Working memory mediates the relationship between intellectual enrichment and long-term memory in multiple sclerosis: An exploratory analysis of cognitive reserve

Joshua Sandry, James F. Sumowski

Research output: Contribution to journalArticle

13 Scopus citations


Some individuals with multiple sclerosis (MS) show decrements in long-term memory (LTM) while other individuals do not. The theory of cognitive reserve suggests that individuals with greater pre-morbid intellectual enrichment are protected from disease-related cognitive decline. How intellectual enrichment affords this benefit remains poorly understood. The present study tested an exploratory meditational hypothesis whereby working memory (WM) capacity may mediate the relationship between intellectual enrichment and verbal LTM decline in MS. Intellectual enrichment, verbal LTM, and WM capacity were estimated with the Wechsler Test of Adult Reading and Peabody Picture Vocabulary Test, delayed recall of the Hopkins Verbal Learning Test-Revised and Logical Memory of the Wechsler Memory Scale, and Digit Span Total, respectively. Intellectual enrichment predicted LTM (B=.54; p=.003) and predicted WM capacity (B=.91; p<.001). WM capacity predicted LTM, (B=.44; p<.001) and fully mediated the relationship between intellectual enrichment (B=.24; p=.27) and LTM (B=.33, p=.03), Sobel test, Z=3.31, p<.001. These findings implicate WM capacity as an underlying mechanism of cognitive reserve and are an initial first step in understanding the relationship between intellectual enrichment, WM, and LTM in MS. (JINS, 2014, 20, 1-5)

Original languageEnglish
Pages (from-to)868-872
Number of pages5
JournalJournal of the International Neuropsychological Society
Issue number8
Publication statusPublished - 1 Aug 2014



  • Cognitive reserve
  • Intellectual enrichment
  • Intelligence
  • Long-term memory
  • Multiple sclerosis
  • Working memory capacity

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