Biopsychology Flashcards
nervous system
specialised network of cells in the body and is our primary internal communication system.
biopsychologists assume behaviours caused by activity in the nervous system.
Central nervous system (CNS)
brain- centre of all conscious awareness
spinal cord- extension of brain, is responsible for reflex actions
PASSES MESSAGES TO AND FROM THE BRAIN AND CONNECTS TO THE PNS
Peripheral nervous system (PNS)
transfers messages to and from the CNS
divided into somatic and autonomic nervous systems
Somatic Nervous System (SNS)
carries sensory and motor information to and from the spinal cord
controls muscle movement and receives information from the sensory receptor sites
Autonomic Nervous System (ANS)
governs vital functions in the body e.g. breathing, digestion
divided into sympathetic and parasympathetic nervous system- their actions are antagonistic
sympathetic nervous system examples
gut- slows digestion
salivary glands- inhibits saliva production
heart- increases heart rate
lives- stimulates glucose production
bladder- stimulates urine–> relaxes bladder
eye- dilates pupil
lungs- dilates bronchi
Parasympathetic nervous system examples
when threat goes away
gut- increases digestion
salivary glands- increases saliva production
heart- decreases heart rate
lives- stimulates bile production
bladder- inhibits urine–> contracts bladder
eye- constricts pupil
lungs- constricts bronchi
neurons
cells that conduct nerve impulses
dendrite
receives nerve impulses from neurons
axon
where electrical signals pass along
Myelin sheath
insulates and protects axon from external influences that can affect the transmission of the nerve impulse
speeds up transmission
nodes of ranvier
speeds up transmission of impulse by forcing it to ‘jump’ across axon gaps
terminal buttons
send signals to an adjacent cell
sensory neuron
found in sense organ receptors
carry nerve impulses to CNS
long dendrites
short axons
relay neuron
in between sensory and motor neurons
short dendrites
short axons
motor neuron
found in CNS and muscles
form synapses with muscles to control their contractions
long axons (lead to muscle)
short dendrites
knee jerk reflex- e.g. of reflex arc
the stimulus (hammer) hits the knee. That’s detected by the sense organs in the peripheral nervous system which conveys the message along a sensory neuron
the message reaches the CNS where it connects to the relay neuron to then the motor neuron.
then the message is carried to an effector, causing the muscle to contract.
synapse
physical junction between 2 neurons
action potential
electrical activity which causes a neuron to send information down an axon
Excitation
more likely the next neurone will fire
Inhibition
less likely that the next neuron will fire
case study
research investigation that involves a detailed study of an event. Provides a rich record of human experience
but is difficult to generalise a whole population
localisation
theory that specific areas of the brain hold particular physical and psychological functions
Lateralisation
the dominance of 1 hemisphere for a particular physical and psychological function
brocas area
converts thought to speech
wernickes area
Understands other people’s speech and produces speech that makes sense
aphasia
damage to Broca or wernickes areas
3 concentric layers that form the brain
- central core
- limbic system
- cerebrum
central core
regulates primitive and involuntary behaviour
limbic system
controls emotions
cerebrum
regulates higher intellectual processes
cerebral cortex
outmost layer of the cerebrum that’s responsible for muscle control and sensory perception
corpus callosum
bundle of fibres in the cerebrum which connects the hemispheres
Pariental Lobe
sensory and motor movements
somatosensory cortex found here
Somatosensory cortex
detects sensory events arising from different regions of the body
uses sensory info from skin to produce sensations of touch, temperature, pain and pressure
Frontal Lobe
location for awareness of what we’re doing in our environment
motor cortex is located here
motor cortex
generates voluntary motor movements
both hemispheres have one, each controls the opposite sides muscles
Temporal Lobe
auditory centres are here
occipital lobe
visual centres here
visual cortex
visual information
visual cortex
visual information
plasticity
brains tendency to change and adapt as a result of experience and new learning
functional recovery
a form of plasticity
after damage through trauma, the brain transfers the functions that the affected area would usually do to other undamaged areas
synaptic/ cognitive pruning
rarely used connections are deleted and frequently used brain connections are strengthened
it shows that the brain’s in a continuous state of change
negative plastcity example
prolonged drug use leads to poor cognitive functioning
ELANOR MAGUIRE ET AL
studied brains of London taxi drivers using MRI scans
found significantly more grey matter in hippocampus than control group (where development of spatial and navigational skills occurs)
Found that the longer they did the job the more pronounced the structural difference
Spontaneous recovery
when unaffected areas adapt to compensate for damaged areas quickly after trauma
what happens in the brain during recovery?
Brain’s able to rewire & reorganise itself by forming new synaptic connections close to the damaged area.
Secondary neural pathways that wouldn’t typically be used to carry out certain functions are ‘unmasked’ to enable functioning to continue
What structural changes occur in the brain during recovery
Axon sprouting: new nerve endings form and connect with undamaged areas
Reformation of blood vessels
Recruitment of homologous (similar) areas on opposite hemisphere to do specific tasks
what are endogenous pacemakers?
the body’s internal body clock
e.g. suprachiasmatic nucleus- the master clock that follows a 24 hour pattern.
Keeps body working to the same time- by working with the cells in the eye that respond to light as it helps keep the suprachiasmatic nucleus in tune with the wider world.
Stops melatonin (sleep hormone) being produced in the day
what are exogenous zeitgebers
external factors in the environment that reset our biological clocks.
E.g. light, social cues
circadian rhythm
24 hour biological clock that regulates sleep/wake cycle, and changes in core body temperature
MICHEL SIFFRE
Lived underground (free of social cues) to study circadian rhythms.
Only endogenous pacemakers were influencing him
Found that his sleep wake cycle was just beyond the usual 24 hour cycle
When he did this experiment for the 3rd time when he was 60, he found that his body clock was much slower
Supports assumption that endogenous pacemakers do exert an influence on circadian rhythms.
ASCHOFF AND RUTGER
For 4 weeks placed participants in a bunker with no natural light
Their sleep/ wake cycle was between 25 and 27 hours
Suggests that endogenous pacemakers control sleep/ wake cycle in absence of light cues
FOLKARD ET AL
12 participants in a dark cave for 3 weeks
manipulated the clocks to 22 hours a day
None of the participants could adjust comfortably to the pace of the clock
Shows the strength off the circadian rhythm as a free running cycle.
Questions the extent to which sleep wake cycles could be overridden by exogenous zeitgebers.
infradian rhythms
longer than 24 hours- weekly, monthly, annually
e.g. menstrual cycle, seasonal affective disorder
RUSSEL ET AL- MENSTRUAL CYCLE
Menstrual cycle’s normally governed by endogenous systems, however it can be controlled exogenous factors
They showed that the synchronisation of periods can be affected by pheromones (exogenous cues)
They daily took samples of sweat from 1 group of women and rubbed it on to the upper lip of women in the 2nd group
Although the two groups were kept separate, their menstrual cycles became synchronised with their odour donor
ultradian rhythms
less that 24 hours
e.g. sleep and meal patterns
sleep cycle- stage 1
light sleep where muscle activity slowly decreases. Slow brain waves (alpha waves)
sleep cycle- stage 2
breathing, heart rate and body temperature decreases. Slow brain waves, sleep becomes a little deeper so theta waves appear
sleep cycle- stage 3
deep sleep begins, the brain then starts to produce slow delta waves.
sleep cycle- stage 4
continuation of the production of delta waves, low muscle activity and deep sleep, but the sleep is more intense.
sleep cycle- stage 5
REM. (rapid eye movement) Heart rate increases, and the breathing is shallow. Brainwaves are sped up and dreaming takes place.
BRAC- Basic Rest Activity Cycle- KLEITMAN
Human biological cycle of 90 minutes but instead of the sleep cycle it occurs in the day and we move from a state of alertness to physiological fatigue after every 90 minutes.
