Paper 2 Biopsychology Flashcards
Discuss the extent to which brain functions are localised (16)
Discuss research into the plasticity of the brain including functional recovery (16)
Discuss split-brain research. Refer to examples of such research in your answer (16)
Describe and evaluate scanning techniques as a way of investigating the (16)
functional magnetic resonance imagining (FMRI)
- measures blood flow in the brain when a person performs a task
- magnetic field and radio waves to monitor blood flow, detecting the changes in blood oxygenation and flow that occur as a result of brain activity
- 3d images = parts of the brain are involved in a particular mental process
Discuss research into circadian rhythms (16)
Siffre
- Deprived of exposure to natural light and sound, but with access to adequate food and drink
- Siffre’s 24-hour sleep-wake cycle was increased by the lack of external cues
- our natural sleep/wake cycle may be slightly longer than 24 hours but that it is entrained by exogenous zeitgebers associated with our 24-hour day (such as daylight, typical meal times, etc.)
Strength: research to support the importance of light in the control of circadian rhythms
- ww1 bunker deprived of natural light = 25-27 hour sleep wake cycle
Limitation: hard to generalise
- research only involves 1 person or small group
- may not be representative of wider population
= Siffre observed, at the age of 60, that his internal clock ticked much more slowly than when he was a young man. This illustrates the fact that, even when the same person is involved, there are factors that vary which may prevent general conclusions being drawn.
Strength: circadian rhythms has practical applications to shift work.
- reduced concentration for shift workers around 6 am = meaning mistakes and accidents are more likely to happen
= economic implications in terms of how best to manage worker productivity
Limitation: doesn’t account for individual differences
- morning people / evening people
= innate individual differences in circadian rhythms
Discuss research into infradian and/or ultradian rhythms (16)
Ultradian rhythms: biological rhythm that lasts less than 24hours (pattern of human sleep)
The sleep cycle: repeats every 90min
- stage 1 and 2 = ‘light sleep’
- stage 3 and 4 = ‘deep sleep’
- stage 5 = REM sleep
AO3:
Strength: research evidence to support the idea that there are distinct stages of sleep
- brainwave activity recorded on EEG
- REM associated with dreaming
Limitation: individual differences = investigating patterns difficult
- different in duration of stages (3 and 4)
= innate individual differences in ultradian rhythms, which means that it is worth focusing on these differences during investigations into sleep cycles.
Limitation: ecological validity
Infradian rhythms: biological rhythm lasting longer than 24 hours (weekly/ monthly/ annually)
Menstrual cycle
- 28 days between each cycle
endogenous and exogenous = hormonal changes and influence of the women
AO3:
exogenous cues can control the cycles that are normally governed by endogenous factors
- synchronisation through odour exposure
= menstrual cycles can be affected by pheromones, which have the effect on people nearby rather than on the person producing them
- holistic approach rather than reductionist
Discuss the effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle (16)
Biological rhythms: circadian rhythms
Endogenous pacemakers = internal body clock
- Superchiasmatic nucleus
- pineal gland and melatonin
= The sensitivity of the pineal gland and the SCN to light, and the role of melatonin in controlling sleep and activity, mean that, despite the endogenous nature of these clocks, their activity must be synchronised with the light-dark rhythm of the world outside.
AO3:
Strength: importance of the SCN as an endogenous pacemaker has been found in many animal studies
- mutant hamsters 20hr sleep/ wake cycle
= endogenous pacemakers are important for biological circadian rhythm
Limitation: changing feeding patterns in mice could alter circadian rhythms of cells in the liver by up to 12 hours
Limitation: issues with generalising animal studies to humans - humans respond very different to manipulations of biological rhythms - vast difference in environmental context
Exogenous zeitgebers = external cues in the environment
- entrainment
- light
- social cues
AO3:
Strength: research support for the role of melanopsin
- blind people who still have some light perception have normal circadian rhythms
- blind without light perception = abnormal circadian rhythms
= importance of exogenous zeitgebers as a biological mechanism and their impact on biological circadian rhythms
Strength: research for the role of exogenous zeitgebers.
- When Siffe returned from an underground stay with no clocks or light, he believed the date to be a month earlier than it was.
=This suggests that his 24 hour sleep-wakecycle was increased by the lack of external cues, making him believe one day was longer than it was.
= This highlights the impact of external factors on bodily rhythms
Limitation: exogenous zeitgebers overstated
- blind man from birth
- despite exposure to social cues his sleep wake cycle could not be adjusted - so he had to take sedatives at night and stimulates in the morning to keep pace with 24 hour world
