Objective and Background
Patients with Alzheimer’s disease (AD) typically have
impaired declarative memory as a result of hippocampal damage early in the
disease. We investigated whether feelings of emotion can persist in patients
with AD, even after their declarative memory for what initially caused the
feelings has faded.
Methods
A sample of 17 patients with probable AD and 17 healthy comparison
participants (case-matched for age, sex and education) underwent two
separate emotion induction procedures that involved watching film clips
aimed at inducing states of sadness or happiness. Real-time emotion ratings
were collected at baseline and at three post-induction time points, and a
test of declarative memory was administered shortly after each
induction.
Results
As expected, declarative memory for both the sad and happy films was
impaired in patients with AD. Despite their severe memory impairment, the
patients continued to report elevated levels of sadness and happiness that
persisted well beyond their memory for the films. This outcome was
especially prominent following the sadness induction, with sustained
elevations in sadness lasting for over 30 minutes, including in patients
with entirely no recollection for the films.
Conclusions
These findings indicate that patients with AD can experience
prolonged states of emotion that persist well beyond their memory for the
events that originally caused the emotion. This extends a similar finding
previously reported in patients with hippocampal amnesia, and has important
implications for the management and care of patients with AD.