The auditory Mismatch Negativity reflects accelerated aging in adults with Down's Syndrome

Downs Syndrome (DS) is associated with premature and accelerated ageing and a propensity for early-onset Alzheimers disease (AD). The early symptoms of dementia in people with DS may reflect frontal lobe vulnerability to amyloid deposition. The Mismatch Negativity (MMN) is a frontocentral component elicited by auditory violations of expected sensory input and it reflects sensory memory and automatic attention switching. In the typically developing (TD) population, the MMN response has been found to decrease with age. In the cross-sectional phase of this study the MMN was used to investigate the premature neurological ageing hypothesis of DS. In the longitudinal phase, we evaluated the MMN as a potential predictor of cognitive decline. The study found that age predicted MMN amplitude in DS but not in those who are TD, showing that the MMN reflects accelerated ageing in DS. However, a follow-up of 34 adults with DS found that neither amplitude nor latency of the MMN predicted cognitive decline one year later.