biopsychology Flashcards
the nervous system
2 functions
1- collect, process and respond to info in the environment
2-coordinate working of different organs and cells
cns and pns
cns= brain and spinal cord,
brain - all conscious awareness
spinal cord - reflex actions, passess messages from brain and connects pns
pns = transmits messages via neurons to and from tns
further divided
autonomic ns - functions in body e.g breathing, heart rate
somatic ns - muscle movement and info from sensory receptors
ans- futher divided to
sns- fight or flight response
pns- back to resting state
endocrine system
controls functions through hormones
glands, organs that produce hormones e.g pituitary gland (master gland)
hormones, secreted in bloodstream effects cells with receptors e.g thyroid (thyroxine) affects heart cells but also throughout body which increases metabolic rates
endocrine and ans work together e.g during stressful event
-stressor recieved by hypothalamus, triggers sympathetic ns
-changes from resting state to aroused symoathetic
-adrenaline released
-triggers change (high breathing and heart rate, dilation of pupils, saliva production)
-once threat has passed, parasympathetic brings back to resting state (rest and digest)
types and functions of neuron
80% located in brain, transmit signals electrically and chemically to provide communication
motor neurons - connect CNS to effectors such as muscles or glands (short dendrites, long axon)
sensory neurons - messages from pns to cns
(long dendrites short axon)
relay neuron - connects sensory to motor or other relay (short both)
structure of neuron and electrical transmission
cell body- nucleus
dendrites- branch like, carry nerve impulses
axon- electrical impulses, myelin sheath, gaps called nodes of ranvier (speeds up transmission)
electrical transmission
-resting state = negatively charged
-activated = positively charged causing action potential
-creates electrical impulse travels down axon
synaptic transmission
synapse- each neuron separated from next, tiny gap between is called a synapse
-signals between neurons transmitted chemically across synapse
-post synaptic neuron - presynaptic terminal - neurotransmitters in vesicles - postsynaptic receptor sites - postsynaptic neuron
-neurotransmitters, chemicals that diffuse across synapse
-lock and key
-serotonin- mood (linked to depression)
-neurotransmitters generally have an excitatory on inhibitory effect on neighbouring neuron
adrenaline, excitatory, increases positive charge (increasing chance of neuron fire)
serotonin, inhibitory, increases negative charge (decreases chance of neural fire)
dopamine, both
summation, superior charge makes action more or less likely
localisation of function in the brain
specific areas of the brain = specific functions
2 hemispheres
left hemisphere (right side of body) and right hemisphere (left side of body)
cerebal cortex- covers inner parts of brain, appears grey, 3mm thick
key areas
motor cortex- frontal lobe, voluntary movements, sends signals to muscles in body
somatosensory cortex- located in parietal lobe, receives incoming sensory info from skin to produce sensations related to pressure, pain, temp etc.
(Robertson, highly adaptable, braille etc)
visual area- occipital lobe, receives and processes visual info
auditory area- temporal lobe, analysing and processing auditory info
Broca’s- left frontal lobe, language and speech production
Wernicke’s- left temporal lobe, language comprehension
AO3
:)Gage, serious brain damage, affected personality, calm - quick tempered, frontal lobe-mood regulation
:) brain scan evidence, peterson, wernickes and brocas (active when listening and reading)
Tulving, sematic and episodic
:( Lashley, contradictory research, removed part of rats cortex, no area of brain was anymore important when learning maze
:( neural plasticity challenges
brain plasticity
during infancy brain experiences rapid growth through synaptic connections
as we age, we rarely use some connections so they get deleted (synaptic pruning) and frequently used ones are strengthened
Maguire
-more volume of grey matter in posterior hippocampus in london taxi drivers
-linked to spatial and navigation skills
-‘the knowledge’ test that recalls city streets and possible routes, this alters structure of their brain
Draginski
-brains of medical students 3 months before and after final exam
-learning induced changes seen in posterior hippocampus and parietal lobe
:) practical applications, contributed to neurorehabilitation includes movement therapy, and electrical stimulation of brain
:( negative consequences, rewiring itself can have maladaptive behaviour consequences e.g prolonged drug use increases risk of dementia, also 60-80% amputees experience phantom limb syndrome
:( relationship between age and plasticity is complex as said to reduce with age but 40 years of golf training showed neural representation of movement
:) hubel and wisel, sewed eye of cat shut, continued to process
functional recovery
following trauma, unaffected areas of the brain take over lost functions
brain rewires by forming new synaptic connections close to area of damage
secondary neural pathways which are not typically used to carry out function are activated to enable functioning to continue
structural changes
axonal sprouting
-growth of new nerve to connect to others to form new pathway
reformation of blood vessels
recruitment of homologous(similar) areas on opposite side of brain to perform specific tasks#
:) EB- tumour, language centers removed, recovered in 2yrs
:)Application to phsiotherapy and economic implications as allowes people back to work
:) deeper understanding of the brain
lateralisation
idea that 2 halves of the brain are functionally different and certain processes or behaviours are controlled by one hemisphere
right- face recognition, drawing and spatial tasks
left- language
corpus collosum connects the two
sperry’s research
Sperry, hemispheric lateralisation
-show individual streams of conscious awareness in each hemisphere
-quasi experiment in lab, 11 participants
-all epileptics with severed corpus collosum
-3 tasks
describe what you see
rvf- can
lvf- couldn’t
recognition by touch
objects shown to lvf, couldn’t be named but selected right one with left hand
Drawing
lvf could
AO3
:) methodology, standardised procedures
:(generalisation, unusual sample, 11, reduces validity
:( overstates differences, modern neuroscientists argue distinctions aren’t clear cut, more flexibile
fMRI
functional magnetic resonance imaging
detects change in blood oxygenation and flow that occurs due to neural activity in specific brain areas
when area of brain is more active it consumes more oxygen and blood flow
fMRI produces 3D image showing which parts of brain are active which must be involved in particular mental process
AO3
:)safe and doesn’t rely on use of radiation
:)high spatial resolution- clear picture
EEG
electroencephalogram
shows overall electric activity via electrodes on skull cap
records present brain waves
often used as diagnostic tool e.g epilepsy following patterns
AO3
:) understanding of sleep/wake cycle
:)high temporal resolution
:(generalised signals, difficult to know exact source of neural activity
ERP
event related potentials
brain waves related to particular events
what is left when all extraneous brain activity from EEG is filtered out
:)more specific
:)excellent temporal resolution
:(lack of standardisation between studies, difficult to confirm findings
:(background noise = extraneous variable
post mortem
analysis of dead persons brain
AO3
:)Broca and Wernicke’s both relied on post mortems so contributed to understanding
:(informed consent
circadian rhythms
(biological rhythms)
biological rhythms governed by exogenous zeitgebers and endogenous pacemakers
e.g internal body clock (end)
e.g environmental changes (exo)
circ= about diem= day (around 24hrs)
sleep wake cycle
-exogeneous zeitgebers- feeling drowsy at night but alert during the day
-endogenous pacemaker- biological clock such as SCN (can be determined by light)
Siffre
-wanted to examine effects of free running biological rhytms
- 2 months in cave of southern alps
-6 months texan cave
-found a regular sleep wake cycle
Aschoff and Wever
-pps spent 2 weeks in ww2 bunker deprived from natural light
-all but one (whose cycle went to 29hr) had a regular 24-25 hr sleep wake cycle
-both suggest natural sleep wake cycle may be longer than 24 hours but exogeneous zeitgebers such as light hours impact this
Folkard
-12 people in dark cave for 3 weeks
-bed 11.45pm, awake 7.45am
-researcher gradually sped this up so 24 day turned to 22
-only 1 participant adjusted to new regime
-endogenous cannot be easily override
AO3
:)Boivin, application to shift work, shift workers feel lack of concentration around 6am and mistakes are more likely
-economic implications in terms of work productivity
:) practical application to drug treatments, cr coordinate body’s processes such as heart rate and hormone levels, with implications for pharmacokinetics, research shows there’s more effective times of the day to use drugs and guidelines have been developed
:( siffre, case study, small sample
:( poor control siffre, still access to artificial light
