Key Findings from the Feasibility Study:
- Provided important proof-of-principle for Kernel Flow as a portable functional system that provides real-time measurements of blood oxygenation changes in the brain associated with neural activity using Time Domain Near Infrared Spectroscopy (“TD-fNIRS”).
- Demonstrated ketamine-induced changes to functional brain biomarkers associated with potential therapeutic effects, including alterations in cortical function associated with psychedelic experiences.
- Ketamine led to a brain-wide reduction in the fractional amplitude of low frequency fluctuations (“fALFF“) and a decrease in the global brain connectivity of the prefrontal region compared to saline. It has been suggested that fALFF is of particular functional importance within the default mode network, which has been shown to be modulated by psychedelics and is associated with a range of neuropsychiatric conditions.
- A model combining neural and physiological metrics successfully predicted mystical experience scores on Revised Mystical Experience Questionnaire, which has been shown in previous research to mediate reductions in depressive symptomatology.
- Demonstrated reliable physiological measurements of pulse rate (“PR“) and pulse rate variability (“PRV“) extracted from TD-fNIRS recordings that match those obtained from commercial external photoplethysmography sensors, thus rendering the use of external sensors to measure cardiac activity unnecessary in future experiments.
- Ketamine led to increased PR, decreased PRV, increased absolute concentrations of oxy-hemoglobin and decreased deoxy-hemoglobin concentrations, and elevated electrodermal activity (measured by an external sensor), providing further physiological measures of the effects of the ketamine doses administered in the study.
