Memory & Cognition Flashcards
What is cognition?
Integration of all sensory information to make sense of a situation
Which process helps with memories and learning from siutaions?
Neuronal plasticity
What do the association areas in the cerebellum do?
Integrate information from multiple sources rather than being concerned about one specific function.
Name the three components of the brain which are vital for learning and memory.
- Hippocampus
- Cortex
- Thalamus
What is the hippocampus responsible for?
Formation of memories
What is the cortex responsible for?
Storage of memories
What is the thalamus responsible for?
Searching and accessing of memories
What does the cingulate gyrus have a role in?
Emotion
Memories are formed in the limbic system. It consists of an ‘old’ and ‘new’ cortex. The old cortex makes connections with the new cortex, especially which two lobes?
Temporal and frontal lobes
What is the limbic system driven by?
Reward or avoiding punishment e.g. eating so we don’t starve etc.
What is the limbic system responsible for?
Behavioural and emotional responses
What is meant by reward areas of the brain?
Parts of the brain which, when stimulated, produce intense feelings of well being, euphoria and sexual drive
What is meant by the punishment areas of the brain?
Area which elicit fear, anger or pain when stimulated
Where does all sensory information go through?
Hippocampus
What happens in people with bilateral hippocampal damage?
They have immediate memory and intact long-term memory but unable to form new long-term memories.
Motor skills still normal.
How long does immediate/sensory memory last?
A few seconds
How quickly do visual immediate/sensory memories disappear?
<1second
How quickly do auditory immediate/sensory memories disappear?
<4seconds
How long does short-term memories last?
Seconds-hours
What is short-term memory used for?
Short term tasks e.g. dialling a phone number, reading a sentence.
How long do intermediate long-term memories last?
Hours to weeks
Give an example of an intermediate long-term memory.
What you did last weekend
What is intermediate long-term memory associated with?
Chemical adaption at the presynaptic terminal
How long can long-term memories last?
Can last a lifetime
What are long-term memories associated with?
Structural changes in synaptic connections
Short term memory is an electrical phenomenon and depends on maintained excitation from reverberating circuits.
Why are these reverberating circuits important?
Keeps the brief short term memory alive but if deemed significant, this reverberation results in consolidation of memory into long-term memory
What happens if reverberation is disrupted?
Memory loss/amnesia
Name the two types of amnesia.
Anterograde
Retrograde
What happens in anterograde amnesia?
Cannot form new memories
What happens in retrograde amnesia?
Cannot access more recent old memories
Can anterograde amnesia be resolved?
Depends on severity of injury causing it- may be short-lived or permanent
How does retrograde amnesia usually present?
With anterograde amnesia
->those with retrograde amnesia cannot remember the events leading up to the injury
If only the hippocampus is damaged, which type of amnesia is seen?
Retrograde amnesia
As previously mentioned, intermediate long-term memory involves chemical changes in presynaptic neurons. What happens when there is increasing calcium ion entry into presynaptic terminals?
Increase in neurotransmitter release
What are the three structural changes at synapses seen in long-term memory?
- Increase in neurotransmitter release sites on presynaptic membrane
- Increase in number of neurotransmitter vesicles stored and released
- Increase in number of presynaptic terminals
What is long term potentiation?
Forms basis of learning and memory, due to increased amplitude in graded membrane potential which ‘strengthens the cell’
Name the two types of long-term memory.
Declarative/explicit memory
Procedural/reflexive/implicit memory
What is the explicit memory used for?
Events, words, rules and language
Which part of the brain does the explicit memory rely heavily on?
Hippocampus
What is the implicit memory used for?
Motor memory for motor skills .e.g. tennis or rules e.g. driving on left
How is implicit memory acquired?
Through repetition
How is short term memory converted into long term memory?
Consolidation through repetition
What does consolidation require?
Attention, hence why it is difficult to learn when tired
What does memory recall depend on?
Significance of an event
Which parts of the limbic system assess the significance of an event?
Frontal cortex and associated reward/punishment centres
Name the points of the Papez circuit.
Hippocampus -> mammillary bodies -> anterior thalamus -> cingulate gyrus
and then back to hippocampus etc.
What is Korsakoff’s syndrome?
Chronic alcoholism
Which vitamin deficiency is seen in Korsakoff’s syndrome?
Vitamin B1
What does the deficiency in Korsakoff’s syndrome lead to?
Damage of limbic system structures and the ability to consolidate a memory is impaired
What happens in Alzheimer’s?
Severe loss of cholinergic neurons throughout the brain, leading to gross memory impairment
Which type of sleep is important for memory?
REM sleep
