concepts and knowledge Flashcards
Memory differences from knowledge: London Taxi drivers example
London taxi drivers have to memorize the spatial layout of london - because of this, they perform better on tests of spatial memory than people who don’t have to memorize london, like bus drivers (just follow the same route)
- because of this, taxi drivers have greater posterior (but smaller anterior) hippocampi
- additionally, posterior hippocampal volume is related to years of experience as a taxi driver
highly superioer autobiographical memory (HSAM)
people who have enhanced autobiographical memory (can remember every single day from their lives in detail)
- doesn’t involved mnemonic strategies - and hsam people aren’t any better than the average person at any other form of memory
downsides of a detailed memory
case of perfect detailed memory
- was able to recall conversations word for word
- recall detailed events from years ago
- could reproduce 70 digits without error
however, this resulted in problems accessing general concept knowledge - e.g. recognizing items if there is a slight change in detail
categories vs concepts vs exemplars
categories: items that are grouped together
concepts: general knowledge of a category
exemplars: individual items in a category
function of concepts
used to predict outcomes, guide behaviour, and for communication
concept organization
superordinate concepts: mammal, fish, etc
basic: deer, dog, trout
subordinate: terrier, spaniel, hammerhead shark
cognitive economy
a balance between simplification and differentiation
using the simplest terms that are still meaningful for the situation
concepts in child development
children learn basic, superordinate, then subordinate concepts
concepts in semantic dementia
ability to use basic level concepts becomes impaired as the disease progresses gets replaced with more general concepts
generalization
process of a deriving a concept from a specific experience
three ways of forming generalizations
- rules
- similarity
- explanation
Defining features - classic approach
necessary and sufficient for category membership
characteristics features - classic approach
are those common but not essential for category membership
classic approach to concept learning
concepts involve forming rules about lists features
- defining and characteristics features
feature comparison between encountered items and list - refines what a defining feature is for a concept
downsides to the classic approach to concept learning
works well for simple concepts, but not so much for
- complex concepts that are subject to variability
- ambiguous concepts
similarity
concepts are not based on defined features, rather are defined by the resemblance to a collection of features
often times there is no single attribute that defines a concept, rather there is a family resemblance, or some inherent similarity
fuzzy boundaries in categories
items are, more or less, part of a category
however, an item can be categorized into more than one category
prototype theory
categories are formed from the overlap of exemplars - these are extracted from experience
each category has an abstracted prototype that is pre stored in memory - this represents the most common features with other members
items are included in a category network around that prototype - similar items are stored closer to the prototype than dissimilar items
prototype theory dot patterns
ps learn to classify dot patterns that were variants of a prototype, but didn’t get to see the prototype
then, classified the studied patterns, new patterns, and the prototype into groups
ps were worse at classifying new compared to old patterns and were equally able to classify prototype and old patterns
prototype
abstracted exemplar - other members resemble the prototype to different degrees
prototype network
a network web like thing with the prototype in the centre and other members of the category branching out - the more obscure members are farther away from the prototype in the network
typicality effect
a preference for processing items close to the prototype
- means that we are faster to recognize things closer to the prototype
prototype theory and context
prototype theory treats context as independent - doesn’t account for how a situation determines concept representations
this is a downfall bc context affects the typicality effect
exemplar theory
no single abstract prototype for a concept - instead, every instance of a category is stored in memory, not a prototype
explains how context can influence concept representations - bc we use personal experience and situation information to form concepts at retrieval
how to determine if a new item is a member of a category exemplar theory
retrieve some or all exemplars of category members - compute similarity to new item at the time of concept determination
