1. Introduction to Long-Term Memory
Psychology 355: Cognitive Psychology Instructor: John Miyamoto 04/26/2018: Lecture 05-4
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2. Lecture probably ends here
Outline
Finish discussion of the central executive (part of working memory)
Introduction to long-term memory
HM - a patient with a famous memory impairment
What were his memory problems?
Why did he display a specific pattern of memory abilities and disabilities?
Multi-component model of long-term memory
How do we know that short-term memory and long-term memory are based on different memory systems?
Episodic memory versus semantic memory: How are they different?
Implicit memory - how does it different from explicit (a.k.a. declarative) memory?
Lecture probably ends here
Psych 355, Miyamoto, Spr '18
Summary: Frontal Lobe Damage & Functions of the Central Executive

3. Frontal Lobe Damage & Impaired Functioning of the Central Executive
Central executive controls attention to relevant information and responses. Inhibits irrelevant information and responses.
Frontal lobe damage leads to difficulty inhibiting irrelevant information and responses.
Stroop task, Wisconsin card sort task, face recognition with irrelevant scenes: To respond correctly, you need to inhibit a response. People with frontal lobe damage have difficulty inhibiting tempting but mistaken responses.
People differ in how effective they are at inhibiting irrelevant information. People who are better at inhibiting irrelevant information are better at performing cognitive tasks that require focusing on relevant stimuli.
Psych 355, Miyamoto, Spr '18
Return to Baddeley’s List of Central Executive Functions

4. Baddeley’s List of Functions of the Central Executive
Only partially understood. Very active area of current research.
Alan Baddeley – chief developer of working memory theory (Baddeley calls the theory of the central executive a "ragbag")
Controlling and allocating attention.
Coordinating current activity of working memory with goals.
Task switching. Multi-tasking.
Selection and launching of responses.
Inhibiting associated but inappropriate responses.
Controlling the interface between STM and LTM, especially LTM search & retrieval.
Chunking
Psych 355, Miyamoto, Spr '18
Introduction to Long-Term Memory

5. Outline - Introduction to Long-Term Memory
Reminder: Distinction between STM / WM and LTM
Different types of long-term memory
Explicit versus implicit memory (declarative vs non-declarative memory)
Episodic versus semantic memory
Procedural memory
Associative memory
HM – a famous clinical case
What was HM's main memory problem?
Evidence for distinction between STM & LTM
Evidence for distinction between episodic and semantic memory
Evidence for distinction between explicit memory and implicit memory.
Psych 355, Miyamoto, Spr '18
Picture Showing the STM/LTM Distinction

6. Figure 6.1: Example of the STM/LTM Distinction
Psych 355, Miyamoto, Spr '18
Diagram of Modal Memory Model – Encoding, Retrieval & Consolidation

7. Encoding, Retrieval & Consolidation
Sensory Store
Short-Term Store
Long-Term Store
Retrieval
Encoding
External World
Control Processes
Encoding, Retrieval & Consolidation
This diagram may be misleading because it suggests that information must pass through STM to get to LTM. Not everyone agrees with this assumption.
Encoding – creating an LTM out of currently processed information.
Retrieval – bringing information that is stored in LTM back to STM
Consolidation - creating a strong LTM by repeatedly retrieving and manipulating an LTM; and by associating it with other memories.
Psych 355, Miyamoto, Spr '18
List of Functions That Are Included in LTM

8. LTM Includes .....
Important information about the self and events in the world, but also, ...
Trivial information about what has happened in the recent past,
“Semantic” knowledge, e.g., what is an apple, a pencil; which is bigger, a mouse or a moose; etc.
How to do things: Tie your shoes, drive a car, dial a phone number, cook a meal, ....
Learned associations that are not explicit, e.g., the atmosphere of a dentist’s office makes you feel apprehensive.
Psych 355, Miyamoto, Spr '18
Diagram Showing the Major Components of the LTM System

9. Different Types of Long-Term Memory
Figure Different Types of Long-Term Memory
Declarative memory (explicit memory) – facts, knowledge, images
Non-declarative memory (implicit memory) – non-conscious memory that is expressed through change in behavior; it doesn’t necessarily include conscious recollection.
Psych 355, Miyamoto, Spr '18
Intro to HM

10. HM – A Famous Clinical Case
HM – initials of a man See links to his biography on the Psych 355 website.
Intractable epilepsy.
August 25, 1953: Medial temporal lobes (left and right) were surgically resectioned to treat his epilepsy. Removal of the hippocampus.
Following surgery, HM had much milder symptoms of epilepsy, but ...
... he was found to have severe problems with memory. .
Psych 355, Miyamoto, Spr '18
Where is the Hippocampus?

11. Where is the Hippocampus?
HM underwent bilateral removal of much of the hippocampus, amygdala and surrounding medial temporal cortices.
This slide is based on instructional material that was downloaded from the Pearson Publishers website ( for Smith & Kosslyn (2006; ISBN ).
Amygdala
Hippocampus
Schematic head facing up. Hippocampi are in red.
Psych 355, Miyamoto, Spr '18
HM’s Memory Problem

12. HM’s Memory Post-Surgery
HM could carry on a conversation, understand current situations.
Severely impaired memory for any events occurring after brain injury. (Severe anterograde amnesia)
Some impaired memory for events occurring before injury. (Some retrograde amnesia)
Could learn new skills like sewing.
Could learn some new semantic information, e.g., his brain surgery was in 1953, but he learned that there was a president named Kennedy who was assassinated.
Psych 355, Miyamoto, Spr '18
Diagram Showing Multiple Memory Systems

13. Episodic & Semantic Memory
HUMAN MEMORY
SHORT-TERM MEMORY
Psych 355, Miyamoto, Spr '18
Memory Terminology – Including Types of Amnesia

14. More Memory Terminology
Discussed on Earlier Slide
Explicit memory (declarative memory)
Episodic memory - memory for personal experiences
Semantic memory - memory for facts
Implicit memory (non-declarative memory)
Priming – exposure to one stimulus can affect ability to perform a cognitive task.
Procedural memory - memory for how to do things, e.g., how to type at a computer.
Associative and non-associative learning
Amnesia
Anterograde – amnesia for events occurring after brain injury.
Retrograde - amnesia for events occurring before brain injury.
Back to HM’s Memory Problems
Psych 355, Miyamoto, Spr '18

15. HM's Memory Problems
Anterograde amnesia – very severe; he could not form new permanent episodic memories.
Retrograde amnesia – very severe for preceding 4 days; some impairment up to 11 year preceding.
Retrograde amnesia was temporally graded, i.e., less amnesia for events that were farther in the past
Declarative memory – severely impaired
Episodic memory – very severe
Semantic memory – severe but he could still learn some new general facts.
Procedural memory – relatively intact
HM learned to sew.
HM learned to draw mirror images.
Psych 355, Miyamoto, Spr '18
Diagram Showing that HM’s Memory Problem Pertains to Encoding

16. HM's Explicit Memory Problem
Sensory Store
Short-Term Store
Long-Term Store
Retrieval
Encoding
External World
Control Processes
(Remember that this diagram is an over-simplification)
HM's worst problem was encoding from STM (WM) to LTM. Impaired transfer from STM to LTM.
STM (WM) was still functioning because he could understand the current situation.
Note: This diagram omits the role of the hippocampus in consolidation (probably HM had difficulty with consolidation as well as encoding).
Psych 355, Miyamoto, Spr '18
Diagram Showing Multiple Memory Systems

17. Episodic & Semantic Memory
Next: How do we know that STM & LTM involve different brain mechanisms?
HUMAN MEMORY
SHORT-TERM MEMORY
Psych 355, Miyamoto, Spr '18
Serial Position Curve Provides Evidence for STM / LTM Distinction

18. How Do We Know that STM and LTM Involve Different Brain Mechanisms?
Evidence from the Serial Position Curve:
Subject views list of 20 words, one word at a time. Each word is presented for 2 seconds.
After viewing the list, subject attempts to recall as many words as possible.
"Serial position" refers to the position of a word in the list, i.e., 1st, 2nd, 3rd, ..., 19th, 20th.
Serial Position
% Recalled
Figure 6.3 Serial Position Curve
Curve shows the percentage of times a word in each position was recalled correctly.
Psych 355, Miyamoto, Spr '18
Interpretation of Standard Result for Serial Position Curve

19. Interpretation of Standard Result for Serial Position Curve
Claims (to be substantiated in subsequent slides)
Primacy effect is due to transfer to LTM.
Recency effect due to words retained in STM.
Standard result for serial position curve is evidence for STM/LTM distinction.
Serial Position
% Recalled
Figure 6.3 Serial Position Curve
Recency Effect
Primacy Effect
How to Prove that Primacy is Due to Transfer to LTM?
Psych 355, Miyamoto, Spr '18

20. How to Prove Primacy Effect Is Due to Transfer to LTM?
Rundus (1971) presented words at the rate of 1 word per 5 seconds. 20 words in the list.
Subjects were instructed to rehearse words aloud.
What Subject Sees What Subject Says
car car, car, car, ...
stone car, stone, car, stone, car, ...
top car, stone, top, car, stone, top, ...
This study has 2 dependent variables:
Frequency of recall for words in each position
Number of rehearsals for words in each position
Subjects were not told which words to rehearse (repeat). They were simply told to repeat whichever words they felt like repeating aloud.
Psych 355, Miyamoto, Spr '18
Results for Rundus Experiment

21. Results for Rundus (1971) Study
Figure 6.4 Effect of Overt Rehearsal
% Recalled
Serial Position
Number of Rehearsals
Figure 6.4 to the right:
Red solid line: Serial position curve (standard result)
Blue dotted line: Number of times a word in each position was rehearsed.
Blue dotted line correlates perfectly with the serial position curve (red dotted line) except for the recency effect. This supports claim that primacy effect is due to transfer to LTM.
Subjects were not told which words to rehearse (repeat). They were simply told to repeat whichever words they felt like repeating aloud.
Psych 355, Miyamoto, Spr '18
How to Prove that Recency Effect Due to Retention in STM?

22. How to Prove Recency Effect Is Due to Retention in STM?
Dashed line shows effect of counting backwards by 3’s for 30 seconds after presentation of list.
Counting backwards prevents retention of words in STM, so recency effect disappears.
This result supports the hypothesis that the recency effect is due to retention of recent words in STM.
Glanzer, M., & Cunitz, A. R. (1966). Two storage mechanisms in free recall. Journal of Verbal Learning and Verbal Behavior, 5,
Figure 6.5 Effect of Counting Backwards
% Recalled
Glanzer, M., & Cunitz, A. R. (1966). Two storage mechanisms in free recall. Journal of Verbal Learning and Verbal Behavior, 5,
No recency effect
Serial Position
How We Know that STM & LTM Are Different Mechanisms - Summary
Psych 355, Miyamoto, Spr '18

23. Neuropsych evidence of double dissociation between STM & LTM.
How Do We Know that STM and LTM Involve Different Brain Mechanisms? (Conclusion)
Assumption of separate STM & LTM explains facts about the serial position curve.
Neuropsych evidence of double dissociation between STM & LTM.
HM & Clive Wearing had normal memory span, e.g., 5-8 digits
KF had reduced memory span, e.g., about 2 digits. LTM was ok.
STM
LTM
HM, Clive Wearing OK
Impaired
K. F.
K.F. suffered to parietal lobe in a motorbike accident. He had digit span of 2 (typical digit span is digits). His serial position curve had a reduced recency effect (probably due to reduced use of rehearsal during the memory task). LTM was ok.
Psych 355, Miyamoto, Spr '18
Surprise Memory Test Items