Flashcards in Biopsychology Deck (89):
What 2 sub systems is the nervous system divided into?
What is the CNS divided into?
What is peripheral nervous system divided into?
Autonomic - controls vital functions eg breathing, heart rate, digestion
Somatic - controls muscle movement and receives information from sensory receptors
Outline the endocrine system
Acts slower than NS but has widespread powerful effects
Various glands eg thyroid produce hormones.
Hormones are secreted into bloodstream and affects target cell.
Main gland of endocrine system = pituitary gland in brain. Controls release of hormones and other endocrine glands
Describe what occurs when a stressor is perceived
Hypothalamus triggers activity in sympathetic branch of autonomic NS.
ANS changes from a parasympathetic state to a sympathetic state.
Stress hormone adrenaline is released from adrenal medulla into bloodstream.
Adrenaline triggers physiological changes in body e.g increased heart rate which creates the physiological arousal necessary for fight or flight.
What are the 3 types of neurones?
Sensory, motor and relay
Describe the structure of a neurone
Cell body (soma) has a nucleus containing genetic material.
Dendrites carry impulses towards cell body.
Axon carries impulses away from cell body. Axon is covered by myelin sheath which protects axon and speeds up electrical transmission.
Myelin sheath is segmented by gaps called nodes of ranvier - forces impulse to jump
End of axon = terminal buttons that communicate with next neurone in chain across a synapse.
Define circadian rhythms
24-hour cycle e.g sleep/wake
Define infradian rhythms
Biological rhythms with a cycle of more than a day, e.g menstrual or SAD
Define ultradian rhythms
Cycle of less than a day but more than 1 hour, eg appetite
Describe a study on infradian rhythms - the menstrual cycle
Stern and McClintock (1998)
29 women with history of irregular periods
Pheromones gathered from 9 women by placing a cotton pad on their armpit for 8 hours
Pads = treated with alcohol and frozen
Rubbed on other lips of participants
- 68% of women experienced changes to their cycle that brought them closer to their odour donor
What is season affective disorder?
Sufferers experience severe depression during winter months due to more production of melatonin
Can also be classed as a circannual rhythm of circadian rhythm
What are the stages of sleep?
1) state of drowsiness, alpha waves in EEG, slow eye rolling and reduced heart rate
2) EEG waves slower and larger with bursts of high frequency sleep spindles, little activity in EOG
3) deeper stage of sleep, slow delta waves with some sleep spindles
4) REM sleep = rapid eye movement and paradoxical sleep, brain = very active
Describe how the sleep cycle works
Sleeper sleeps stages 1-4
At stage 4 the cycle reverses until stage 2
Then enters REM sleep
Complete cycle = 90 mins, usually 5 cycles a night
Each cycle time spent in REM sleep increases and stage 4 sleep decreases
Describe a study on ultradian rhythms - the sleep cycle
Case study (1964)
Randy Gardner (17)
Awake for 11 days/264 hours
After, slept for 15hoyrs and recovered 25% of sleep he missed
Recovered 70% of stage 4 sleep and 50% REM sleep
Shows REM and stage 4 = most important
Define exogenous zeitgebers
External events that have an impact on sleep - wake cycle eg light-dark cycle
Define endogenous pacemakers
Internal biological mechanisms that influence the sleep wake cycle
Describe a study on circadian rhythms - sleep wake cycle
Green (1994) - Siffre
Deprived of natural light and sound
Good access to food and drink
Spent 2 months underground, resurfaced in September thinking it was August
Developed endogenous pacemaker of 25hours
Describe a study on endogenous pacemakers
Ralph et al (1990)
Transplanter suprachiasma nuclei from foetus hamster with a 2 hour sleep-wake cycle into adult hamsters with sleep-wake cycles of 25hours
Adult hamsters adopted a 20hour sleep-wake cycle
Internal clock or pacemaker is adjusted to match environmental events or zeitgebers
- needed to travel across timezones
Describe a study in melatonin
Shochat et al
Ptps spent 29hours in a sleep lab
Spent 7mins in every 20 lying down in bed in a darkened room trying to sleep
Measured levels of melatonin by taking blood samples up to 3 x an hour
Findings = relationship between circadian rhythms of tendency to sleep and melatonin
What is synaptic pruning?
As we age neural connections we do not use are deleted and frequently used connections are strengthened
Outline Maguire's research into plasticity
Studied brains of London taxi drivers and found more volume of grey matter in posterior hippocampus than control group - sea of navigational skills. Test 'the knowledge' alters structure of brain
Correlation between amount of grey matter and time being taxi driver
Outline two studies into plasticity (not Maguire)
Draganski et al (2006) - imaged brains of medical students 3 months before and after final exams - found changes in posterior hippocampus and parietal cortex.
Mechelli et al (2004) found larger parietal cortex in brains of bilingual people than monolingual control.
What structural changes in the brain occur during recovery?
Axonal sprouting - growth in new nerve endings connecting to undamaged nerve cells
Reformation of blood vessels
Recruitment of homologous areas - opposite side of brain carries out function
Name the evaluation points for plasticity
Age and Plasticity
Support from animal studies
Concept of cognitive reserve
Outline practical application of brain plasticity research
Contributed to field of neurorehabilitation - shoes brain can fix self to extend but also need intervention for complete success
Outline what is meant by negative plasticity
Can cause behaviour consequences e.g Medina et al (2007) - 60-80% of amputees suffer phantom limb syndrome due to cortical reorganisation in somatosensory cortex
Describe findings on age and plasticity
Tends to reduce with age but Bezzola et al (2012) - 40 hours of golf training produces changes in neural representation in ptps age 40-60. Observed reduced motor cortex activity in novice golfers than control, shows neural plasticity continues throughout life span.
Outline support from animal studies for plasticity
Hubel and Wiesel (1963) sewed one eye of kitten shut and analysed brains cortical responses found continued to process information from open eye
What did Schneider et al (2014) discover about brain plasticity?
More time brain injury patients had spent in education the greater their chance of a disability free recovery. 2/5 of patients who had DFR spent more than 16 years in education.
Give 4 ways of investigating the brain
Event Related Potentials (ERP)
Post Mortem Examinations
Strength - doesn't use radiation, risk free and harmless. Easy to use. High spatial resolution
Weaknesses - expensive, must stay perfectly still, poor temporal resolution and can only measure blood flow in brain.
Evaluate Electroencephalograms (EEG)
Strengths - valuable in diagnosis and understanding stages of sleep, high temporal resolution.
Weaknesses - generalised information. Signal not useful in pinpointing exact source of neural activity.
Evaluate Event Related Potentials
Strengths - more specific, high temporal resolution, can identify many types of ERP
Weaknesses - lack of standardisation in method, background noise must be completely eliminated which is not always possible
Evaluate Post Mortems
Strengths - vital for early understanding
Weaknesses - issue of causation and ethical issues of consent
What are the evaluation points of circadian rhythms
Practical Application to Shift Work
Practical Application to Drug Treatments
Use of Case Studies and Small Sample
Poor control in studies
Outline practical application to shift work
Boivin et al (1996) - night workers experience period of reduced concentration at around 6am = mistakes more likely.
Outline practical application of drug treatments
Circadian rhythms coordinate with body's processes showing there are certain times when drugs are most effective - leading to drug dosing guidelines
Describe control in circadian rhythm studies
Participants in study still had access to artificial light - Siffre turned lamp on everytime he woke up. Czeisler et al (1999) adjusted ptps circadian rhythms from 22 to 28 hours using dim light
Describe the effect of individual differences on circadian rhythms
Individual cycles can vary from 18-65 hours. Duffy et al (2001) - some people have natural preference for going to bed early. Therefore difficult to generalise
What are the evaluation points of infradian and ultradian rhythms?
Evolutionary basis for menstrual cycle
Methodological limitations in synchronisation studies
Evidence supports stages of sleep
Outline evolutionary basis of menstrual cycle
Valuable for ancestors - new borns born together to make social group and increase survival
Outline methodological limitations in synchronisation studies
Confounding variables may affect women's cycle such as stress and diet. Research also involves small samples and self reporting on own cycle. Other studies failed to show same evidence.
Outline evidence supporting stages of sleep
Demet and Kleitman (1957) - monitored 9 participants in sleep lab, brainwave activity recorded with EEG and caffeine and alcohol controlled. Found REM activity during sleep highly correlated with experience of dreaming. All participants woke during dreams gave accurate recall. Replications had similar findings. Small sample criticised
What effect do animal studies have on McClintocks research?
Knowledge of pheromones come from animal studies - not know effect on humans
What is practical application of ultradian rhythm research
Phototherapy for SAD sufferers - light box stimulates strong light in morning and evening - relieved symptoms for 60% of sufferers, placebo effect on 30% - doubt on chemical influence
What are the evaluation points for endogenous pacemakers and exogenous zeitgebers
Beyond suprachiasmatic nucleus
Ethics in animals studies
Influence of exogenous zeitgebers may be overstated
Methodological issues in studies
What did Damiola et al (2000) show?
Changed feeding patters in mice altered circadian rhythms of liver cells of up to 12 hours but SCN unaffected - shows other influence to sleep/wake cycle other than SCN
What evidence is there of exogenous zeitgebers being overstated
Miles et al (1997) man had circadian rhythm of 24.9 hours - despite social cues and sedatives at night and stimulants in morning it wouldn't change.
Why is Siffres case rare and lacking validity?
Rare that endogenous pacemakers are free running and unaffected by exogenous zeitgebers - in real life they interact
What methodological issues are there with Campbell and Murpheys study?
Have yet to be replicated.
A major confounding variable - may have been some limited light exposure to participants eyes
Isolating one exogenous zeitgeber does not give us insight into other zeitgebers that influence the sleep/wake cycle
What is hemispheric lateralisation?
The idea that the 2 hemisphere of the brain are functionally different and certain processes and behaviours are dominated by different hemispheres.
Who studied split-brain research?
What sample of people did Sperry study?
Group of individuals who had undergone commissurotomy - corpus callosum and other tissues which connect 2 hemispheres is cut down middle to separate them, used to control severe epileptic seizures.
What was the procedure of Sperrys research?
Image/word projected to patients right visual field (processed by left hemisphere) and the same or different image could be presented to left visual field (processed by right hemisphere)
In split brain patients information could not be shared between both hemispheres.
What did Sperry find in terms of describing what you see?
When a picture was shown to a patients right visual field, they could easily describe what was seen. If the object was shown to the left visual field the patient could not describe and typically said there was nothing there. This is due to language being in left hemisphere
What did Sperry find about recognition by touch?
Patients could not attach a verbal label to objects projected to left visual field but they could select a matching object using their left hand. When placed behind a screen the left hand could also chose the object most closely associated with object presented in left visual field.
What did Sperry find about composite words?
If 2 words were presented simultaneously, one on either side of of the visual field, the patient would write with their left hand what they saw in the left visual field and say the word in the right visual field.
What did Sperry find about matching faces?
Right hemisphere dominated in terms of recognising faces. When asked to match a face from a series of other faces, the picture processed by the right hemisphere was consistently chosen and the picture from left hemisphere was constantly ignored. When a picture made up of 2 different halves of a face was presented - one to each hemisphere , the left hemisphere dominate in description and the right dominated in selecting a matching picture.
What are the evaluation points for split brain research?
Demonstrated lateralised brain functions
Strengths of methodology
Issues with generalisation
Differences in function may be overstated
Why is there issues with generalisation in split brain research?
Split brain patients were an unusual sample of people and only 11 who took part. Some patients experienced more disconnection than others. The control group of 11 with no history of epileptic seizures may be inappropriate
What are the strengths of methodology in split brain research?
Use of highly specialised and standardised procedures. Ensured patients would not have time to move eye across image and spread information across both visual fields.
Useful and well controlled procedure.
What theoretical debate has arisen from Sperrys research?
The degree of communication between the 2 hemispheres in everyday functioning. Some theorists eg Pucetti (1977) suggest the 2 hemispheres function so differently that in effect we have 2 minds. Others argue that the 2 hemispheres form an highly integrated system and most are involved in everyday tasks.
Describe how differences in function may be overstated in split brain research?
Neuroscientists say the distinction is less clear cut and many behaviours typically associated with one hemisphere can be performed by the other when the situation requires it.
Describe how split brain research demonstrated lateralised brain functions
Produced a good amount of findings - main conclusion = left hemisphere is associated with analytic and verbal tasks where as right is associated with emotional, holistic content and language.
Left = analyser, Right = synthesiser
What is holistic theory of the brain?
That all parts of the brain are involved in the processing of thought and action
What is localisation of function?
The theory by Wernicke and Broca that different areas of the brain are responsible for different behaviours processes or activities
What is lateralisation?
That some physical and psychological functions are dominanted by a particular hemisphere
What are the 4 lobes of the brain?
Frontal, occipital, parietal and temporal. Each lobe has particular function
Describe the motor area
At the back of frontal lobe in both hemispheres, controls voluntary movement in opposite side of body. Damage results in lack of control over fine movements
Describe the somatosensory area
Front of both parietal lobes - separated from motor area by central sulcus. Where sensory information from the skin is represented.
Describe the visual area
The occipital lobe at back of brain. Each eye sends information from right visual field to left visual cortex and from left visual field to right visual cortex. Damage to left hemisphere can produce blindness in right visual field of both eyes.
Describe the auditory area
In the temporal lobes which analyses speech-based information. Damage may cause partial hearing loss, more extensive the damage the more extensive the loss. Damage to Wernickes area in the temporal lobe may affect ability to comprehend language.
What happens if Broca's area is damaged?
Causes Broca's aphasia which is characterised by slow speech, laborious and lacking fluency
What happens if there is damage to Wernickes area?
Wernickes aphasiais characterised by produci nonsense words (fluent but meaningless speech)
What are the evaluation points for localisation of function?
Brain scan evidence
Case study evidence
Describe brain scan evidence of localisation
Peterson et al (1988) used brain scans to demonstrate how Wernicke's area was active during a listening task and Broca's area was active during a reading task - suggests these areas of he brain have different functions.
Describe neurosurgical evidence for localisation of function
The practice of surgically removing or destroying areas of the brain to control aspects of behaviour.
Dougherty et al (2002) reported on 44 OCD patients who had undergone cingulotomy (lesioning of cingulate gyrus) a post surgical follow up after 32 weeks - 1/3 had met the criteria for successful response to the surgery and 14% for partial response.
Success of procedures like this strongly suggest that symptoms and behaviours associated with serious mental disorders are localised
Describe case study evidence of localisation of function
Phineas Gage - metal rod went through left frontal lobe, survived but changed from calm and deserved to quick tempered and rude. Suggests frontal lobe is responsible for regulating mood
Describe Lashley's research on localisation of function
Lashley (1950) suggests higher cognitive functions e.g learning is not localised but more holistic. Removed 10-50% of the cortex of rats brains that we're learning a maze. No area was proven to be any more important than another are in terms of the rats ability to learn the maze. Process of learning appeared to require every part of the cortex. Suggests learning is too complex to be localised.
Describe how plasticity is evidence against localisation
When the brain becomes damaged and a particular function is lost, the rest of the brain appears able to reorganise itself to recover the lost function. = law of equipotentiality. Common is stroke victims.
What are androgens?
Sex hormones (et testosterone) present larger quantities in men than women
What are oestrogens?
Sex hormones (e.g. Oestradiol) present in larger quantities in females than males
What is congenital adrenal hyperplasia?
An inherited disorder of the adrenal gland causing the levels of male sex hormones in foetuses of both sexes to be unusually high.
What is sex typed behaviour?
The idea that boys play with boy toys e.g. diggers and girls play with girl toys e.g. Dolls.
What did Berenbaum and Beltry (2011) find about girls with congenital adrenal hyperplasia?
They play more than other girls with boys toys and when they grow up women are more likely than other women to choose male-dominant professions, enjoy rough sports and have non-heterosexual orientation.
What did cohen-kettenis and van Goozen find about testosterone and aggression?
Studied transsexuals undergoing hormone treatment and found female-to-male transsexuals who were exposed to high dosages to testosterone showed increased aggression where as male-to-female transsexuals who were exposed to female hormones showed lower levels of aggression.