Source memory errors in schizophrenia, hallucinations and negative symptoms: a synthesis of research findings.
BACKGROUND
Previous research has shown associations between source memory errors and hallucinations in patients with schizophrenia. We bring together here findings from a broad memory investigation to specify better the type of source memory failure that is associated with auditory and visual hallucinations.


METHODS
Forty-one patients with schizophrenia and 43 healthy participants underwent a memory task involving recall and recognition of lists of words, recognition of pictures, memory for temporal and spatial context of presentation of the stimuli, and remembering whether target items were presented as words or pictures.


RESULTS
False recognition of words and pictures was associated with hallucination scores. The extra-list intrusions in free recall were associated with verbal hallucinations whereas the intra-list intrusions were associated with a global hallucination score. Errors in discriminating the temporal context of word presentation and the spatial context of picture presentation were associated with auditory hallucinations. The tendency to remember verbal labels of items as pictures of these items was associated with visual hallucinations. Several memory errors were also inversely associated with affective flattening and anhedonia.


CONCLUSIONS
Verbal and visual hallucinations are associated with confusion between internal verbal thoughts or internal visual images and perception. In addition, auditory hallucinations are associated with failure to process or remember the context of presentation of the events. Certain negative symptoms have an opposite effect on memory errors.
Institute of Psychiatry, King's College London, UK. gildas.brebion@kcl.ac.uk
G
G
Brébion
R I
RI
Ohlsen
R A
RA
Bressan
A S
AS
David
D000328:Adult; D059445:Anhedonia; D001245:Association Learning; D001288:Attention; D005260:Female; D006212:Hallucinations / Q000175:diagnosis* / Q000523:psychology*; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000523:psychology*; D008570:Memory, Short-Term; D008875:Middle Aged; D009949:Orientation; D010364:Pattern Recognition, Visual; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics; D012094:Repression, Psychology; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D013067:Speech Perception; D013223:Statistics as Topic; D014706:Verbal Learning