Raleigh Miller

Different classes of anesthetics can induce unconsciousness despite acting through distinct biological mechanisms. This raises the possibility that they produce a convergent effect on the dynamics or temporal evolution of neural population activity. To explore this, we analyzed intracortical electrophysiological recordings during infusions of propofol, ketamine, and dexmedetomidine, using a rigorous method to estimate dynamical stability. We found that all three anesthetics, despite their molecular differences, similarly affect cortical states by destabilizing their dynamics. This destabilization matched the slower recovery from sensory perturbations and longer stimulus-induced autocorrelation times observed during the anesthetic infusions. The destabilization was also reflected predominantly in lower-frequency ranges, linking it to the well-known increase in low-frequency power during anesthesia. Finally, destabilization closely tracked real-time fluctuations in consciousness. Together, these findings suggest that cortical destabilization may be a shared neural correlate of anesthetic-induced unconsciousness, offering a mechanistic explanation for low-frequency oscillations observed during anesthesia.

In this paper I argue, with many leading commentators, that Kant is a conceptualist. I support this conclusion, argued for independently by Hannah Ginsborg and John McDowell, by appeal to the analyticity of Kant’s apperception principle in the transcendental deduction. I argue that the apperception principle, if taken as an analytic proposition, implies that any mental representation that figures into discursive cognition is the product of a priori synthesis. I further argue that making a priori synthesis a condition for the possibility of any mental representation is sufficient to make mental representation conceptual in the relevant sense. This, I argue, strongly suggests that Kant is a conceptualist.