BIOPSYCHOLOGY

Discuss what research has shown about localisation of function in the brain 

• Evidence from neurosurgery > Dougherty > Damage to areas of brain linked to mental disorders > Patients had a cingulotomy (linked to OCD) > Almost half of patients had a successful or partial response to the surgery 

• Evidence from brain scans > Petersen > Broca’s area active during reading task, Wernicke’s active during listening 

• Language localisation questioned > May not be just Wernicke’s / Broca’s > Dick and Tremblay found many researchers don’t think W and B are the only ones responsible > fMRI 

• Case study evidence > Such as Phineas Gage > Questionable to generalise 

Discuss research on hemispheric lateralisation 

• Lateralisation applies even in the connected brain > Each processes info differently during a visual task according to PET scans (Fink et al) > HL is a feature in both connected and split 

• Lateralisation is shown in animals > Rogers > Lateralised chickens could find food while looking for predators, normal could not > Adaptive advantage 

• Research support > Gazzaniga > Split-brains performed better on ‘odd-on-out' task > LH’s cognitive abilities are compromised by inferior RH 

• Ethical issues > Patients not harmed for study > Full informed consent given > However trauma from operation could mean that patients didn’t know what they were consenting to 

Discuss research into plasticity and functional recovery of the brain after trauma 

Support for plasticity > Maguire > MRI scans discovered that London taxi drivers had a larger posterior hippocampus compared to non-taxi driver control > Positive correlation between time working and size > Brain adapted structurally to adapt to memorisation 

Support for functional recovery after trauma > Danelli et al. > EB had a left hemispherectomy at age 2.5 and developed aphasia > By 14 he gained some ability back and fMRI showed his right hemisphere acted like the left > Shows how brain can adapt after significant damage 

Practical applications > Understanding how brain works helps physiotherapists treat effectively > Beneficial for economy, people return to work > Deeper understanding of brain function by looking at initially damaged areas of brain 

Functional recovery varies > Mathias > Meta-analysis found higher IQ and educational background are positively correlated with better recovery > Some people have a greater cognitive reserve, so full functional recovery may not be achievable for everyone 

Discuss research into circadian rhythms 

Provides understanding of adverse consequences > Night shift workers experience a circadian trough at 6am where accidents are most likely to happen (Boivin) > Shift workers 3 times more likely to develop heart disease (Knutsson) > Research provides economic improvements in managing worker productivity 

Used to improve medical treatments > Bonten et al > Timing of drug intake is important (chronotherapeutics) > Aspirin reduces blood platelet activity and risk of heart attack > heart attack most likely to occur during early morning, so taking drugs which delay function until needed > Research can improve drug effectiveness 

Individual differences > Studies conducted are on a small number of PPTs > Sleep / wake cycles have been found to vary by 13-65 hours (Czeisler) > Jeanne Duffy revealed larks and owls > Even Siffre found his cycle had changed over the years > Difficult to use data to discuss anything apart from averages, which may be meaningless 

Potential real-life applications > Wolfson and Carskadon > Suggest that school day should start later to fit teenage sleep pattern > Teens get tired later due to hormonal shifts > Adolescent Sleep Working Group > Reduced dependence of caffeine and better academic performance > Research could help young people achieve higher potential 

Discuss research into infradian and / or ultradian rhythms 

Support for distinct stages > Dermot and Kleitman > Sleep recordings made of 33 PPTs over a night's sleep showed cyclic patterns of activation > Body relaxation in SWS and rapid eye movement in REM > PPTs woken at different stages reported more vivid dreaming during REM 

Support for the role of N3 > Shapiro > Ultramarathon runners showed longer sleep after intense physical activity > Higher proportion of N3 > Suggests that SWS is needed for physical recovery 

Conflicting theories on the role of REM > Haider > Found that those who had drug overdose had more REM sleep > Suggests REM is needed for mental recovery 

Individual differences > Newborn babies spend 80% in REM compared to 20-25% in adults > Although order of stages = same, duration was not > Suggests stages of sleep are not a simple process and adapt to needs of individual 

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

Support from animal studies > Decoursey > 30 chipmunks sleep / wake cycle disappeared when their SCN was removed > Ralph found that normal hamsters who had the SCN of mutant hamsters transplanted had an altered sleep / wake cycle which matched the 20-hour mutant cycle >  

May obscure other body clocks > Limitation of SCN research > Different circadian rhythms in different parts of the body (peripheral oscillators) > Damiola et al > Changing feeding patterns in mice can alter circadian rhythms of liver cells by 12 hours, whilst SCN remained unaffected > Suggests there are other complex influences on the sleep / wake cycle 

Support from Siffre > Stayed in a cave > Circadian rhythm altered from 24 to 25 hours as no natural light > Thought it was August when it was mid-September > Displays light’s importance / influence as an exogenous zeitgeber 

Interactionist system > EPs can’t be studied in isolation > Studies like Siffre’s include artificial light which could be a confounding variable > EPs and EZs interact in everyday life > Would make more sense to conduct research combining them to improve validity