Head direction cells efference copy") preparing the network for an impending head turn. HD cells continue to fire in an organized manner during sleep, as if animals were awake. However, instead of always pointing toward the same direction—the animals are asleep and thus immobile—the neuronal "compass needle" moves constantly. In particular, during rapid eye movement sleep, a brain state rich in dreaming activity in humans and whose electrical activity is virtually indistinguishable from the waking brain, this directional signal moves as if the animal is awake: that is, HD neurons are sequentially activated, and the individual neurons representing a common direction during wake
Consciousness and the Brain of patterns in sounds. Dehaene explores consciousness in human babies, non-human animals, and machines. Dehaene reviews evidence that young infants are indeed conscious, although their global workspaces may run 3-4 times slower than in adults, perhaps because their myelin is not well established. Monkeys can be trained to "report" on their conscious experiences via actions rather than speech, and monkeys show the same sorts of brain and behavioral patterns as humans in response to consciousness tests. Dehaene adds that some animals, like monkeys and dolphins, show evidence not just of consciousness but also of metacognition. He speculates that maybe what