Response Time Data: A Novel Measure of Cognitive Function and Cognitive Decline

Scholarly, clinical, and policy interest in cognitive function has grown over the last several decades in part due to large increases in Alzheimer’s Disease and related dementias as populations age. However, adequate measures of cognitive function have not been available in many research data sets. We argue that a wealth of previously unexploited survey data exists to model cognition and cognitive decline. We use metadata of the time it takes older respondents in the National Social Life, Health and Aging Survey, which we label response times (RT), to answer questions in a standard cognitive assessment. We develop a measure of RT to a survey-adapted form of the Montreal Cognitive Assessment (MoCA) and show that RT predict both concurrent and future MoCA scores. Our results show that longer RT at baseline predict lower MoCA scores five year later, net of baseline scores and controls. We show that RT also have predictive validity; they are highly correlated with other measures of physical decline and mortality. Our paper demonstrates that RT constitute a separate powerful measure of cognitive functioning and are particularly useful for individuals whose measured cognition suggests mild cognitive impairment, a part of the cognition distribution where errors are meaningful and particularly problematic. RT may be remarkably useful both to clinicians and social scientists because they can increase accuracy of cognitive assessment without increasing the time it takes to administer the assessment. <br>