Learning and Memory Flashcards
What is procedural memory?
Skills and habits that have been used so much they are automatic; also known as implicit memory, non-declarative memory, reflexive memory
What structures are involved with procedural memory?
Cerebellum (motor skills) and nucleus accumbens (non-motor)
What is declarative memory?
Conscious recognition/recollection of learned facts and experiences and is subdivided into episodic (memory of events) and semantic (memory of words, language, and rules); also known as explicit memory
How long is short-term memory?
Seconds to hours
How long is long-term memory?
Years
How long is working memory?
Recalling a fact/memory for use - it may be a subset of short-term memory
What is plasticity?
Alterations in the CNS based on use; may be synaptic function that’s altered; may be changes in the physical structure of the neurons; more synapses and new branches to new cells
Plasticity has different forms. What forms are considered changes in synaptic functioning? What forms are considered changes in the structure of the neurons?
Changes in synaptic functioning: post-tetanic potentiation and long-term potentiation
Changes in structure of neurons: gain/loss of synapses, structural changes in dendrites, structural changes in the soma of the neuron
Under what conditions does post-tetanic stimulation occur?
Brief, high-frequency discharge of presynaptic neuron; produces an increase in neurotransmitter release that lasts about 60 seconds; increases probability of action potentials in post-synaptic cell
What is the mechanism of post-tetanic stimulation?
High level of stimulation allows more calcium to enter to the terminal than could be “dealt” with, leading to greater neurotransmitter release and a greater probability of action potentials in the post-synaptic cell
What is long-term potentiation?
Series of changes in the pre- and post-synaptic neurons of a synapse which leads to increased response to the released neurotransmitter; usually follows strong stimulation
What is neuronal plasticity?
Also associated with gene transcription related to increased CREB in both pre and post-synaptic cells; proteins produced include NT synthetic enzymes, NT receptors, and proteins required for growth/synapse formation
What does CREB cause?
Changes in synapse structure (permanent) and creation of new synapses via protein synthesis
What are the 4 steps for creating declarative (explicit) memories?
1) Encoding
2) Storage of information
3) Consolidation
4) Retrieval
What is encoding?
Attending to new info (focus, attention), linking it to previous memories; emotion is important component
What is the storage of the information step for creating a memory?
Retention of information over time; this is short-term memory
What structures function in short-term memory?
Hippocampus, parahippocampal cortex, prefrontal cortex; there are also interconnections to the neocortex and amygdala via the nucleus basalis of Meynert (cholinergic projection, a particular target of Alzheimer’s disease)
How is short-term memory created physiologically?
Long-term potentiation
What is consolidation of memory formation?
Process of making a memory permanent; involves physical changes in synaptic structure
What structures function in consolidating a memory from short to long-term?
Requires hippocampus, temporal lobes, Papez circuit
What is the mechanism for consolidating a memory from short to long-term?
Memory is repeatedly sent through Papez circuit, thus setting up the conditions required to induce LTP and neuronal plasticity, back to the cortex; eventually, limbic system is not required for access to the memory
What is the retrieval step for creating a memory?
Recalling or using the memory; bringing it into working memory; can be modified/lost at this point
What structures are involved in reassembling a memory?
Neocortex, parahippocampal regions, hippocampus
What is the pathway for retrieving a memory?
Information related to each component of the memory is sent to the parahippocampal regions; those components are sent to the hippocampus, where the entire memory is “reconstructed”; information then travels back through the parahippocampus to the cortex
What are the 3 components of the 3-component model for working memory?
Central executive component (prefrontal cortex), phonological loop component (broca’s and wernicke’s), visuospatial loop component (occipital cortex associated with vision)
Where is spatial memory stored?
Detailed memory of space is stored in hippocampus, using special pyramidal cells in CA1 known as place cells; appears this spatial map serves as an “anchor” for the reconstruction of memory
What are place cells?
Neurons that are active only at specific places (and one newly discovered type is especially strongly activated if you got a reward at that place)
What inputs do spatial memory receive?
Grid cells, entorhinal cortex, create a map of a place you are in, grid map, triangular or hexagonal grid, head direction cell, border neurons, others
