Clinical Manifestations

Area of Science:

• Cognitive Psychology
• Neuroscience
• Linguistics

Background:

• The digit span task is a global standard for assessing auditory verbal short-term and working memory.
• Limited research exists on language-based digit span performance variations in older adults.
• This study addresses this gap by examining digit span across 14 languages in individuals aged 40-90.

Purpose of the Study:

• To investigate digit span performance variations in older adults across fourteen languages.
• To explore the influence of lexical and numerical properties on cognitive assessment outcomes.
• To identify language-specific factors affecting memory performance in aging populations.

Main Methods:

• Analyzed digit span performance in 3,681 participants across 14 language cohorts, including cognitively normal (CN), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups.
• Utilized ANOVA and general linear models to assess language differences in CN participants.
• Conducted Receiver operating characteristic (ROC) analyses for AD cutoff values and regression analyses to examine linguistic/numerical influences.

Main Results:

• Significant differences in forward and backward digit span performance were observed across the 14 language cohorts in CN individuals, even after controlling for age and education.
• Optimal cutoff values for AD detection varied significantly by language.
• Digit and syllable counts interacted to affect forward digit span accuracy in English speakers, while digit count negatively impacted backward digit span performance.

Conclusions:

• Language-specific variations in digit span performance underscore the impact of linguistic and numerical factors on cognitive assessments.
• These findings emphasize the critical importance of incorporating language diversity into cognitive research and assessment.
• Cognitive tests using digit stimuli are influenced by language, even when not directly assessing linguistic abilities.