Abstract
Dyslexia, defined as a specific impairment in decoding the written script, is the most widespread learning difficulty. However, individuals with dyslexia (IDDs) also consistently manifest reduced short-term memory (STM) capacity, typically measured by Digit Span or non-word repetition tasks. In this paper we report two experiments which test the effect of item frequency and the effect of a repeated sequence on the performance in STM tasks in good readers and in IDDs. IDDs’ performance benefited less from item frequency, revealing poor use of long-term single item statistics. This pattern suggests that the amply reported shorter verbal spans in dyslexia may in fact reflect their impaired sensitivity to items’ long-term frequency. For repeated sequence learning, we found no significant deficit among IDDs, even when a sensitive paradigm and a robust measure were used.
- short-term memory
- long-term memory
- dyslexia
- chunking
- statistical learning
Footnotes
Author Note Eva Kimel, the Edmond and Lily Safra Center for Brain Sciences, the Hebrew University of Jerusalem.
Itay Lieder, the Edmond and Lily Safra Center for Brain Sciences, the Hebrew University of Jerusalem.
Merav Ahissar, the Edmond and Lily Safra Center for Brain Sciences and the Department of Psychology, the Hebrew University of Jerusalem.
This work was supported by the Canadian Institutes of Health Research, the International Development Research Center, the Israeli Science Foundation, and the Azrieli Foundation (grant No. 2425/15), and a personal grant from the Israel Science Foundation (grant No. 1650/17).