Altered coordination between the default mode, central executive, and salience networks is linked to schizophrenia, but its role in earlier at-risk stages is unclear. Using dynamic functional connectivity and co-activation pattern analysis of resting-state fMRI, this study examined right anterior insula interactions in 19 individuals with subthreshold delusions and hallucinations (UHR), 28 with basic symptoms of self-experienced subclinical disturbances (BS), and 29 healthy controls. The right anterior insula governs transitions from the central executive to default mode network, which become dysfunctional before psychosis onset, especially when attenuated psychotic symptoms emerge.
Heart rate variability (HRV) metrics commonly used in biofeedback, such as RMSSD, preferentially weight higher-frequency heart rate fluctuations, making them unsuitable for tracking slow, mindful breathing. A new metric called the autonomic balance index (ABI) uses Respiratory Sinus Arrhythmia to quantify the fraction of HRV contributed by the parasympathetic nervous system. Applied to data from two meditation techniques, ABI was significantly elevated during mindful breathing, indicating it is a good signal for biofeedback during meditation sessions.