NEURO: Learning and Memory Flashcards
What is the difference between learning and memory?
LEARNING: acquisition of new information
MEMORY: retention of learned information
What are the different types of memory?
DECLARATIVE MEMORY (EXPLICIT): facts and events [hippocampus]
NON-DECLARATIVE MEMORY (IMPLICIT): procedural memory (motor skills, habits) [striatum]
What are the different types of declarative and non-declarative memory?
Declarative memory involves the medial temporal lobe and the diencephalon, and stores:
- facts
- events
Non-declarative memory stores:
- procedural memory: skills and habits (involving the striatum)
- classical conditioning in the skeletal musculature (involving the cerebellum)
- classical conditioning in emotional responses (involving the amygdala)
What are the different types of declarative memory?
WORKING MEMORY:
- temporary storage, lasting seconds
SHORT-TERM MEMORIES:
- vulnerable to disruption
- facts and events stores in short-term memory
- subset are converted to long-term memory
LONG-TERM MEMORIES:
- recalled months or years later
What is memory consolidation?
It is the process of converting short-term memories to long-term memories.
It involves the medial temporal lobes.
What part of the brain is involved in working memory?
The prefrontal cortex is involved with working memory.
Other functions of the prefrontal cortex include:
- self-awareness
- capacity for planning
- problem solving
Other brain regions are involved, for example, the lateral intraparietal cortex neuron response in the delayed-saccade task.
Where is memory stored?
Memory is stored in the engram, which is a collection of neurons which, when they act together, they store a memory.
Describe information flow through the medial temporal lobe.
We get sensory information coming in to our cortical association areas. This send the information through to the parahippocampal and rhinal cortical areas. This finally gets forwarded to the hippocampus.
Via the fornix, the information is sent to the thalamus and the hypothalamus. The hippocampus also relays back to the cortical association areas.
What is amnesia?
Amnesia is the serious loss of memory and/or ability to learn.
CAUSES: concussion, chronic alcoholism, encephalitis, brain tumour, stroke
Describe the relationship between spatial memory and place cells.
Via animals learning the Morris water maze, we know that learning to do with spatial memory requires the hippocampus.
The place cells will fire when the animal is in a specific place. The place fields are dynamic.
What are the two models of memory consolidation?
STANDARD MODEL OF MEMORY CONSOLIDATION:
- information from the neocortex areas associated with sensory systems is sent to medial temporal lobes for processing
- synaptic consolidation, systems consolidation
- for post consolidation, the hippocampus is not necessary
MULTIPLE TRACE MODEL OF CONSOLIDATION:
- hippocampal involvement is continued
- there are multiple memory traces
These models are dependant on synaptic plasticity – ‘the biological process by which specific patterns of synaptic activity result in changes in synaptic strength’.
Describe how the engram enables us to learn something.
In the beginning, we have the cell assembly of neurons with reciprocal connections between them.
There is the activation of the cell assembly by a stimulus. The reverberating activity continues activation after the stimulus is removed.
Hebbian modification strengthens the reciprocal connections between neurons that are active at the same time. The strengthened connections of the cell assembly contain the engram for the stimulus.
After learning, partial activation of the assembly leads to activation of the entire representation of the stimulus.
Describe the model of distributed memory.
Instead of memory of a face being stored in one neuron, the information is stored across multiple neurons, meaning that each of them is partially responsible for the recognition of the face.
It can also explain when, when we lose some neurons, we don;t necessarily lose all our memories associated with the neurons, as there are others with the information stored.
How does information travel through the hippocampus?
Information from the entorhinal cortex enters the perforant pathway , which synapse onto the granule cells. These synapse onto Schaffer collaterals, which synapse onto C1 motor neurons.
Describe the mechanisms of long term potentiation in CA1.
Glutamate receptors mediate excitatory synaptic transmission (AMPA [initially] and NMDA receptors).
Structural changes following LTP include dendritic growth.
