Dorsal attention network activity during perceptual organization is distinct in schizophrenia and predictive of cognitive disorganization

Abstract

Visual shape completion is a canonical perceptual organization process that integrates spatially distributed edge information into unified representations of objects. People with schizophrenia show difficulty in discriminating completed shapes, but the brain networks and functional connections underlying this perceptual difference remain poorly understood. Also unclear is whether brain network differences in schizophrenia occur in related illnesses or vary with illness features transdiagnostically. To address these topics, we scanned (functional magnetic resonance imaging, fMRI) people with schizophrenia, bipolar disorder, or no psychiatric illness during rest and during a task in which they discriminated configurations that formed or failed to form completed shapes (illusory and fragmented condition, respectively). Multivariate pattern differences were identified on the cortical surface using 360 predefined parcels and 12 functional networks composed of such parcels. Brain activity flow mapping was used to evaluate the likely involvement of resting‐state connections for shape completion. Illusory/fragmented task activation differences (‘modulations’) in the dorsal attention network (DAN) could distinguish people with schizophrenia from the other groups (AUCs > .85) and could transdiagnostically predict cognitive disorganization severity. Activity flow over functional connections from the DAN could predict secondary visual network modulations in each group, except in schizophrenia. The secondary visual network was strongly and similarly modulated in each group. Task modulations were dispersed over more networks in patients compared to controls. In summary, DAN activity during visual perceptual organization is distinct in schizophrenia, symptomatically relevant, and potentially related to improper attention‐related feedback into secondary visual areas.

Functional dysconnectivity of visual and somatomotor networks yields a simple and robust biomarker for psychosis

“…While this result is much better than what has been obtained with single edges from a FC matrix [mean ICC=. 29,56], future studies might consider using multi-echo fMRI or more advanced denoising strategies for image reconstruction [45,57,58]. Although the analyzed studies involved an eyes-open protocol, it is possible that patients more often fell asleep, which could explain their weaker cortico-cortical visual or somatomotor connectivity [59].…”

“…We considered whether our proposed biomarker could be found in two independent data sets, each of which incorporated eyes-open resting-state data. The first was collected at Rutgers University and comprised 19 healthy controls and 22 chronically ill psychosis patients (14 schizophrenia, 1 schizoaffective disorder, 7 bipolar disorder); these data were collected on an older scanner (Tim Trio) with a different pulse sequence (e.g., MB 6, iPAT=2), a different scan duration (10 minutes; 765 TRs), and a different scrubbing threshold (0.3 mm) [29] The preprocessing has been described (ibid), with the only differences being that we also included subcortex (358 parcels), applied GSR, and derived the RSFC via graphical lasso, as above. The second independent data set was from the UCLA Consortium for Neuropsychiatric Phenomics-and compared people with ADHD (n=35) or schizophrenia (n=36), and healthy controls (n=93) [30].…”