title: Procedural learning deficits in specific language impairment (SLI): a meta-analysis of serial reaction time task performance.
abstract: Meta-analysis and meta-regression were used to evaluate whether evidence to date demonstrates deficits in procedural memory in individuals with specific language impairment (SLI), and to examine reasons for inconsistencies of findings across studies. The Procedural Deficit Hypothesis (PDH) proposes that SLI is largely explained by abnormal functioning of the frontal-basal ganglia circuits that support procedural memory. It has also been suggested that declarative memory can compensate for at least some of the problems observed in individuals with SLI. A number of studies have used Serial Reaction Time (SRT) tasks to investigate procedural learning in SLI. In this report, results from eight studies that collectively examined 186 participants with SLI and 203 typically-developing peers were submitted to a meta-analysis. The average mean effect size was .328 (CI95: .071, .584) and was significant. This suggests SLI is associated with impairments of procedural learning as measured by the SRT task. Differences among individual study effect sizes, examined with meta-regression, indicated that smaller effect sizes were found in studies with older participants, and in studies that had a larger number of trials on the SRT task. The contributions of age and SRT task characteristics to learning are discussed with respect to impaired and compensatory neural mechanisms in SLI.
authors: School of Psychology, Deakin University, Melbourne, Australia.
authors: Jarrad A G
authors: JA
authors: Lum
authors: School of Psychological Sciences, The University of Manchester, Manchester, UK. Electronic address: gina.conti-ramsden@manchester.ac.uk.
authors: Gina
authors: G
authors: Conti-Ramsden
authors: Murdoch Children's Research Institute, Melbourne, Australia.
authors: Angela T
authors: AT
authors: Morgan
authors: Department of Neuroscience, Georgetown University, Washington, D.C., USA.
authors: Michael T
authors: MT
authors: Ullman
mesh_terms: D006801:Humans; D007806:Language Disorders / Q000503:physiopathology*; D007859:Learning Disabilities / Q000503:physiopathology*; D008568:Memory / Q000502:physiology; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology*; D013647:Task Performance and Analysis
keywords: Meta-analysis; Procedural Deficit Hypothesis (PDH); Procedural memory; Serial reaction time (SRT) task; Specific language impairment (SLI)