EMERGENCE OF A POWERFUL CONNECTION BETWEEN SENSORY AND COGNITIVE FUNCTIONS ACROSS THE ADULT LIFE-SPAN - A NEW WINDOW TO THE STUDY OF COGNITIVE AGING

Six hundred eighty seven individuals ages 25-103 years were studied cr oss-sectionally to examine the relationship between measures of sensor y functioning (visual and auditory acuity) and intelligence (14 cognit ive tasks representing a 5-factor space of psychometric intelligence). As predicted, the average proportion of individual differences in int ellectual functioning connected to sensory functioning increased from 11% in adulthood (25-69 years) to 31% in old age (70-103 years). Howev er, the link between fluid intellectual abilities and sensory function ing, albeit of different size, displayed a similarly high connection t o age in both age groups. Several explanations are discussed, includin g a ''common cause'' hypothesis. In this vein, we argue that the incre ase in the age-associated link between sensory and intellectual functi oning 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.