PSYC 224, Semantic Memory Chapter
What are semantic features?
From Smith's Feature Overlap model, they are simple, one-element characteristics or properties of a concept that make up a feature list.
What is stage I of feature comparison?
This is the global comparison of features, meaning a randomly selected subset of features on each of the two concept's lists are compared for overlaps.
How are semantic memory tests different from episodic memory tests?
A semantic memory test requires no period of teaching the subject and focuses on reaction time. An episodic memory test requires the subject to learn new info and focuses on the accuracy of memory.
What is spreading activiation?
As part of Collin & Quillian's (1972) model of semantic memory, it is the mental activity of accessing and retrieving information from the nodal networks. Activation then spreads through the network, activating other concepts; however, this process takes time.
What are characteristic features?
As part of Smith's Feature Overlap model, they are common/frequent features of a concept that are not essential to its meaning.
What are defining features?
As part of Smith's Feature Overlap model, they are essential features of a concept that are stored near the top of the feature list.
What is cognitive economy?
From Quillian's Teachable Language Comprehender (1968), it is the idea that semantic memory economizes the number of concepts that must be stored, avoiding redundant facts.
What happens as semantic memory activation spreads further into a network according to Collins & Quillian (1972)?
It becomes weaker and more diffuse, to the point that it has little to no effect.
What happens to a concept in the time after it is activated according to Collins & Quillian (1972)?
Once activated, a concept does not remain activated indefinitely. Instead, activation decays over a short time, returning the nodes to their baseline of inactivity.
What is semantic memory?
Permanent store of general world knowledge. Described as a combination of a dictionary, thesaurus, and encyclopedia.
What is Collin & Quillian's model (1972) of semantic memory based on?
Quillian's Teachable Language Comprehender (1968), a computer program for understanding language.
How are semantic memory and episodic memory different?
Semantic memory is generic, meaning that it is made up of commonly known information. Episodic memory is different for different people because it is autobiographical, meaning each person has their own specific memories for events in their life.
What problem did Conrad (1972) bring up with Smith et al's (1974) research?
Smith et al. focused only on superordinate statements (is one concept related to another concept), while Conrad incorporated property statements (does one concept have a certain property). According to Smith's model, there would have been a feature list for every property.
How was Smith's Feature Overlap model (1974) different from Collins and Quillian's network model in explaining semantic memory?
Smith's model made much simpler assumptions about the structure of semantic memory. Consequently, it also had more elaborate assumptions for the process of retrieval.
What is the typicality effect?
Supported by Smith et al. (1974), it is when typical members could be judged as belonging to the category more rapidly than atypical members (e.g., "robin is a bird" vs. "chicken is a bird").
What problem did Conrad (1972) find with the strict cognitive economy principle?
The frequency with which different properties occurred in written lists showed that frequency was a better explanation of RT results than hierarchical levels tested by Collins & Quillian (1969). Also, there was little evidence for the economical scheme implied. Instead, properties throughout the hierarchy were stored repeatedly, in a messy, redundant fashion.
What is a feature list?
The most basic structural element of Smith's Feature Overlap model. It is a collection of lists, with each concept represented as a list of semantic features.
What are the two integral parts of Collin & Quillian's (1972) model?
The structuring of semantic memory as nodes in a network and the process of retrieving information from there through spreading activation.
What are the two main differences between Collins & Loftus's revised network model (1975) and the original network model?
The two main differences are in typicality and cognitive economy. Pathway lengths were used to show the strength of two concepts' relationship, addressing the issue of typicality. Additionally, they justified the clutter of their diagrams through the principle of semantic relatedness. This is the idea that related concepts are stored closely together in the network with strong pathways connecting them.
How did Collin & Quillian (1972) view items in semantic memory?
They believed these items were nodes in a network. A node is a point in semantic space. Each node is linked to other nodes by pathways, which are associations between concepts. All these nodes and pathways form networks, or interrelated sets of concepts, that form a hierarchy of knowledge.
What task did Collins & Quillian (1969) use to test the prediction that two closer concepts should require less retrieval time than two that are farther apart?
They used the sentence verification test, in which simple sentences are presented to participants, who make timed yes/no decisions.
In Collins & Quillian's (1972) model, what happens when two close concepts are activated at the same time?
When they are close enough and there is a pathway between them, there will be an intersection. This retrieves the pathway that connects the two concepts.
What is stage II of feature comparison?
When two concepts moderately overlap, feature comparison moves to its second stage. In this stage, the defining features of each concept are used for comparison. This type of comparison takes longer than just the first stage.