Two types of ambiguities commonly encountered during sentence comprehension are lexical and syntacticambiguities. Disambiguation is typically achieved easily, as it is aided by language cues, such as thefrequency of occurrence and/or the plausibility of interpretation with relation to the surrounding context. Thisresearch will investigate the use of frequency and plausibility cues within lexical and syntactic ambiguities,as a function of working memory capacity. Frequency cues will be manipulated while plausibility cues areheld constant, and vice versa, in high and low working memory groups. An individual's ability to resolveambiguities will be calculated by comparing ambiguous sentences to unambiguous control sentences usinga self-paced reading paradigm, previously shown to be sensitive to ambiguity effects and differences inworking memory capacity.
The first aim i s to investigate whether a common cognitive mechanism is utilizedwhen resolving these ambiguities. In the 1990s, lexical processing, syntactic processing, and language cueswere proposed to utilize a single mechanism. This idea countered the concept of modularity proposed byFodor in the 1980s. No work has been published to test whether a single mechanism is used to resolvethese ambiguities, despite significant implications for language processing models and theories.
The secondaim i s to determine whether frequency cues are used to a greater extent than plausibility cues within anindividual, as plausibility cues may be more difficult to process.
The third aim i s to determine whetherfrequency and plausibility cues are used differently in sentence processing as a function of working memory,as individuals with low working memory may have increased difficulty processing language cues. Theresults of this research will increase scientific knowledge of normal ambiguity resolution in sentenceprocessing, and the cognitive resources that support ambiguity resolution.Previous research has suggested that ambiguities in sentence comprehension are disambiguated bylanguage cues and mediated by an individual's working memory capacity. The goal of this research is tofurther the pursuit of fundamental knowledge regarding the mechanisms that support the disambiguation oflexical and syntactic ambiguities as a function of working memory capacity. The results of this research maybe applied to the development of more detailed models of normal language processing, which may lead tobetter diagnostic tools and treatment programs for rehabilitating persons with disordered language andimproving their quality of life.
