VI. That nervous systems differ — so a measure of presence must be baselined to each person, never to a population norm

• Reduced heart-rate variability in adults with autism spectrum disorder (Autism Research, 2019). [verify authors] — Lower resting parasympathetic (HF, RMSSD) activity in autistic adults versus neurotypical controls.
• Heart-rate variability in autism spectrum disorder: a meta-analysis (2020). [verify authors/venue] — Aggregated evidence of autonomic differences in ASD.
• Autistic traits moderate relations between cardiac autonomic activity, interoceptive accuracy, and emotion processing (2020). [verify authors] — Trait-level differences change how autonomic signals, interoception, and emotion relate.
• Feasibility of HRV as an outcome measure for emotion-regulation interventions in autism (Scientific Reports, 2024). [verify] — Indicates HRV-based tools may support neurodivergent people, not exclude them.

This appendix is itself a nest: woven from what we could gather, left open on purpose. If you know of work that belongs here — confirming, complicating, or refuting what this volume claims — it belongs to the next hands to add it.