Dealing with negated knowledge and inconsistency in a neurally motivated model of memory and reflexive reasoning

TitleDealing with negated knowledge and inconsistency in a neurally motivated model of memory and reflexive reasoning
Publication TypeTechnical Report
Year of Publication1995
AuthorsShastri, L., & Grannes D. Jeffrey
Other Numbers981
Keywordsdynamic bindings, inconsistent knowledge, knowledge representation, long-term memory, negation, neural oscillations, rapid reasoning, synchrony, tractable reasoning, working memory
Abstract

Recently, SHRUTI has been proposed as a connectionist model of rapid reasoning. It demonstrates how a network of simple neuron- like elements can encode a large number of specific facts as well as systematic knowledge (rules) involving n-ary relations, quantification and concept hierarchies, and perform a class of reasoning with extreme efficiency. The model, however, does not deal with negated facts and rules involving negated antecedents and consequents. We describe an extension of SHRUTI that can encode positive as well as negated knowledge and use such knowledge during reflexive reasoning. The extended model explains how an agent can hold inconsistent knowledge in its long-term memory without being "aware" that its beliefs are inconsistent, but detect a contradiction whenever inconsistent beliefs that are within a certain inferential distance of each other become co-active during an episode of reasoning. Thus the model is not logically omniscient, but detects contradictions whenever it tries to use inconsistent knowledge. The extended model also explains how limited attentional focus or action under time pressure can lead an agent to produce an erroneous response. A biologically signficant feature of the model is that it uses only local inhibition to encode negated knowledge. Like the basic model, the extended model encodes and propagates dynamic bindings using temporal synchrony.

URLhttp://www.icsi.berkeley.edu/ftp/global/pub/techreports/1995/tr-95-041.pdf
Bibliographic Notes

ICSI Technical Report TR-95-041

Abbreviated Authors

L. Shastri and D. J. Grannes

ICSI Publication Type

Technical Report