Neural Network Models of Schizophrenic Language
Since 2003
Very little is known about the underlying causes of schizophrenia. Currently, the most reliable means for diagnosing schizophrenia is to observe certain disturbances of language, such as (1) positive thought disorder (i.e. derailed conversational language), (2) delusion formation of the idee fixe type, and (3) negative thought disorder (i.e. curtailed language output). We are using DISCERN, a connectionist natural language processing system that learns stories in order to paraphrase them and answer questions about them, to test hypotheses about the neuropathology that underlies schizophrenia: excessive developmental pruning of network connectivity, dopamine instability of dynamic learning, and semantic network hyperpriming. The original DISCERN model was extended to learn a larger corpus of stories that consist of multiple scripts and include emotion-coding and self-reference. It is then lesioned in several ways modeling the possible underlying causes and the degree to which the system displays the characteristic symptoms of schizophrenia is observed in each case. A parallel, pilot study will test normal and schizophrenic human subjects on similar story-processing tasks, helping to refine the model as well as allowing the results from the model to guide clinical research.
Peggy Fidelman Former Ph.D. Student
Risto Miikkulainen Faculty risto [at] cs utexas edu
Uli Grasemann Postdoctoral Alumni uli [at] cs utexas edu
Ralph E. Hoffman Collaborator ralph hoffman [at] yale edu
Modeling Acute and Compensated Language Disturbance in Schizophrenia Uli Grasemann, Ralph Hoffman and Risto Miikkulainen In Proceedings of the 33rd Annual Meeting of the Cognitive Science Society, 2011. 2011

Using Computational Patients to Evaluate Illness Mechanisms in Schizophrenia Ralph E. Hoffman, Uli Grasemann, Ralitza Gueorguieva, Donald Quinlan, Douglas Lane, and Risto Miikku... Biological Psychiatry, 69:997--1005, 2011. 2011

A Computational Model of Language Pathology in Schizophrenia Uli Grasemann PhD Thesis, Department of Computer Science, The University of Texas at Austin, Austin, TX, December ... 2010

A Subsymbolic Model of Language Pathology in Schizophrenia Uli Grasemann, Risto Miikkulainen, Ralph Hoffman In Proceedings of the 29th Annual Conference of the Cognitive Science Society, 311-316, Hill... 2007

A Subsymbolic Model of Complex Story Understanding Peggy Fidelman, Risto Miikkulainen and Ralph Hoffman In Proceedings of the 27th Annual Meeting of the Cognitive Science Society, 2005. 2005

Subsymbolic Natural Language Processing: An Integrated Model Of Scripts, Lexicon, And Memory Risto Miikkulainen , Cambridge, MA, 1993. MIT Press. 1993

DISLEX

This package contains the C-code and data for training and testing the DISLEX model of the lexicon, which is also par...

1994

PROC The PROC package contains the C-code and data for training and testing the story processing modules of the DISCERN syste... 1994

DISCERN DISCERN is a large, modular neural network system for reading, paraphrasing and answering questions about stereotypical ... 1993