Biopsychology

Question 1

Discuss research into plasticity of the brain including functional recovery (AO1)

Answer 1

• plasticity = neural connections can change, or new neural connections can be formed, as a result of learning and experience
• Maguire et al - london taxi drivers - ‘the knowledge’ test, longer they’d been in the job, the more pronounced was the structural difference - higher volume of grey matter in the posterior hippocampus ( part of brain that deals with development of spatial skills)
• Draganski et al - medical students - 3 months before and after exams - changes occured in posterior hippocamus and parietral cortex
• functional recovery - unaffected areas of the brain can compensate for the damaged areas and take over their functions

Question 2

Discuss research into plasticity of the brain including functional recovery (AO3)

Answer 2

• Maguire’s study is flawed - she didn’t measure the taxi drivers brains before ‘the knowledge’ so there’s nothing to compare it against - also biological reductionism
• research is limited - most research only looks into one single factor - the posterior hippocampus
• neurorehabilitation - motor therapy and electrical stimulation of the brain to counter negative effects and defecits in motor and cognitive functions after a stroke or injury

Question 3

Discuss split-brain research (AO1)

Answer 3

• hemispheric lateralisation - language is controlled by left hemisphere
• Sperry - all participants had commissurotomy - to control epileptic seizures by cutting the corpus callosum in half so the two hemispheres cant interact anymore
  - image or word presented to the right visual field (left hemisphere) and the same or different word/image presented to the left visual field ( right hemisphere) - hemispheres can’t communicate so don’t have a complete picture of the full word
  - Describing what you see - can’t describe image shown on left visual field as the right hemisphere doesn’t control language
  - Recognition by touch - could pick matching object by touch in left visual field - couldn’t describe it but could understand what it was using the right hemisphere
  - Composite words - two words presented simultaneously - left hemisphere would say the word on the right, right hemisphere would write the word on the left - right hemisphere has supereriority in drawing
  - Matching faces - right faces dominant in recognising faces, picture of face presented to right hemisphere always picked whilst face presented to left hemisphere ignored - one pic of two different halves of face, left hemisphere could describe it, right hemisphere could select a matching picture

Question 4

Discuss split-brain research (AO3)

Answer 4

• issues with generalising - low ecological/population validity - only people who had gone through the specific surgery - only 11 participants
• scientific- reliable and replicable - standardised procedures
• high internal validity - measured what he was supposed to be measuring
• differences between 2 hemispheres overmephasised - complex communication

Question 5

Discuss research into circadian rhythms (AO1)

Answer 5

• circadian rhythm - lasts about 24 hours a day
  - sleep/wake cycle and core body temperature
• sleep/wake cycle - exogenous zeitgeber - daylight
• Siffre - deprived of natural light and sound - 2 months in caves of the southern Alps - 6 months in Texas - his sleep/wake cycle was nearly the same as a normal one (25 hours)
• Aschoff and Wever - group of people spent 4 weeks in a WW2 bunker - all but one = 24 - 25 hour sleep cycle ( 1 had 29 hours) - may suggest natural cycle is longer than 24 hours but entrained by daylight hours and meal times
• Folkard et al - don’t overestimate external cues - 12 people lived in a dark cave for 3 weeks and slept and wake when the clock said specific times - researches gradually sped up the clock until it was only a 22 hour cycle - but only 1 person could adapt - may suggest that the cycle can’t be influenced by external factors so easily

Question 6

Discuss research into circadian rhythms (AO3)

Answer 6

• application to drug therapy - certain peak times to take medication - lead to development of guidelines to do with timing of drug dosing
• small samples - can’t generalise
• individual differences - Duffy et al - some people have a preference for waking early and some have a preference for waking late
• confounding variable - Siffre still had a lamp - artificial light could have affected his cycle

Question 7

Discuss the research into infradian and or/ultradian rhythms (AO1)

Answer 7

• infradian - last longer than a day
  - menstrual cycle - typically 28 days
  - McClintock - studied how pheromones can influence the menstrual cycle - 29 women with irregular periods - cotton pads under arm pits for 8 hours on 9 women to gather pheromones - then treated with alcohol and froze before rubbing on other women’s lips - 68% cycles changed to become closer to the women’s whose armpit they licked
• ultradian - more than one a day - sleep cycle - 5 stages, about 90 minutes
  - stage 1 and 2 = light sleep - alpha waves - slow and rhythmtic, theta waves - even slower as sleep deepens
  - stage 3 and 4 = slow wave sleep/deep sleep - delta waves - slower and a greater amplitude
  - stage 5 = REM sleep - body is paralysed but brain is working fast - rapid eye movement - fast jerky activity of eyes under the eye lid - highly correlated with dreaming

Question 8

Discuss the research into infradian and or/ultradian rhythms (AO3)

Answer 8

• methodlogical limitations of McClintock - confounding variables such as stress, changes in diet, etc could be the reason for change in cycle
  - also small samples of women so hard to generalise
• Russell et al - used similar methodology- also found that pheromones contribute to the synchronisation of menstrual cycles, depending on when during the cycle the odor was collected
• Dement and Kleitman - monitored sleeping patterns of 9 people- recorded using an EEG - REM activity during sleep was highly correlated with dreaming
• animal studies- most research done on pheromones is used on animals

Question 9

Discuss the effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle (AO1)

Answer 9

• Endogenous Pacemakers - internal body clock
  - the suprachiasmatic nucleus (SCN) - tiny bundle of nerve cells in the hypothalamus - recieves information about light from the optic chiasm (nerve fibers connected to the eye cross) - happens when eyes are closed- biological clock can adjust to changing daylight patterns whilst asleep
  - pineal gland and melotonin - SCN passes information about daylight to the pineal gland - during night it increased production of melotonin - induces sleep and inhibits wakefullness
• Exogenous Zeitgebers - external factors which reset our biological clocks through a process called entrainment
  - light - can reset the SCN
  - Campbell and Murphy - can be detected by skin receptor sites even when the eyes can’t see light - 15 participants were woken up by having light pads shone at the back of their knees - could change the sleep/wake cycle by 3 hours
  - social cues - parents, alarms

Question 10

Discuss the effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle (AO3)

Answer 10

• animal studies - DeCoursey - destroyed SCN connections in chipmunks - returned to natural habitate and observed - sleep/wake cycle had disappeared and most were killed as they were attacked by predators when they should’ve been sleeping- ethical issues - animals were harmed
• methodlogical issues - Campbell and Murphy - findings haven’t been replicated - confounding variable of limited light exposure to eyes
• exogenous zeitgebers effect overemphasised - Miles et al - blind man had a cycle of 24.9 hours - exposed to social cues but couldn’t change his cycle so had to take sedatives at night and stimulants in the morning

Question 11

Discuss the extent to which brain functions are localised (AO1)

Answer 11

• localisation v holistic theory - used to believe the brain worked together in the process of thought and action
  - Broca and Wernicke - localisation of functions - different parts of brain has different functions
• left hemisphere = controls right side, right hemisphere = controls left side
• frontal lobe = decision area - at the back is the motor area
• parietal lobe = somatosensory area
• occipital lobe = visual area
• temporal lobe = auditory area
  LEFT ONLY&raquo_space;> Broca’s area = speech producing ( frontal lobe)
  Wernicke’s area = speech comprehension (temporal lobe)