Learning & Memory Flashcards
Procedural Memory
- aka implicit memory, non-declarative memory, reflexive memory
- skills and habits that have been used so much they are autonomic
- involves cerebellum (motor skills) and nucleus accumbens (non-motor, habits)
Declarative Memory
- aka explicit memory
- conscious recognition/recollection of learned facts and experiences
- subdivided into two forms: episodic and semantic
Episodic Memory
Memory of events
Semantic Memory
Memory of words, language and rules
How long does Short-Term Memory last?
seconds to hours
How long does Long-Term Memory last?
years
Working Memory
- recalling a fact
- looks like short-term memory
- you’ve learned it and now you are retrieving it for use
Plasticity
- alterations in the CNS based on use
- can be changes in synaptic functioning (post-tetanic potentiation, long term potentiation) or changes in the structure of the neurons (gain/loss of synapses, changes in dendrites, changes in soma of the neuron)
Post-Tetanic Stimulation: Condition
- brief, high-frequency discharge of presynaptic neuron
- produces an increase in NT release that lasts about 60sec
- increases probability of APs in post-synaptic cell
Post-Tetamic Stimulation: Mechanism
brief high level of stimulation allowed more calcium to enter to enter the terminal than could be dealt with; leads to greater NT release and a greater probability of AP in the post-synaptic cell
Long-Term Potentiation
Changes in both pre- and post-synaptic repsonses to NT release so same NT release creates larger response (NMDA reeptors); lasts for hours
CREB
changes in synapse structure (permanent) and creation of new synapses via protein synthesis
Creating Declarative (Explicit) Memories: 4 Step Process
(1) Encoding
(2) Storage of the information
(3) Consolidation
(4) Retrieval
Explicit Memories: Encoding
- attending new info (focus, attention)
- linking it to previous memories
- emotion is an important component
- may require moving from default mode network to salience mode
Explicit Memories: Storage of the Information
- retention of information over time
- initial stage involves formation of short-term memory
Short-Term Memory: Anatomical Structures
- Hippocampus
- Parahippocampal Cortex
- Prefrontal Cortex
also interconnections to the neocortex and amygdala via the nucleus basalis of Meynert (cholinergic projection)
Target of Alzheimers Disease:
Nucleus Basalis of Meynert
Short-Term Memory: Physiological Substrate
LTP (allows us to store information)
Declarative Memory: Consolidation
- process of making a memory permanent
- involves physical changes in synaptic structure
- short-term memory –> long term memory
Brain structures involved in consolidating memory from short- to long-term memory (consolidation):
- Hippocampus
- Temporal Lobes
- Papez Circuit
Where are Long-Term Memories stored?
The area of the cortex related to the modality of the individual components (ex. visual info stored in visual cortex)
Physiology of Consolidation
- requires continued activation of Papez Circuit
- LTP –> papez circuit –> formation of new synapses in associated regions of the brain
Declarative Memory: Retrieval
- recalling or using the memory
- bringing it into working memory
- can be modified/lost at this point
Structures involved in reassembling of Long-Term Memory:
- Neocortex
- Parahippocampal Region
- Hippocampus
Steps of Recalling/Retrieving Memories
(1) PFC decides what information you want to recall
(2) Signal sent to Parahippocampal region
(3) Signal sent to Hippocampus which retrieves what components of the memory the neocortex needs; entire memory reconstructed here
(4) Reconstructed memory from Hippocampus then travels back through the Parahippocampal region to the cortex
The ___ is important in prolonging the life of the cortical “trace” of the memory
Parahippocampus
What are the 3 components of the Working Memory Model?
- Central Executive
- Phonological Loop
- Visuospatial Loop
Working Memory: Central Executive
- Prefrontal Cortex
- Most active when “doing things”
Working Memory: Phonological Loop
- Broca and Wernicke Area
- Provide/interpret the auditory information associated with the memory
Working Memory: Visuospatial Loop
- Occipital Cortex associated with vision
- Provide/interpret the visual information associated with the memory
Place Cells
- Detailed memory of space; neurons that are active only at specific places
- Located/stored in Hippocampus using special pyramidal cells in CAI
- Creates a spacial map that serves as an “anchor” for the reconstruction of memory
Place cells receive inputs from 3 other spatially activated cells:
- Grid Cells
- Head Direction Cell
- Border Neurons
Grid Cells
- Located in Entorhinal Cortex
- Create a grid map of a place you are in
Head Directional Cell
Tells you what direction your head is facing
Border Neurons
Active when near walls or other borders
