Dyslexia is a clinical diagnosis often associated with phonological processing deficits. There are, however, other areas of concern, such as the presence of auditory temporal processing (ATP) disorders. One method of investigating ATP is the gap detection (GD) paradigm. This study investigated GD performance using the Gaps-in-Noise© (GIN) test in three groups of 30 children, aged 8 to 9 years. GD thresholds and gap identification scores (%) were determined for each participant. The three groups of participants included (Group I) children with dyslexia and phonological deficits, (Group II) children with dyslexia and no significant phonological deficits, and (Group III) normal reading peers. Repeated-measures ANOVA showed that GD thresholds for the three groups were significantly different. Group I showed longer GD thresholds (RE, 8.5 msec; LE, 8 msec), than did Group II (4.9 msec for both ears) or Group III (RE, 4.2 msec; LE, 4.3 msec). Close inspection of the threshold values for the three groups revealed that the thresholds for Group II overlapped substantially with those of Group III, but not with those of Group I. Similar trends were also noted for the gap identification analysis. From a clinical perspective, the majority of participants in Group II and all participants in Group III performed within normal limits on both measures (i.e., thresholds and identifications), while performance of participants in Group I fell below established norms on these measures. Finally, additional analyses revealed that ATP was highly correlated with phonological processing measures indicating a relationship between the presence of phonological deficits and ATP deficits. This study confirmed that ATP deficit is a factor to be considered in dyslexia and suggested that the GIN© test is a promising clinical tool that should be incorporated in the evaluation procedures for children with reading difficulties.

Four experiments investigated how verb-specific lexical information is used in resolving the noun phrase complement/tensed sentence complement ambiguity, extending prior research (Ferreira & Henderson, 1990; Holmes, Stowe, & Cupples, 1989; Trueswell, Tannenhaus, & Kello, 1993). Predictions from the Constraint Satisfaction Approach (MacDonald, 1994; MacDonald, Pearlmutter, & Seidenberg, 1994a; 1994b; Tannenhaus & Trueswell, 1994; Trueswell, Tannenhaus, & Kello, 1993) and the Lexical Filtering Proposal (Clifton, Speer, & Abney, 1991; Ferreira & Henderson, 1990; 1991; Frazier, 1987; Frazier & Clifton, 1989) were contrasted. The former approach assumes that lexical information is used to guide the analysis of syntactically ambiguous phrases, predicting that comparable effects of verb bias should be observed for ambiguous versus unambiguous tensed sentence complements as for sentences containing temporarily ambiguous noun phrase complements and for sentences containing unambiguous tensed sentence complements. The latter proposal, an extension of the Garden Path Model (Frazier, 1978; Frazier & Fodor, 1978; Frazier, & Rayner, 1982), assumes that lexical information may be used when it becomes available; however, the analysis of syntactically ambiguous phrases is not delayed until lexical information becomes available, but instead is made in accordance with the syntactic parsing principles Minimal Attachment and Late Closure. Therefore, larger effects of verb bias are predicted for ambiguous versus unambiguous tensed sentence complements than for sentences containing temporarily ambiguous noun phrase complements or for sentences containing unambiguous tensed sentence complements. In Experiments 1-3, two self-paced reading methods (phrase by phrase and word by word presentation) and eye tracking were used to compare reading time on sentences containing ambiguous and unambiguous tensed sentence complements, containing either short or long ambiguous noun phrases, preceded by either NP-biased verbs, i.e., verbs generally occurring most frequently with noun phrase complements, or S-biased verbs, i.e., verbs generally occurring most frequently with tensed sentence complements. In Experiment 4, eye tracking was used to compare reading time on sentences containing temporarily ambiguous tensed sentence complements, temporarily ambiguous noun phrase complements, and unambiguous tensed sentence complements, containing either short or long ambiguous noun phrases, preceded by either NP-biased or S-biased verbs. Results from these four experiments are most compatible with the Lexical Filtering Proposal. Implications for models of human sentence processing are discussed.