When the brain lacks sufficient sleep, processes in the brain interact in ways that slow what researchers call “slow behavioral performance” or cognitive lapses. Researchers studied program participants in a variety of situations including after a full night of sleep deprivation. The results showed that just before one of the so-called cognitive lapses (and fortunately none of the participants were driving a vehicle during the study!), “the selective spiking responses of individual neurons in the medial temporal lobe (MTL) are attenuated, delayed, and lengthened.” So no wonder that drivers don’t even realize at times that they are tired and yet can “zone out” enough to result in a vehicle accident. More tomorrow.