Biopsychology Flashcards
nervous system
based on electrical signals
specialised network of cells responsible for:
- collecting, processing and responding to information in environment
- co-ordinating different organs and cells to work
divided into:
- central nervous system (cns)
- peripheral nervous system (pns)
central nervous system
made up of brain and spinal cord
- brain is centre of all conscience awareness and is divided into two hemispheres
- cerebral cortex is 3mm thick and only found in mammals
- spinal cord is extension of brain that passes messages to and from brain
- connects nerves to pns
- responsible for reflex actions such as moving hand from hot plate.
peripheral nervous system
transmits messages via neurons to and from cns
divided into:
- autonomic nervous system(ans)
- somatic nervous system(sns)
endocrine system
major information system that instructs glands to release hormones into bloodstream
- communicates via chemicals
- acts slower but with more widespread and powerful effects
autonomic nervous system
governs vital functions such as breathing, heart rate, digestion, sexual arousal and stress responses
somatic nervous system
governs muscle movement and receives info from sensory receptors
pituitary gland
master gland that controls the release of hormones from other glands in body
hypothalamus gland
-connected to pituitary gland so is responsible for stimulating release of hormones from it
thyroid gland
produces thyroxine
- affects cells in heart and increases heart rate
- aids digestion
- increases metabolic rates
adrenal gland
produces adrenaline
-triggers physiological changes in the body to prepare for fight or flight
ovaries
produces oestrogen and progesterone
-used in menstrual cycle to prepare uterus for pregnancy
testes
produce testosterone
- primary male sex hormone
- produce sperm
fight or flight
endocrine system and ans work together when stressor perceived
- hypothalamus activates pituitary gland which triggers sympathetic system
- adrenal gland triggered to produce adrenaline
- ans changes from resting parasympathetic state to aroused sympathetic state
immediate and automatic response to stimulus
adrenaline
- released into bloodstream from adrenal medulla
- triggers physiological changes such as increased hr, redirects blood flow to vital organs (inhibits saliva and digestion)
parasympathetic response
rest and digest response
works as antagonist to sympathetic by acting as a brake
-hr decreased
-breathing rate decreased
-constricts pupils
-stimulates digestion
stimulates saliva production
-relaxes rectum
sympathetic response
fight or flight
- hr increases
- breathing rate decreases
- dilates pupils
- inhibits digestion
- inhibits saliva production
- contracts rectum
neuron
signal sent makes cell positively charged when going through it. called action potential as going down
- dendrites (tree branches) that receive signal at one end
- cell body containing nucleus
- axon (long string) covered in myelin sheath which speeds up signal
- axon terminals at end to pass on signal
motor neuron
transmits messages from cns towards muscles and organs
long axons
short dendrites
looks like wheel
relay neuron
connect neurons together
short dendrites
short axons
looks like relay race with stuff either end
sensory neuron
carry messages to cns from senses processed by pns
long dendrites
short axons
sensitive octopus shape
neuron location
- motor neurons may be stretched across both cns and pns
- sensory neurons located in pns in ganglia clusters
- relay neurons make up 97% of all neurons
synaptic transmission
communicate in neural networks
each neuron separated by tiny gap called synapse, signals across these transmitted chemically
when impulse reaches end of neuron (pre synaptic terminal) it triggers release of neurotransmitters from tiny sacs (synaptic vesicles) its then taken up by postsynaptic receptor sites
neurotransmitter
brain chemicals released from synaptic vesicles that relay signals across synapses
each neurotransmitter has a specific molecular shape that fits into a specific post synaptic receptor site
either perform:
- excitatory function
- inhibitory function
excitation
neurotransmitter that increases positive charge, making it more likely to fire (dopamine)
inhibition
neurotransmitter that increases negative charge, making it less likely to fire (serotonin)
summation
the addition of positive and negative post-synaptic potentials
potentials are summed and if the net effect on the postsynaptic neuron is inhibitory, the neuron will be less likely to fire, if the net effect is excitatory, the neuron will be more likely to fire.
localisation of function
different parts of the brain are responsible for specific behaviours, processes or activities
brain hemispheres
cerebrum of brain divided into two hemispheres
some physical and psychological functions are controlled by one specific side - lateralisation
right hemisphere controls right side of body and left hemisphere controls left side of body-linked to language too
motor area
located in frontal lobe
controls voluntary movement on opposite side of body
somatosensory area
located in parietal lobe
sensory information from skin is recognised
amount of somatosensory area devoted to area equates to sensitivity of area
visual area
located in occipital lobe
eyes send info from one sides visual field to opposite visual cortex
auditory area
located in temporal lobe
analyses speech-based information
broca’s area
responsible for speech production
1880’s paul broca identified area, located in temporal lobe
damage cases brocas aphasia which is slow + nonfluent
gcse language speaking
wernickes’s area
responsible for language comprehension
1880’s karl wernicke found area in temporal lobe
wernickes aphasia causes difficulty understanding language or meaningful sentences
foreign language
dougherty et al (2002)
- reported on 44 people with ocd that had a cingulotomy
- 30% has successful response
- 14% had partial response
neurosurgery sometimes used to treat mental disorders- targeting specific areas of brain
success shows some mental disorders are localised
petersen et al (1988)
used brain scans to show wernicke’s area active during listening tasks and broca’s during reading task
brain scans are objective methods of measuring brain activity that provide scientific evidence
buckner and petersen (1996)
long term memory study that revealed semantic and episodic memories are in different parts of the prefrontal cortex
localised areas for everyday behaviours
karl lashley (1950)
removed 10-50% of cortex in rats learning maze route
- no area proven to be any more important for rat to learn the route
- learning needed all part of cortex for optimum
higher cognitive processes like learning aren’t localised but more holistic
dick and tremblay (2016)
found only 2% of researchers now believed language is only controlled by brocas and wernickes area
development of fmri means neural processes can be studies more clearly to show more holism
some language streams identified in right hemisphere such as thalamus
phineas gage (ao3)
case study of man with metal pole through left side of his head, taking out most of frontal lobe
changed his personality from calm and reserved to quick tempered and rude
hemispheric lateralisation
two sides of brain called hemispheres
certain processes lateralised to one side
left side is analyser - language
right side is synthesiser - emotional context to words
contralateral wiring
cross wiring of the brain
left hemisphere controls right side of body
right hemisphere controls left side of body
split brain research
operation severing connection between LH and RH (corpus callosum)
used to reduce epilepsy as during epileptic fit excessive electrical activity sent between hemispheres
sperry (1968)
11 people who had split brain surgery
see how split brain reacted without communication across hemispheres
- image projected to rvf (processed by lh)
- image projected to lvf (processed by rh)when object shown to rvf (lh) they could describe object
on lvf (rh) couldn’t describe anything as no link to language centre
lvf could match object out of sight using left hand and could produce emotional reaction
lh is verbal and rh is ‘silent’ but emotional
fink et al (1996)
hemispheres process info differently
pet scans to identify which areas where active in visual processing task
- when looking at whole picture rh more active
- when looking at finer detail lh more active
in visual processing - hemispheric lateralisation
lateralisation vs plasticity (ao3)
lateralisation is adaptive as it allows two tasks to be performed at once with greater efficiency
-rogers et al (2004) lateralised chickens could find food and watch for predators
plasticity could also be seen as adaptive because after damage some functions taken over by non specialist areas on opposite hemisphere
luck et al (1989)
split brain perform better than connected on some tasks
-faster at identifying odd one out
in normal brain lh’s better cognitions are watered down by rh
generalisation (ao3)
sperrys control group were neuro-typical and none had epilepsy
confounding variable as any differences could have been due to epilepsy rather than split brain
hard to generalise to the general population
lateralisation changes with age (ao3)
- appears not to stay exactly the same throughout lifetime, but changes with age
- across types of tasks and brain areas, lateralised patterns found in younger individuals tend to switch to bilateral patterns in healthy older adults.
szaflarski et al (2006) found that language became
more lateralised to the left hemisphere with increasing age in children and adolescents, but after 25, lateralisation decreased
this implies that a lateralised brain is in fact only a feature of young adults and not true for everyone.
brain plasticity
brain changing and adapting as a result of new experiences and learning
during infancy brain has around 15,000 synaptic connection’s aged 2-3 - double of adult brain
synaptic pruning
rarely-used connections are deleted and frequently used connections are strengthened
maguire et al (2000)
studied brains of london taxi driver finding significantly more grey matter in hippocampus compared to control
-part of brain associated with navigation + spatial skills
maguire found the learning for the knowledge alters the structure of their brain - the long they had been doing it the larger their hippocampus got (positive correlation)
