biopsychology

Question 1

what is the nervous system sub divided into?

Answer 1

peripheral nervous system and central nervous system

Question 2

what is the peripheral nervous system sub divided into?

Answer 2

somatic nervous system (voluntary skeletal muscles) and autonomic nervous system (involuntary muscles eg. organs)

Question 3

what is the autonomic nervous system divided into?

Answer 3

parasympathetic - eg ‘rest and digest’

sympathetic ‘fight or flight’

Question 4

what is the central nervous system divided into?

Answer 4

brain and spinal cord

Question 5

what is the function of the myelin sheath on neurons?

Answer 5

it is a fatty layer which protects the axon and speeds up electrical transmission

Question 6

what is the role of the cell body?

Answer 6

it includes a nucleus which contains the genetic material

Question 7

what is the role of the sensory neuron?
describe the length of its dendrites and axon

Answer 7

the sensory neuron carries message from PNS to CNS

long dendrites , short axon

Question 8

what is the role of the relay neuron?
describe the length of its dendrites and axon

Answer 8

the relay neuron connects sensory and motor neuron

short dendrites, short axons

Question 9

what is the role of the motor neuron?
describe the length of its dendrites and axon

Answer 9

transport message to effector

short dendrites, long axon

Question 10

What do the nodes of Ranvier do?

Answer 10

speed up and force impulse to jump axon

Question 11

what do terminal buttons do?

Answer 11

help communication across the synapse

Question 12

describe the process of synaptic transmission

Answer 12

action potential travels through neuron to pre synaptic terminal

this stimulates vesicles which release the neurotransmitters

neurotransmitters travel across synapse and bind to receptors on post synaptic neuron

the chemical message is then converted back to an electrical impulse and the action potential begins on the next neuron

neurotransmitters either return to pre synaptic neuron where vesicles reuptake them OR they diffuse in the synaptic gap

Question 13

define neurotransmitter

Answer 13

chemical messengers that are able to travel across synaptic gap and share signals between neurons

Question 14

what is an excitatory neurotransmitter?

Answer 14

have a positive charge which pass impulse onto next neuron , for example adrenaline

Question 15

what is an inhibitory neurotransmitter?

Answer 15

have a negative charge which block of prevent chemical messages from being passed on

Question 16

outline the endocrine system

Answer 16

works with the nervous system to regulate processes and control vital functions in the body, promote growth and help metabolise
made from glands which produce hormones

hypothalamus- activates pituitary gland

main endocrine glands:

pituitary- produces thyroxine which affects cells on heart, inc heart rate
located in brain
“master” gland
controls release of hormones from all other glands

parathyroid
adrenals
pancreas
ovaries
testes

Question 17

define gland

Answer 17

an organ in the body which synthesises substances such as hormones

Question 18

define gland

Answer 18

an organ in the body which synthesises substances such as hormones

Question 19

define hormones

Answer 19

chemicals that circulate in blood stream, carries to target site

Question 20

fight or flight evaluated

Answer 20

-not universal
some suggest fight or flight response only occurs in males
Taylor et al (2000)- women’s behavioral response to stress is ‘tend and befriend’. tend meaning caring for selves/young through nurturing behaviors and befriending meaning forming alliances with other women

-not a useful response for modern life
increased blood pressure (as a result of SNS) can cause damage to blood vessel and therefore heart disease
although cortisol may assist body in fighting infection, too much suppresses immune response

-suggest fight or flight response is not first phase of reaction to stress
Gray (1988)- first phase of reaction is to avoid confrontation
‘freeze’ response, initially ‘stop look and listen’ , animal is hypervigilant and focuses attention.
suggests fight or flight response has limitations as there are other aspects such as freeze.

Question 21

outline fight or flight

Answer 21

Cannon (1915)- came up with term ‘fight or flight’ to describe animla’s response to threats

stress - actute/chronic

ANS- autonomic nervous system (acute stress)
-amygdala detects stressor
-signal to hypothalamus
-noradrenaline released
-message sent to adrenal glands in medulla
-adrenaline released
-body prepared to dight/flight

amygdala associates sensory signals with emotions and sends message to hypothalamus

the hypothalamus is small part of brain which releases neurotransmitter noradrenaline

adrenal gland has medulla (center) and adrenal cortex (outer layer)

Question 22

outline localisation

Answer 22

suggests different parts of the brain are responsible for different tasks/parts of the body

FRONTAL LOBE :
motor cortex- voluntary movement for opposite side of the body
Broca’s area- speech production , damage results in Broca’s aphasia> slow, not fluent (left hemi only)

CENTRAL SULCUS- divides frontal and parietal lobes

PARIETAL LOBE:
somatosensory area- where sensory info from skin (especially touch) is represented

OCCIPITAL LOBE:
visual cortex- receives and processes visual info

TEMPORAL LOBE:
Wernicke’s area- language understanding, if damaged results in Wernicke’s aphasia, nonsense words (left hemi only)
auditory area- analyses speech based info

Question 23

evaluate localisation

Answer 23

+support from brain scans
Peterson (1988), used brain scans to find Wernicke’s area active during listening tasks and Broca’s area active during reading task

-study challenging localisation
Lashley (1950) -removed area of cortex in rats who were learning a maze
no area was proven to be more important in learning
suggests higher cognitive processes are not localised , rather distributed in a holistic way

-plasticity can challenge localisation
Lashley - law of equipotentiality
brain has ability to adapt, another part of brain can take on that function
e.g recruitment of homologous areas on opposite side of brain , such as Broca’s area

Question 24

outline plasticity and functional recovery

Answer 24

plasticity:
brain has ability to change physically and functionally as a result of new experience/learning
Maguire (2000) - London taxi drivers had more grey matter in hippocampus compared to control group , this is associated with navigational skills
part of taxi training > test called ‘The Knowledge’>test altered structure of taxi driver’s brains
Draganski (2006) - studied medical students 3 months before exams, learning induced changes occurred in hippocampus and parietal cortex

functional recovery:
functional recovery is an example of neuroplasticity
healthy areas take over role of damaged area quickly (spontaneous recovery) then it slows and rehab may be needed
Doidge (2007)-secondary neural pathways are ‘unmasked’ enabling functions the same as before
this process is supported by functional changes:

axonal sprouting - growth of new nerve endings connect with undamaged cells, forming new neural pathways

denervation super sensitivity- axons doing similar job become aroused and compensate (can have negative consequences e.g pain)
brain can adapt, other parts of brain compensating

recruitment of homologous areas- specific tasks still performed if other area takes ion role , e.g using Broca’s area on other side of hemisphere

Question 25

evaluate plasticity and functional recovery

Answer 25

-negative plasticity
may have negative behavioural consequences
Medina (2007)- brain’s adaption to prolonged drug use leads to poorer cognitive function later in life
60-80% of amputees have phantom limb syndrome, Hirstein (1998) painful sensations due to cortical reactions in the somatosensory cortex

+plasticity may be lifelong
Bezzola (2012)- 40hrs gold training produced change in neural representation of movement in participants age 40-60
using fMRI, shown decreased motor cortex activity in novice golfers- suggesting more efficient representations after training, showing neuroplasticity can continue throughout lifespan

+RWA
understanding processes has contributed to neurorehabilitation
e.g understanding axonal growth meant new therapies that had never been tried before were
e.g after a stroke, constraint-induced movement

Question 26

outline the four ways of studying the brain

Answer 26

fMRI
detects changes in blood oxygenation and flow
when an area is active, more oxygen is used- haemodynamic response

EEG
measures electrical activity using electrodes

ERPs
measures types of brainwaves which are triggered by particular events

post mortem examination
analysis of brain after death

Question 27

evaluate the four ways of studying the brain

Answer 27

fMRI
+no radiation
+non-invasive
+high spatial resolution
-expensive
-poor temporal resolution (5s time lag)

EEG
+high temporal resolution
+RWA, sleep, epilepsy
-generalised nature, doesn’t pinpoint exact source of activity

ERPs
+more specific to measurement of neural processes
-lacks standardisation
-extraneous material has to be removed

post mortem
+_provided foundational understanding of brain’s structure
-ethical issues
-0difficult to establish accurate causation

Question 28

outline hemispheric lateralisation and split-brain research.

Answer 28

lateralisation is the idea that the two hemispheres are functionally different and certain processes are controlled by each hemisphere
e.g: left side of brain responsible for language tasks, right side for spatial/face recognition tasks

Split-brain research
- patients had corpus callosotomy (corpus callum is severed so hemispheres are separated) to help with epileptic fits
-Sperry (1968) compared patients with connected and split brains using visual and tactile tasks

describe what they see:
if shown to left visual field, couldn’t describe it (goes to RH which isn’t responsible for language)

recognition by touch:
object in each hand, lose it and find it again - can find object but only with original hand (e.g, left hand sends message to RH, the RH then controls the left hand to find the same object again)

drawings:
consistently better when drawn with left hand (controlled by RH which does spatial tasks)

face recognition:
shown picture that’s half man, half woman
right eye> message to LH> say man
left eye> message to RH> find other half of woman

Question 29

evaluate hemispheric lateralisation and split-brain research

Answer 29

+supporting evidence for lateralisation
Fink (1966)- used brain scans to identify which brain areas were active during a visual processing task.
participants with connected brains asked to look at global elements of an image, RH more active, but when asked to look at specific elements, LH dominated
suggests hemispheric lateralisation is a feature of split-brain and connected brain people.

-issues with generalisation
researchers urge caution is accepting these findings
difficult to generalise when research groups are so small - e.g in Sperry’s study, only 11 people took part in all variations, all had experienced epileptic seizures and had different levels of disconnection

-differences in function may be overstated
pop-psychological literature over-emphasises and oversimplifies the functional distinction between LH and RH
‘verbal’ and non-verbal’ labels are contended by modern neuroscientists who argue the distinction is far too clear cut
in the connected brain, the two hemispheres are in constant communication and behaviours typically associated in one hemisphere can often be performed in the other hemisphere.

Question 30

outline circadian rhythms

Answer 30

a circadian rhythm is a biological rhythm that has a cycle length of roughly 24 hours.

The sleep-wake cycle is an example of a circadian rhythm. It dictates when we should be awake/asleep, with light and darkness helping determine when the cycle occurs.

The internal ‘clock’ is ‘free running’, and it will maintain a cycle of 24-25 hours even in the ABSENCE OF EXTERNAL CUES.

the sleep wake cycle can be represented on a graph of alertness. You are the most alert around 6pm-9pm, closely followed by 9am. The body experiences dips after midday and around 6am.

Siffre did a field experiment by staying in caves and studying his own circadian rhythms. no external cues, only thing influencing his behaviour was internal body clock.
study 1 —— 61 days in Alps in 1962.
study 2—— 6 months, established body clock was 24 hrs
study 3—— body clock ticked more slowly to when he was younger, sometimes stretching his circadian rhythm to 48 hours.

Question 31

evaluate circadian rhythms

Answer 31

+support from other research
Aschoff and Wever (1976)- group of participants spent a week in WW2 bunker, deprived of natural light.
all but one had a circadian rhythm of 24-25 hours.

+shift work
provides an understanding of the consequences that occur when circadian rhythm is disrupted- desynchronisation.
e.g: night workers experience decreased concentration at 6 in the morning, meaning accidents more likely- Boirin (1996)
Knuttson (2003), relationship between poor health and shift work- 3x more likely to develop heart disease

-individual differences
genralisations difficult to make
studies based on small samples
sleep-wake cycle varies from person to person
Czeisler (1999)- cycles vary from 16-65 hours
difficult to use data to discuss anything other than averages, which may be meaningless

Question 32

what does the somatic nervous system control?

Answer 32

voluntary movements, connects the CNS and the senses

Question 33

sensory neurons carry information

(in relation to the brain)

Answer 33

towards the brain

Question 34

outline endogenous pacemakers and exogenous zeitgebers

Answer 34

endogenous pacemaker:
-internal body clocks
-main one is SCN which is group of cells found in hypothalamus, linked via neural pathway to pineal gland (melatonin production)
low light>optic chasm in eye>stimulates SCN>stimulates pineal gland>produces melatonin>brain activity falls (sleep)

exogenous zeitgebers:
-outside time givers
-biological clock needs to be reset to allow organisms to adjust to changing daylight in seasons- this is done via environmental cues
light cues- sunrise/sunset- affects hormones and blood circulation
social cues- research on jet lag shows adjusting to local time (not following body cues) on when to eat/sleep is an effective way of entraining circadian rhythm.
entrainment is- alignment of our internal body clocks with the external environment.

Question 35

evaluate endogenous pacemakers and exogenous zeitgebers

Answer 35

+animal studies
demonstrated the importance of SCN
Morgan (1995) bred hamsters with abnormal circadian rhythms of 24 hours.
Transferred their SCN neurons to healthy hamsters, which they displayed the same abnormal circadian rhythm.

+power of light
light is a powerful exogenous zeitgeber
Campbell and Murphy- light may be detected by receptors on skin
25 participants were woken at various times and a light was shone on back of their knees.
In some cases, managed to shift circadian rhythm by 3 hours.
Supports importance of light, even suggesting it need not necessarily rely on eyes to exert influence over the brain.

-other exogenous zeitgebers overexaggerated
Miles (1977)- recount story of blind man who had an abnormal circadian rhythm of 24.9 hours.
Despite exposure to social cues (regular mealtimes) his sleep wake cycle could not be adjusted to 24 hours.
Suggests there may be occasions certain exogenous zeitgebers have little bearing on our internal rhythm.

Question 36

outline infradian and ultradian rhythms.

Answer 36

INFRADIAN
menstrual cycle
oestrogen rises>ovary develops egg and releases it (ovulation) > progesterone rises> womb lining grows thicker> if no pregnancy, comes away from body and egg absorbed by body.
cycle typically 28 days
endogenous cycle , but Stern and McClintock demonstrated it may be affected by exogenous factors.
had 29 women , took samples of pheromones from 9 women. 20 had this cotton pad rubbed on their lip. 68% experienced cycle change which brought them closer to the cycle of their ‘odour donor’
* seasonal affective disorder (SAD) *
depressive disorder which has a seasonal pattern, triggered by fewer daylight hours which disrupts sleep/wake cycle- melatonin continues to be produced, which causes serotonin to be produced too (this is associated with depressive symptoms)
circannual rhythm- subject to yearly cycle.

ULTRADIAN
sleep stages

stage 1 -
alpha waves/high frequency/short amplitude/easily woken

stage 2-
alpha waves and occasional sleep spindles

stage 3+4 -
delta waves/slow wave sleep (SWS)/lower frequency/higher amplitude

stage 5- body paralysed/brain activity as though awake/ theta waves/REM (dreams likely)

Question 37

evaluate infradian and ultradian rhythms

Answer 37

EVOLUTIONARY VALUE
if menstruate at same time, fall pregnant at same time, raise babies collectively.
EXTRA:
However, would also mean more competition for highest quality males so may be advantageous to avoid synchrony.

SLEEP STAGES
Dement and Kleitmen (1957)- studied 9 adults in sleep lab using EEGs to measure brainwaves.
Caffeine and alcohol effects controlled
REM activity correlated with dreaming
participants were woken during dreaming and could report dreams vividly.

practical application
light therapy> resets body’s internal clock
Sanassi (2014)- helped 80% with SAD symptoms
preferred to antidepressants as it’s deemed safe
EXTRA: Rohen (2009)- relapse rate of light therapy is 46% compared to 27% of those receiving CBT