What was the previous model of semantic memory? What influenced the change?
Viewing memory as a library of knowledge = not a good model because inaccurate, proposing we have specific locations for memories
- Development of computers -> rather we have network where everything is interconnected
What were the 2 assumptions about artificial intelligence?
Assumption 1: If we know how a computer generates knowledge and uses it, we will know how human memory works
Assumption 2: If we know how human memory works -> we can create a superpowerful computer/software e.g. ChatGPT
How do models (in general) look like know?
We have different nodes and arrows - all of which serve a specific function
- The node here: knowldge that “dog eats meat”
Why are some sentences easier to evaluate as correct or incorrect? Model?
- Collins and Quillian Model
- every animal has its own characteristics
- different categories
- If knowledge is tied directly to the activated word will be easier
- E.g. easy to say canary can sing X as opposed to canary can fly (moving up to a bird category.
Is Collins and Quillian Model still relevant? Why?
Typicality effects
- A robin is a bird x chicken is a bird => first is faster because it is a prototype of a bird
=> frequency of association is more important than distance in the hierarchy
- Also don’t explain NO-answers e.g. Dog can fly -> No
How does the later model from Collins looked like?
- Same idea - but leaving hierarchy behind
- Just a flat network which connects nodes based on association
What’s the difference between associative and semantic priming? E.g.?
Associative priming
- E.g. “cats and dogs” may prime “weather” (from the expression “it’s raining cats and dogs”)
Semantic priming
- E.g. “Dog” primes “labrador”
Explain priming x lexical desicion task.
Procedure: fixation -> flash a related or unrelated word -> flash a target word -> decide whether it is a word or not
Findings:
=> RT faster for priming, related words
=> also for rule based expectations
- E.g. telling people after category “body” you would get item from category of “building”
What is categorization? Why do we have it? What is meant by “level of organization”?
= ability to categorize stimuli
- relevant for survival e.g. recognizing toxic food
- Level of organization
- Subordinate e.g. Granny Smith
- Basic e.g. Apple
- Superordinate e.g. fruit
What is meant by “prototype x exemplar” in categorization
If I ask “Is this a bird?”
- Central tendency e.g. robin x graded membership (harder to categorize) e.g. pinguin
- we can move within these degrees of “birdness” => frequency of encounter creates prototypes
How did the recognition task used for studying categorization go?
Procedure: showing 4 pictures of random dots of the same category to participants -> giving them an another set
=> asked which one’s are from the same or different category
Findings:
=> If the test item resembled the prototype (pictures present in the training phase) - more likely to say it is the same category
=> after many many examples people reach quite good classification
=> Even people with anterograde amnesia can learn this type of categories
What’s the difference between prototype theory and exemplar models?
Prototype theory
- has NO information about size of the category or variaty within the category
- It’s only about central tendency e.g. this is a bird because it resembles our bird prototype
Exemplar models
- We retrieve all the exemplars of the category e.g. all the birds - if it matched with one it is a bird
=> ongoing debate, but exemplar models seem to explain data a bit better
What did sir Frederic Bartlett propose regarding memory? How did he call it? Name of the phenomenon?
- Sir Frederik Bartlett
- When recalling something we are reconstructing it - not just a snapshot of reality but also additions from our previous knowledge
Procedure: read a story -> recall instantly -> after 3 weeks
=> personal background affects recall
E.g. what the black thing? how did he know they were ghosts?
=> They called these patterns of addition = schemas
Why may schemas be useful?
- Can help with encoding but also cause distortions
- Can steer memory in a specific direction
- e.g. instructions for washing clothes
Recall the study with pictures and their interpretations.
Procedure: presented with a vertical line of drawings and instructed to remember them
- 2 groups, each given a different explanation of the pictures
Findings
=> Exlanations influenced how people drew it afterwards
How did the research in schemas in real world go?
Procedure: P. instructed with “try to remember as many objects as you can from the office in which you were waiting”
Findings:
=> Claimed to have seen more “academic office schem” e.g. desks, chairs, bookcases
=> Fewer less predictable objects e.g. bulletin board
What are the advantages and disadvantages of schemas?
Advantages
- create expectations
- makes it easier to make inferences
- easier to remember things (or not needing to remember all)
Disadvantages
- Distorts memories
- allow manipulation by others e.g. politicians, magicians
What is a script?
Script = a schema with an explicit time ordering
- E.g. restaurant script - go in -> sit -> pick up a menu etc.
What can you say about semantic dementia?
- Adopted to name a new form of dementia - considered a subtype of fronto-temporal dementia
- Almost a mirror-image to amnesia
- Bilateral damage of infero-lateral temporal cortex
Qullian model could be used in predicting progression of semantic dementia
What marks semantic dementia?
- Progressive loss of semantic knowledge
- Telling you about their day - everything seems normal
- BUT if you ask them about their e.g. grandchildren -> they ask “What is that?”
=> worsens over time
- Word-filling problems
- Comprehension difficulties
- No problems with new learning (hippocampus is intact)
What do we mean by “what appear semantic in corresponding dementia may just be episodic”?
What happens when we let people with semantic dementia draw a swan after seeing one?
- Cannot properly do so
- Seem to draw on the remaining knowledge e.g. giving it wheels, human-like head
How would we “define” the loss pattern of semantic dementia?
- Patients firts lose detailed distinctions, subordinate categories
-> superordinate deteriorates later - High-frequency words also survive for longer
