The aim of the present study is to investigate the neural correlates of the semantic network of patients with recent non-affective psychosis, first degree relatives of patients with psychosis and healthy controls. Furthermore, the relationship…
ID
Source
Brief title
Condition
- Schizophrenia and other psychotic disorders
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Reaction times in the different conditions will be compared between the three
groups.
Mean amplitude and latency of the N400, P3 and the LPP ERP components will be
compared between the different conditions and between the groups.
Source localization will be conducted for each condition and each group.
All words or combinations of words from the participants will be analysed if it
is a existing word of the narratives or if it is a non-existing word of the
narratives. The amount of words, and the longest phrase - counted as the number
of words reported by the participant - comprised the length of speech illusion
(LSI score).
Correlations between reaction times and ERP components of the different
conditions and the level of positive and negative symptoms will be
investigated.
Secondary outcome
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Background summary
Several studies have shown that patients with psychosis may have disturbances
of language processing (e.g. disturbed associational processes). It has been
suggested that the semantic network of patients with psychosis shows
disinhibited spread of activation. This disturbance of the semantic network is
reflected in an abnormality of the N400 component, an EEG component sensitive
to semantic relations between words. Furthermore, these language disturbances
of patients with psychosis are influenced by the emotional quality of the
information. For example, patients showed more language abnormalities when
talking about emotional themes. The lexical decision task is a widely used
method to investigate the semantic network. Furthermore, with the
multiple-speakers task it is possible to investigate differences in
speech-perception in patients with psychosis, healthy family members and
healthy control participants.
Using stimulus material with emotional valence the influence of emotional
processes can be investigated. Because of an increased genetic vulnerably in
first degree relatives of patients with psychosis, a qualitatively similar
disturbance of the semantic and affective network at a more attenuated level is
expected.
Study objective
The aim of the present study is to investigate the neural correlates of the
semantic network of patients with recent non-affective psychosis, first degree
relatives of patients with psychosis and healthy controls. Furthermore, the
relationship between semantic and affective priming and the multiple speakers
task and positive and negative symptoms of patients with psychosis will be
investigated.
Study design
In this study, brain activity of all participants will be measured with EEG
while the participants conduct a lexical decision task at the computer. The
participants will read words presented on the computer screen and indicate if
the word is a real Dutch word or a non-word using buttons. After the EEG
experiment, the participants will conduct the multi-speaker task. This task
consists of a multi-speaker phonetic noise or *babble*, which consists of six
narrative speakers (three male speakers and three female speakers). All
narratives of each speaker were simultaneity recorded in a *babble* fragment of
2.30 minutes. The babble will be presented though a headphone.
After these experimental tasks, the participants will fill in a questionnaire
about symptoms over the last years. Further, a word test and a short interview
about well-being in the last two weeks will be administered.
Study burden and risks
Medical and mental risks of the study for the participants are limited. The
duration of the study will be around 3 hours one-time for each participant. Due
to experiences from earlier studies this is acceptable for this group of
patients.
Vijverdalseweg 1
6200 MD Maastricht
Nederland
Vijverdalseweg 1
6200 MD Maastricht
Nederland
Listed location countries
Age
Inclusion criteria
1. between 18 and 50 years
2. native speakers of Dutch
3. able to read and understand the inform consent
4. patients: (a) Diagnosed with a non - affective psychosis (b) first contact with a psychiatric institution because of psychotic symptoms 10 years maximum
5. first-degree relatives: brother or sister of the patient who was diagnosed with a non-affective psychosis
6. healthy controls: (a) never diagnosed with a lifetime diagnosis of non-affective psychosis; (b) none of first-degree relatives were diagnosed with a psychotic disorder
Exclusion criteria
1. mental retardation (IQ<70)
2. head trauma (with loss of consciousness)
3. psychotic disorder due to a general medical condition
4. alcohol and drug related substance disorder according to the DSM-IV
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL17175.068.07 |