Chaos analysis of the cortical boundary for the recognition of psychosis.

BACKGROUND: Structural MRI studies in people with first-episode psychosis (FEP) and those in the clinical high-risk (CHR) state have consistently shown volumetric abnormalities that depict changes in the structural complexity of the cortical boundary. The aim of the present study was to employ chaos analysis in the identification of people with psychosis based on the structural complexity of the cortical boundary and subcortical areas. METHODS: We performed chaos analysis of the grey matter distribution on structural MRIs. First, the outer boundary points for each slice in the axial, coronal and sagittal view were calculated for grey matter maps. Next, the distance of each boundary point from the centre of mass in the grey matter was calculated and stored as spatial series, which was further analyzed by extracting the Largest Lyapunov Exponent (lambda [λ]), a feature depicting the structural complexity of the cortical boundary. RESULTS: Structural MRIs were acquired from 77 FEP, 73 CHR and 44 healthy controls. We compared λ brain maps between groups, which resulted in statistically significant differences in all comparisons. By matching the λ values extracted in axial view with the Morlet wavelet, differences on the surface relief are observed between groups. LIMITATIONS: Parameters were selected after experimentation on the examined sample. Investigation of the effectiveness of the method in a larger data set is needed. CONCLUSION: The proposed framework using spatial series verifies diagnosis-relevant features and may contribute to the identification of structural biomarkers for psychosis.

Views on disability and prenatal testing among families with Down syndrome and disability activists: A comparative analysis of interviews from Germany and Israel.

The prenatal genetic testing arena has witnessed great changes over the past decades and has been the focus of extensive discussion of its ethical, legal, and social implications. Germany and Israel were previously known for strongly contrasting regulations and attitudes of both professionals and laypeople towards genetic testing. Based on qualitative analysis of 37 semi-structured interviews, this study compares German and Israeli family members of individuals with Down syndrome and disability activists, thereby examining the interplay between lived experience and cultural scripts and their impact on the formation of personal views toward disability and prenatal testing. We have found that the differences between Germany and Israel remain, despite the emergence of new technologies, and that family members and disability activists reflect the norms of their socio-cultural environments, thereby emphasising the role society plays in shaping the views of those with direct experience of disability.