Biopsychology research studies Flashcards
Aschoff and Wever (1976)
PPs spent four weeks in a disused WW2 bunker with no natural light
Found that all but one PP (whose cycle extended to 29 hours) had a circadian rhythm between 24-25 hours
Circadian rhythms
Bezzola et al. (2012)
When placed into an fMRI and asked to imagine a golf swing,
PPs who had undergone 40 hours of golf training showed less activity in thier motor cortex compared to matched control
Plasticity and functional recovery
Boivin et al. (1996)
Shift workers experience a period of reduced concentration around 6am (during circadian trough), making mistakes and acciedents more likely
Circadian rhythms
Bonten et al (2015)
Taking aspirin to reduce heart attacks is more effective last thing at night as it reduces blood platelet activity that otherwise peaks at early morning
Circadian rhythms
Campbell and Murphy (1998)
Conducted a story where 15 PPS were woken at various times in the night and a light pad was shone onto the back fo their knees
Caused a deviation in PPs usual sleep/wake cycle by up to 3 hours
Exogenous zeitgebers
Czeisler et al (1999)
Vast individual differences in the sleep wake cycle - ranging from 13 to 65 hours
So difficult to discern baseline for normal circadian rhythm length
Circadian rhythm
Damiola et al. (2000)
Demonstrated how switching to feeding mice only at night could alter circadian rhythms of cells in the liver by up to 12 hour but did not affect the cells in the SCN, suggesting peripheral ocillators can act independently of SCN
Endogenous pacemakers
Danelli et al (2012)
Reported a functional recovery in 14 year old patient EB, born with a brain tumour and had much of his left hemisphere removed when he was 2
He lost nearly all functioning after surgery but regained near normal use of language after 2 years
He developed language in his right hemisphere, though needed frontal lobe compensation and had dyslexia
Plasticity and functional recovery
Decoursey et al (2000)
Destroyed SCN connections in 30 chipmunks which disrupted their regular circadian rhythm
When returned to natural habitat, a significant proportion were killed by predators over the 80-day observation period
Endogeneous pacemakers
Dick and Tremblay (2016)
Found only 2% of researchers now believe that language is processed in only Broca and Wernicke’s areas
Localisation of function
Dougherty et al (2002)
Reported on 44 people with OCD who had a cingulotomy, in which connections with the cingualte gyrus are severed
30% of patients exerienced a significant reduction in symptoms and 14% a partial reduction
Localisation of function
Elbert et al (2001)
The brain’s ability to recover from trauma diminshes with age
Plasticity and functional recovery
Fink et al (1996)
Evidence from PET scans supports the view that functioning is lateralised in neurotypical brains
Hemispheric lateralisation
Gopnik et al. (1999)
As a child grows, the brain experiences a rapid increase in the number of synpatic connections it has peaking at around 15,000 neurones per synapse in two year olds
Plasciticty and functional recovery
Hood et al (2004)
Found that management of insomnia was imporved if elderly people were more active and had more exposure to natural light by going out during the day
Exogenous zeitgebers
Kim Peek
Man born without a corpus collosum, who displayed additional functioning rather than detrimental
He could read one book with his LVF an done with his RVF, indicating bilateral functioning
Hemispheric lateralisation
Klein and Wegmann
Found that circadian rhythms of air travellers adjusted faster to their destination time zone if they spent more time outside and exposed to light and mealtimes of their travel destination
Exogenous zeitgebers
Knutsson (2003)
Outlined that shift workers are 3x more likely to develop heart disease than people who work typical patterns
Circadian rhythms
Lashley (1950)
Removed large areas of the cortex in rats learning to complete a maze
Found that learning was not localised to a specific area of the cortex but affected by how much brain was removed
Localisation of function
Maguire et al. (2000)
Measured the hippocampal volume of 16 drivers in comparison to a matched control of 50 non-taxi drivers
Found a significantly greater volume of grey matter in the posterior hippocampus and the longer the taxi dirver had worked the more pronounced the structural difference
Plasticity and functional recovery
Miles et al (1997)
Reported the case of a man blind from brith with an abnormal circadian rhythm of 24.9 hours
Despite exposure to social cues such as mealtimes for all his life, his cycle could not be adjusted
Exogenous zeitgebers
Ralph et al (1990)
Transplanted SCN cells from mutant hamsters with a 20 hour sleep/wake cycle into normal hamsters with a 24 hours cycle
Endogenous pacemakers
Schnieder et al (2014)
Found that 40% of people with a DFR after trauma had more than 16 years in education
10% of those with a DFR had less than 12 years in education
Plasticity and functional recovery
Siffre (1962,1967)
Conducted self isolation studies where he spent months in caves deprived of natural light and any clocks
His sleep/walke cycle settled to around 25 hours
Circadian rhythms
Sperry (1968)
Study 11 “split brain” patients who couldn’y transfer information across hemispheres, evidencing language in LH and visual motor tasks and emotions iN RH
Hemispheric lateralisation
Sperry and Gazzaniga
Developed the split brain procedure: PPs stare at a fixed central point on screen and stimuli are flashed to either the LVF or RVF
Hemispheric lateralisation
Szoflarski et al (2006)
Found that the brain becomes less laterlised with age by comparing fMRIs of children and adults aged 5-67
Lateralisation increased from 5-25 then decreases with each decade
Hemispheric lateralisation
The Adolscent Sleep Working Group (2014)
Report benefots in academic and behavioural performance when lessons start later in the day
Circadian rhythms
Tucker et al (2007)
Studied PPs over 11 consecutive days and nigths in a hihgly controlled lab experiment
Found large individual differences in sleep duration, time to fall asleep adn amount of time PPs spent in each stage, most significantly deep sleep
Suggested these differences are likely genetically determined
Ultradian rhythms
Turk et al. (2002)
Split brain patient JW developed the capacity to produce language in the RH and learnt to verbalise information presented in both visual fields
This indicated that lateralised functions are flexible, rather than fixed to one hemisphere
Hemispheric lateralisation
Van cauter et al. (2000)
Sleep deficit may explain various issues in old age, such as reducted alertness
Ultradian rhythms
Wolfson and Carskadon (1998)
Recommend a later start to the school day to fit the typical teenage chronotype (sleep pattern) of slow alertness after waking
Circadian rhythms
