NEUROPSYCHOLOGICAL PROCESSES OF AUTOMATIC SPEECH IN APHASIA (BRAIN, LANGUAGE).

摘要

In the commonly observed phenomenon of automatic speech, aphasic patients can occasionally produce lengthy grammatical utterances which are strikingly different compared to their typical language output. These automatic utterances are most apparent in Broca's aphasia where it has been argued that the major deficit is a disorder in syntactic processing. If this explanation is correct, it becomes difficult to explain how, in the absence of syntactic processing abilities, these aphasics can still produce the lengthy grammatical phrases seen in automatic speech production.;To test the question of the role of syntactic analysis in automatized phrases, eight chronic Broca's aphasics were asked to decide as quickly and as accurately as possible, if strings of words constituted possible English phrases. The stimuli were either AUTOMATIC phrases, COMMON (familiar though non-automatic) phrases of equal length and complexity, or non-grammatical phrases (serving as catch-trials). If Broca's aphasics actually process automatized phrases without involving syntactic analysis, then these patients' linguistic judgments about automatic phrases should be faster and more accurate than for the common phrases which require syntactic analysis. To determine if these automatic phrases are processed as single lexical items, the same patients were also asked to perform a lexical decision task. Responses to these SINGLE WORDS were compared to the judgments regarding automatic phrases.;Results indicated that Broca's aphasics responded to automatic phrases significantly faster and more accurately than to common phrases. This would imply that the automatized phrases require less processing than more propositional (non-automatic) language. In addition, there was no significant difference between reaction times and accuracy scores to single words and automatic phrases, indicating that similar processes may be involved in the accessing of single words as with automatized phrases.;It is proposed here that automatic speech utterances in aphasia are units of speech which have become so automatized, they no longer require the patient to actively work through the complications of syntactic processing. These phrases now become processed much like single lexical items. With the syntactic information already fixed into the utterance, their production no longer depends on that linguistic mechanism which participates in generating new linguistic utterances.