ARTIFICIAL INTELLIGENCE LABORATORY THE lJSF OF TIIREAD MEMOR\' IN AMNESIC APHASIA AND CONCEPT LEARNING.(note

~~~T~!\g. We propose a new type of semantic memory, called thread memory. Thc primitives or this memory are threads, dcfined as keyed multilink, loop-frce chains, which link semantic nodes. All links run from superordinate cat.egories to subordinate categories. This is the opposite direction to those in the usual tree structure in that brother nodes in the trce share t.he str"ucture above their common ancestors. The most valuable fcilture of the thread memory is its capacity to learn. A program which can lei1rn concepts using as data children's primer books, was written by R. Greenhlatt and runs on the LISP-MACHINE at the MIT-AI Laboratory. We have considered the thread memory as working hypothesis for exploring the mechanisms of naming deficits in aphasia and the ways of rehabilitation.