou - exposure to artificial light at night results in disruption of circadian rhythms - blue light component in phones leads to melatonin suppression + circadian disruption resulting in irregular, disrupted sleep
69
biological rhythms
distinct patterns of changes in body activity that conform to cyclical time periods
influenced by EPs and EZs
70
circadian rhythm
type of biological rhythm subject to 24 hour cycle
regulates a number of body processes e.g. sleep/wake cycle + changes in core body temperature
71
circadian rhythm - Siffre's Cave Study
spend 6 months in cave
no natural light - had electricity
biological clock allowed to free-run
wired up to record body functions
erratic S/W cycle at first then settled to 25 hours
he emerged 17th September believing it was 20th August
we do have internal mechanism (EP) that regulates S/W cycle but it shifts as we don't have EZs to reset it
72
circadian rhythms - Aschoff & Wever
PPs spent 4 weeks in WW2 bunker with no natural light
most PPs displayed circadian rhythms of 24-25 hours (one 29 hours)
findings support idea that S/W cycle longer than 24 hours + has been entrained by EZs
73
circadian rhythm - Folkard et al
studied 12 people in cave for 3 weeks
PPs asked to go to sleep + wake up at certain times + researchers gradually sped up clock
majority unable to comfortably to adjust
suggests existence of strong free running S/W cycle
74
evaluation of circadian rhythms - strengths
shift work Bovin et al: period of reduced concentration in shift workers - 3x more likely to develop heart disease might be due to adjusting to different S/W cycle - research in this may have economic implications
real world application: Chronotherapy - refers to how well drugs are absorbed by body - research into CR helped develop guidelines for most effective drug dosing for patients
75
evaluation of circadian rhythms - weaknesses
individual differences: larks & owls: not every S/W cycle same, makes generalisations - people vary from 13 to 65 hours - Duffy et al: larks display preference going to bed early + owls prefer opposite
76
evaluation of circadian rhythms - Siffre's Cave Study
confounding variable: artificial light is EZ - inhibits melatonin so doesn't go to sleep - he controls when light in on/off so controls sleep/wake
can't generalise to women - he is experiences cave explorer so comfortable in cave environment - isolation impacted mental health leading to likely impact on behaviour - unrepresentative samle
cold environment - stay in sleeping bag + lie down which can cause sleep - sleep to keep warm - research suggests temperature can influence S/W cycle
77
infradian rhythms - the menstural cycle
governed by monthly changes in hormone levels which regulate ovulation
typical cycle takes approx 28 days
during cycle, oestrogen levels risk causing ovary to develop and release egg - after ovulation , progesterone helps womb lining thicken readying body for pregnancy - if not pregnant, egg absorbed into body, womb lining comes away + leaves body
78
infradian rhythms - the menstrual cycle research study
evidence suggests cycle influence by exogenous factors (other women):
Stern & McClintock: cycles can sync as influence of female pheromones - 29 women with history of irregular periods - samples of pheromones gathered from 9 at different stages of cycle via cotton pad in armpit - pads treated with alcohol & frozen to be rubbed on upper lib of other PPs - on day 1, pads from start of cycle applied to 20 PPs - day 2 all given pad from 2nd day of cycle and so on - 68% of women experienced changes to cycle which brought them closer to 'odour donor'
79
infradian rhythms - SAD
depressive disorder which has seasonal pattern
persistent low mood, lack of activity + interest in life
triggered during winter months when number of daylight hours become shorter
circannual rhythm (subject to yearly cycle) - also classed as circadian rhythm as experience of SAD due to disruption of sleep-wake cycle + can be attributed to prolonger periods of darkness
psychologists hypothesised melatonin implicated in cause of SAD - during winter, lack of light in morning means secretion of M continues longer - knock-on-effect of production of serotonin
80
ultradian rhythms - stages of sleep cycle
5 stages that span approx 90' - cycle continues through night
each stage characterised by different level of brainwave activity monitored using EEG
Stage 1&2: light sleep (easily woken) - brainwave patterns become slow & more rhythmic (alpha waves) becoming slower as sleep becomes deeper (theta waves)
Stage 3&4: delta waves - slower & greater amplitude than earlier wave patterns - deep sleep/slow waves sleep + difficult to rouse somewhere
Stage 5: REM sleep - body paralysed + brain activity speeds up significantly in manner that resembles awake brain REM (rapid eye movement) - highly correlated with dreaming
81
evaluation - infradian - evolutionary basis of menstrual cycle
menstrual synchrony may have evolutionary value - for ancestors advantageous to menstruate together + fall pregnant same time - new-borns cared for collectively increasing chances of survival
validity questioned: Schank: if too many females cycling together, would produce competition for highest quality males thereby lowering fitness of offspring - from this point of view avoidance of synchrony would appear to be most adaptive evolutionary strategy
82
evolution - infradian - methodological limitations of synchronisation studies
many factors may effect change in women's menstrual cycles e.g. stress, changes in diet, exercise act as confounding variables TMT any supposed pattern of synchrony is no more than would have been expected to occur by change
involved small samples of women + relies on PPs self-reporting
83
evaluation - infradian - evidence supports idea of distinct stages in sleep
Dement & kleitman monitoring sleep patterns of 9 adult PPs
EEG recorded brainwaves activity + controlled effects of caffiene/alcohol
REM highly correlated with experience of dreaming
replications noted similar findings through small sample critised in original
84
evaluation - infradian - practical application SAD
effective treatments is phototherapy
lightbox that stimulates very strong light in morning & evening
Eastmann et al: resets melatonin levels, releaving symptoms in up to 60%
85
evaluation - ultradian rhythm - BRAC: Kleitman
90' rhythm cycle during waking hours
Basic Rest-Activity Cycle: period of alertness followed by a spell of physiological fatigue
mind focuses for 90' - towards end body begins to run out of resources - loss of concentration, fatigue, hunger
86
evaluation - ultradian rhythm - Ericsson et al
best performers in study of violinists were those who practices for 3 sessions during the day - session lasted no more than 90' + break between
87
evaluation - ultradian rhythm - individual differences: Tucker et al
differences in PPs duration of each sleep stage - likely to be biologically determined
research evidence: growth hormone produced during slow-wave sleep, SWS reduced in older people - deficit explain issues in old age (reduced alertness)
