Cognitive Psych ch 9

Compare and contrast the ideas of local and distributed representations in our mental networks.

A local representation means that an idea is represented as a single node in the network. However, distributed representations are when ideas are represented not by the node but by the combination and pattern of certain activated nodes.

How might prototype theory, via graded membership, account for categorization.

Each prototype would be the center of a category, essential the "perfect" specimen for that given category. Graded membership would act as the meter which determines how far an object is from the center of that category (the prototype). In a nutshell, categorization has two parts: the center, which is the prototype, and the level of similarity that object has to our prototype, which is the graded membership.

Explain how an exemplar model could account for basic categorization evidence.

In an exemplar model, we are basically performing the same operation as in the prototype theory. However, instead of evaluating a subject against the same thing to evaluate if it's part of a category, we are pulling from memory examples of a target subject. We still do the same evaluation categorically.

Describe the evidence surrounding the notion that we are inclined to use a "basic" level of categorization

Some of the most common evidence is that when prompted to identify objects, materials, people etc, we use very high-level categories, which would be the base level. For example, we say that's a dog, not "that's a golden brown retriever". There's been numerous studies done that show that people will use these basic levels of categorization, and that even young children will typically learn these before anything else.

Identify the neural correlates of various categories, and explain the deficits that are associated with damage to those areas.

There are brain structures used for conceptual knowledge like: natural objects, man-made objects, inanimate objects, living objects etc. When damaged subjects can have a hard time identifying objects belonging to those concepts, but won't have any problems identifying other objects belonging to a different concept.

Provide examples to illustrate how typicality and category membership are different and similar.

Typicality usually refers to the characteristics of a subject - how tall, how many legs, what color, etc. Category membership can be determined with typicality, but there's also something deeper that takes place. For example, if we see a horse painted black and white like a Zebra, we still know it's a horse, and we categorize it this way. Beliefs take part in our categorical appraisal of objects.

Explain how propositional networks work and the evidence supporting them.

A propositional network works similarly to neural networks in that there are nodes and associative links, however, a proposition is the smallest unit of knowledge that can be true or false. The purpose of this network is to identify the distinct relationship between two ideas. The evidence is shown in past theories that show we use nodes for ideas and associative links, this theory builds on this but adds more depth via what those associative links mean.

Explain how categorization influences our beliefs and how previous beliefs influence our categories.

If you were teaching a child about birds, you could build this category as: have a beak, fly, caw etc. As the child got older, they'd see ostrich's, and penguins. They'd have to build this into their category theory as: not all birds fly. So this would cause them to look for other similarities that they could use to identify other birds as well, perhaps the fact that they have feathers and lay eggs would be added. Now their theory has been altered due to categorization and in the future they'll be able to perhaps identify more birds as part of this new knowledge and beliefs.

Compare and contrast prototype and exemplar theories with explanatory theories.

Prototype theory is almost entirely focused on the physical nature of something, which is how we make a categorical determination. Exemplars are similar, albeit they do take into account some contextual elements to help us identify subjects in different environments and situations. Explanatory theories are just another layer, but they bring together the physical nature of categories and also our prior knowledge of that category. We form conceptual theories of how a category is, and we use this theory to make a determination of whether an object belongs to said category or not.

Describe the experiments of Collins and Quillian, and explain what they can and cannot tell us about our mental organization.

The experiment was to have subjects identify if sentences were true or false. They would measure the speed of the reaction and whether it was correct, or not. This helps us map out organization of knowledge, but it does not explain why certain subordinates create slower reaction times than others, such as an eagle is a bird (faster response time) vs an ostrich is a bird (slower response time). We believe that this is due to an eagle being closer to our prototype or exemplar than that of the ostrich. It also doesn't tell us why certain redundant features actually help in the recall of certain objects vs others.