Transcript
Learning & Memory
Chapter 12
Learning
Learning the process by which experiences change
the nervous system resulting in changes in behavior
MemoriesChanges in the nervous system and
behaviorNetworksSynaptic plasticity
Learning
Perceptual learning
Stimulus-response learning
Motor learning
Relational learning
Hebbian Learning
Hebb ruleLearning involves
the strengthening of a synapse that is repeatedly active when the post synaptic neuron fires
Classical vs. Operant Conditioning
Classical Conditioning
Unconditioned Stimuli (US)
Unconditioned Response (UR)
Neutral Stimuli (NS)
Conditioned Stimuli (CS)
Conditioned Response (CR)
Operant Conditioning
Target behavior
ConsequenceThe stimuli
Effect on behaviorReinforcePunish
Classical vs. Operant Conditioning
Long-term Potentiation
Long-term potentiation (LTP)A long-term increase in the excitability of a
neuron to a particular synaptic input caused by repeated high frequency activity of that input.
Sensitization
Long-term PotentiationHippocampal formation
Synaptic strengthening occurs when synapses are active while the membrane of the postsynaptic cell is depolarized
Long-term PotentiationAssociative LTPconcurrent
stimulation of weak and strong synapses to a given neuron
strengthens the weak synapses
Receptors
NMDA Receptor
glutamate receptor that controls a calcium channel that is normally blocked by Mg2+ ionsneurotransmitter-
and voltage-dependent ion channel
AMPA Receptor
An ionotropic glutamate receptor that controls a sodium channel; when open, it produces EPSPs.
Long-term Depression
Long-term depression (LTD)
A long-term decrease in the excitability of a neuron to a particular synaptic input
Caused by stimulation of the terminal button while the postsynaptic membrane is hyperpolarized or only slightly depolarized.
Classical Conditioning
Conditioned emotional responses
AmygdalaLateral nucleus
Classical Conditioning
Cerebellum
Lateral interpositus (LIP) nucleus
Timing of brief intervals
>1 second
Instrumental Learning(a.k.a. operant conditioning)
Basal GangliaAlso important
for implicit procedural memories
Instrumental Learning: Reward
Nucleus accumbensReceives inputs from VTA
Ventral tagmental areaDopminergic
Involves memory for current thoughts
DurationRoughly 20 seconds without rehearsalCan be increased by maintenance
rehearsal
Capacity5-9 itemsCan by increased by chunking
Short-Term/Working Memory
Long-Term Memory (LTM)
Relatively permanent memory storage
Believed to have unlimited capacity
Several systems of organization
Episodic vs. Semantic
Non-declarative vs. Declarative
Semantic and Episodic Memory
Semantic memoryFactsWordsGeneral knowledge
Episodic memoryExperiencespersonal events
Procedural vs. Declarative Memory
Procedural memory: Knowing “how”HabitsMotor skillsBasal Ganglia
Declarative memory: Knowing “that”Includes semantic and episodic memory
Declarative vs. Non-declarative Memory
Declarative memoryConscious, EffortfulIncludes semantic and episodic memories
Non-declarative memoryAutomatic, HabitualIncludes perceptual, motor, stimulus-
response memoriesDoes not require hippocampal formation
Amnesia
Typical Presentation of Amnesia
Normal working memory
Severe anterograde amnesia for declarative memoryespecially episodic memories.
Some degree of retrograde amnesiamainly limited to episodic memories.
Better implicit than explicit memory.
Nearly intact procedural memory.
The hippocampal formation
Consolidation of memories
Declarative memories
Spatial Memory
Contextual Memorydetail
Neurogenesis
New neurons more amenable to synaptic plasticity
Relational learning
Korsakoff’s Syndrome
Wernicky-Korsakoff syndrome
Sever thiamine deficiencyB1
Symptoms similar to prefrontal cortex damage apathy, confusion, and memory loss.
hippocampal damage impairment of episodic memory and sparing of implicit
memory.
Confabulations
Alzheimer’s Disease
Plaques & Tangles
Cell Death
top related