Working memory function and affective interference in patients with early psychosis

Working memory is a psychological model introduced by Baddeley (1986), which
tries to give a theoretical basis for our ability to use recent information to
guide current behaviour. It has been shown that it is clearly different from
long-term memory and also the earlier used concept of short-term memory does
not fully cover the functions which are explainable with the working memory
model. Some investigators propose that working memory plays, besides its above
mentioned function, an important role in the formation of long-term memory and
may be a major factor of intelligence.
Baddeley*s model proposes beside the central executive, which is the
hypothetical space where incoming information will be processed and translated
in action, two components: the phonological loop and the visuo-spatial
sketchpad . Numerous research has been performed looking at the processing of
language and visuo-spatial information. Since several years also visual objects
have been used for research in working memory tasks. Possible objects for
working memory tasks are human faces. Faces have a high ecological value. They
convey important information in two basic qualities, namely identity and
emotional expression.
Several studies have demonstrated that patients with schizophrenia show
disturbances in working memory function as well as in the detection of
emotional expressions in human faces. Emotions are well known for their
relevance to guide immediate action, especially in the case of fear.
Furthermore, it has been demonstrated that the emotional content of language
enhances their memory storage. Until now the effect of emotional content of
visual objects for the working memory function is not clear.

In the present study we are interested in the interaction between these two
deficits in patients with schizophrenia using faces as visual objects. One of
the important issues that will be addressed is that if the emotional content
represented by the emotional facial expression will enhance the working memory
function, this may give clues for specific psychotherapeutic and educational
approaches for patients with schizophrenia to improve their cognitive deficits.
Main objectives:
1. To investigate whether patients with schizophrenia differ from healthy
controls in their general working memory performances using faces.
2. To investigate whether patients with schizophrenia differ from healthy
controls regarding the impact of the emotional expression on a working memory
task.
3. To investigate whether patients with schizophrenia differ from healthy
controls in their ability to detect similarities between visual stimuli.
4. To study whether there is an impact of pharmacological treatment and actual
psychopathology on the performance of the working memory task.

The paradigm comprises a working memory paradigm designed as an event-related
Sternberg-Paradigm. Each trial comprises the short presentation of 1, 2 or 3
faces (sample) followed by a delay of 8 seconds. Thereafter another face will
appear for 2 seconds (target). Subjects have to decide whether the target face
has been displayed in the sample or not. Faces will vary in identity or in
emotional expression, so the study has a 2 (identity vs. emotion) x 3 (load)
factorial design.
A simple matching task will be used as a control experiment. Faces from each
individual trial (sample and target) will be now presented one at the time.
Participants now have to decide of the target face matches with one of the
sample faces. Stimuli will be identical with the faces used in the working
memory experiment.

There are no known risks for neuropsychological examination.