Class Notes (811,170)
Canada (494,539)
Psychology (4,979)
PSYCH 1X03 (1,055)
Joe Kim (989)

Categories and Concepts.docx

12 Pages
Unlock Document

McMaster University
Joe Kim

Categories + Concepts 28/05/2013 5:14:00 PM Categorization Introduction  Interactions with the world are flooded with colours, shapes, textures, smells, tastes and sounds, and yet you are still able to make sense of it all and take appropriate action  How is this possible? o Part of the answer comes from two cognitive mechanisms we have already discussed:  Attention, which helps you focus finite mental resources on key parts of the active scne  Memory, which can help you recall specific behaviours which are appropriate to your current needs  Imagine a would where you couldn‟t categorise o Every sensory experience would be completely unique o unable to draw connections with the past and being forced to make unique decisions on even the most routine actions  categorization happens so seamlessly that it‟s easy to take for granted, but you are constantly categorizing your experiences to guide your decision making o wake up in the morning and you have a hangover, from previous experience, you know that you should take some aspirin, drink plenty of water and quiet Functions of Categorisation Four Basic Functions of Categorization  Classification o Allows you to treat objects that appear differently as belonging together  Green apples, red apples and yellow apples can appear different on a colour dimension but still classified as „apples‟  Understanding o If we categorise the scene in front of us as two people shouting, we understand that they are probably in a fight  Predicting o By categorising your current experience and comparing it to similar experiences in memory you can make predictions about your current situation  If you know that there is a dog in front of you, you can predict that it would like to be scratched behind its ears and wag it‟s tail when happy  Communication o Using category name allows for efficient communication (don‟t have to describe everything you are trying to say)- many words in our language refer to some type of category or concept The Illusion of the Expert: feeling that something must be simple because you are so good at it  Everyone is an expert on something which may seem simple to them but not to others  Categorization is a very complex field with a number of conflicting theories seeking to explain the ease with which humans are able to categorise Rules Dr. Lee Brooks  Professor emeritus of psychology at McMaster  Asked first and second year students- are there some set of features you can use to identify a new member of a given category?  Consider definition of bottle, dog, etc. o Simple categories, we are quite susceptible to the illusion of the expert  If considering more complex categories like fruit and furniture, the number of people who can identify a simple categorisation rule decreases  Interestingly, you can understand even more complicated ideas such as beauty, freedom or justice, but much more difficult to devise simple rules to define more abstract categories When Rules Aren‟t Enough  What is a bachelor? o A simple rule to define a bachelor is an unmarried male o This simple rule applies to the Pope and a 6-month old baby boy, both of which meet our criteria but not our typical bachelor  When asked to define rules, it is difficult to properly include and exclude items for category membership, yet when given a test stimulus, you can effortlessly decide membership  This suggested to psychologists that humans have an internal representation of categories that is independent of the rules we try to define Prototype Theory Prototypes  Prototype theory suggests that we categorize objects by comparing them to an internal representation of the category called a prototype  Prototypes are thought to be the average or „best‟ member of the category o Picture a fruit: perhaps an apple or orange came to mind o Picture a bird: something that looks like a robin comes to mind  Everybody has a prototype that quickly comes to mind for particular categories  Prototypes are formed through experience and can be very personal o All the objects you‟ve previously encountered are averaged together o Ex: your bird prototype may look like a robin because most birds you‟ve seen in your life looks similar to a robin o However, if you have never seen a robin before and grew up in an area with tropical birds, they would be your prototype instead Categorization Using Prototypes  According to prototype theory you categorize new objects by comparing them to your prototypes o Ex: you go on vacation in the tropics and take a break from watching modules and go on a walk where you encounter some interesting flora you‟ve never seen before o Is this new object a tree?  To answer this question, you automatically compare this object to your tree prototype  The further away the object is from your tree prototype, the less likely it is to be categorised as a tree, perhaps it is a bush  If it is close to your bush prototype, you later tell people of the interesting bush you noticed on the walk Evidence supporting the prototype theory  Subjects were asked to verify whether a series of statement were true or not o “A robin is a bird” – subjects responded very quickly o “A penguin is a bird” – subjects responded significantly slower  this suggests that more typical category members which are likely closer to the prototype are categorised more quickly than atypical category members  Problems with Prototypes  Although prototype theory provides a powerful framework to explain human categorization, there is evidence indicating that it can‟t explain all findings o Ex: if I asked you to write down your „protypical‟ fruit, bird, chair, house, pet, and book and then ask them the same question a week later, there is a good chance they might be different o If we are comparing our experiences to an internal prototype, e should expect it to be stable over time Exemplar Theory Exemplars  Contrast prototype theory  Exemplar theory suggests that instead of storing only one average category prototype, you store your entire lifetime worth of experiences o Ex: instead of remember just one prototype of dog, exemplar
More Less

Related notes for PSYCH 1X03

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.