Memory & cognition Flashcards
What do association areas of the Brain do
integrate information from multiple sources, rather than being concerned with one specific function
3 key components of the brain needed for learning + memory
Hippocampus
Cortex
Thalamus
Function of hippocampus in regards to learning + memory
Forms memories
Function of cortex in regards to learning + memory
Stores memories
Function of thalamus in regards to learning + memory
Searches and accesses memories
Limbic system gives events … that is essential for memory
Emotional significance
Why is the emotional component of an event important for memory
the more emotion associated with the situation, the more you remember it
Most primitive part of the cortex / ‘old cortex’ is known as what
Limbic system
Limbic system consists of what 4 things
Cingulate gyrus
Hippocampus
Amygdala
Hypothalamus
What is the cingulate gyrus involved in
Emotion
What is the amygdala involved in
Emotion
Function of hypothalamus with regards to learning + memory
link between emotion and autonomic NS responses
Limbic system is responsible for what 2 types of behaviour + what drives these behaviours
Instinctive, e.g. thirst, sex, hunger
Emotive
Driven by seeking reward of avoiding punishment
Punishment areas in the limbic system those that cause
Terror, anger, pain
Reward areas of the limbic system are those that cause
intense feelings of well-being, euphoria and sexual arousa
What parts of the brain assess the significance of an event
Frontal cortex and its association with the reward/punishment centres in the limbic system
Limbic system responsible for selecting what
selecting what experiences are stored in memory
What is the sensory relay station
Thalamus
People with bilateral hippocampal damage are characterised by what (2)
Immediate (sensory) memory - lasts a few secs
Intact long term memory- remember things from before brain damage
People with bilateral hippocampal damage are in a permanent state of what
RETROGRADE + ANTEROGRADE AMNESIA
4 types of memory
Immediate/sensory
Short-term
Intermediate long term
Long term
Immediate/sensory memory lasts how long
Few secs
What memories decay fastest
Visual
Short term memory (or working memory) lasts how long
Secs - hours
Short term memory associated with that circuits
Reverberating circuits
Intermediate long term memory lasts how long
hours - weeks, e.g. what you did last weekend
How is intermediate long term memory associated with chemical adaptation at the presynaptic terminal (2)
Chemical changes in presynaptic neurons - increasing Ca2+ entry to presynaptic terminals –> increasing neurotransmitter release
This strengthens synaptic connection of pre-and-post synaptic neuron because more neurotransmitter release means increased likelihood of exciting post synaptic neurons
Long term memory is associated with what structural changes in synaptic connections (3)
Increase in neurotransmitter release sites on presynaptic membrane.
Increase in number of neurotransmitter vesicles stored and released.
Increase in number of presynaptic terminals
What does long term potentiation involve
Increased amplitude in graded membrane potential (EPSP) in the post-synaptic cell
–>This “strengthens the synapse”
forms the basis of learning and memory
Long term memory is basically a well established, well rehearsed pattern of what
Neuronal firing unique to that particular memory
2 types of long term memory
Declarative (explicit) memory
Procedural (reflexive) memory
Describe declarative (explicit) memory [a type of long term memory]
Abstract memory for events (episodic memory) + words, language (semantic memory)
Declarative/explicit memory relies heavily on what part of brain
Hippocampus
Describe procedural (reflexive) memory
Acquired slowly through REPETITION
Includes motor memory for acquired skills, e.g. playing tennis
Procedural (reflexive memory) [a type of long term memory] is based mainly in what part of the brain
Cerebellum
What does short term memory depend on
Maintained excitation from reverberating circuits
Are synapses in a reverberating circuit excitatory or inhibitory
Excitatory
If the event is deemed significant, reverberation of the short term memory results in what
Consolidation of the memory into long term memory storage
If an event is deemed insignificant, the reverberation of the short term memory…
…fades and is not consolidated into long term memory storage
2 types of amnesia
Anterograde
Retrograde
Define retrograde amnesia (2)
Can’t access memory of events leading up to the injury
Although can recall events that happened a long time ago before the injury
If only the thalamus damaged and hippocampus spared, what type of amnesia would be seen
Retrograde
Suggests thalamus needed for ‘searching’ our existing memory bank
Define anterograde amnesia (2)
Can’t form new memories leading to an inability to recall events that happen after the injury, e.g. may not even remember a question you asked a few secs ago
But long term memories from before the event remain intact
Destruction of hippocampus means what in regards to memories
Permanent inability to form new memories
Short term memory is converted to long term memory through a process called what
Consolidation
What mechanisms does consolidation involve in order to convert short term memory into long term memory (3)
Strengthening of synaptic connections through:
- repetition of the reverberating circuits
- chemical changes in presynaptic neuron
- structural changes in synaptic connections
How long does consolidation take (converting a short term to long term memory)
Hours - days
What does coding of new memories mean
Means they’re stored with existing memories that the brain deems similar then they’re stored in the sensory and associated areas of the cortex
How are memories created from sensory information
1) Sensory input into the somatosensory cortex and the sensory association areas
2) Info is passed onto frontal cortex which assesses significance of the event and passes the info to the limbic system
3) The sensory info then passes through the hippocampus of the limbic system which relays the info to other parts of the limbic system (papez circuit)
4) Limbic system reward/punishment centres assess the significance of the event and decides if it should be stored in memory
5) If deemed significant, this electrical activity then reverberates back to the frontal cortex then to the primary somatosensory cortex and the sensory association areas to be written into long-term memory
6) If experience still deemed significant and useful, the frontal cortex ‘GATES’ the papez circuit
7) Reverberating activity then continues between the Papez circuit, the frontal cortex, the sensory and association areas until the consolidation process of short term into long term memory is complete
If the experience/event is deemed significant, the frontal cortex ‘gates’ what circuit + describe the components of this circuit
Papez circuit
- hippocampus
- mamillary bodies
- anterior thalamus
- cingulate gyrus
Why is sleep important for memory processing
REM sleep is important for memory
-dreaming may enable memory consolidation, reinforce weak circuits
If deprived of REM sleep, what can be impaired
Memory consolidation for complex cognitive tasks
What is Korsakoff’s syndrome + common cause
chronic memory disorder caused by severe deficiency of thiamine (vitamin B1)
commonly caused by chronic alcoholism
Theory behind ‘smells can ring bells’
Olfactory stimuli are relayed via the olfactory tract to the primary olfactory cortex where substantial connections to the amygdala and hippocampus are found
This association with the limbic system, and hippocampus in particular, explains why smells are especially powerful in evoking long-term memories
