The relationship of nonlinguistic visual processing capacity, speed, and vocabulary ability in children with specific language impairment

Abstract

Objectives: The purpose of this study was to investigate whether children with specific language impairment (SLI) show their deficits when performing nonlinguistic processing tasks, and whether the relationship of nonlinguistic information processing tasks (processing capacity/speed) and language (receptive/expressive vocabulary) differ in children with and without language impairment. Methods: Sixty-four children (SLI=32, NL=32) aged 4-8 years participated in this study. This study used matrix forward (Matrix_f) and backward (Matrix_b) for examining nonlinguistic processing capacity, and a visual number search to examine nonlinguistic processing speed. Results: SLI group had significantly lower performance in Matrix_b, VNS_ Acc(C5), and slower in VNS_RT(C1) expect for Matrix_f. In addition, there was a significant correlation between language and nonlinguistic information processing (Matrix_b, VNS_C1C4_Acc) in NL group, but there was no significant correlation in the SLI group. Conclusion: Children with SLI store and retrieve visual information sequentially similarly to their NL peers, but they have difficulty remembering the information in reverse. In addition, the relationship between nonlinguistic processing ability and vocabulary was not significant in SLI group. These results indicate that children with SLI need various opportunities to improve their visual processing capacity and speed because of a weak connection between processing and vocabulary.