title: Working memory span in mild cognitive impairment. Influence of processing speed and cognitive reserve.
abstract: BACKGROUND
  Mild cognitive impairment (MCI) often includes episodic memory impairment, but can also involve other types of cognitive decline. Although previous studies have shown poorer performance of MCI patients in working memory (WM) span tasks, different MCI subgroups were not studied.
  
  
  METHODS
  In the present exploratory study, 145 participants underwent extensive cognitive evaluation, which included three different WM span tasks, and were classified into the following groups: multiple-domain amnestic MCI (mda-MCI), single-domain amnestic MCI (sda-MCI), and controls. General linear model was conducted by considering the WM span tasks as the within-subject factor; the group (mda-MCI, sda-MCI, and controls) as the inter-subject factor; and processing speed, vocabulary and age as covariates. Multiple linear regression models were also used to test the influence of processing speed, vocabulary, and other cognitive reserve (CR) proxies.
  
  
  RESULTS
  Results indicate different levels of impairment of WM, with more severe impairment in mda-MCI patients. The differences were still present when processing resources and CR were controlled.
  
  
  CONCLUSIONS
  Between-group differences can be understood as a manifestation of the greater severity and widespread memory impairment in mda-MCI patients and may contribute to a better understanding of continuum from normal controls to mda-MCI patients. Processing speed and CR have a limited influence on WM scores, reducing but not removing differences between groups.
authors: Department of Developmental and Educational Psychology, University of Santiago de Compostela, Spain.
authors: David
authors: D
authors: Facal
authors: Department of Developmental and Educational Psychology, University of Santiago de Compostela, Spain.
authors: Onésimo
authors: O
authors: Juncos-Rabadán
authors: Department of Developmental and Educational Psychology, University of Santiago de Compostela, Spain.
authors: Arturo X
authors: AX
authors: Pereiro
authors: Department of Developmental and Educational Psychology, University of Santiago de Compostela, Spain.
authors: Cristina
authors: C
authors: Lojo-Seoane
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000145:classification / Q000175:diagnosis* / Q000523:psychology; D058245:Cognitive Reserve; D005260:Female; D006801:Humans; D008297:Male; D061212:Memory, Episodic; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011930:Reaction Time / Q000502:physiology; D014825:Vocabulary