Biomarkers of both cognitive capacity and psychological resilience are extremely interesting, and I haven't seen many done well that provide explainable insight. Statistics would let you correlate an EEG signal with anything (for example), but not sure if it is often meaningful for the individual.

If I were to dream up the perfect test it would be brain ATPmax in response to a cognitive challenge (using 31P magnetic resonance spectroscopy: onlinelibrary.wiley.com…). Perhaps a scalable proxy of this done in a laboratory could be used more widely for cognitive resilience. Essentially a VO2max test of the brian.

Thanks for your reply, and would love to hear more about your practice!