Download Learning and Memory (Chapter 12). Lecturer

Lecture 18 (Nov 24th): LEARNING & MEMORY #1
Lecture Outline
This Lecture: Psychology of Memory and Brain Areas Involved
Next lecture: Neural Mechanisms for Memory
1) Psychology of Memory:
Short Term Memory vs. Long Term Memory
Explicit Memory vs. Implicit Memory
2) Types of Explicit and Implicit Memory
(and involved brain areas/mechanisms)
4) Role of Hippocampus in Memory
PSYCHOLOGY of Memory
Some Memory Terms:
Encoding: processing new information into a form that can be stored
Storage: maintaining a memory
Recall: to bring back to mind, to retrieve
Recognition: to perceive something as previously known, it is “familiar”
Short Term Memory (STM) vs. Long Term Memory (LTM)
STM: memory for things that just happened
limited storage 7 items (+/- 2)
LTM: memory for things that do not currently occupy your attention;
they must be recalled or recognized
Permanent memories require:
STM -> consolidated -> LTM
LTM: Explicit Memory vs. Implicit Memory
Explicit: memory for events or facts
1) Semantic memory
2) Episodic memory
Implicit: memory that does not require recollection of specific
events or facts, yet affects our behavior
1) Procedural Memory
2) Priming Effects
3) Conditioned Responses
Psychology of Memory
Memory
STM
LTM
Explicit
Episodic
(events)
Semantic
(facts)
Implicit
Procedural
Priming
Conditioned
Responses
Psychology of Memory
Memory
STM
LTM
Explicit
Episodic
(events)
Semantic
(facts)
Implicit
Procedural
Priming
Conditioned
Responses
LTM: Explicit Memory
Semantic: facts that can be stated, things that you “know”
Episodic: memory for events that you’ve experienced, things that
you “remember”
Video – Anton Ego Episodic
Memory
Psychology of Memory
Memory
STM
LTM
Explicit
Episodic
(events)
Semantic
(facts)
Implicit
Procedural
Priming
Conditioned
Responses
Psychology of Memory
Memory
STM
LTM
Explicit
Episodic
(events)
Semantic
(facts)
Implicit
Procedural
Priming
Conditioned
Responses
LTM: Implicit Memory
Procedural memory: procedures, motor skills, habits
Mirror Drawing
Tower of Hanoi
LTM: Implicit Memory
Procedural memory: procedures, motor skills, habits
Mirror Drawing
Tower of Hanoi
Psychology of Memory
Memory
STM
LTM
Explicit
Episodic
(events)
Semantic
(facts)
Implicit
Procedural
Priming
Conditioned
Responses
LTM: Implicit Memory
Priming: exposure to one stimulus influences response to
another stimulus
LTM: Implicit Memory
Priming: exposure to one stimulus influences response to
another stimulus
DEMOS
Mot_____
Str_____
Thr_____
Win_____
Psychology of Memory
Memory
STM
LTM
Explicit
Episodic
(events)
Semantic
(facts)
Implicit
Procedural
Priming
Conditioned
Responses
LTM: Implicit Memory
Conditioned Responses
A) Operant Conditioning:
1) Reinforcement-> increase the likelihood of behavior X
i) positive: “if you do X, I’ll give you candy”
ii) negative: “if you do X, I’ll stop hitting you”
2) Punishment -> decrease the likelihood of behavior Y
i) positive: “if you do Y, I’ll hit you”
ii) negative: “if you do Y, I’ll stop giving you candy”
LTM: Implicit Memory
Operant Conditioning
LTM: Implicit Memory
Conditioned Responses
A) Operant Conditioning: “If you do this, I'll do that”
B) Classical Conditioning: uses “natural”, automatic response
“When I do this, you'll do that”
Developed by Ivan Pavlov, Nobel Prize 1904
After
During
Before
Classical Conditioning
Unconditioned Unconditioned
Neutral
Stimulus (UCS) Response (UCR) Stimulus
Neutral
Stimulus
Conditioned
Stimulus (CS)
Unconditioned
Stimulus (UCS)
No Conditioned
Response
Unconditioned
Response (UCR)
Conditioned
Response (CR)
Donald Hebb (1950s): Learning/Training is an increase in
connectivity between neurons as a result of simultaneous activity in
those neurons (“Hebbian” Mechanisms) (more next lecture)
So, let’s use Hebbian Mechanisms to explain Pavlov’s Dog!
Training
Strong
connection
CR
Classical Conditioning
Psychology of Memory
Memory
STM
LTM
Explicit
Episodic
(events)
Semantic
(facts)
Implicit
Procedural
Priming
Operant
Conditioned
Responses
Classical
Role of the Hippocampus in Memory
Human Hippocampal Damage -> Memory Loss (“Amnesia”)
-But what types of memory loss?
Role of the Hippocampus in Memory
Control
Patient HM
Patient EP
Patient HM: surgical removal of hippocampus and some
surrounding structures (like amygdala)
Patient EP: medial temporal lobe damage caused by viral
encephalitis (including all of hippocampus)
(Corkin et al., 1997; Stefanacci et al., 2000)
Role of the Hippocampus in Memory
Symptoms following Hippocampal damage:
Video: Patient EP Memory Tests
Role of the Hippocampus in Memory
Symptoms following Hippocampal damage:
-Cognitive ability? Intact (except for memory)
-STM? Intact
-LTM?
-Implicit memory?
Intact
Role of the Hippocampus in Memory
Symptoms following Hippocampal damage:
-Cognitive ability? Mostly intact (except for memory)
-STM? Intact
-LTM?
-Implicit memory? Intact
-Explicit memory? IMPAIRED
% Recall
control
time of
diagnosis
patient
Year
Role of the Hippocampus in Memory
Symptoms following Hippocampal damage:
-Cognitive ability? Mostly intact (except for memory)
-STM? Intact
-LTM?
-Implicit memory? Intact
-Explicit memory? IMPAIRED
Two Additional Classifications of Memory
-Anterograde Memory: memories formed after the injury
IMPAIRED
-Retrograde Memory: memories formed prior to injury
PARTIALLY IMPAIRED (can remember OLD memories)
Role of the Hippocampus in Memory
So what does this say about the function of the hippocampus?
-Involved with explicit LTM
-NOT where memories are stored
(partial retrograde amnesia –> OLD memories intact)
-NOT always necessary for recall
(partial retrograde amnesia -> can recall OLD memories)
-Involved with encoding or consolidation? Seems so!
(can explain both anterograde amnesia and partial retrograde
amnesia)
BRAIN INJURY
retrograde
anterograde
consolidation
TIME
The Role of the Hippocampus in Spatial Memory
Water Maze
Task
Hippocampal Lesions in Rats:
- Lose ability to learn new platform locations in the
watermaze (suggests hippocampus is necessary to
form new spatial memories)
-Lose all memory for platform locations formed
before hippocampal damage – complete retrograde
amnesia (suggests that this is where the spatial
memory is stored)
Other Evidence that Rat Hippocampus is Involved
in Spatial Learning
“Place Cells” in Hippocampus have spatial
receptive fields based on sensory cues in
room (O’Keefe & Dostrovsky, 1971)
The Role of the Hippocampus in Spatial Memory
What about the human hippocampus?
Video: Patient EP tested on memory of childhood neighborhood
Spatial memory in the hippocampus is
CONTROVERSIAL!
NEXT LECTURE:
NEURAL MECHANISMS:
Long Term Potentiation
Long Term Depression