The Effects of Age on Processing and Storage in Working Memory Span Tasks and Reading Comprehension

Abstract

Background/Study Context: Declines in verbal working memory span task performance have been associated with deficits in the language processing abilities of healthy older adults, but it is unclear how storage and processing contribute to this relationship. Moreover, recent studies of the psychometric properties of span measures in the general cognitive literature highlight the need for a critical reassessment of age-related differences in working memory task performance.

Methods: Forty-two young (M_age = 19.45 years) and 42 older participants (M_age = 73.00 years) completed a series of neuropsychological screening measures, four memory span tasks (one-syllable word span, three-syllable word span, reading span, and sentence span), and a measure of reading comprehension. Each span measure was completed under self-paced and timed encoding conditions. A 2 (age) × 2 (task type) × 2 (encoding conditions) mixed-model design was used.

Results: (1) Age effects were reliable for both simple and complex span task performance; (2) limiting the available encoding time yielded lower recall scores across tasks and exacerbated age differences in simple span performance; and (3) both encoding condition and age affected the relationship between each of the span measures and the relationship between span and reading comprehension.

Conclusion: Declines in both storage and processing abilities contributed to age differences in span task performance and the relationship between span and reading comprehension. Although older people appear to benefit from task administration protocols that promote successful memory encoding, researchers should be aware of the potential risks to validity posed by such accommodations.

Notes

¹The omitted passage was approximately four paragraphs longer than the seven other passages and consisted of eight questions.

²Studies have shown that span task scoring procedure affects the magnitude of the relationship between span and verbal cognition (Friedman & Miyake, 2005; Waters & Caplan, 2003). The span task scoring procedure used in the current study (total words recalled) was selected based on the recommendations of Friedman and Miyake (2005) who reported that it was a more reliable span metric than other scoring methods.