Learning/Memory and Reward, dopamine, and addiction Flashcards
learning
process of encoding new information
memory
the newly encoded information ⇒ formalizing with physiological and biological change
- Can be stored/present in the brain across short seconds to long years over timescales
- The expression of learned memories allows for new behavior, decision making, and adaptation
long term potentiation (LTP)
strengthening of synaptic connections (potentiation) as a consequence of repeated activation
- Cells that fire together wire together
- Initially discovered in rabbit hippocampus
what does balance of synaptic strengthening/weakening across brain regions reflect?
the storage and decay of information during learning and forgetting
what is memory consolidation necessary for? When does it happen?
stability; sleep
what does LTP stimulate?
an input neuron and get output activity
components of LTP? (5)
- LTP is a change in the baseline strength of a synaptic connection
- Durability depends on how the stimulus is induced ⇒ most often it is not permanent for a given synapse
- The collective cells underlie learning
- There are also depressions across synapses after the experience
- You can demonstrate an increase in the connection strength
how does repeated activation change neurons? (3)
- morphology
- membrane receptor makeup and concentration
- gene expression
how does morphology change from repeated activity of neurons?
If the protrusions change in shape/multiply at the synapse this can change morphology of neurons in striatum
what does morphology refer to?
dendritic spines/synaptic contact points
how does membrane receptor makeup and concentration change from repeated activation?
The pre learning state has less vesicles and less receptors but after LTP both are increased
- Neurotransmitter release
- Neurotransmitter receptors
how does gene expression change from repeated neural activation?
epigenetics or gene alterations
Non-declarative/Procedural memory
automatic, motor, and skill based learning ⇒ sequences of action we engage in a lot
- Also things with background associations such as pavlovian
Nondeclarative types of memory (3)
- Skills and habits ⇒ basal ganglia, cerebellum, neocortex
- Emotional associations ⇒ amygdala
- Adjusting reflexes ⇒ cerebellum
declarative memory
what and where memories that are explicit ⇒ encyclopedia information
types of declarative memory?
- episodic
- semantic
episodic memory
remembering events
- Autobiographical
- Spatial
semantic memory
knowing facts
what lobe is involved in declarative memory?
the medial temporal lobe
associative learning
pavlovian conditioning and operant conditions results in non declarative or implicit memories
- Forming unconscious associations and expectations about the world
- Procedural memories ⇒ motor plans and skills
HM
treated for temporal lobe epilepsy with a bilateral lesion of part of his medial temporal lobe
- removal/disconnection of the hippocampus and amygdala
what happened after HM’s surgery?
He was unable to form new declarative memories after ⇒ facts, events, people
which memories were intact after HM’s surgery?
Procedural memories were intact (aka motor memories)
what happens when people without declarative memory are repeatedly asked to draw a star?
- The same people can do a procedural task where they draw lines between the two stars and stay in between the lines
- After multiple days of working on this they get better at it even though they don’t remember doing it prior