Memory and cognition Flashcards
what is cognition
the integration of all sensory information to make sense of a situation
requires an ability to remember events and learn from them
what is neuronal plasticity
the ability of central neurons to adapt their neuronal connections in response to learning experiences
what is the cerebrum mostly comprised of
association areas
what do association areas do
integrate information from multiple sources - i.e. multiple parallel processing
what re the 3 key components of learning and memory and what does each do
hippocampus - formation of memories
cortex - storage of memories
thalamus - search and access of memories
where are memories formed
the limbic system
what are the components of the limbic system
hypothalamus (ANS response)
hippocampus (learning and memory)
cingulate gyrus (role in emotion)
amygdala (emotion and memory)
what is the limbic system responsible for
forming memories - choosing what memories are significant to keep
instinctive behaviour - e.g. thirst, sex, hunger, etc
emotive behaviour
what drives emotive behaviour (and almost every conscious thing we do)
reward or punishment - form the affective components of sensory experiences
what are the rewards and punishment responses that can be elicited by electrical stimulation of the limbic system in patients
rewards - can elicit intense feelings of well being, euphoria, sexual arousal
punishments - can elicit terror, anger, pain
what happens to experiences that are neither rewarding or punishing
deemed insignificant and barely remembered
where does sensory information for memories first travel
first through hippocampus - then relayed to other limbic system structures
what can happen to people with bilateral hippocampal damage
have immediate (sensory) memory and intact long-term memory (from before damage) BUT unable to form new long term memories
relfexive motor memory (motor skills) remain intact
**unilateral damage not as severe
what are the 4 type of memory
immediate/sensory
short term
intermediate long term
long term
what is immediate/sensory memory
a few seconds.
describes the ability to hold experiences in the mind for a few seconds.
based on different sensory modalities.
Visual memories decay fastest (<1s), auditory ones slowest (<4s)
what is short term memory
seconds - hours.
often called Working Memory.
used for short term tasks such as dialling a phone number, mental arithmetic, reading a sentence.
associated with reverberating circuits
what is intermediate long term memory
hours to weeks e.g. what you did last weekend.
associated with chemical adaptation at the presynaptic terminal.
what is long term memory
can be lifelong. e.g. where you grew up and your childhood friends.
associated with structural changes in synaptic connections
what does short term memory depend on
maintained excitation from reverberating circuits - i.e. need to be constantly refreshed
how does a reverberating circuit work
A to B with a loop of synapses off to the side in-between
each synapse is excitatory so a brief excitatory stimulus at A will cause long lasting neuronal activity at B as the reverberating circuit neurons continue to excite all neurons in the pathway
keeps the short term memory alive
what happens to short term memory if they are deemed insignificant or significant respectively
insignificant - reverberation fades, memory lost
significant - reverberation results in consolidation of the memory into long term memory
how can reverberation be disrupted
head injury, infection involving hippocampus and or/thalamus
what is the result of disruption to reverberation
memory loss - amnesia
what are the two types of amnesia
anterograde - cannot form new memories
retrograde - cannot access (more recent) old memories
