A conscious brain is a thing-as-a-whole
In an instant of frozen time a brain is just a sack of fragmented material, each part of which has not had time to interact with any other part, and therefore has conveyed no meaning and has no significance.
Over a cognitive cycle, of a few tenths of a second, every part of the brain has time to potentially affect every other part. This is essential to the survival of the organism. It must consider all sensory inputs, in case one requires urgent action; it must generate candidate actions and pick the best out of all considered possibilities; and it must seize control of the muscles to take that action in a coordinated way, under control of the correct attended sensory information.
Thus a conscious brain becomes a thing-as-a-whole only when considered over the time period of the cognitive cycle of a few tenths of a second. There is a sense in which consciousness only exists when considered over this period of time and over the physical extent of the brain, as though a new reality was emerging from the substrate of interacting neurons making up a whole brain.
An analogy can be made between the brain and a struck bell. At any one moment in time each part of the bell may be subject to a certain displacement, velocity and tension. It is only over a time period of at least one period of the frequency of sound it produces, and over the spatial extent of the bell as a whole, that it could be said to ring.