• The P50 is an early cortical potential that is elicited in response to both standard and
deviant stimuli. It is thought to reflect neural activity in the temporal gyrus, a region that is
important for speech and language.
• P50 amplitude in response to standard stimuli is increased in subjects at heightened risk
of developing AD, and recently published literature suggests that high P50 amplitude can
be predictive of positive amyloid status in MCI patients.
• The increase in P50 amplitude is no longer significant in subjects with probable mild AD.
However, these subjects may still show an increase in the peak average amplitude.
