1. Cognitive Psychology
Chapter 7
Knowledge, Part I

2. Knowing 2/23/2019 December exam Semantic Memory Empirical Tests Models
“Now! That should clear up a few things around here!”
Knowing
December exam
Semantic Memory
Empirical Tests
The sentence verification task
Models
TLC
Feature Comparison
Spreading Activation
Study Questions.
• Describe four well established findings from the sentence verification task. Which of these findings are predicted by TLC and which findings are not handled well by TLC? Which findings can Feature Comparison and Spreading Activation handle?

3. Knowing December Exam Question A B C D Actual 1 2 1 4 38 D

4. Knowing December Exam Question A B C D Actual 14 34 5 2 4 A

5. Knowing December Exam Question A B C D Actual 29 4 30 2 9 B

6. Knowing December Exam Jeopardy-style Subtractive method Hebb’s synapse
Corpus callosum
Saccades
Geons
Endogenous
Exogenous
Automatic processes
Brown-Peterson
Recency effect

7. Knowing December Exam Jeopardy-style Retroactive interference
Slave systems
Encoding specificity
Method of loci
Priming
Savings score
Serial recall
Mnemonists
Elaborative rehearsal
Subjective organization

8. Knowing Semantic Memory The sentence verification task
e.g., True or false:
A robin is a bat
Findings from the sentence verification task:
The true/ false effect
In general, our cognitive processes handle positive information better than negative information.
E.g., He is honest vs. He is not dishonest

9. Knowing Semantic Memory Findings from the sentence verification task:
The true/ false effect
How fast can you spot what is unusual about this paragraph? It looks so ordinary that you might think nothing was wrong with it at all, and, in fact, nothing is. But it is atypical. Why? Study its various parts, think about its curious wording, and you may hit upon a solution. But you must do it without aid; my plan is not to allow any scandalous misconduct in this psychological study. No doubt, if you work hard on this possibly frustrating task, its abnormality will soon dawn upon you. You cannot know until you try. But it is commonly a hard nut to crack. So, good luck!
I trust a solution is conspicuous now. Was it dramatic and fair, although odd?

10. Knowing Semantic Memory Findings from the sentence verification task:
Category size effect
It is easier to confirm membership in a small category
A poodle is a dog
Versus
A squirrel is an animal

11. Knowing Semantic Memory Findings from the sentence verification task:
Semantic distance effect
A.K.A. The typicality effect

12. Knowing Semantic Memory Findings from the sentence verification task:
Semantic priming effect
E.g., Loftus (1974)
Fruit - a
Fruit - b
Furniture - s
Etc.
First item 1.53 secs.
Second of two successive “fruit”s secs
1 intervening item secs
2 intervening items secs

13. Knowing
Semantic Memory
Collins & Quillian’s TLC

14. Knowing
Semantic Memory
Collins & Quillian’s TLC

15. Knowing Semantic Memory Collins & Quillian’s TLC Assessing TLC Pros
• Precursor for other models
• Accounts for empirical data
• Cognitive Economy - Information is not stored redundantly in Semantic memory if it can be inferred from already stored information.

16. Knowing Semantic Memory Collins & Quillian’s TLC Assessing TLC Cons
• Strictly hierarchical
• Only works for “true” propositions
• Cannot account for typicality or category size effects

17. Knowing Semantic Memory Smith et al.’s Feature Comparison Model
The meaning of a concept is contained in a bundle of semantic features which are divided into two sets:
Characteristic features are not necessary to the meaning, but instead describe the concept and many of its members.
Used to make fast confirmations or rejections.
e.g., A bird can fly
Defining features are necessary to the meaning of the concept.
Used to make slow, methodological confirmations or rejections.
e.g., A bird has wings

18. Knowing
Semantic Memory
Smith et al.’s Feature Comparison Model

19. Knowing Semantic Memory Smith et al.’s Feature Comparison Model
Handling the sentence verification task
The true/ false effect
• Thresholds, deadlines, list lengths, etc.
Semantic distance (typicality) effect
• Function of featural overlap
Semantic priming effect
• Pre-activating feature bundles?
Category size effect
• May predict the opposite
-> Smaller categories have larger number of defining features

20. Knowing Semantic Memory Smith et al.’s Feature Comparison Model
Other Problems
Non experts may not be guided by defining features
What is the distinction between ‘defining’ and ‘characteristic’ features?
Circularity: Relies on subjects’ ratings of similarity to make predictions.

21. Knowing
Semantic Memory
Collins & Loftus’ Spreading Activation

22. Knowing Semantic Memory Collins & Loftus’ Spreading Activation
Intersection search
Activation spreads from both nodes in the proposition
E.g., A robin can breathe
When they “encounter one another” an intersection has been found
Decision processes determine if the pathway is legitimate

23. Knowing Semantic Memory Collins & Loftus’ Spreading Activation
Intersection search
robin
breathe
has
Red Breast
Blue eggs
bird
isa
animal
can
sing
feathers
fly
canary
yellow is
skin

24. Knowing Semantic Memory Collins & Loftus’ Spreading Activation
Intersection search
robin
breathe
has
Red Breast
Blue eggs
bird
isa
animal
can
sing
feathers
fly
canary
yellow is
skin

25. Knowing Semantic Memory Collins & Loftus’ Spreading Activation
Intersection search
robin
breathe
has
Red Breast
Blue eggs
bird
isa
animal
can
sing
feathers
fly
canary
yellow is
skin

26. Knowing Semantic Memory Collins & Loftus’ Spreading Activation
Intersection search
robin
breathe
has
Red Breast
Blue eggs
bird
isa
animal
can
sing
feathers
fly
canary
yellow is
skin

27. Knowing Semantic Memory Collins & Loftus’ Spreading Activation
Handling the sentence verification task
The true/ false effect
Semantic distance (typicality) effect
• Length of links
Semantic priming effect
• Spreading Activation
Category size effect
• The Fan Effect
-> Activation as a limited resource