Problem 4
Learning goals:
1. What are the theories of categorisation?
2. How do our knowledge categories? How to form? + Separate
categories stored in different places in our brains?
3. What affects speed recalls?
4. How do we modify the visual memories?
5. How do we perceive the visual stimuli?
6. How do schemas affect our perceptual memories?
7. How do our brains use schemas to understand/ make sense of
information?
8. How important is context? (schemas)
Problem A
Categories and concepts
Theories of concepts- people learn a summary description of a
whole category or learn exemplars of the category
Category- a set of objects that can be treated as equivalent in
some way
- Psychology of categories concerns how people learn, remember
and use informative categories
Concepts- mental representations of categories
- Tells you what they are and what you’re supposed to do with
them
- Allow you to extend what you’ve learned about a limited number
of objects to a potentially infinite set of entities
categories are well defined i.e. the definition allows you to specify
what’s in and out of the category
- it provides the necessary features for category membership
- features must be jointly sufficient for membership
sometimes we can’t find exact definitions for many familiar
categories
- definitions are neat and clear cut, the world is messy and often
unclear
- e.g. a mute dog with 3 legs is still a dog
Fuzzy categories
Hampton- found that items weren’t clear members or non-members
of a category and subjects disagreed greatly between them
Borderline members- items that aren’t clearly in or out of the
category
McCloskey and Glucksberg- found people often change their minds
about borderline items (22%) when tested twice, separated by two
weeks
Fuzzy category- unclear boundaries that can shift over time
, Typicality
Even among items that clearly are in a category, some seem to be
‘better’ than others
- E.g. robins and pigeons are better members among the category
of ‘Birds’ than ostriches or turkeys
Category prototype- the most typical category member
- Items that are less similar to the prototype become less and less
typical
- Changes in typicality borderline members
Influences of typicality on cognition:
1. Typical items are judged as category members more often
2. Speed of categorisation is faster for typical items
3. Typical members are learned before atypical ones
4. Learning a category is easier if typical examples are provided
5. References to typical members are understood more easily in
language comprehension
6. People tend to say typical items before atypical ones in language
production
Family resemblance theory (Rosch and Mervis)- items are more
typical if they:
- Have the features that are frequent in the category
- Don’t have features frequent in other categories
Category hierarchies
Important categories fall into hierarchies, in which more concrete
categories are nested inside larger, abstract categories
- E.g. brown bear, bear, mammal, vertebrate, animal, entity
We have a preference for which category we use to label things –
basic level of categorisation
- E.g. we say ‘move that chair’ instead of ‘move that desk chair’ or
‘move that piece of furniture’
- Easier to learn and identify basic-level categories
Not universal
- industrialised countries (USA) use words such as ‘tree’ ‘fish’ and
‘bird’
- less industrialised countries use words such as ‘elm’ ‘trout’ and
‘finch’
- experts in the domain often have a more specific preferred level
than non-experts e.g. bird watchers will see sparrows rather than
just birds
basic-level categories are more differentiated- category members
are similar to each other, but differ from members of other
categories
Theories of concept representation
Learning goals:
1. What are the theories of categorisation?
2. How do our knowledge categories? How to form? + Separate
categories stored in different places in our brains?
3. What affects speed recalls?
4. How do we modify the visual memories?
5. How do we perceive the visual stimuli?
6. How do schemas affect our perceptual memories?
7. How do our brains use schemas to understand/ make sense of
information?
8. How important is context? (schemas)
Problem A
Categories and concepts
Theories of concepts- people learn a summary description of a
whole category or learn exemplars of the category
Category- a set of objects that can be treated as equivalent in
some way
- Psychology of categories concerns how people learn, remember
and use informative categories
Concepts- mental representations of categories
- Tells you what they are and what you’re supposed to do with
them
- Allow you to extend what you’ve learned about a limited number
of objects to a potentially infinite set of entities
categories are well defined i.e. the definition allows you to specify
what’s in and out of the category
- it provides the necessary features for category membership
- features must be jointly sufficient for membership
sometimes we can’t find exact definitions for many familiar
categories
- definitions are neat and clear cut, the world is messy and often
unclear
- e.g. a mute dog with 3 legs is still a dog
Fuzzy categories
Hampton- found that items weren’t clear members or non-members
of a category and subjects disagreed greatly between them
Borderline members- items that aren’t clearly in or out of the
category
McCloskey and Glucksberg- found people often change their minds
about borderline items (22%) when tested twice, separated by two
weeks
Fuzzy category- unclear boundaries that can shift over time
, Typicality
Even among items that clearly are in a category, some seem to be
‘better’ than others
- E.g. robins and pigeons are better members among the category
of ‘Birds’ than ostriches or turkeys
Category prototype- the most typical category member
- Items that are less similar to the prototype become less and less
typical
- Changes in typicality borderline members
Influences of typicality on cognition:
1. Typical items are judged as category members more often
2. Speed of categorisation is faster for typical items
3. Typical members are learned before atypical ones
4. Learning a category is easier if typical examples are provided
5. References to typical members are understood more easily in
language comprehension
6. People tend to say typical items before atypical ones in language
production
Family resemblance theory (Rosch and Mervis)- items are more
typical if they:
- Have the features that are frequent in the category
- Don’t have features frequent in other categories
Category hierarchies
Important categories fall into hierarchies, in which more concrete
categories are nested inside larger, abstract categories
- E.g. brown bear, bear, mammal, vertebrate, animal, entity
We have a preference for which category we use to label things –
basic level of categorisation
- E.g. we say ‘move that chair’ instead of ‘move that desk chair’ or
‘move that piece of furniture’
- Easier to learn and identify basic-level categories
Not universal
- industrialised countries (USA) use words such as ‘tree’ ‘fish’ and
‘bird’
- less industrialised countries use words such as ‘elm’ ‘trout’ and
‘finch’
- experts in the domain often have a more specific preferred level
than non-experts e.g. bird watchers will see sparrows rather than
just birds
basic-level categories are more differentiated- category members
are similar to each other, but differ from members of other
categories
Theories of concept representation
