Biopsychology - Paper 2 Flashcards
What are the two divisions of the human nervous system?
The central nervous system
The peripheral nervous system
What makes up the central nervous system?
The brain and spinal cord
What makes up the peripheral nervous system?
Nerve cells - carry information to and from CNS
What is the brain responsible for?
Physiological processes
What is the spinal cord responsible for?
Receiving / transmitting information to and from the brain and PNS
Reflex actions
What are the two systems within the PNS?
Somatic and autonomic
What does the somatic nervous system do?
Voluntary acts
Received info from sensory receptors
Sends info to CNS - control muscle movement
What does the autonomic nervous system do?
Involuntary acts
Heart rate
Digestive system
What are the two sub divisions within the autonomic nervous system?
Sympathetic and parasympathetic
What does the sympathetic nervous system do?
Prepares body for emergency
Increase HR - blood pressure - vasodilation
What does the parasympathetic nervous system do?
Relaxes body
Decrease HR - blood pressure
What are neurons?
Building blocks of nervous system
Transmit messages
Electrical and chemical signals
What are dendrites
End of neuron
Receives signals
What are dendrites connected too?
Cell body
What is connected to the cell body?
Axon
What is the axon covered in?
Myelin sheath - protects axon and speeds up electrical impulse
What is at the end of the axon?
Terminal buttons
What do terminal buttons do?
Communicate with the next neuron
What is the gap between neurons called?
Synapse
What are sensory neurons?
Carry messages from sensory receptors
Convert messages to neural impulses
What is the structure of sensory neurons?
Long dendrites
Short axon
What are relay neurons?
Connect sensory to motor
Allow communication between neurons
Found in CNS
What is the structure of relay neurons?
Short dendrites and short axon
What are motor neurons?
Connect CNS to muscles and glands
Control muscles
Release neurotransmitters
What is the structure of motor neurons?
Short dendrites and long axon
What are neurotransmitters?
Chemicals that diffuse across the synapse to the next neuron
What is excitation?
Leads to post synaptic neuron becoming positively charged - more likely to fire
E.g. adrenaline
What is inhibition?
Leads to post synaptic neuron becoming negatively charged - less likely to fire
E.g. GABA
What is the endocrine system?
Second system
Made up of specialist glands
Glands release hormones
Hormones transmit messages
Name 4 endocrine glands
Thyroid
Pineal
Adrenal medulla
Adrenal cortex
What does the thyroid gland hold and its effects?
Thyroxine
Metabolic rate, growth rate
What does the pineal gland hold and its effects?
Melatonin
Arousal, biological rhythms, sleep-wake cycle
What does the adrenal medulla gland hold and its effects?
Adrenaline
Fight / flight
Heart rate
Blood flow
What does the adrenal cortex hold and its effects?
Gluco-corti-coids
Sur their release of glucose
Suppression of immune system
Inflammatory response
What is the fight / flight response
Generate from autonomic nervous system
Reflex response
Increase reaction time
Facilitates optimal functioning
What is the process of the fight / flight response?
Stressful event
Hypothalamus
Pituitary gland
Adrenal cortico trophic hormone
Adrenaline
Fight / flight response
Fight / flight response hypothalamus send message to the
Pituitary gland
Fight / flight response pituitary gland releases
Adreno - cortico - trophic hormone
Fight / flight response ACT causes adrenal gland to release
Adrenaline
Fight / flight - adrenaline causes physiological changes, leading to the
Fight / flight response
Fight / flight after the stress the …
Parasympathetic branch is activated
What are the 6 locations in the brain
Motor cortex
Somatosensory cortex
Visual cortex
Wernicke’s area
Auditory cortex
Broca’s area
What lobe is Broca are in?
Frontal
What lobe is the motor cortex in?
Frontal
What lobe is the somatosensory cortex in?
Parietal
What lobe is the visual cortex in?
Occipital
What lobe is the Wernicke’s area in?
Temporal
What lobe is the auditory cortex in?
Temporal
Define localisation of function
The concept that different parts of the brain are responsible for individual and discrete functions
What is the motor cortex responsible for?
Voluntary muscle movement
What is the somatosensory cortex responsible for?
Processes sensory input form the skin, muscles and joints related to touch
Produces sensations of touch pressure, pain and temp
What is the visual cortex responsible for?
Vision - processing colour, shape, size
What is the auditory cortex responsible for?
Hearing - volume, pitch, location of sound
What is the Wernicke’s area responsible for?
Understanding language
What is the Broca’s area responsible for?
Producing speech, expressing thoughts, through writing
What are the common symptoms of aphasia?
Problems with
Reading
Listening
Speaking
Writing / typing
What are the common causes of aphasia?
Stroke
Severe head injury
Brain tumour
Progressive neurological conditions
What is localisation?
Different areas of the brain being responsible for specific functions
What is lateralisation
The idea that different hemispheres have different specialisations
What is Broca’s aphasia?
Inability to articulate speech fluently - disjointed words - understanding of speech is normal
What is Wernicke’s aphasia
Breakdown in the ability to understand speech - sentences are deficient in meaning
How do Broca’s and Wernicke’s areas interact?
Sensory region picks up audio / visual input
Wernickes recognise language and associates meaning
Broca’s are identifies what speech needs to be produced
What are the strengths of localisation of functions?
+ neurosurgery - damaged linked mental disorder - as treatment
+ brain scans - everyday functions localised, Wernickes during listening tasks, memories localised
What are the weaknesses of localisation of function
- language holistic - FMRI - language distributed holistic - contradicts theory
Define brain lateralisation
Two halves of the human brain are not exactly alike - each hemisphere has functional specialisms
Who carried our split brain research?
Sperry
What is split brain research
Observing people
Corpus callosum cut down middle
Treat epilepsy
Why was split brain research carried out?
To test the capabilities of each hemisphere when separated
What are the strengths of split brain research?
Methodology - high control - sperry stopped natural tendency for pp to move their eye - stimulus presented 200 milliseconds
Support research - Miller et al - L hemisphere more concerned language. R hemisphere concerned with spatial
What are the limitations of split brain research?
Methodology - low ecological validity - usually use both eyes
Population validity - 11 males - differences in the operations
Counter evidence - Tuck et al - JW able to speak out R hemisphere - brain can adapt
What is brain plasticity
The ability of the brain to change and adapt
Synapses, pathways and structures in light of various experiences
What is plasticity like in childhood
By the end of first year brain more neurons than will ever have
Older brain sculptured by environment and experiences
What is synaptic pruning?
Pathways and networks that aren’t used will die off
When does brain plasticity stop?
Neural connections can change at any age, as result new learning
What research was done into brain plasticity?
Maguire et al
London taxi drivers
16 male taxi - 50 male non taxi
Posterior hippocampus larger
Correlation between years as taxi driver and volume of hippocampus
What is functional recovery?
A form of plasticity whereby other areas of the brain take over function of the damaged area
How does functional recovery occur?
Axon sprouting
Denervation super sensitivity
Recruitment of homologous areas (similar)
What is axon sprouting
The axons of surviving neurons grow new branches that make synapses in areas of the brain formerly supplied by damaged neurons
What is denervation super sensitivity
Occurs when axons that do a similar job become aroused to a higher level, to compensate for the ones that are lost
What is recruitment of homologous areas
Example - Broca’s areas damaged - right side equivalent would take over
What research was done into functional recovery?
Danelli
EB - left hemisphere removed at 2 - intensive rehabilitation = regain ability to speak. 17 years, language was comparable to normal controls
What are the strengths of brain plasticity and functional recovery
Practical applications - therapy e.g. movement therapy
Research evidence - Draganski et al - students before and after finals. Posterior hippocampus.
Michelle et al - bilingual = larger parietal cortex
What are the weaknesses of brain plasticity and functional recovery?
Not straight forward - speech requires a lot of effort, affected by other factors (stress, alcohol)
Gender - women better at attention / memory / language
Men better at visual analytical skills
What is a fMRI
Records energy released by haemoglobin
Active area = more oxygen
1 sec time difference
What are the strengths of fMRI’s
Non invasive - no brain exposure, more ethical
Objective - no verbal report, not affected by researcher bias
What are the limitations for fMRI’s
Impractical - expensive, patient must be still, uncomfortable, temporal resolution
What is an EEG
Measures electrical activity in the brain
Electrodes detect small electrical changed
Shown on graph
Used to show neurological abnormalities - epilepsy
What are the strengths of an EEG
Accuracy - real time
Non invasive
What are the weaknesses of an EEG
Not specific enough - gives general overview, cannot pinpoint
Surface measurement - superficial regions of the brain - not very deep. Limit what we can study
What is an ERP
More specific than EEG
Uses statistical averaging techniques to filter put extraneous brain activity
What are the strengths of ERP (event related potentials)
Accuracy - continuous measurement - determine how processing is affected by experimental manipulations
Demand characteristics - response to stimuli measure without individual giving a response
What are the weaknesses of an ERP
Surface measurement - only detects neural activity of a certain strength
What is a post mortem examination
See what damage has occurred
Happen on people who had rare disorder
Link psychiatric disorders and brain abnormalities
What are the strengths of post mortem’s
Full access to the brain
Detailed / deeper
Hypothalamus / hippocampus
What are the weaknesses of post mortem’s
Lack of control - confounding variables
Retrospective - issues establishing causation, observed damage may not be a result of the suspected cause
What is a biological rhythm?
Something in out body that follows a regular cycle
What is a biological rhythm governed by
Endogenous pacemakers
Exogenous zeitgebers
What are endogenous pacemakers
Bodys internal biological clocks
What are exogenous zeitgebers
External changes in the environment
What are circadian rhythms
Lasts 24 hours
Sleep wake cycle
Regulated by release of hormones / metabolic rates / body temp
What are the strengths of circadian rhythms
Support research - Folkard et al - 12 pp lived dark cave for 3 week - sped up clock 24 hours to 22 hours - no pp adjust
Practical application - shift work, consequences of adjusting cycle
What are the limitations of circadian rhythms
Individual differences - Duffy, rise early or go to bed late, despite EP’s being innate there are some variations
Methodology - poor control, pp were isolated form variable - artificial light confounding variable
Small sample size - individual differences
What did Siffre do?
Lived in a cave alone for 6 months
Artificial light
Sleep wake cycle 26 hours
What is the SCN - suprachiasmatic nucleus
Regulated by light
Master clock
Adjust due to changing patterns of daylight
Where is the SCN located
Hypothalamus
What research was done to the SCN?
Ralph et al - removed SCN from genetically abnormal hamsters
Put into normal hamsters
20 hours sleep wake - normal hamsters adopted
What is the pineal gland
Receives signals from SCN
Increases melatonin at night
Inhibits brain mechanisms
How do social cues affect the sleep wake cycle
Mealtimes
Adapting to local times of eating when travelling changes circadian rhythms
What research evidence had been done of social cues
Klein and Wegmann - jet lag - adjust better when they go outside
What are the strengths of endogenous pacemakers and exogenous zeitgebers
Research evidence - Siffre cave study
Practical application - jet lag, shift work
What are the limitations of endogenous pacemakers and exogenous zeitgebers
Methodology - Siffre - small sample size, repeated when 60, internal clock slower, hard to generalise
Artificial experiments - interact in real life
Conflicting research - arctic circle - 6 months light / no light - maintain sleep cycle
What are infradian rhythms
Longer than 24 hours
What is an example of monthly cycle
Menstrual cycle - mainly endogenous (hormones)
What research has been done into the menstrual cycle
McClintock - 29 women, odourless compounds form armpit of other women
68% cycle became closer to odour donor
What is an example of an annual cycle
Seasonal affective disorder - mainly endogenous (light)
What is SAD?
Occurs in winter months
Persistent low mood
Lack of sunlight
Effects production of serotonin
What is a ultradian rhythm
Less than one day
What is BRAC
Kleitman
90 min ultradian cycle
Periods of alertness
Periods of fatigue
Human mind focus for 90 minutes
What are the strengths of infradian and ultradian rhythms
Research evidence - 9 pps EEG during sleep, everyone REM sleep, those woken during REM more likely to remember dreams
Practical applications - SAD, light box, reset melatonin, relived 60% of sufferers however placebo affect 30%
What are the limitations of infradian and ultradian
Individual differences - assessed sleep duration, time to fall asleep, amount of time in each stage
Large differences in each stage especially 3 and 4
Conflicting evidence - 186 Chinese women, dorms together, periods did not sync
