RT Journal Article
SR Electronic
T1 Reduced parietofrontal effective connectivity during a working-memory task in people with high delusional ideation
JF Journal of Psychiatry and Neuroscience
JO J Psychiatry Neurosci
FD Canadian Medical Association
SP 195
OP 204
DO 10.1503/jpn.180043
VO 44
IS 3
A1 Yu Fukuda
A1 Teresa Katthagen
A1 Lorenz Deserno
A1 Leila Shayegan
A1 Jakob Kaminski
A1 Andreas Heinz
A1 Florian Schlagenhauf
YR 2019
UL http://jpn.ca/content/44/3/195.abstract
AB Background: Working-memory impairment is a core cognitive dysfunction in people with schizophrenia and people at mental high risk. Recent imaging studies on working memory have suggested that abnormalities in prefrontal activation and in connectivity between the frontal and parietal regions could be neural underpinnings of the different stages of psychosis. However, it remains to be explored whether comparable alterations are present in people with subclinical levels of psychosis, as experienced by a small proportion of the general population who neither seek help nor show constraints in daily functioning.Methods: We compared 24 people with subclinical high delusional ideation and 24 people with low delusional ideation. Both groups performed an n-back working-memory task during functional magnetic resonance imaging. We characterized frontoparietal effective connectivity using dynamic causal modelling.Results: Compared to people who had low delusional ideation, people with high delusional ideation showed a significant increase in dorsolateral prefrontal activation during the working-memory task, as well as reduced working-memory-dependent parietofrontal effective connectivity in the left hemisphere. Group differences were not evident at the behavioural level.Limitations: The current experimental design did not distinguish among the working-memory subprocesses; it remains unexplored whether differences in connectivity exist at that level.Conclusion: These findings suggest that alterations in the working-memory network are also present in a nonclinical population with psychotic experiences who do not display cognitive deficits. They also suggest that alterations in working-memory-dependent connectivity show a putative continuity along the spectrum of psychotic symptoms.