Learning And Memory Flashcards
Learning
. Process by which nervous system acquires new info
. Can occur in absence of overt behavior but can only be inferred from changes in behavior
Memory
. Mechanism for storage and retrieval of new info
Non-associative learning
. Exposed once or repeatedly to a single type of stimulus
. Habituation and sensitization
Classical conditioning
. Pairs a neutral stimulus (novel stimulus) w/ a second stimulus (unconditioned stimulus)
. Unconditioned stimulus reliably elicits a respons (unconditioned response)
. Repeated pairing of novel stimulus and unconditioned stimulus result in novel eliciting unconditioned response (now conditioned response)
Operant conditioning
. Delivery of reinforcing stimulus contingent on expression of designated behavior
. Law of effect: behaviors that are rewarded tend to be repeated, behaviors that are punished are usually not repeated
positive Reinforcement
. Inc. freq. of behavior by presenting good stimulus following behavior
Negative reinforcement
. Inc. freq. of behavior by removing an aversive stimulus following the behavior
Positive punishment
. Dec. freq. of behavior by presenting aversive stimulus
Negative punishment
. Dec. frequency of behavior by removing good stimulus following behavior
Social learning/modeling
. New responses acquired through observation and imitation of role models
. Through this individuals develop understanding of social consequences of behavior that leads to new patterns of behavioral expression and self-regulation
Cognitive behaviorism
. Learner develops cognitive map that influences subsequent learning and performance
. Gives person expectation of rewards or punishment and the kind of responses appropriate in social situations
Explicit memory
. Storage and retrieval of material that is available to consciousness and can be expressed by language
. Subtypes: episodic, semantic (factual), autobiographical, and spatial memory
. Recall is by a deliberate conscious effort
. Acquired through processing in 1+ of the 3 polymodal association cortices (parieto-occipital-temporal cortices) that synthesize visual, auditory, and somatic info
. From there info is conveyed to parahippocampal and peririhinal cortices and then entorhinal cortex, hippocampus, then back to neocortical areas for storage
Implicit memory
. Memory not in consciousness
. Procedural
. Builds up slowly through repetition over many trials and is expressed primarily in performance and not words
. Memory acquired through fear is from amygdala
. Memory from operant conditioning is from striatum and cerebellum
. Memory from classical conditionings sensitization, and habituation changes sensory and motor systems involved in learning
Sensory memory
. Routine ability to hold ongoing experiences in mind for fractions of a second
. Usually it does not reach level of consciousness
. Provides an ongoing sense of the present
. Subliminal advertising utilizes this
Short term memory
. Hold in consciousness for seconds to minutes once present moment has passed
. Items must be rehearsed so they don’t leave consciousness
Max capacity for remembering relatively meaningless info is 7-9 items
. Most info in short term memory is lost
Intermediate term memory
. Transition btw short-term memory and long-term memory
. Items can be retained for a few hours but may not reach permanency of long term memory
Long term memory
. Retention of info in permanent form of storage for days, weeks, or longer
. Items acquired, dropped from consciousness, and then recalled some time later
What is key to memorization?
Concentration
Potential causes for forgetting
. Lack of need . Lack of interest . Lack of motivation . Lack of attention or concentration . Lack of organization
Reverberating circuits
. Possible mechanism for short-term memory is ongoing neural activity that is maintained by excitatory feedback connections btw neurons
. If all neuronal activity is temporarily stopped, memories represented by reverberating circuit will be permanently lost
Habituation in aplysia
. Reduced behavioral response to a repeated non-noxious stimulus
. Caused. By dec. Ca channel activity in presynaptic cells which acts to dec. NT release
Sensitization in aplysia
. Enhanced response to a repeated intense stimulus
. Acts through second messenger system to inc. Ca channel activity in presynaptic cell which enhances NT release
What is responsible for long term memory
. Permanent physical changes in nervous system
. Formation of new synaptic connections, altered NT synthesis and changes in pre or post-synaptic membranes cause of this
. May involve altered protein expression
Long term potentiation.
. Patterns of synaptic activity that produce long-lasting inc. in synaptic strength
. Last for days to weeks
. Prevalent in hippocampus
. Involves changes in both presynaptic and postsynaptic neurons at a given synapse
Long term depression
. Patterns of synaptic activity yeast produce long-lasting dec. in synaptic strength
Long term potentiation and depression contribute to ___
Synaptic plasticity
Complementary actions of long term potentiation and depression are mediated by ___
. Different intracellular signal transduction pathways
. May reversible affect synaptic efficiency by acting at a common neuronal site
Changes presynaptically in long term potentiation
. Enhancement of transmitter release
What occurs postsynaptically during long term potentiation
. Inc. nu,new or effectiveness of Glu receptors (AMPA and NMDA)
. Induction of LTP depends on an inc. in postsynaptic intracellular Ca conc. Levels through NMDA receptor channels
. Inc. in postsynaptic Ca conc. Activates 2 kinases
. This produces cascade of events that results in altered protein synthesis and relatively permanent changes in synaptic structure
. Rapidly diffusing retrograde messenger (NO) may carry a signal from postsynaptic neuron back to presynaptic terminal
Earliest pathological changes in Alzheimer’s occur in ___
Entorhinal cortex
. Negatively affects explicit memory storage
Parts of brain important in making decision about which thoughts are important enough to be stored
. Hippocampi
. Some thalamic nuclei
Consolidation of explicit memories likely occurs during ___
Sleep
Lesions of medial temporal lobe
. Encompass dental gyrus, hippocampus, and subiculum
. Interfere w/ long-term storage of new memories
. Long term storage of episodic and semantic knowledge occurs in assoc. areas that initially processed sensory info
Working memory
. Short-term memory store in prefrontal cortex that is required for encoding and recall of explicit knowledge
. Temporary storing of info is used to guide future actions
. Refers to the active maintenance of info relevant to an ongoing behavior
People w/ hippocampus lesions
. Difficulties w/ explicit memories, but implicit are intact
People w/ stratum and cerebellum lesions in regard to memory
. Have difficulty w/ implicit memories but can recall facts normally
Most amnesias are due to problems in ___
. Storage
. In cases of damage to certain thalamic nuclei there can be trouble w/ retrieval
Retrograde amnesia
. Inability to remember past
. Loss of short term memories prior to consolidation
. Very long term memories are stored and used still
Anterograde amnesia
. Inability to form new long-term memories
. Due to lesion in temporal lobe (hippocampus)
. Can retain memories prior to trauma/surgery but nothing after
