| |
Abstract:
Abstract: Language abnormalities are common symptoms to both
schizophrenia and Alzheimer's disease. Alzheimer's patients are
thought to suffer from loss of semantic and lexical information. In
schizophrenia there is evidence that patients with disorganized
speech (i.e. thought disorder) have an intact lexical system but a
disturbed semantic system. Few studies have directly, however,
compared the two diseases, nor have they examined in detail the
relationship between lexical and semantic system deficits within
the two groups. In the present study, we wish to determine the
relationship among lexical integrity (measured by the Boston Naming
Test and Peabody Picture Vocabulary Test) to spreading activation
in the semantic system (measured by various priming paradigms) and
coherence in discourse (as rated on the Scale for the Assessment of
Thought, Language, and Communication) in schizophrenic and
Alzheimer's patients. Specifically, we address the questions of
whether degradation of the lexical system (as experienced by
Alzheimer's patients) will lead to a disruption in organization in
speech and spreading activation and secondly, how these patients
compare to a group of patients who experience a deficit in semantic
organization but maintain an intact lexicon (e.g. schizophrenics).
We hypothesize that patients with Alzheimer's disease will be more
susceptible to manipulations of cerebral distance than
schizophrenic patients, whereas schizophrenics will be more
susceptible to manipulations of semantic distance than Alzheimer's
patients in novel priming paradigms.
|
