Source memory and recognition of emotional versus neutral pictures in patients with Alzheimer's Disease

The amygdala is a neural structure that is involved in modulating memory for
emotional material. It has strong connections with the hippocampus, where
information is stored. In psychological experiments, emotional content seems to
enhance long term memory, but disturb working memory processes (for example,
binding of features). This may be due to attentional processes that focus on
the content of the picture rather than the context in which it appears.
In patients with Alzheimer*s Disease, the function of the amygdala and the
function of the hippocampus may be diminished due to atrophy. Therefore,
enhanced memory for emotional compared to neutral material (the *emotional
enhancement effect*) may be absent or rarely present. Because results from
other studies with similar objectives are inconclusive, further research is
needed to clarify the processes underlying emotional memory in Alzheimer
patients.
In this study, source memory (memory for locations) and long term memory
(recognition) for emotional versus neutral pictures will be tested. It is
expected that healthy participants will remember the location of emotional
pictures less accurately than the location of neutral pictures in a working
memory task, but that they will recognize these emotional pictures better than
neutral pictures in a delayed recognition task. In Alzheimer patients, we do
not expect to see a difference between emotional and neutral pictures, neither
in the relocation task nor in the recognition task. Furthermore, it is expected
that the patient group will perform less than the control group, in general.

The main objective of the study is to acquire more insight in memory for
emotional information in patients with Alzheimer*s Disease, compared to healthy
elderly people. A second objective is to explore the effect of emotional
content on working memory compared to long term memory.

This is a case-control study.
Two repeated measures ANOVA's will be done:
One with performance on the working memory task as the dependent variable,
valence (emotional-positive, emotional-negative, and neutral) as within subject
factors, and group (Alzheimer patients and healthy control subjects) as between
subject factor.
The second ANOVA will be done with the number of errors in the recognition task
as the dependent variable, valence (emotional-positive, emotional-negative, and
neutral) as within subject factors, and group (Alzheimer patients and healthy
control subjects) as between subject factor.

The burden of participating in this study is minimal, because it only involves
one session of 45 minutes (maximally).
This can be combined with a regular visit to the department of Geriatrics, if
participants are not able to come to the department especially for the
experiment. The study is not physically invasive and will only involve
cognitive tasks and some questionnaires. Some people may find it uncomfortable
to perform the cognitive tasks. The pictures that are used can be experienced
as positive, negative or neutral. Should people find it uncomfortable, they are
allowed to quit directly. This will be emphasized before starting the
experiment. In our opinion, there are no risks involved. The study is group
related because the main objective is to acquire knowledge about emotional
memory in Alzheimer patients.