<p>Neuroscience lacks a standard conceptual framework for interpreting and reporting experimental results. Consequently, the neuroscience literature is full of heterogeneous “filler verbs” (‘underlying’, ‘supporting’, etc.) linking neural activity with cognition. In this paper, I focus on the possibility that mental phenomena are “realized” in the brain. I begin by examining how philosophers have explicated the realization relation, drawing out two conditions that are common across accounts: metaphysical sufficiency and synchrony. I then develop a two-pronged argument. At the mesoscale of neural circuits, sufficiency fails. At the macroscale of multi-circuit mechanisms, synchrony fails. There is no empirical evidence of mental processes synchronized with neural mechanisms, and none is forthcoming given actual research practices in neuroscience. A major upshot is that we should not expect the same terminology to be suitable for theorizing about the mind in both philosophy and science.</p>