Lecture 6: Concepts and Semantic Memory Flashcards
Concept
=a mental representation of a category of objects, typically derived from experience
- efficient way of representing knowledge of the world
- help us focus n similarities among objects
How are concepts defined
¥ Initial explanations of concepts relied on the idea that we use the notion of ‘essential, common features’
¥ For example, dogs have fur, paws, tails, they bark etc. –rely on essential features
¥ This is problematic though as some concepts defy definition in this way
¥ e.g. Wittgenstein’s problem of defining ‘games’ and ‘sports’
¥ Some concepts have fuzzy boundaries, where they cross over with others, so defining them by essential features is not really workable
Prototype model (Rosch and Mervis, 1975, Hampton, 2010)
¥ A prototype is an abstract idealised representation of the category member. It is defined by the list of attributes we think is characteristic of the category.
¥ Items in any given category differ in their prototypicallity – a robin vs. a penguin
¥ Allows for fuzzy boundaries – if an object shares only a few features with the prototype then it likely shares features with another prototype – e.g. dolphins are fish
¥ People also offer ‘typical’ features rather than essential features. For example – ‘birds fly’ even though some do not, but it is a feature shared by most category members, and is, thus, prototypical (Hampton, 2010).
Family resemblances
An object can be classified as belonging to a category when there is a match between it and the prototype. This is called ‘family resemblance’ – that members share attributes / features
some categories show little evidence of family resemblance – goal derived categories, like ‘things to take on holiday’-no family resemblance at all, and yet they are still grouped together (Barsalou, 1985).
Hamilton 1981
-some categories don’t have clear prototypes, concepts such as justice, belief etc
“Friendship” prototypes
¥ Fehr (2004) found that there is a prototype for “friendship intimacy” in same-sex friendships. ¥ Prototypical features of friendship intimacy: ¥ Self-disclosure ¥ Emotional support ¥ Loyalty ¥ Less prototypical features: ¥ Shared activities ¥ Practical support
Exemplar approach
Instead of using an abstract description (e.g. prototype) we make category judgments by comparing new stimuli with instances already stored in memory. The instance stored in memory is the “exemplar”.
- new exemplars compared with known, most similar item will influence classification the most
- More able to account for tricky categories like ‘games’, because actual exemplars, not prototypes are used.
Situated nature of concepts
¥ Representation of any given concept will vary from situation to situation depending on our current goals and important aspects of situation.
¥ We need to focus on the connections between conceptual, perceptual and
¥ motor/action systems.
¥ There is reasonable evidence to suggest that we access perceptual / situational and motor / action information when we process concepts, there is more to them than simply an abstract representation of the concept itself.
Embodiment of concepts
- Assessing perceptual and motor info when thinking about words, enough to activate relevant area
- Concepts must store not just abstract but also situational information and what are the possible things that can happen in terms of movement ect
Hierarchy of concepts
Superordinate level
• furniture, animals, tools
Basic level: used most often as most of the time other information is too much/too little
• chairs, dogs, screwdrivers
Subordinate level
• desk chair, collie, Phillips screwdriver
Hierarchy of concepts
Superordinate level
• furniture, animals, tools
Basic level: used most often as most of the time other information is too much/too little
• chairs, dogs, screwdrivers
Subordinate level
• desk chair, collie, Phillips screwdriver
Spreading activation model
¥ Collins and Loftus (1975) suggest that semantic memory is organized on the basis of semantic relatedness (semantic distance).
¥ Whenever we see, hear or think of something appropriate “node” in semantic memory is activated.
¥ That activation spreads strongly to closely related concepts and weakly to distantly related concepts.
¥ Explains the typicality effect – it takes less time to decide that a typical member belongs to a category (e.g. apple – fruit) than a less typical member (e.g. kumquat – fruit)
Schemas
¥ Schema is a mental structure we use to organize and simplify our knowledge of the world around us.
¥ We have schemas about ourselves, other people, mechanical devices, food, and in fact almost everything.
¥ They are larger knowledge units than the concepts.
Scripts
¥ A narrower term than schema and refers to a well structured sequence of events associated with a particular activity.
¥ Scripts could interfere with memory by replacing expected events that were missing from stories.
¥ Western social structure encourages a strong degree of behavioural scripts to be utilized within everyday interactions with others.
Schemas and memory
¥ Schemas help us to understand situations – we know how to behave in certain situations because we have a schema for the situation.
¥ They allow us to form expectations and make predictions about a situation.
¥ They can influence our memory of an event as we are more likely to notice things and events that are congruent with a schema.
¥ They help us prevent cognitive overload.
¥ BUT… They can cause various errors in memory and perception
Stereotypes
- Type of schema
- Explicit measures- not always reliable because they can be influenced by social desirability bias Association Test have been developed
