Emergence of a powerful connection between sensory and cognitive functions across the adult life span: A new window to the study of cognitive aging?

TLDR

The study discusses various explanations for sensory–cognitive links, notably the common‑cause hypothesis. The authors aim to show that the growing age‑related sensory–cognitive link reflects brain aging and to encourage focusing on shared factors to explain cognitive aging. A cross‑sectional study of 687 adults aged 25–103 measured visual and auditory acuity alongside 14 cognitive tasks to assess sensory–intelligence relationships. The proportion of intellectual variance explained by sensory function rose from 11 % in adults to 31 % in older adults, and fluid cognition showed a similarly strong age‑related sensory link across both age groups.

Abstract

Six hundred eighty seven individuals ages 25-103 years were studied cross-sectionally to examine the relationship between measures of sensory functioning (visual and auditory acuity) and intelligence (14 cognitive tasks representing a 5-factor space of psychometric intelligence). As predicted, the average proportion of individual differences in intellectual functioning connected to sensory functioning increased from 11% in adulthood (25-69 years) to 31% in old age (70-103 years). However, the link between fluid intellectual abilities and sensory functioning, albeit of different size, displayed a similarly high connection to age in both age groups. Several explanations are discussed, including a "common cause" hypothesis. In this vein, we argue that the increase in the age-associated link between sensory and intellectual functioning may reflect brain aging and that the search for explanations of cognitive aging phenomena would benefit from attending to factors that are shared between the 2 domains.