biopsychology Flashcards
what is the nervous system made up of?
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
What are the subdivisions of the PNS
- Autonomic nervous system: controls involuntary vital functions of the body
e.g maintaining heart and breathing rate - Somatic nervous system: receives information from sensory receptors belonging to each of the 5 senses, and results in effectors being stimulated by the CNS by the motor neurones
What is the autonomic nervous system divided into?
-parasympathetic nervous system
-symapthetic nervous system
-work as an antagonist pair during the “rest and digest” response
-crucial in producing physiological arousal needed to maintain the fiight or flight response
Outline the role of the subdivisons of the autonomic nervous system
-sympathetic NS : increases heart and breathing rate and causes pupil dilation and vasoconstriction
-parasympathetic NS : decreases heart rate , breathing rate and causes pupil constriction and vasodilation
Outline the endocrine system
- main chemical messenger of the body
-hormones are secreted into the bloodstream from the glands to regulate bodily functions
-chemical system of communication via blood
Outline the role of the pituitary gland with an example
- “master gland” :
- controls the release of hormones from all other glands of the body
e.g : thyroid releases the hormone thyroxine, which increases heart rate and therefore increases the rate of growth.
Outline the role of the adrenal gland with an example
- releases adrenal from adrenal medulla
-creates the psychological arousal preceded by the flight or flight response - through increasing activity within the sympathetic branch of the NS
e.g : increase heart rate and increases respiration and sweating
Outline the flight or fight response
1) body senses and becomes aware of a change in the environment
(e.g sound of speeding car)
2) sensory receptors and sensory neurones in the PNS send this information to the hypothalamus in the brain , coordinating a response
3) This triggers an increase in levels of activity in thee sympathetic branch in the ANS
4) Adrenaline is released from the adrenal medulla in the adrenal glands and is transported to target effectors
(through the blood and through action of the Endocrine system)
5) Due to this , the rectum contracts ,saliva production is inhibited and breathing rate increases.
- this creates the psychological response needed to sustain the fight or flight response
6) When the stressor is no longer a threat , as part of the antagonist pairing the hypothalamus triggers less activity in the sympathetic branch and more in the parasympathetic branch of the ANS
(“rest and digest” response)
What is the purpose of the flight or fight response
has an adaptive purpose to enable us to escape the stressor and so increase the likelihood of our survival.
Why is the fight or flight response referred to as the “rest and digest” response
this is because the parasympathetic branch decreasing the activity which was originally increased through the action of the sympathetic branch.
Outline the role of synaptic transmission
the process of how neighbouring neurons communicate with each other by sending chemical messages across synapse gaps that separate them
Outline the full process of synaptic transmission
1) an electrical message travels down the axon of pre-synaptic neuron to the terminal button
2) vesicles (in pre-synaptic neuron) are activated to fuse with surface of the terminal button membrane and release neurotransmitters across the synaptic cleft
3) neurotransmitters diffuse (high to low conc) across synapse to post-synaptic cell , where it binds to complementary receptor sites on dendrite
4) post synaptic effects are either excitatory or inhibitory , depending on the result of summation
what is the excitatory effect of neurotransmitters?
- depolarisation
-increase likelihood of post- synaptic neuron firing
-causes action in post synaptic neuron
-message continues to move through neuron across brain/body
what is the inhibitory effect of neurotransmitters?
- hyperpolarisation
- decreases likelihood of post synaptic neuron firing
-causes inaction in the post-synaptic neuron
-message does not continue to other neurones
Outline the what summation is and its results
- influences of the excitatory and inhibitory effects of neurotransmission on the post-synaptic neuron added together
e.g if net effect on post-synaptic neurone inhibitory/excitatory
Outline an example of excitatory neurotransmission
Dopamine
- fires off a message in the neuron
Message is passed on
Outline an example of inhibitory neurtransmission
GABA
-they are the nervous system “off” switch in that they decrease the likelihood of neurons firing.
-makes receptor sites difficult to stimulate , reducing anxiety
What does the localisation theory suggest?
suggests that certain areas of the brain are responsible for certain processes,
behaviours and activities.
Outline the location and function of the motor area in the brain
Function :
involved in regulating and coordinating movements
- lesions or damage to such area results in an inability to control vital body movements
Location:
frontal cortex in both hemispheres
Outline the location and function of the auditory area in the brain
function :
responsible for processing auditory information and speech
-lesions/damage could lead to hearing loss or wernicke aphasia
location :
temporal lobe in both hemispheres
Outline the location and function of the visual area in the brain
function:
processes visual information (from eyes via retina)
location :
occipital lobe in both hemispheres
Location and function or Wernicke’s area
function :
language understanding such as speech comprehension
location : temporal lobe , in left hemisphere
what happens when there is damage to wernicke’s area?
- wernicke aphasia
- individuals ability to understand language is severely impaired
- inability to understand language in verbal or written form , however connected speech production not affected
Location and function of Broca’s area
function:
sentence creation and formation (speech production)
location:
frontal lobe - in left hemisphere only
what happens when there is damage to the broca area?
-broca’s aphasia
-speech production severely impaired
-difficulty forming complete sentences and understanding sentences, as well as
failing to understand the order of words in a sentence and who they are directed towards
What is the left hemisphere of the brain associated with?
-language production and comprehension
-language is an example of a cognitive ability which is both localised and lateralised (to the
left hemisphere).
Location and function of somatosensory area
function:
detecting sensory touches (5 senses)
location: parietal lobe in both hemispheres
-highly localised
Evaluate a strength of localisation of function theory (BRAIN SCANS)
P- brain scans provide evidence that many everday brain functions are localised
E- Peterson et al. used brains scans and demonstrated how wernicke’s area was active during a listening task & broca’s area active during reading task
E- strength : highly scientific methods that areas of brain have specific functions supporting the theory of localisation of function .
(Broca and Wernicke area explain)
-if this wasnt the case there would be no change in location of activity in the brain when completing different tasks
Evaluate a strength of localisation of function theory (PRACTICAL ISSUES)
P- research into functional localisation have practical applications
E- in cases of extreme OCD or depression the patient might have a cingulotomy (lesioning an area responsible for emotional processing and behavioural control)
-Dougherty reported 1/3 of patients were identified as having successful outcomes 32 weeks after surgery
E- strength : highlights how localisation research can work to improve the quality of life for patients with severe mental illness , which in turn benefits the economy
-surgery success also indicates that symptoms and behaviours associated with mental illness are localised
Evaluate a Weakness of localisation of function theory (language localisation)
P-Language localisation has been questioned
E- In a study of silence reading Bavelier et al (1997) found a large variability in individual patterns of activation of the brain across different individuals. They observed activity in the right temporal lobe as well as the left frontal temporal and occipital lobes
E-limitation : because it suggests that rather than being confined too a couple of key areas, language may be organised more holistically in the brain.
-This directly contradicts the localisation theory as it does not identify one specific location for language function
Outline the idea of hemispheric lateralisation
- the idea that the the two hemispheres of the brain function differently
certain behaviours , processes. and activities are mainly controlled by one hemisphere rather than the other
how are the two hemispheres split? + example
- they are connected through a bundle of nerve fibers such as corpus callosun
-corpus callosun allows the two hemispheres to communicate and send / recieve information from one another
Outline the role of the left hemisphere
- processing the right visual field
- understanding of language and reading
Outline the role of the right hemisphere
- processing the left visual field
-facial recognition
