Ketamine is metabolized into several compounds, and this study shows that norketamine is not the main metabolite circulating in the blood after a single 40-minute infusion of 0.5 mg/kg ketamine in patients with treatment-resistant bipolar depression. Instead, dehydronorketamine was the major metabolite in four out of nine patients, norketamine in three, and hydroxynorketamine in two. Large inter-patient variation in metabolite levels was observed. The findings suggest that future research on ketamine's effects should measure these downstream metabolites.
Large language models challenge Hubert Dreyfus's claim that AI cannot match human know-how. Reinterpreting Dreyfus through Heidegger, the paper argues the key difference is not rules versus skilled coping but correlational patterning versus teleological causation. This teleological causation, called causal-intentional binding, is Dasein's future-oriented act of opening meanings for which it remains ethically responsible. Modern AI achieves contextual fluency but remains stuck in Heidegger's idle talk, lacking the binding that turns coping into conscience. The paper distinguishes two horizons: AI-as-curator, a static mirror organizing human insights, and AI-as-co-evolver, which might acquire proto-teleology through self-referential causal modeling, approaching an artificial Dasein. The consciousness debate thus shifts from embodiment to ontological directionality.