Accommodation of stress clash by children with typical and impaired language development

1. Accommodation of stress clash by children with typical and impaired language development Introduction Children with SLI have difficulty producing unfooted weak syllables [2, 3, 4] Generalized motor (e.g., [1]) and speech motor (e.g., [3]) deficits have been identified in children with SLI; one prominent hypothesis is that the organization of sequencing and timing (as needed for rhythmic alternation or stress clash resolution) underlies both language and generalized motor deficits [5] Thus, rhythmic alternations that are noncanonical (e.g., stress clash) may be particularly difficult for children with SLI • Procedure • Children saw two pictures corresponding to the target phrases • One picture was named for them • The other they named • Analyses & Results • Segmental Accuracy: no group difference (F < 1, p = .36) • See panels to the right for: • Word duration and variability • Phrase duration and variability • Pause duration and variability Word Duration Results* Word STI Results Word Analysis No main effect of group (F = .55, p = .46) Marginal effect of stress (F = 3.56, p = .07) Stress clash resulted in greater articulatory variability Word x Group (F = 9.77, p < .01) Children with TD produced pupup with more variability than paimib (F = 8.73, p = .01); children with SLI may not have differed in variability across words (F = 2.12, p = .17). Weak effect of group (F = 2.94, p = .1) children with SLI produced longer adjectives *Comparisons of paimib and pupup are, in general, not presented Question In the present study we asked whether task demands associated with stress clash would influence the production of phrases containing iambic words in children with SLI or in their TD peers • Conclusions • Both children with TD and SLI showed sensitivity to the increased demands associated with stress clash; these difficulties were especially pronounced in children with SLI. • Group differences were clearly differentiated in the longer analysis window, likely as the result of the increased pause time between the adjective and the noun, and especially in the clash condition. • The longer analysis window may be a better means of measuring procedural memory/processing Pause Analysis Phrase Analysis Phrase Duration Results Phrase STI Results • Method • Participants • 16 children with SLI or a history of SLI (5;5 – 8;11) • 16 age-matched children with TD (6;0 – 8;8) • Materials Kinematic Record Pause Results Trimmed Productions Normalized Productions Acknowledgments This research was supported by NIH/NIDCD R01 DC04826 to Dr. Lisa Goffman and NIH T32 DC000030-17 to Dr. Laurence Leonard. Dr. Richtsmeier is a trainee on the latter grant. Effect of group (F = 11.17, p < .01) Children with SLI produced longer phrases Effect of stress (F = 4.58, p = .04) Stress clash resulted in longer phrases Effect of group (F = 16.77, p < .001) Children with SLI were more variable Word x Stress (F = 8.47, p < .01) Children were more variable for paimib when stress alternated (F = 13.16, p < .01) but the same or slightly more variable for pupup when stress clashed (F = 2.31, p = .14) Spatiotemporal Index (STI) • References • Bishop, D. V. M. (2002). Motor immaturity and specific speech and language impairment: Evidence for a common genetic basis. American Journal of Medical Genetics, 114, 56–63. • Goffman, L. (1999). Prosodic influences on speech production in children with specific language impairment. Journal of Speech, Language, and Hearing Research, 42, 1499–1517. • Goffman, L. (2004). Kinematic differentiation of prosodic categories in normal and disordered language development. Journal of Speech, Language, and Hearing Research, 47, 1088–1102. • McGregor, K. K. & Leonard, L. B. (1994). Subject pronoun and article omissions in the speech of children with specific language impairment: A phonological interpretation. Journal of Speech and Hearing Research, 37, 171–181. • Ullman, M. T. & Pierpont, E. I. (2005). Specific language impairment is not specific to language: The procedural deficit hypothesis. Cortex, 41, 399–433. Effect of group (F = 7.33, p = .01) Children with SLI had longer pauses Effect of stress (F = 4.94, p = .04) Stress clash resulted in longer pauses