Testing the Generalized Slowing Hypothesis in Specific Language Impairment

• Published in: Journal of speech, language, and hearing research Vol. 42; no. 5; pp. 1205 - 1218
• Main Authors: Windsor, Jennifer, Hwang, Mina
• Format: Journal Article
• Language: English
• Published: Rockville, MD ASHA 01.10.1999; American Speech Language Hearing Association; American Speech-Language-Hearing Association
• Subjects: Age Factors; Biological and medical sciences; Child; Child clinical studies; Child, Preschool; Children; Children & youth; Delayed Language Acquisition; Expressive Function of Language; Female; Humans; Language; Language and communication disorders; Language Disorders - complications; Language Disorders - diagnosis; Language Impairments; Language Skills; Language Tests; Learning disabilities; Learning Disorders - complications; Male; Medical sciences; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Reaction Time; Reaction times; Reading Comprehension; Response time; Severity of Illness Index; Specific Language Impairment; Speech Pathology; Theories; Young children; Human; Communication disorder; School age; Language processing; Response time; Pathogenesis; Child; Language disorder
• ISSN: 1092-4388; 1558-9102
• DOI: 10.1044/jslhr.4205.1205

This study investigated the proposition that children with specific language impairment (SLI) show a generalized slowing of response time (RT) across tasks compared to chronological-age (CA) peers. Three different theoretical models consistent with the hypothesis of generalized slowing—a proportional, linear, and nonlinear model—were examined using regression analyses of group RT data. Each model was an excellent fit with the RT data. The most parsimonious model indicated that the SLI group was proportionally slower than the CA group. Mean RTs of the SLI group were about one fifth slower across tasks than the CA group's mean RTs. Less slowing was evident for a subgroup of young children with expressive SLI than for children with mixed (expressive and receptive) SLI. Although the mean RT data reflected many individual SLI children's RT performance, not all SLI children showed generalized slowing.