Impairment of sentence comprehension

Area of Science:

• Psycholinguistics
• Neurolinguistics
• Cognitive Neuroscience

Background:

• Thematic role assignment is crucial for sentence comprehension, determining agent-patient relationships.
• Two distinct comprehension impairments, semantic dementia and asyntactic comprehension, offer insights into this process.

Purpose of the Study:

• To investigate the role of semantic and syntactic information in thematic role assignment.
• To differentiate the comprehension mechanisms in semantic dementia and asyntactic comprehension.

Main Methods:

• Examined thematic role assignment in patients with semantic dementia and asyntactic comprehension.
• Assessed sentence plausibility judgments in normal subjects and aphasic patients.
• Analyzed the influence of semantic constraints on thematic assignment.

Main Results:

• Loss of word meaning in semantic dementia did not hinder thematic role assignment.
• Syntactic information and verb knowledge are sufficient for thematic assignment.
• Normal subjects show semantic influences on thematic assignment, evidenced by faster plausibility judgments.
• Asyntactic comprehenders exhibit heightened semantic constraint effects on plausibility judgments.

Conclusions:

• Syntactic processing plays a sufficient role in thematic role assignment, independent of semantic knowledge.
• Semantic influences normally modulate sentence processing, becoming more prominent in specific comprehension deficits.
• Findings contribute to understanding sentence processing and the neural underpinnings of language comprehension.