Early detection of cognitive deficits using eyeblink classical conditioning

In three separate studies, we demonstrated that production of less than 25% conditioned responses (CRs) in the 400 ms delay eyeblink classical conditi oning (EBCC) paradigm had a sensitivity for Alzheimer's disease (AD) of 95% , 86%, and 100%. In a 3-year longitudinal study of normal older adults, poo r EBCC predicted dementia onset in 63% of the participants who were poor co nditioners (<25% CRs). Here we present longitudinal neuropsychological test data collected two years after EBCC testing with 17 elderly subjects (8 go od and 9 poor conditioners) who scored in the normal range on clinical deme ntia screening measures at the beginning of the study. EBCC scores below 25 % CRs predicted statistically significant deficits on neuropsychological te sts, and one poor conditioner has subsequently received a diagnosis of prob able AD. These results provide additional evidence that EBCC may have utili ty in the early identification of dementia and AD.