Increased Spatial Entropy in Temporoparietal Region in Early Psychosis: A Resting-State fMRI Study
Poster No:
2020
Submission Type:
Abstract Submission
Authors:
Haley Wang1, Carolyn Amir1, Andrea Luppi2
Institutions:
1University of California, Los Angeles, Los Angeles, USA, 2University of Cambridge, Cambridge, United Kingdom
First Author:
Co-Author(s):
Introduction:
Early psychosis is characterized by disrupted neural dynamics and cognitive processing, but the precise nature of these alterations remains unclear. While previous studies have found differences in neural dynamics in psychosis using measures such as temporal signal variability, neural entropy-which captures the complexity and predictability of neural activity patterns-remains understudied. Brain entropy offers unique insights into neural organization by quantifying the regularity and complexity of activity patterns. We investigated whether spatial entropy of resting-state functional magnetic resonance imaging (fMRI) differs between early psychosis patients and healthy controls using complementary entropy metrics. Based on theories of disrupted neural organization in early psychosis, we hypothesized that early psychosis patients would demonstrate higher spatial entropy compared to healthy controls, indicating more disorganized neural dynamics, particularly in regions involved in higher cognitive and affective functioning.
Methods:
We analyzed resting-state fMRI data from the Human Connectome Project Early Psychosis dataset (Release 1.1), including 122 early psychosis patients and 57 healthy controls. Brain parcellation was performed for both cortical and subcortical regions using the Schaefer 2018 atlas (200 parcels) and Tian 2020 atlas (16 parcels), respectively. We calculated spatial entropy at the regional level using two complementary approaches: Lempel-Ziv complexity (LZ76), which captures algorithmic complexity of spatial patterns, and Shannon's entropy, which measures information content of activity distributions. General linear models were used to compare entropy metrics between groups, controlling for age, age-squared, and sex, with false discovery rate (FDR) correction for multiple comparisons.
Results:
Analysis revealed a significant group difference in LZ76 complexity in the left temporoparietal region (17Networks_LH_TempPar_1; β=0.050, q=.048), with early psychosis patients showing higher spatial complexity. Interestingly, LZ76 and Shannon's entropy measures showed a moderate negative correlation across regions (r=-0.412, p<.001), suggesting they capture distinct aspects of spatial organization. No regions showed significant group differences in Shannon's entropy after FDR correction. These findings indicate subtle but specific alterations in the spatial organization of brain activity in early psychosis, particularly in regions associated with social cognition and sensory integration.
Conclusions:
Our results provide novel evidence for increased spatial complexity of brain activity in early psychosis, specifically in temporoparietal regions. This region represents a key node in the default mode network (DMN) critical for self-referential processing and social cognition. The dissociation between LZ76 and Shannon's entropy measures suggests different aspects of spatial disorganization that may reflect distinct neurobiological mechanisms in the context of early psychosis. These complementary entropy metrics may provide a novel window into understanding how altered neural dynamics and network organization contribute to psychosis pathophysiology. Future work will examine the relationship between these entropy alterations and clinical symptoms, as well as expand analyses to network-level spatial entropy and temporal dynamics to build a more comprehensive picture of neural complexity in early psychosis.
Disorders of the Nervous System:
Psychiatric (eg. Depression, Anxiety, Schizophrenia) 2
Modeling and Analysis Methods:
Connectivity (eg. functional, effective, structural)
fMRI Connectivity and Network Modeling
Neuroinformatics and Data Sharing:
Informatics Other
Perception, Attention and Motor Behavior:
Consciousness and Awareness 1
Keywords:
Computational Neuroscience
Consciousness
FUNCTIONAL MRI
Pre-registration
Psychiatric Disorders
Schizophrenia
Statistical Methods
Other - Entropy
1|2Indicates the priority used for review
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