Preserved global network properties in schizotypy: A multi-echo resting-state fMRI study

Poster B58, Friday, October 21, 11:30 am - 1:00 pm, Le Baron

Kurtis Stewart1, Owen O'Daly1, Meghan O'Sullivan1, Katrina McMullen2, Veena Kumari1, Gareth Barker1, Steve Williams1, Gemma Modinos1; 1Institute of Psychiatry, Psychology and Neuroscience, King's College London, 2Centre for Brain Health, University of British Columbia

Graph-based network analysis allows the characterization of complex brain organization at the whole-brain level. Recent evidence shows that schizophrenia presents with abnormal global network properties, including altered global and local efficiency (reflecting poor information transmission) and modularity (suggesting the breakdown of information encapsulation between specialized brain systems). Investigations of functional brain organization in schizotypy, referring to phenotypic traits reflecting the subclinical manifestation of schizophrenia in the general population, may help elucidate etiological mechanisms of schizophrenia. The present study examined global network properties in schizotypy using resting-state fMRI (rs-fMRI). 42 participants with high (HS) or low schizotypy (LS), defined by the Oxford and Liverpool Inventory of Feelings and Experiences (O-LIFE), were recruited, matched on demographic variables. Participants underwent multi-echo rs-fMRI and imaging data were parcellated into 90 regions-of-interest using a standard atlas. Functional brain networks were constructed and transformed to binary matrices at a range of sparsity thresholds. Three network properties were computed: global efficiency (Eglob), local efficiency (Eloc), and modularity. The groups were compared using permutation tests. Both groups displayed similar Eglob, Eloc, and modularity across the range of sparsity thresholds (p’s>.05, FDR-corrected, 10000 permutations). Post-hoc correlation analyses revealed that modularity was positively associated with O-LIFE scores in the HS group (r’s>.43, p’s<.05). Contrary to recent research in schizophrenia, our findings indicate that global network properties are largely conserved in schizotypy. However, those with more severe schizotypy display subtle changes in modularity, indicating a potential mechanism underlying subclinical psychotic experiences.

Topic Area: Neuroimaging

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