Atypical functional connectivity in the maturing brains of 22q11.2 deletion syndrome (22q11DS) may contribute to the expression of early psychotic symptoms commonly reported by these youths. This study's objective was to examine functional connectivity in cerebral networks at rest (Resting-State Networks; RSNs) and their relationship to symptomatic and neuropsychological characteristics putting them at very high risk factor for developing psychosis. Twenty-seven adolescents with 22q11DS and 33 typically developing control adolescents matched for age, gender and handedness underwent an 8-minute resting state functional MRI session. RSNs identification procedure employed Independent Component Analysis (ICA). We tested for potential group differences in functional connectivity within-networks. Then, we examined relationships between network connectivity and symptomatic/neuropsychological characteristics in the 22q11DS group. A total of nine resting-state networks were identified. Between-group differences suggested both increased and decreased functional connectivity in the 22q11DS group, involving the default-mode, sensorimotor, visuo-spatial, and high level visual networks. Finally, atypical connectivity in the default-mode network, specifically within the left superior frontal gyrus region, correlated with prodromal symptom intensity and neuropsychological performances in the 22q11DS group. The results suggest that atypical functional connectivity may sustain both increased vulnerability to psychosis and characteristic cognitive impairments in 22q11DS.

The rising interest in temporally coherent brain networks during baseline adult cerebral activity finds convergent evidence for an identifiable set of resting state networks (RSNs). To date, little is know concerning the earlier developmental stages of functional connectivity in RSNs. This study's main objective is to characterize the RSNs in a sample of adolescents. We further examine our data from a developmental psychopathology perspective of psychosis-proneness, by testing the hypothesis that early schizotypal symptoms are linked to disconnection in RSNs. In this perspective, this study examines the expression of adolescent schizotypal traits and their potential associations to dysfunctional RSNs. Thirty-nine adolescents aged between 12 and 20 years old underwent an 8-min functional magnetic resonance imaging (fMRI) “resting state” session. In order to explore schizotypal trait manifestations, the entire population was assessed by the Schizotypal Personality Questionnaire (SPQ). After conventional processing of the fMRI data, we applied group-level independent component analysis (ICA). Twenty ICA maps and associated time courses were obtained, among which there were RSNs that are consistent with findings in the literature. We applied a regression analysis at group level between the energy of RSN-associated time courses in different temporal frequency bins and the clinical measures (3 in total). Our results highlight the engagement of six relevant RSNs; (1) a default-mode network (DMN); (2) a dorso-lateral attention network; (3) a visual network (VN); (4) an auditory network (AN); (5) a sensory motor network (SMN); (6) a self-referential network (SRN). The regression analysis reveals a statistically significant correlation between the clinical measures and some of the RSNs, specifically the visual and the AN. In particular, a positive correlation is obtained for the VN in the low frequency range (0.05 Hz) with SPQ measures, while the AN correlates negatively in the high frequency range (0.16–0.19 Hz). Trend-like significance for the SRN may hint to its implication in disorganized thoughts and behaviors during adolescence. Unlike DMN activity in schizophrenic patients, adolescent DMN was unrelated to schizotypal trait expression. This suggests that relationships between the DMN and schizotypy may be modified in later developmental stages of both functional connectivity and psychotic expression. These results are discussed in light of RSNs literature involving children, adults, and individuals with schizophrenia.

Much like adults performing a similar reality monitoring task, adolescents exhibit a common pattern of brain activity during origin and context monitoring, with functional specialization within the prefrontal cortex involving preferential activation of BA 10 during origin monitoring. Greater schizotypal trait expression appears to be significantly associated to reduced BA 10 activity during origin monitoring trials. Results are discussed in relation to cortical specialization within the PFC and trait expression during adolescence.

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