Representation/organization in LTM

1 / 9

Representation/organization in LTM - PowerPoint PPT Presentation

Representation/organization in LTM. Typical empirical testing paradigm: propositional verification task – rt to rose is flower, vs. rose is plant.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

PowerPoint Slideshow about ' Representation/organization in LTM' - chuong

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Representation/organization in LTM

Typical empirical testing paradigm: propositional verification task – rt to rose is flower, vs. rose is plant.

Set Theoretical Models: categorical – hierarchical storage. Along with items, feature list are stored. Decisions are made based on comparisons of feature lists – feature overlap. Support found in some vs. all comparisons and most sub vs. immediate super. Problem with atypical category members (whale is mammal vs. whale is animal).

Categorical/Hierarchical Model of Memory
• Some birds are robins vs. all birds are robins
• Crow-bird; crow-animal whale-mammal; whale-animal (atypical problem)
Representation/organization in LTM
• Semantic feature comparison model: two stage process – 1. General feature overlap; 2. (if necessary) comparison of defining features
• Characteristic vs. defining features
• Generally solves atypical category member problem
• Problem raised: cognitive economy
Encode comparison

Low overall similarity (rock is bird)

High overall similarity (robin is bird)

Compare all features

Intermediate similarity (ostrich is bird)

Compare just defining features

Mismatch

Match

“Yes”

“No”

Representation in LTM
• Network model (Collins & Qullian): retains categorical – hierarchical organization, but only unique features stored with each item. Items assumed to retain features of superordinate category members. Spreading activation key concept. Return of atypical category member problem.
• Modified semantic network model (Collins & Loftus). – removes hierarchical assumption. Distance represents semantic relatedness
Representation in LTM
• Propositional network model: Memory composed of interconnect network of fundamental propositions
• Proposition: smallest unit of information that can be judged t/f; typically represents relationship between concepts.
ACT* Propositional Network Model: J.R. Anderson
• Susan gave Maria, the president of the club, a white cat.