Brain Processing of Language Meanings

Study Summary

This research trial will study discourse processing-that is, how the brain processes the meaning of language. It will examine, for example, how words and sentences are interpreted in cases where more than one meaning is possible. The study will include two parts: 1. An investigation of the role of the prefrontal cortex of the brain in discourse processing will compare test performance of patients with prefrontal cortex damage with that of healthy age-matched normal volunteers. 2. An investigation of the role of aging in discourse processing will compare test performance of young healthy subjects (18 to 40 years old) with older healthy subjects (41 to 80 years old). All study candidates-both normal volunteers and patients with brain damage-must be at least 18 years old, speak English as their native language, have a high school degree or equivalent (GED), read on a minimum fourth grade level and be right-handed. Study candidates who have central nervous system disease, dysfunction or trauma will have a routine history and neurological examination. They will also undergo neuropsychological testing if they have not already done so. Patients with neurological damage who have not had a magnetic resonance imaging (MRI) scan within six months or a year will be asked to undergo this procedure. Study participants will take verbal or written tests; sit in front of a computer screen and press computer keys in response to what they are shown; answer questions from an examiner, which may be tape-recorded; and fill out questionnaires. There will be rest breaks between tasks. The studies will be spread over three to four days, with sessions lasting from 30 minutes to three hours.