Biopsychology extension Flashcards
What does localisation of function refer to?
The theory that different parts of the brain are responsible for different behaviours, processes or activites
What is the brain divided into?
2 hemispheres (left and right)
What is lateralisation?
Where some of our functions are controlled/dominated by a particular hemisphere (language dominated by left)
Which hemisphere controls activity on the left hand side of the body?
Right and visa versa
What is the outer layer of the hemispheres called?
Cerebral cortex - 3mm thick - separates us from animals
What are both hemispheres further sub divided into?
Four lobes - frontal, parietal, temporal and occipital
What does the frontal lobe help with?
awareness of the environment
What cortex is located in the frontal lobe?
Motor cortex - generation of voluntary motor movements
What does the parietal lobe help with?
sensory info (touch, heat, pressure)
Which cortex is located in the parietal lobe?
Somatosensory cortex - devoted to particular body part
What separates the motor cortex and the somatosensory cortex?
central sulcus
What does the temporal lobe help with?
Auditory info
Which cortex is located in the temporal lobe?
Auditory cortex - analysing speech based info DAMAGE TO PARTICULAR AREAS MAY AFFECT ABILITY TO COMPREHEND LANGUAGE
What does the occipital lobe help with?
Visual info
Which cortex is located in the occipital lobe?
Visual cortex - eyes send info from RVF to LVC visa versa
Where is Broca’s area located?
Left frontal lobe
What is Broca’s area?
Responsible for speech production - damage to this can cause Broca’s aphasia - slow speech lacking fluency
Where is Wernicke’s area?
Left temporal lobe
What is Wernicke’s area?
Responsible for producing language and language comprehension - damage to this causes Wernicke’s aphasia - meaningless speech and nonsense words
What are 2 strengths of localisation of function?
Strong scientific evidence to support idea that functions are localised - Peterson 1988 used brain scans to show W’s area active during listening and B’s area during reading
Case studies e.g Phineas Gage - frontal lobe damaged - personality changes NOT GENERALISABLE
What is 1 weakness of localisation of function?
Karl Lashley 1950 removed 10-50% parts of cortex in rats when learning a maze - no area seemed to be more important - seemed to require every part
What is hemispheric lateralisation?
Idea that certain functions and processes are mainly controlled by 1 hemisphere (language - left)
What did Sperry investigate?
Whether neural processes are associated with a particular hemisphere
What was the focus of Sperry’s study? (exploring)
Explore effects when 2 hemispheres are separated - hemispheric separation
Who were Sperry’s participants?
Patients who had undergone a commissurtory (cutting the corpus collosum) SPLIT BRAIN PATIENTS - had been done in attempt to treat epilepsy
What was Sperry’s general procedure?
An image, word or object projected or given to a patient to be processed by a particular hemisphere
What were the results of Sperry’s patients when describing what they saw?
When a picture shown to RVF patient could describe it, to LVF they could not (RVF went to LH language)
What were the results of Sperry’s patients when recognizing items by touch?
Could not attach labels to objects presented to LVF but were able to select a matching object using left hand (know what is is but can’t say it as RH)
What were the results of Sperry’s patients when they were looking at Composite words?
If presented simultaneously to both VF’s patient would say which word presented to RH and write word presented to LH
What were the results of Sperry’s patients when they were trying to match faces?
RH dominated recognizing faces - when asked to match a face to a series of other faces picture processed by RH consistently selected, to the LH consistently ignored
What did Sperry conclude?
Both perception and memory in each hemisphere is independent - argued his study supported lateralisation of function
Why are Sperry’s split brain patients different to ‘normal’ brains?
‘Normal’ brains exchange info through corpus collosum
What are 2 strengths of Sperry’s research?
Provides evidence for lateralisation of function (Language - left) (spatial tasks - right)
Used highly controlled and standardized procedure increasing reliability and internal validity
What is 1 weakness of Sperry’s research?
Issues of generalisability - only 11 people with history of epileptic seizures - may have caused unique changes in brain - he did use control group of 11 people without E
What would have made a better control group for Sperry?
11 individuals who had epilepsy but no surgery - if epilepsy caused changes in brain it would be in ALL 22 PARTICIPANTS
What is neural plasticity?
Brains tendency to adapt as a result of experience
What is functional recovery?
A type of neural plasticity
What does the brain have the ability to do?
Change through life - originally thought they were restricted to childhood
What does general research show about neural connections?
Existing ones can change and new ones formed
What is the hippocampus?
Part of brain associated with spatial and navigational skills and memory
Give some research evidence for brain plasticity…
Maguire et al 2000 - whether brains of London taxi drivers were structurally different to brains of London bus drivers (follow same routes)
18 taxi drivers 17 bus drivers - no significant differences at all (personality etc)
each given MRI - looked at r=grey matter volume
taxi drivers - more grey matter in posterior hippocampus (used in complex spatial info) this increased the amount of time they’d been driving
Give some early research evidence for brain plasticity…
Rosenzweig and Bennett 1972 - rats - 1 group in environment with toys 1 without - kept there for 40 days - post-mortem study showed cerebral cortex of enriched rats was heavier and thicker (responsible for movement, memory and learning)
NOT GENERALISABLE BUT DOES SHOW BRAINS ADAPT DUE TO LEARNING
What does functional recovery usually do following trauma?
Distribute/transfer functions usually preformed by damaged areas to undamaged areas
What do neuroscientists suggest about functional recovery?
Occur quickly after trauma (spontaneous recovery) and then slow down after several weeks
What happens in functional recovery?
Brain reorganises itself by forming new synaptic connections close to area of damage (AXONAL SPROUTING)
What does the brain sometimes to to best ensure working items in functional recovery?
Recruits similar area’s to damaged one on other hemisphere
What are 2 strengths of brain plasticity and functional recovery?
Practical applications - development of neurohabilitation
Range of supporting evidence (Maguire) (animal research) (case studies)
What are 2 weaknesses of brain plasticity and functional recovery?
Up to 80% of amputee’s develop phantom limb syndrome - unpleasant sensations
Both N.P and F.R tend to reduce with age
What are the 4 ways of studying the brain?
Functional magnetic resonance imaging (FMRI)
Electroencephalogram (EEG)
Event-related potentials (ERPs)
Post-mortem examinations
What are FMRI’s?
Measuring brain activity whilst preforming a task, looking at blood flow to detect levels of oxygen (increases when focused) - known as HAEMODYNAMIC RESPONSE
What can FMRI’s produce?
3d images (activation maps) showing which parts of the brains are involved in particular mental processes
What are 2 strengths of FMRI’s?
Do not rely on use of radiation (risk-free)
Provide detailed moving pictures - high spatial resolution
What are 2 weaknesses of FMRI’s?
Poor temporal resolution (five second time delay)
Expensice to buy and maintain
What are EEG’s?
Electrical recording of the brain with small electrodes attached to a cap picking up electrical signals of brain activity - helps diagnose certain conditions e.g sleep disorders
What are 2 strengths of EEG’s?
High temporal resolution (single millisecond)
Useful in diagnosing and understanding conditions
What is 1 weakness of an EEG?
Only provide generalised info - can’t pinpoint exact source of neural acitvities
What are ERPs’?
Measured brain response direct to a specific sensory, motor or cognitive event, measuring brain waves
What is 1 strength of an ERP?
Identifying precise role of specific cognitive functioning
What is 1 weakness of an ERP?
Lack of standardized procedures (ALL FACTORS SUCH AS BACKGROUND NOISE MUST BE ELIMINATED) - results difficult to compare
What is a PM examination?
Study of brain following death - likely if you have a rare disorder - damaged areas are reviewed to see the cause of the affliction
What is a strength of a PM?
Provides us with foundational understanding of the brain (Broca and Wernicke used this)
What is a weakness of PM?
Can’t establish cause and effect and raises issues of consent
What is a biological rhythm?
Change in bodily processes/behaviour in response to changes in the environement
What can disruption of biological rhythms lead to?
Disrupted sleep and increased anxiety
What is a circadian rhythm?
Bodily rhythm occurring across a 24 hour period
What is an example of a circadian rhythm?
Sleep wake cycle
What are the 2 things biological rhythms include?
Endogenous pacemakers (body clocks) and exogenous zietgebers (environmental changes)
What endogenous pacemaker is the sleep wake cycle influenced by?
Suprachiasmatic nnucleus (SNC) and the pineal gland which releases melatonin (a hormone)
What is the SCN in the sleep wake cycle part of?
The hypothalamus (brains internal mechanisms for us to sleep and wake)
What exogenous zietgebers is the sleep wake cycle influenced by?
Light, daily routine, alarm!
When do E and E factors work together?
In the evening so we can sleep, and in the morning to help us wake
How do we fall asleep?
SCN detects reduced light levels, passed to the pineal gland so melatonin is released to make us sleep. In the morning when the SCN detects light the melatonin production reduces
What is the SCN’s own natrual rhythm?
25 hours (as shown by Siffre - over 6 months in texas cave recorded by camera and had telephone)
What is animal research to support the sleep wake cycle?
Morgan (Hamsters - mutant strain 20 hour sleep wake cycle and transplanted their SCN’s into normal hamsters - they adapted
What is one weakness of circadian rhythms?
Relies on case studies which is not generalisable - Siffre in extreme circumstances
Morgan rats
What is one strength of circadian rhythms?
Practical applications - learnt more about shift work - helpful for the economy Drug treatments (taking them however many times a day)
What does research into sleep wake cycles of teenagers suggest?
Age differences in circadian rhythms (tendency to stay up later and get up later)
Who claimed environmental factors had been over emphisised?
Miles 1977 - man with blindness had difficulty keeping to a 24 hour cycle had to take sedatives and stimulants
When is body temprature at its lowest and highest?
Lowest (36 degrees celcuis) at 4am
Highest (38 degrees celcius) at 6pm
COGNITIVE ABILITES ARE THOUGHT TO BE BETTER WHEN TEMP IS HIGHER
What is an infradiam rhythm?
Longer than 24 hours - e.g menstrual cycle
What does the menstrual cycle refer to?
Time between first day of a womans period to day before her next one (typically 28 days)
What happens during the menstrual cycle?
Rising levels of hormone oestrogen cause ovary to develop an egg and release it, after this hormone progesterone helps womb lining grow thicker, if pregnancy does not occur egg is absorbed into body, womb lining comes away and leaves the body (flow)
What is research to support infradian rhythms?
McClintock and Stern 1998 - 29 woman irregular periods - samples of pheromones taken from armpits each day of cycle, frozen then rubbed on upper lip of other participants
Found 68% of women experienced changes in cycle closer to odour doner
What is another example of an infradian rhythm?
SAD (Seasonal affective disorder)
CIRCANNUAL RHYTHM - yearly cycle
Hormone melatonin is implicated in the cause of SAD
Melatonin production goes on for longer/shorter times and is thought to have a knock on effect to sertonin (linked to one of the depressive symptoms)
What is one strength of infradium rhythms?
Evidence supports the idea of distinct stages in sleep
Evolutionary basis of menstrual cycle - menstrual synchrony (seen in M and S study) meaning new borns can be cared for collectively
what is one limitation of infradian rhythms?
Methodlogical limitations in synchronisation studies - many factors can affect sleep such as stress
What is an ultradium rhythm?
Biological rhythms lasting more than once every 24 hours
What is an example of an ultradium rhythm?
Sleep cycle/stages of sleep
What are the first 2 stages of sleep?
1 and 2 - sleep esculator, light sleep so can be easily woken,brain waves become slower and more rhythmic (alpha waves) and slower when deeper sleep (theta waves)
What are the 3rd and 4th stages of sleep?
Deep sleep - slow wave sleep, more difficult to wake someone, involves slow wave patterns (delta waves)
What is the 5th stage of sleep?
REM sleep - rapid eye movement sleep - lots of brain activity - similiar to wakefullness - dreaming - muscular paralysis (except eyes and respiratory muscles)
What is one strength of idea of distinct stages of sleep?
Evidence to support - Dement and Kleitman 1957 - 9 adult participants in sleep lab sleep patterns recorded on EEG - REM correlated with dreaming and when woken during this could accurately recall dreams
