This study will use an anticholinergic pharmacological probe to examine attention network
function in SCD using EEG. The overall hypothesis is that in older adults with SCD, normal
cognitive performance is maintained by compensatory attention network activity, supported by
enhanced cholinergic function. The investigators anticipate that SCD will be associated with
greater compensatory attention network activity and that disrupting this compensatory process
through anticholinergic challenge will result in a greater negative effect on attentional
performance (Attention Network Test, ANT) and attention network functioning (EEG) in older
adults with SCD compared to those without SCD.