Consciousness with open eyes

Common sense says: awake equals conscious, asleep equals switched off. Research disproves it. The dream is proof that an intense experience, sometimes more vivid than waking, can happen while we are disconnected from the world. Consciousness has no switch: it changes shape. And not always downward.

On the threshold it can even intensify. In a lucid dream attention reignites inside sleep; in yoga nidra dopamine release rises and the state of consciousness shifts, it does not switch off. Waking is not the peak of consciousness: it is only one of its forms.

How it changes can be measured. Massimini and Tononi, with a brief magnetic pulse and EEG, showed that the same stimulus produces a rich, widespread response in waking and in dreaming, and only a simple, local wave in deep dreamless sleep. Hence the Perturbational Complexity Index: high in waking and dreaming, low in deep sleep. Not a switch, but a slider that rises and falls (Casali and colleagues, 2013). For Giulio Tononi's integrated information theory, the signature of consciousness is how much united and differentiated activity the brain can hold at once.

And the road? Here there is no amplification. Recordings inside the brain show that sleep is often local: some areas sleep while others stay awake. At the wheel it is the most insidious risk, because consciousness does not fall uniformly: it splits. One part keeps driving, another has already slipped into sleep (Vyazovskiy and colleagues, 2011). Microsleeps are exactly this: pieces of sleep inside waking.

Sleepiness at the wheel, then, is not a light dimming: it is a threshold crossed without noticing, while part of you stays at the wheel and another is already across.