awareness

Meaning: Awareness is the experience of internal states (thoughts, emotions, bodily sensations) and external stimuli. It is the central feature of consciousness. It varies in degree: it is highest in alert, focused wakefulness and lower in drowsiness and sleep. Attention shapes it, because selective attention narrows what you notice, and well-practiced tasks can run with little awareness (automatic processing). Freud's model divides the mind into conscious (in awareness now), preconscious (outside awareness but retrievable with little effort, like your phone number) and unconscious (not readily accessible).

On the MCAT: Expect passages on states of consciousness. You may be asked to rank states by level of awareness, or to link EEG patterns to them: beta waves in alert wakefulness, alpha waves in relaxed wakefulness with eyes closed, and theta and delta waves as sleep deepens. Other items cover altered states (hypnosis, meditation, psychoactive drugs) and attention, such as selective or divided attention limiting what reaches awareness.

Common confusion: Awareness is not all-or-none, and sleep is not complete absence of it, since the brain still processes sensory input (hearing your own name can wake you). Also, "unconscious" in Freud's sense (mental content outside awareness) is not the same as being unconscious from anesthesia or injury.