Biopsychology

Biopsychology AQA Psychology

DeCoursey et al (2000)

destroyed the SCB connections in the brain on 30. chipmunks who were then returned to their natural habitat and observed
- the sleep-wake cycle disappeared and by the end a significant proportion had been killed bu predators
- presumably because they were awake and vulnerable to attack when they should have been asleep

what are multipolar neurone?

neurones that transmit and receive messages

Divisions of the nervous system

central nervous system (CNS)
- brain
- spinal chord
peripheral nervous system (PNS)
-autonomic nervous system
- sympathetic nervous system
- parasympathetic nervous system
- somatic nervous system

what is the central nervous system?

the processing centre for the nervous system
- receives information from and send information to the PNS
- two main organs are the spinal chord and the brain

what does the brain do in the CNS?

processes and interprets sensory information sent from the spinal chord

what are ventricles?

a system of hollow cavities in the CNS
- filled with cerebrospinal fluid which surrounds

three main components of the brain

- the forebrain
- the midbrain
- the hindbrain

what is the forebrain responsible for?

- receiving and processing sensory information
- thinking

which components is the brainstem made up of?

- midbrain
- hindbrain

what is the midbrain responsible for?

- auditory and visual responses
- motor function
- portion of the brainstem that connects the forebrain and the hindbrain

what is the hindbrain responsible for?

contain structures such as the pons and cerebellum which assist in maintaining:
- balance and equilibrium
- movement coordination
- conduction of sensory information
also contains the medulla oblongata

what is the medulla oblongata responsible for?

controlling autonomic features like:
- breathing
- heart rate
- digestion

what is the spinal chord and what does it do?

- a cylindrical shaped bundle of nerve fibres that is connected to the brain
- runs down the centre of the protective spinal column extending from the neck to the lower back

what do the nerves in the spinal chord do?

- transmit information from body organs and external stimuli to the brain and send information from the brain to other areas of the body
- grouped into bundles of nerve fibres that travel in two pathways

what are the two nerve tracts in the spinal chord and what do they do?

ascending
- carry sensory information from the body to the brain
descending
- send information pertaining motor function from the brain to the rest of the body

what are neurons and what are they composed of?

- the basic unit of the nervous system
- contain nerve processes which are 'finger-like' projections that extend from the nerve cell body

what do the nerves consist of?

- axons
- dendrites

what do nerves do?

send signals between:
- the brain
- the spinal chord
- other body organs
via nerve impulses

what are axons and what do they do?

- long nerve processes that may branch out to convey signals to various areas
- typically carry out signals away from the cell body

what do dendrites do?

carry signals toward the cell body

how many spinal nerves is the PNS made up of?

31

what are the types of cells in the PNS and what do they do?

sensory nervous cells
- carry information to the CNS from internal organs or from external stimuli
motor nervous cells
- carry information away from the CNS to organs

what is the motor nervous system divided into?

- somatic nervous system
- autonomic nervous system

what does the somatic nervous system do?

controls skeletal muscle as well as external sensory organs
- ie. the skin

why is the somatic nervous system said to be voluntary?

the responses can be controlled consciously

why are reflex reactions an exception of the somatic nervous system?

they are involuntary reactions to external stimuli

what does the autonomic nervous system do?

controls involuntary muscles (ie. smooth+cardiac muscle) and is vital for maintaining homeostasis as it helps the organism become independent of they environment
- ie. can control our body temperature regardless of the weather

what is the autonomic nervous system split up into?

- the sympathetic nervous system
- the parasympathetic nervous system

what does the sympathetic nervous system do to the body's organs?

involved in the fight or flight response as a response to potential danger:
- slows digestion (gut)
- inhibits saliva production (salivary glands)
- increases heart rate (heart)
- stimulated glucose production (liver)
- relaxes bladder to stimulate urination (bladder)
- dilates pupils (eye)
- dilates bronchi (lungs)

what does the parasympathetic nervous system do to the body's organs?

- increases digestion (gut)
- increases saliva production (salivary glands)
- decreases heart rate (heart)
- stimulated bile production (liver)
- contracts bladder to inhibit urination (bladder)
- constricts pupils (eye)
- contracts bronchi (lungs)

what do neurones and what do they do?

neurones are nerve cells that carry information as tiny electrical signals called actions potentials

three different types of neurones?

- sensory neurones
- relay neurones
- motor neurones

what is the function of sensory neurones?

- unipolar neurones that tell the rest of the brain about the internal and external environment by processing information through the 5 sense and pain
- sensory information carried in afferent pathways which run from sensory receptors through spinal nerves to the spinal chord and onwards to the brain

what are unipolar neurones?

neurones that only transmit messages

what is the function of relay neurones?

- multipolar neurones that carry messages from one part of the CNS to another
- connect motor and sensory neurones

what are the majority of neurones in the brain?

relay neurones

what is the function of motor neurones?

- multipolar neurones that carry signals from the CNS to organs

what are reflex reactions in humans controlled by?

the reflex arc

what is the reflex arc?

the nerve pathway which makes fast

how does a reflex arc/action work?

- when the safety of an organism demands a very quick response

what is saltatory conduction?

Rapid transmission of a nerve impulse along an axon

what are synapses?

the small gaps that separate neurones made of synaptic fluid

how does synaptic transmission occur?

- an electrical impulse travels along an axon to the terminal
- this triggers the nerve-ending of a neurone to release chemical messengers from neurotransmitters (synaptic vesicles)
- these chemicals diffuse across the synapse and bind with receptor molecules on the membrane of the receiving neurone cell body/dendrite
- the receptor molecules on the second neurone bind only to the specific chemicals released from the first neurone
- this stimulates the second neurone to transmit the electrical impulse

what do excitatory potentials do?

make it more likely for an action potential to generate in a presynaptic neurone
- increases the probability of an action potential occurring in a postsynaptic cell
- positively charged ions flood into the receiving cell

dopamine as an example of excitatory neurotransmitter actions

- regulates motor behaviour
- plays a critical role in the reward system
- people with Parkinson's disease have been linked to low levels of dopamine
- people with schizophrenia have been linked to high levels of dopamine

adrenaline as an example of excitatory neurotransmitter actions

- released from the adrenal glands
- plays a role in:
- sleep
- one's ability to stay alert
- fight or flight response

what do inhibitory potentials do?

make it less likely for an action potential to occur in a presynaptic neurotransmitter
- negatively charged ions flood into the receiving cell
- if the message if likely to be stopped at the post synaptic neurone

GABA as an example of inhibitory neurotransmitter actions

GABA is an inhibitory neurotransmitter as its binding on the post synaptic receptor enables negatively charged chloride ions to enter the receiving cell through the receptor channel

drugs as an example of inhibitory neurotransmitter actions

drugs like benzodiazepines can be prescribed to prevent excitation and therefor anxiety by:
- enhancing the effectiveness of GABA
- reducing the effect of excitatory pathways ie. serotonin

what is the endocrine system?

the collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards a distant target organ

what is the 'master gland' in the endocrine system?

pituitary gland

what is a gland?

a body organ that releases hormones into the bloodstream

what is a hormone?

a chemical released from endocrine glands into the bloodstream that acts on target structures to alter their function or to release other hormones

what is the main hormone the thyroid gland releases?

thyroxine

what effects does thyroxine have on the body?

regulates the body's metabolic rate and protein synthesis

what is the main hormone the adrenal medulla gland releases?

adrenaline

what effect does adrenaline have on the body?

- fight or flight response
- increased heart rate and breathing blood
- blood flow increases to muscles and brain and glucose and fait is released from energy from stores

what is the main hormone the pineal gland releases?

melatonin

What effect does melatonin have on the body?

regulation of arousal and biological rhythms
- sleep-wake cycle

what two portions is the pituitary gland divided into?

- anterior
- posterior

what hormones come from the anterior pituitary?

ACTH
TSH
prolactin
FSH
growth
MSH

what hormones come from the posterior pituitary?

ADH
oxytocin

what does the amyglada do?

sends a distress signal to the hypothalamus when the body is under threat

flight/fight response A03: Taylor et al (2000)

suggest that for females

flight/fight response A03: Lee and Harley (2012)

found evidence of a genetic basis for gender different responses.
- SRI gene promotes aggression and results in the flight/fight response to stress
- only found on the Y chromosome of men
- suggests this may prime males to respond in this way due to increased adrenaline and blood flow to organs.
- absence of this in women

flight/fight response A03: Von Dawans et al (2012)

found that acute stress can actually lead to greater cooperative behaviour

flight/fight response A03: negative consequences

- the stressors of modern daily life rarely require hight levels of physical activity
- ie. running away from a stressor
- problems arise when the stress response is repeatedly activated
- example:
- increase blood pressure associated with SNS activation can lead to physical damage in blood vessels and lead to heart disease.
- too much cortisol can suppress the immune response

what is localisation?

the idea that different parts of the brain perform different tasks and are involved in different parts of the body

what is the brain divided into and which part of the body do they control?

two symmetrical halves:
- left hemisphere which controls the right side of the body
- right hemisphere which controls the left side of the body

what are the two hemispheres connected by?

the corpus callous

what are the cortexes of the hemispheres divided up into?

four lobes
- frontal lobe
- parietal lobe
- temporal lobe
- occipital lobe

what are the functions of the frontal lobe?

regulation social behaviour
- cognition
- problem-solving and reasoning
- motor skill development
- parts of speech
- impulse control
- spontaneity
- regulating emotions
- planning

what can damage to the frontal lobe result in?

- personality changes
- impulsive and risk-taking behaviours

where is the motor area and what does it control?

- at the back of the frontal lobe in both hemispheres
- controls voluntary movement in the opposite side of the body

what are the functions of the parietal lobe?

- sensation of
- touch
- pain
- pressure
- perception
-spatial reasoning
- regulation and processes the 5 senses
- movement and visual orientation
- such and cognition
- information processing

what can damage to the parietal lobe result in?

problems with:
- spatial reasoning
- reading
- writing
- language
right side damage:
- ability to dress/groom oneself
left side damage:
- language disorders

where is the somatosensory area and what is its function?

- at the front of the parietal lobes in both hemispheres
- where the sensory information from the skin is represented
- the amount of somatosensory area devoted to a particular body part denotes its sensitivity
- ie. the hands and face occupy over half of the area

what are the functions of the temporal lobe?

primary function is to process auditory sounds
- very close proximity to ears
other functions:
- forming long-term memories
- processing new information
- formation of visual and verbal memories
- interpretation of smells and sounds

what can damage to the temporal lobe result in?

- difficulty processing auditory sensations and visual perceptions
- problems concentrating on visual/auditory stimuli
- long-term memory problems
- changes in personality
- changes in sexual behaviour

where is the auditory area and what does it do?

- in the temporal lobe
- analyses speech- based information

what are the functions of the occipital lobe?

primary visual processing centre
- visual spatial processing
- movement
- colour recognition

what can damage to the occipital lobe result in?

- loss of colour recognition
- visual hallucinations/illusions
- problems recognising objects
- difficulty understanding language

why is damage to the occipital lobe less likely?

protected by the skull

where is the visual area and what does it do?

- in the occipital lobe
- each eye sends information from the right visual field to the left and from the left to the right
- means damage to the left hemisphere can result in blindness in the right eye

Lashley (1920s)

studied how rats learn mazes
- found large legions on visual areas impaired maze learning
- but smaller legions covering the same areas had no effect
- SO size of legion was significant

Law of Equipotentiality (Lashley)

different areas of the cortex have similar capacities to process learning

which side of the brain is language restricted to (in most)?

left

Broca

identified a small area in the left frontal lobe responsible for speech production in the 1880s
- called this Broca's area

What is Broca's aphasia and how is it characterised?

- damage to Broca's area
- characterised by speech that is:
- slow
- laborious
- lacking in fluency

Wernicke

identified an area in the left temporal lobe as being responsible for language comprehension

what is Wernicke's aphasia and how is it characterised?

- damage to Wernicke's area
- characterised by:
- the production of neologisms

what are neologisms?

nonsense words

localisation A03: brain scan evidence (Peterson et al 1988)

lots of evidence providing support that many neurological functions are localised
- particularly in relation to language and memory
ie. Peterson et al:
- used brain scans to demonstrate how:
- Wernicke's area was active during a listening task
- Broca's area was active during a reading task
- suggests that these areas in the brain have different functions

localisation A03: neurosurgical evidence (Dougherty et al 2002)

- reported on 44 OCD patients who had undergone a cingulotomy
- at post-surgical follow ups

What is a cingulotomy?

lesioning the cingulate gyrus to treat OCD

How does Dougherty et al's research go against localisation?

2/3s of the sample had an unsuccessful response to surgery
- suggests that surrounding areas may also be connected to the development of mental disorders

localisation A03: case study evidence (Phineas Gage)

suggests that the area that the steel rod went through and damaged is responsible for personality

summarise the Phineas Gage case study

On the 14th September

Why is it difficult to draw general conclusions from the case of Phineas Gage?

- it was a very long time ago
- there are a lot of accounts that describe him before and after

localisation A03: Lashley's research

removed areas of the cortex in rats that were learning a maze
- no area was proven to be more important than another in terms of the rats' ability to learn the maze
- the process required every part of the cortex