The search for common ground: Part II. Nonlinguistic performance by linguistically diverse learners.

Below-average performance on some nonlinguistic tasks often is considered a potential correlate of primary language impairment (LI). If nonlinguistic cognitive processing truly is deficient in children with LI, then measures may be identified that distinguish language learners at risk for LI that are independent of the number and type of languages learned. This study focuses on within- and across-task performance on 4 basic nonlinguistic processing tasks. The aim was to systematically investigate areas of potential overlap and divergence among 3 groups of linguistically diverse children: English-only speakers with LI, typically developing English-only speakers (EO), and typically developing bilingual Spanish-English speakers (BI). The performance of the 100 8-13-year-old children who took part in J. Windsor and K. Kohnert's (2004) study was analyzed. Experimental tasks were simple and choice versions of auditory- and visual-detection tasks. Each task included 4 levels of motor difficulty: responding with the preferred and nonpreferred hand and foot. Analyses revealed no significant differences among groups in simple auditory detection. The EO group was significantly faster than the LI group in each of the other 3 tasks. While the same pattern was evident for the BI group, the difference was significant only in choice visual detection. Overall patterns of response latency within and across tasks were qualitatively similar across the 3 groups. Development, indexed here by chronological age, played a significant role in predicting response latencies for children in all 3 groups.