Listeners tend to categorize an ambiguous speech sound so that it forms a word with its context (Ganong, 1980). This effect could reflect feedback from the lexicon to phonemic activation (McClelland & Elman, 1986), or the operation of a task-specific phonemic decision system (Norris, McQueen, & Cutler, 2000). Because the former account involves feedback between lexical and phonemic levels, it predicts that the lexicon's influence on phonemic decisions should be delayed and should gradually increase in strength. Previous response time experiments have not delivered a clear verdict as to whether this is the case, however. In 2 experiments, listeners' eye movements were tracked as they categorized phonemes using visually displayed response options. Lexically relevant information in the signal, the timing of which was confirmed by separate gating experiments, immediately increased eye movements toward the lexically supported response. This effect on eye movements then diminished over the course of the trial rather than continuing to increase. These results challenge the lexical feedback account. The present work also introduces a novel method for analyzing data from 'visual-world' type tasks, designed to assess when an experimental manipulation influences the probability of an eye movement toward the target. (PsycINFO Database Record

Purpose We piloted two new treatments, one based on sentence to picture matching (SPM) and the other based on object manipulation (OM), that train participants on the thematic roles of sentences using pictures or by manipulating objects. Methods Using a single subject multiple baseline design, sentence comprehension was trained on the affected sentence type in one task-related protocol in 15 participants with aphasia. The two tasks were SPM and OM and the treatment stimuli were Object relatives; Object clefts; Passives and Unaccusatives as well as two control structures; Object relatives with a complex NP, active sentences with three NPs. Results The criteria for efficacious treatment was an increase in the level of performance from the pre-treatment probes to post-treatment probes for the treated structure such that accuracy rose from at or below chance to above chance and either a) accuracy on rose by 33% or b) the effect size was 2.6. Based on these criteria, the success rate for training the target structure was 4/7 participants in the OM condition and 2/6 participants in the SPM condition. Conclusions The outcome of this study illustrates the utility of this theoretically-motivated and efficacious treatment for sentence comprehension deficits in participants with aphasia.

Purpose Prior studies of discourse comprehension have concluded that the deficits of persons with aphasia (PWA) in syntactically based comprehension of sentences in isolation are not predictive of deficits in comprehending sentences in discourse (Brookshire & Nicholas, 1984; Caplan & Evans, 1990). However, these studies used semantically constrained sentences in discourse, which do not require syntactic analysis to be understood. We developed a discourse task to assess the effect of syntactic complexity, among other factors, upon discourse comprehension. Method 38 PWA and 30 healthy control subjects were presented with passages that contained 2 – 3 semantically reversible sentences that were either syntactically simple or syntactically complex. The passages were presented auditorily and comprehension was assessed with the auditory and written presentation of four multiple-choice questions immediately following each passage. Results Passages with syntactically simple sentences were better understood than passages with syntactically complex sentences. Moreover, semantically constrained sentences were more likely to be accurately interpreted than semantically reversible sentences. Comprehension accuracy on our battery correlated positively with comprehension accuracy on an existing battery. Conclusions The results show that the presence of semantically reversible syntactically complex sentences in a passage affects comprehension of the passage in both PWA and neurologically healthy individuals.