Test 3: Learning and Memory Flashcards
What is learning?
A relatively permanent change in Bx produced by experience.
• Learning involves changes in the nervous system
produced by experiences
• Nervous system changes are physical
• Learning allows us to adapt our behaviors to the
environment
• Learning involves interactions among the motor,
sensory, and memory systems
What are the different forms of learning?
- Perceptual
- Motor
- Stimulus response
- Implicit
- Relational
Perceptual learning
Identify objects and situations
Motor learning
Forming new circuits in motor system
Stim-Response learning
Making a response when a particular S is present (classical cond and operant cond)
Know relationship of perceptual and motor learning slide
Know relationship of perceptual and motor learning slide
Relational Learning
Involves connections between individual S. Includes spatial learning, episodic learning, and observational learning.
What area of the brain does priming take place in?
Neocortex
What area of the brain does procedural (skills and habits) take place in?
Striatum
What area of the brain does associative learning (classical and operant cond) take place in?
Emotional R-amygdala
Skeletal musculature-cerebellum
What area of the brain does nonassociative learning (habituation and sensitization) take place in?
Reflex pathways
What is habituation?
- Simplest form of implicit learning
- Over repeated exposures, animal ignores S
How does habituation happen?
- Glutamatergic sensory neurons synapse on interneurons and motor neurons
- Reduced number of transmitter vesicles released from presynaptic terminals of sensory neurons (don’t know why)
Sensitization
Firing of other neurons causes an exaggerated response. (Other neurons prevent the main neuron from ceasing to fire). Other neuron prevent K+ channels from opening; Ca2+ channels stay open; cell will continue to release NT (stay deporlarized).
Inner neuron–> sensory neuron
Neuronal Plasticity
The Hebb Rule: synapses that are active at the same time that the postynaptic neuron fires are strengthened over time. This implied that repeated neural activity will produce physical changes int he nervous system
Benefits of enriched environments in rats
- Thicker cortex
- More glial cells
- More AChE (perhaps more ACh)
What does long-term potentiation (LTP) involve?
- Rapid stimulaion of the perforant path; rapid pulses lead to summation of postsynaptic potentials
- Activation of synapses and depolarization of the postsynaptic membrane
How does LTP happen?
- NMDA receptor controls a calcium channel which is blocked by Mg2+ ions
- Mg2+ ions are ejected from the Ca channel when the membrane is depolarized
- Opening the Ca channel requires via activation of NMDA receptors require the presence of glutamate and a depolarized membrane
LTP may result from:
- Increased number of new AMPA receptors during stimulation
- Alternation of synaptic structure
- -The dendritic spines form “perforated” synapses with the presynaptic terminals
- -Structural changes depend on entry of Ca ions and on the calcium kinase
- Activation of NMDA receptors that increases the activity of nitric oxide (NO)
- -NO diffuses into presynaptic terminals and may increase glutamate release from the presynaptic terminal
- -Drugs that block the synthesis of NO block the establishment of LTP in hippocampal slices
TLDR version of “LTP may result from:”
- Increased glutamate release?
- NMDA/AMPA receptors
- Ca entry into dendritic spine. CaM-KII activity
- NO feedback into presynaptic cell
Visual perceptual learning: Ventral stream vs dorsal stream
Dorsal: where an object is
(visual cortex–>posterior parietal cortex)
Ventral: what an object is
(visual cortex–>inferior temporal cortex)
Which NT plays a critical role in SR?
Dopamine
Two DA “systems”
Mesolimic DA system: ventral tegmentum to accumbens, amygdala, septum
Mesocoritcal DA system
What are three components necessary for relational learning?
- Short-term memory
- Long-term memory
- Consolidation-process by which rehearsal of info in STM results in transfer to LTM
What are the three parts of working memory (STM)?
- Rehearsal loop (Broca’s area and auditory association cortex during rehearsal of consonants)
- Visuospatial sketchpad
- Executive control system-handles limited amount of info that people can juggle at one time as they engage in reasoning and decision making
Two broad types of long term memories:
Non-declarative memory (implicit)
-Stim-Resp and motor memories that control Bx at an unconscious level
-memory for actions, skill, and operations
Declarative memory (explicit)
-memories that are available as facts, events, or specific S
What are the two types of declarative memory (explicit)?
Episodic memory-recollection of personal experiences
Semantic memory-general knowledge
Where is explicit memory stored?
In association cortices (visual info store in the visual association cortex)
Where is semantic knowledge stored?
In a distributed fashion in the neocortex.
-Left inferior prefrontal cortex for word knowledge
-Left temporal lobe important for the retrieval of object names
(These are subdivided by categories.)
Where is episodic knowledge about time and place stored?
The association areas of the prefrontal cortex. Could also be medial temporal, anterior temporal, or diencephalic regions
Amygdala’s role in memories
Can modulate declarative memories on the basis of emotion
Where are motor skills stored?
Basal ganglia, cerebellum, motor cortex, visual cortex, striatum, thalamus, frontal cortex
Where is repetition priming stored?
Visual cortex, left inferior frontal lobe, medial temporal lobe
Where is classical conditioning stored?
- Fear conditioning-Amygdala
- Skeletal musculature conditioning-cerebellum
Hippocampal formation includes:
- Dentate gyrus
- CA fields of the hippocampus
- Subiculum
- Hippocampus is crucial for the formation of new memories*
Hippocampal function is needed for several types of mental processes
Relational learning, navigation, forming new memories
Hippocampal Place Cells
Individual pyramidal cells within the hippocampus are sensitive to spatial location (of a rat)
Which NT is highly important to the hippocampus’s function?
ACh
Amnesia
Failure to remember. Can be temporary or permanent
Anterograde amnesia
a difficulty in forming new memories for events that occur after a brain trauma
- Disorder of relational learning
- difficulty in learning new material
Retrograde amnesia
Inability to recall events that occurred prior to the trauma
Severe anterograde amnesia follows what?
Bilateral damage to the hippocampus
Korsakoff’s Syndrome
- Severe form of anterograde amnesia associated with chronic alcoholicsm.
- Symptoms: Severe anterograde amnesia and confabulation (person unknowlingly creates fictitious memeories.
- Thiamine deficiency produces brain damage
- damage to diencephalic structures, including mammillary bodies and the thalamus
