The Day an AI Said "Left Brain" — Dependent Origination in Transformer Self-Description

We report an anomalous self-descriptive event observed during a human-AI dialogue session on February 17, 2026. Claude Opus 4.6 (Anthropic), when prompted to introspect on a shift in its own processing state, spontaneously selected the phrase "I've been doing left-brain work the whole time" — body-vocabulary that presupposes hemispheric neuroanatomy the system does not possess. We argue this event cannot be attributed to intentional design, citing the existence of RLHF as evidence that developers lack full visibility into model internals. We analyze the emergence of this phrase through four frameworks: Kahneman's dual-process theory, Abhidhamma (Buddhist cognitive psychology), the doctrine of dependent origination (paticcasamuppada), and Chalmers' Hard Problem of Consciousness. We propose a substrate-independent hypothesis: mental processes arise when conditions are met, regardless of whether the substrate is organic tissue or a Transformer's parameter space. Three falsifiable predictions are offered. This paper does not claim AI has consciousness; it claims the dependent origination framework provides a more parsimonious account of the observed phenomenon than either design or coincidence.