lecture 7 Flashcards
gene environment interaction
environment can change the way genes are expressed
genetic code contains
instructions on how to respond to the environment
how do nervous systems change
neural activity changes synaptic connections
fire together wire together- strengthen
out of sync lose your link - weaken
synaptic activity - baseline activity
neural activity without stimulation
action potentials are generated randomly
neural signalling
change in activity relative to baseline level
action potential can either become
more forewent than baseline (excitation) or less frequent (inhibition)
persisent signalling
causes the synapse to change
increased activity causes short term molecular changes
frequent APS cause an increase in
neurotransmitter release and number of receptor molecules
increased neural activity can also cause
long term structural changes
long term structural changes
sustained activity - frequent AP’S can cause
growth of new synapses
synaptic takeover
how do changes affect behaviour
optimising existing behaviour
increased transmission rate
react more quickly , reliably to important changes in the environment
decrease transmission rate
makes you more likely to ignore unimportant changes in the environment
acquiring new behaviour growth of new synapses
combine info from previously unrelated sources
respond to old stimuli in a new way
synaptic takeover
reroute info to new pathways
respond to old stimuli in a new way
damage to CNS can lead to
memory failures
lesion studies in cortex conclusion
no specific place in cortex where memories are stored
loss of memory function is due to the
size of lesion
certain cortical lesions can destroy
types of memories
removal of medial temporal lobes
hippocampus , amygdala and surrounding cortex
anterograde amnesia - unable to consciously remember any new events
diencephalon damage
korsakoffs syndrome - degeneration of neurons in nuclei of the thalamus and in the maxillary bodies
what are the effects of korsakoffs syndrome
suffered from retrograde amnesia - lost past memories
anterograde amnesia
learn new skills
inability to forget can cause
memory problems just as severe as the inability ti remember
all experiences
shape our brains
post traumatic stress disorder
memory of a traumatic experience does not fade overtime but begins to dominate the persons life
flashbacks, concentration problems
why do some people develop PTSD
hormones
hormones
chemicals generated by the endocrine system
transported in to the brain via the bloodstream
specific hormones are associated
with different emotional states
eg stress and arousal - adrenaline and noradrenaline
stress hormones affect
memory
experimental evidence that stress hormones affect memory
2 groups - pictures presented with exciting story or neutral story
pictures were remembered better if pairs with an exciting story
when given an noradrenalin antagonist this effect disappeared
amygdala
crucial for emotional memories
experimental evidence for amygdala
lesion of amygdala - animals appear over sexed but emotionally flat
can no longer learn a fear response
amygdala is directly connected to the
hypothalamus
biological model of PTSD
stress- traumatic experience, processed by amygdala, activates hypothalamus, activates ES, releases adrenaline and noradrenalin improves memory of stress- keeps activating amygdala
