Chapter 7 Knowledge Representation.

Identify BASIC-LEVEL, SUBORDINATE LEVEL, & SUPERORDINATE LEVEL categories

(Superordinate categories) A musical instrument (Basic-level categories) Guitar (Subordinate categories) Classical guitar, folk guitar.

Understand the key theory underlying connectionist models

- what is stored in the memory is a set of changes in the instructions neurons send to each other affecting what pattern of activity can be constructed from given inputs. SEE QUESTION 8.

Be familiar with the three types of memory systems defined by the ACT model.

1. Declarative memory (information, facts) 2. Working memory (information that is currently at a high level activation) 3. Procedural Memory, for example-IF the goal is to classify a person• And he is unmarried• THEN classify him as a bachelor

What is a SCHEMA?

A large unit of organized information used for representing concepts, situations, events, and actions.

What is a SCRIPT?

A list of cues, for example the topic of going to a restaurant includes first getting seated, next ordering your food, then receiving a check, lastly paying for the check. It's a routine.

What are the important aspects of the PROTOTYPE view of concepts?

Denies the existence of necessary and sufficient feature lists. • Concepts are represented not by features, but by a mental "prototype"—an idealized representation of the category. Members of a concept share "family resemblance" rather than a specific set of necessary features

Typicality effect

In general typical instances of a concept are responded to more quickly than atypical instances, most peoples lives robin are typical birds while turkeys are not. People can verify "A robin is a bird" faster than "A turkey is a bird." Because they see robins more often and it shares features more noticeably.

What are the important aspects of the EXEMPLAR view of concepts?

It asserts that concepts include representations of at least some actual individual instances. It assumes that people categorize new instances by comparing them to representations of actual instances called exemplars. It explains people's inability to state necessary and defining features.

Lexicons

Our mental dictionaries, are organized by the first letter, not the fourth in a word. (like thinking of the word lucky, we'd look through all of the L words in a dictionary until we find this.

Cognitive Economy

Properties and facts are stored at the highest level possible. To recover information you use inference much as you did to answer the earlier question about Bernese mountain dog's has livers. Cognitive Economy- Principle of hierarchal; semantic networks such that properties and facts about a node are stored at the highest level possible. The fact "alive" would fall under mammals rather than dog, cat, horse, sheep.

Identify how the weights are set in a connectionist model

The conections between units have weights that are all set at random and neutral values from 0 (minimum) to 1(maximum). These types of weights, are set by how much training. For example, you may first hear that a Pidgin is a bird, the more you associated Pidgin with bird the stronger the weight becomes, as where pidgin and cute may be a weaker weight.

Spreading Activation

The idea that exciting spreads along the connections of notes in a semantic network, e.g when someone think about a bread it automatically think about butter (priming effect)

Category-

a class of similar items.

Production rules-

a hypothesized mental representation of procedural memory, which specifies a goal to be achieved, one or more conditions that must be true in order for the rule to be applies, and one or more actions that result from the application of the rule. (Get an A on the test (goal), the tv is on at home (condition), go into a quiet area to study (action).

Semantic priming-

a phenomena in which exposure to one word facilitates the recognition of semantically related words. The word "nurse" triggers the word "doctor."

Concept-

mental representation of some object, event, or pattern that has stored in it much of the knowledge typically thought relevant to that object, event or pattern.

Semantic Network-

the collection of nodes associated with all the words and concepts one knows about.

Spreading activation-

the idea that excitation spreads along the connections of nodes in a semantic network.

How does Collins and Loftus' SPREADING ACTIVATION MODEL differ from Hierarchical models?

• Got rid of hierarchy- there's no dominant feature that has the quickest reaction time (noticing a robin has feathers, may or may not be faster than noticing it has a beak) • Got rid of cognitive economy • Allowed links to vary in length to account for typicality effects • Spreading activation - Activation is the arousal level of a node - Spreads down links - Used to extract information from network

What is an example of your PROCEDURAL MEMORY system according to the ACT model?

• IF the goal is to classify a person • And he is unmarried • THEN classify him as a bachelor