The procedural learning deficit hypothesis of language learning disorders: we see some problems

Abstract

Impaired procedural learning has been suggested as a possible cause of developmental dyslexia (DD) and specific language impairment (SLI). This study examined the relationship between measures of verbal and non-verbal implicit and explicit learning and measures of language, literacy and arithmetic attainment in a large sample of 7 to 8-year-old children. Measures of verbal explicit learning were correlated with measures of attainment. In contrast, no relationships between measures of implicit learning and attainment were found. Critically, the reliability of the implicit learning tasks was poor. Our results show that measures of procedural learning, as currently used, are typically unreliable and insensitive to individual differences. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=YnvV-BvNWSo.

Figure 1

Immediate serial recall and Hebb task verbal and non‐verbal stimuli

Figure 2

Non‐verbal serial reaction time task. Children pressed the button on the controller that matched the location of the stimulus

Figure 3

Example matrices for the non‐verbal and verbal conditions of the contextual cueing task

Figure 4

Response times for the SRT and contextual cueing implicit learning tasks, and recall scores for the Hebb tasks. Error bars are 95% confidence intervals

Figure 5

Confirmatory factor analysis showing relationship of memory and attainment tasks to latent variables of verbal and non‐verbal memory. WL‐L = Word Lists learning score; WL‐D = Word Lists delay score; WL‐C = Word Lists consolidation score; DL‐L = Dot Locations learning score; DL‐D = Dot Locations delay score; DL‐C = Dot Locations consolidation score: ISR(V) = verbal immediate serial recall; ISR(NV) = non‐verbal immediate serial recall; Language = TROG‐2 total score; Literacy = Literacy composite of WRAT spelling, TOWRE word and non‐word reading and Picture Word Matching; Arithmetic = composite of TOBANS addition, subtraction and multiplication subtests