Biopsych

Question 1

Nervous system

Answer 1

• central nervous system; brain (cerebral cortex is outer layer), highly developed in humans
• spinal cord connects brain to PNS, reflex actions

Question 2

Endocrine System

Answer 2

• glands + hormones; hormones distributed in bloodstream, pituitary is the master gland
• fight or flight; sympathetic arousal: pituitary →> adrenal gland -> adrenaline

Question 3

Localisation of function in the brain A01

Answer 3

• localisation vs holistic theory; are brain functions in specific areas or across the whole brain?
• hemispheres of the brain; brain (cerebrum) divided in half + each hemisphere controls
  the opposite side of the body = lateralisation
• motor, somatosensory, visual + auditory centres; each of the 4 lobes of the brain (frontal, parietal, occipital + temporal lobes) is linked to different fut nctions
• language centres in the brain; Broca’s related to production (left frontal), Wernicke’s related to understanding (left temporal)

Question 4

Localisation of function in the brain A03

Answer 4

• evidence from neurosurgery; isolation (severing connections) of cingulate gyrus (cingulotomy) improves OCD in 30% of ppts (Dougherty et al)
• evidence from brain scans; Broca’s + Wernicke’s areas identified (Peterson et al), semantic + episodic areas identified (Buckner + Peterson) → COUNTER →> learning in rats is holistic not localised (Lashley)
• language localisation questioned; multiple pathways (e.g. right hemisphere + thalamus), not just Broca’s + Wernicke’s (Dick + Tremblay)

Question 5

Neurons

Answer 5

• types of neurons; sensory, relay + motor neurons
• structure of a neuron; cell body contains nucleus, has dendrites + axon covered in myelin sheath divided by nodes
  of Ranvier
• electrical transmission; positive charge leads to action potential

Question 6

Synaptic transmission

Answer 6

• synapse; terminal buttons at synapse, presynaptic vesicles release neurotransmitter
• neurotransmitters; postsynaptic receptor site receives neurotransmitters from dendrites of adjoining neuron + specialist functions, e.g. acetylcholine for muscle contraction
• excitation, inhibition + summation; adrenaline is excitatory, serotonin is inhibitory + postsynaptic neuron triggered if sum of excitatory + inhibitory signals reaches threshold
• psychotherapeutic drugs; SSRIs increase serotonin activity

Question 7

Plasticity A01

Answer 7

• brain plasticity; research suggests that neural connections can change or new connections can be formed
• research into plasticity; hippocampus in taxi drivers changes structure after learning The Knowledge (Maguire et al) + changes in hippocampus and the parietal cortex betore and after exams (Draganski et al)

Question 8

Plasticity A01

Answer 8

• brain plasticity; research suggests that neural connections can change or new connections can be formed
• research into plasticity; hippocampus in taxi drivers changes structure after learning The Knowledge (Maguire et al) + changes in hippocampus and the parietal cortex betore and after exams (Draganski et al)

Question 9

Plasticity A03

Answer 9

• negative plasticity; drug use may cause neural changes (Medina

et al) + phantom limb syndrome due to reorganisation in

somatosensory cortex (Ranachandran + Hirstein)

• age + plasticity; plasticity reduces with age, though Bezzola et al

showed how golf training caused neural changes in over-40s

Question 10

Functional Recovery A01

Answer 10

• after brain trauma; healthy brain areas take over lost functions after trauma, happens quickly
• what happens in the brain during recovery?; new synaptic connections, secondary pathways ‘unmasked’ -> axon sprouting + denervation supersensitivity + recruitment of homologous brain
  areas

Question 11

Functional Recovery A03

Answer 11

+ Real-world application: understanding of brain recovery aids in neurorehabilitation
therapy, e.g. after strokes

+ Cognitive ability correlation: (Schneider et al) negative correlation between cognitive

functioning and time spent in recovery after brain damage, higher level of education =

less time in recovery = more likely to recover

• Functional & spontaneous recovery limited: law of equipotentiality means the brain can

only repair itself up to a certain point, after which rehabilitation is needed to continue
recovery

Question 12

Hemisphere Lateralisation A01

Answer 12

• localisation + lateralisation; some functions localised (e.g. vision), or localised + lateralised (e.g. language)
• left + right hemispheres; language areas in LH (for most), LH is the analyser, RH is the synthesiser
• motor areas are contralateral + visual areas are contralateral & ipsilateral, LVF of both eyes to RH and RVF to LH - same for auditory
  areas

Question 13

Hemisphere lateralisation A03

Answer 13

• lateralisation in the connected brain; global elements processed by RH and finer detail by LH
  (Fink et al)
• one brain; certain hemispheres dedicated to certain tasks but no dominant RH O LH (Nielsen et al)

Question 14

Split Brain Research A01

Answer 14

• procedure; 11 participants, split-brain operation for epilepsy (deconnect hemispheres)
• findings; objects shown to RVF (LH), person describes object, shown to LVF (RH), says ‘nothing there’ - object shown to LVF (RH), cannot name but can select item with left hand - pinup picture to LVF, participant giggles but reports nothing
• conclusions; lateralised brain, LH verbal + RH ‘silent’ but emotional

Question 15

Split Brian research A03

Answer 15

• research support; split-brain participants faster at some LH tasks (Luck et al), normally slowed down by inferior
  RH (Kingstone et al)
• generalisation issues; epilepsy is a confounding variable when comparing ppts to ‘normal’ controls

Question 16

Ways of studying Brian A01

Answer 16

• fMRI; detects changes in blood flow to show active areas (where more oxygen consumed), 3D
• EEG; measures brainwave patterns from 1000s of neurons via electrodes
• ERP; types of brainwave triggered by particular event filtered out from
  EEG recordings
• post-mortems; study of the brain after death, in order to link brain areas to observed behaviour deficits

Question 17

Ways of studying brian A03

Answer 17

• fMRI; + risk-free, non-invasive + high spatial resolution & - expensive, poor temporal resolution
• EEG; + real-world uses (e.g. sleep stages + diagnosing epilepsy), high temporal resolution & - comes from 1000s of neurons, can’t identify source
• ERP; + more specific than EEG, higher temporal resolution than fMRI & - no standardised method, background ‘noise’ not easy to control
• post-mortem; + early research (e.g. Broca) & - causation an issue, consent issues (e.g. HM)

Question 18

Circadian Rhythms A01

Answer 18

• biological rhythms; controlled by internal body clocks (endogenous pacemakers) and

external cues (exogenous zeitgebers) -> take 24hrs to complete

• the sleep/wake cycle; governed by daylight and by biological clock (suprachiasmatic

nucleus), gets light information from the eyes

• Siffre’s cave study; his free-running rhythm extended slightly to 25 hrs when deprived of
  daylight
• other research; support for exogenous zeitgebers entraining internal clock (Aschoff +

Wever, bunker, natural rhythm longer) + support for endogenous cues if difference is too
big (Folkard et al, cave with 22 hr day)

Question 19

Circadian Rhythms A03

Answer 19

+ Application: provides knowledge applicable to night-shift work and the negative consequences of disrupted circadian rhythms - shift workers are 3x more likely to develop heart disease (Knutsson)
+ Application: used to improve medical treatments by co-ordinating administrating medication with the body’s processes, eg. aspirin is most effective for treating heart attacks when taken late at night + Research support: Siffre’s cave studies
+ Research support: (Aschoff & Wever) a group of participants who spent four weeks in a WW2 bunker had sleep/wake cycles that extended to 25 hours (except one: 29 hours)
+ Research support: (Folkard et al) 12 people lived in a cave for 3 weeks with a clock and were told to sleep at 11:45
They did not know the clock was running fast to adjust their sleep/wake cycles to 22 hours unconsciously: only one adjusted comfortably
- Individual differences make generalisations difficult: Czeisler found significant individual differences in sleep/wake cycles from 13-65 hours, and sleep/wake cycle studies (Siffre, Folkard et al, Aschoff & Wever) have small samples.
(Duffy et al.) different people have different weferences, ‘morning’ vs ‘evening people’

Question 20

Infradian Rhythms A01

Answer 20

• takes more than 24hrs to compete
• the menstrual cycle; ostrogen regulates ovulation, progesterone readies body for pregnancy (endogenous factors)
• synchronising the menstrual cycle; menstrual cycles synchronised through pheromones, exogenous factor (Stern + McClintock)
• seasonal affective disorder; form of depression triggered in the winter months + regulated by melatonin, a circannual rhythm

Question 21

Infradian Rhythms A03

Answer 21

+ Menstrual synchrony may have an evolutionary basis, as females menstruating and becoming pregnant at the same time to raise offspring together and to protect females from males
- Confounding variables in menstrual synchrony studies: stress, changes in diet, exercise, etc. may impact the menstrual cycle which are confounding variables as they cannot be controlled and making any results likely due to chance

Question 22

Ultradian Rhythms A01

Answer 22

• takes less than 24hrs to complete
• stages of sleep; 5 stages that occur in a 90-minute cycle:
• stages 1 + 2: alpha waves + sleep spindles
• stages 3 + 4: deep sleep, delta waves
• stage 5: REM sleep, theta waves

Question 23

Ultradian Rhythms A03

Answer 23

+ Improved understanding: research into sleep and ultradian rhythms has improved our understanding of impacts of age on sleep, slow-wave sleep (stages 3&4) reduces with age, which is the stage where the growth hormone is mostly produced, which may explain various issues of old-
age such as attention
+ Research support: (Kleitman) EEGs have been used to research sleep cycles by detecting brain activity in different stages and waking participants in different stages to assess dream recall and ease of waking up
- Significant individual differences: (Tucker et al.) large differences in the duration of sleep stages between people, and may be largely biologically determined, so research lacks generalisability

Question 24

Endogenous Pacemakers and sleep/wake cycle A01

Answer 24

• the suprachiasmatic nucleus; SCN receives information about light from optic chiasm
• animal studies + the SCN; sleep/wake cycle disappeared when SCN destroyed (DeCoursey et al) + SCN transplanted from mutant hamsters with 20-hour sleep cycle (Ralph et al)
• the pineal gland + melatonin; the SCN passes information to the pineal gland that control melatonin

Question 25

Endogenous Pacemakers and sleep/wake cycle A03

Answer 25

• Beyond the master clock; other body clocks (peripheral oscillators), e.g. circadian rhythm of liver cells in mice altered but SCN unaffected
  (Damiola et al)
• interactionist approach; research looks at pacemakers/zeitgebers in isolation, approach lacks validity
• ethics; mammals used to study sleep/wake cycle, but may lead to their death (e.g. DeCoursey et al.’s chipmunks)

Question 26

Exogenous Zeitgebers and sleep/wake cycle A01

Answer 26

• exogenous zeitgebers; ‘time-givers’ entrain free-running
  endogenous rhythms
• light; light shone on back of knees changed rhythm by up to
  3 hours (Campbell + Murphy)
• social cues; babies’ rhythms + jet lag are entrained by
  bedtimes + mealtimes

Question 27

Exogenous zeitgebers and sleep/wake cycle A03

Answer 27

• environmental observations; EZs do not have same effect on people who live in darkness in summer and little light in winter (e
  Inuit people in Arctic Circle)
• case study evidence; man blind from birth with sleep/wake cyc of 24.9 hours, could not adjust despite social cues e.g. mealtime:
  (Miles et al.)