A series of 3 studies is proposed to measure brief, time-varying neurocognitive patterns of basic phonemic and lexical linguistic processes: 1) phonemic and non-phonemic sounds divorced of semantic content, 2) acoustic phonemic judgements compared with semantic judgments, and 3) visual physical vs internal phonemic encoding of graphemes. A high degree of control of stimulus, response and performance-related factors will permit strong inferences about the spatiotemporal course of neurolinguistic processing. If successful, the proposed research may reveal previously unseen or unmeasured aspects of such processes and set the stage for further work in normals and patients. Measurements will be made using Neurocognitive Pattern (NCP) Analysis, a new method which has been successfully applied in studies of simple spatial and numeric judgments. In the proposed studies NCP analysis will be used to extract task-related signals from the obscuring background activity of the brain by applying mathematical pattern recognition to fraction-of-a-second data samples from 56 sensors placed on the scalp.
