Memory and Cognition Flashcards
Define cognition
The integration of all sensory information to make sense of a situation, relying on the ability to learn and remember
What is required for learning and remembering to occur
Motivation
What allows memory and cognition to work together
Ability of central neurons to adapt their neuronal connections in responses to “learning” experiences
What areas of the cerebrum allows the process of cognition to occur
The association areas
What are the three components of the brain required for learning and memory
The hippocampus
Cortex
Thalamus
What is the function in hippocampus in cognition
Formation of memories
What is the function of the cortex in cognition
Storage of memories
What is the function of the thalamus in cognition
Searches and accesses
What does the limbic system do thats essential for memories to be formed
Gives emotional significance
Why does the limbic system have connections with the temporal and frontal lobes
which allow us to make sense of situations through learning
What is the 4 distinct areas of the limbic system
Cingulate gyrus
Hippocampus
Amygdala
Hypothalamus
What is the function of the cingulate gyrus
Plays a role in emotion
What is the function of the amygdala
involved in emotion and memory
What does the hypothalamus from a link between
Emotion and autonomic NS response
What drives our consciences and instinct behaviour
The seeking of reward and the avoiding of punishment
Stimulation of what areas in the limbic system makes a memory significant to be remembered
Electric stimulation of reward or punishment areas
Where does all sensory information go first in the limbic system
The hippocampus which is essential for the formation of memories
What occurs in bi-lateral hippocampal damage
Patients have immediate (sensory) memory (seconds in length) and intact long-term memory (from time before damage), but are unable to form new long-term memories
What is the affect of bilateral hippocampal damage on motor skills
The reflexive (motor memory) remains intact
What is the 4 divisions of memory
Immediate memory
Short term memory
Intermediate long term memory
Long term memory
What is immediate memory
Describes the ability to hold experiences in the mind for a few seconds
What decays faster visual or auditory memories
Visual memories decay fastest (<1s), auditory ones slowest (<4s).
How long does short term memory last and what is it used for
seconds - hours
Often called Working Memory as performs tasks such as dialling a phone number, mental arithmetic, reading a sentence etc
How long does intermediate long term memory last
hours to weeks e.g. what you did last weekend
What memory can be life long
Long term memory
Why is short term memory a electrical phenomenon
It depends on maintained excitation from reverberating circuits
What occurs in reverberating circuits in short term memory
On a constant positive feedback loop, as brief excretory stimulus will cause long lasting neuronal activity, as the revertebraing circuit neurones will continue to excite all the neurones in the pathway
How does short term memory convert to long term memory
Repeated reverberation circuit results in consolidation of memory to long term memory storage
What happens if memory is deemed insignificant
Reverberation fades and no consolidation occurs
What occurs if reverberation is disrupted
Amnesia - memory loss
What is the likely cause of reverberation disruption
following a head injury or infection, especially if it involves the hippocampus and/or thalamus
What is the two types of amnesia
Anterograde – cannot form new memories
Retrograde – cannot access (more recent) old memories
Why would a person with retrograde amnesia remember an events from years and years ago but cant remember what happens in the events leading up to the injury
As the memories from long time ago are better rehearsed and deeper ingrained
Both types of amnesia are usually present but when would only retrograde amnesia be present
If the thalamus is damaged and the hippocampus spared due to the thalamus not being able to search fro existing memories
What changes occur in intermediate long term memory and what does this cause
Chemical changes in presynaptic neurons:
leads to an increase in Ca++ entry to presynaptic terminals to increase neurotransmitter release
What changes occur in long term memory
Structural changes at the synapses
What are the three potential structural changes occurring at the synapse in Long term memory
Increase in NT release sites on presynaptic membrane.
Increase in number of NT vesicles stored and released.
Increase in number of presynaptic terminals
What is often observed in the post-synaptic cell in the formation of long term memory
Increased amplitude in graded membrane potential = Long term potentiation
What is the purpose of Long term potentiation
Strengthens the synapse and forms the basis of learning and memory
What is unique to each particular memory in the long term memory
Well rehearsed pattern of neuronal firing
What is the two main types of long term memory
Declarative/explicit memory
Procedural/reflexive/implicit
Where is declarative memory usually based
The hippocampus
What is decorative memory
Abstract memory for events (episodic memory)
and for words, rules and language (semantic memory).
What is procedural memory
Motor memory for acquired motor skills
How is procedural memory usually acquired
acquired slow through repetition
What occurs if you think about procedural memories
Impairs performance
Where is procedural memoires usually based
The cerebellum
What is procedural memories independent of
The hippocampus
Define consolidation
Selective strengthening of synaptic connections through repetition
What does memory exist as during consolidation process
Electrical activity
Memory can easily be wiped during consolidation, therefore what does it require for long term memories to actually form
Attention
What asses the significant of an event in short term memory
Frontal cortex and its association areas and the reward/punishment areas in the limbic system
How and where are new memories stored
New memories are coded and stored in the association areas of the cortex along with other existing memories the brain deems similar
What process allows a memory to stay within long term memory until consolidation process is complete
The frontal cortex gating memory into papez circuit
What is papez circuit made up of
Cingulate gyrus
Hippocampus
Mammillary bodies
Anterior thalamus
Where are different components of memory laid down in the long term memory
Long term memory stored in relevant cortex
What recalls long term memories
Multiple associations - memories have strong emotional component to them
Why are smells an especially powerful in evoking long term memorys
Olfactory stimuli are relayed from the olfactory tract through the amygdala and hippocampus to the prefrontal cortex where they can be acknowledged,
so pass continually through limbic system
Why in Korsakoffs syndrome is the ability to consolidate memory impaired
As the chronic alcoholism leads to Vitamin B1 deficiency which leads to damage of limbic system structures
How does alzheimers disease cause gross impairment of memory
due to severe loss of cholinergic neurons throughout the brain
What is the link between REM sleep and memory
Dreaming may enable memory consolidation, reinforce weak circuits
as subjects deprived of REM sleep show significant impairment of memory consolidation for complex cognitive tasks
What affect does Korsakoffs syndrome or alzheimers have on REM
Reduces REM sleep
cholingeric neurones responsible for REM
