Memory and cognition Flashcards
How to we understand things?
-Remember memorable events are learn from them
what do we need in order to remember and learn things?
MOTIVATION
What is neuronal plasticity
ability of the central neurones to adapt and form new pathways based on new information they are given.
What do the association units of the brain do?
They put together information to make sense of it
Which are the components of cognition and memory and their function?
- Hippocampus: formation of memories
- Cortex: storage of memories
- Thalamus: Filter through memories
Different types of memory
- Immediate/sensory
- short-term
- Immediate long term
- Long term
properties of immediate/sensory memory?
- Lasts a few seconds
- Visual memories are the first to disappear (<1s)
- Auditory are the longest (<4s)
properties of short-term memory
- Can last from a few seconds to hours
- Usually what allows us to carry out small tasks e.g. phone number
How short term memory work?
-Electrical phenomenon - based on reverberating circuits- continues to be refreshed
-Each stimulus in a reverberating circuit is excitatory
-Small stimulus at A will cause a long lasting effect at B as it continues to excite all the neurones in the pathway
-If deemed significant then the memory will become part of long term memory
I-f the reverberating circuit is interrupted then this will lead to amnesia
what is amnesia
When the reverberating circuit is interrupted e.g. by bang to the head/ infection
Two types of amnesia
- anterograde
- retrograde
properties of anterograde amnesia
- Cannot form new memories
- Can be permanent or temporary
- If hippocampus destruction is involved then it will be impossible to form new memories
properties of retrograde amnesia
- Cannot remember events leading up to the event
- Can remember events from a long time ago
- Usually associated with anterograde amnesia
- If hippocampus is spared and only thalamus is affected: most likely to be only retrograde- so thalamus involved in searching existing memories
properties of immediate long term and how it works
From a few hours to days
Reminds us of events from the previous week
How it works:
Involves chemical changes in pre-synaptic neurones e.g
Increase of Ca2+ into cells- increases release of NT from pre-synaptic terminal
How does Long term memory
Structural changes at neuron synaptic connections e.g:
- Increase in number of NT vescicles released at presynaptic terminal
- Increase of NT releasing sites on presynaptic terminal
- Increase in number of presynaptic terminals
- Long term potentiation
what is long term potentiation
increase in the amplitude of graded membrane potential of post-synaptic terminal
Two types of long term memory
Declarative/ explicit
Implicit/reflexive/ procedural
Declarative memory
- Based on an episodic memory or words
- Depends on the hippocampus
Reflexive/procedural/implicit memory
Acquired through repetition e.g. driving on the left
Depends on the cerebellum
Independent of the hippocampus
Similar to consolidation
what is coding of memory
- When an event is significant it becomes stored in the sensory areas of the cortex
- An even is deemed to be more or less important by the frontal lobe in association with the limbic system
- An even is deemed to be significant in the PAPEZ circuit of the limbic system
- Different memories are stored in different parts of the cortex
what is the papez circuit?
Cingulate gyrus
hippocampus
mammillary bodies
anterior thalamus
Conditions associated with loss of memory
Korsakoff’s and ability to store memories: due to damage to the limbic system
- Alzheimers’: loss of cholinergic neurones involved in storing memories in the hippocampus
- REM sleep: needed for the formation of the memories of complex cognitive tasks. Patients with kosakoffs and Alzheimers have reduced REM sleep
Which sense has a strong link with the limbic system
olfactory
What makes up the limbic system?
hippocampus, cingulate gyrus, amygdala and hypothalamus
what does the hypothalamus do?
link between memory and ANS response
what does the limbic system do?
responsible for emotive response which is based on a reward/punishment system.
This means that stimulation of certain areas of the brain will lead to a feeling of reward and others will lead to a feeling of fear/punishment.
Motivation= desire for reward/ avoidance of punishment
Memory given to experiences which give reward/ punishment (SIGNIFICANCE)
What is consolidation
If short term memory in a reverberating system is deemed significant it will become part of long term memory
