You can be aware without being awake, and awake without being aware
Awareness feels like the simplest fact of life, yet scientists and philosophers still argue over what it is. Dreamers are aware while asleep, some brain-damaged patients seem awake with nothing registering, and people with blindsight respond to things they insist they cannot see.
At its broadest, awareness means perceiving or knowing something and being able to respond to it. It is always about some content: a tree, a voice, warmth on the skin, a desire, an abstract thought. What gets in depends on how strong or novel a stimulus is and on a person's goals, expectations and memories. Some accounts treat it as all or nothing, while others see it as coming in degrees, with contents ranging from vivid to vague.
The word traces back to the Old English gewær, which became iwar in Middle English and then aware. The noun awareness first appears in the 1830s, in the writing of the physician David Macbeth Moir. Many theorists use it almost interchangeably with consciousness, meaning the felt, first-person quality of experience. Others separate the two, treating awareness as access: the capacity to take in information and act on it.
Attention is the spotlight within this wider field. It pushes some contents to the centre while background material stays noticed but peripheral. That fringe matters: talking with a friend on a busy street, you can still register an approaching car. Because the nervous system delivers more information than thinking regions can handle, attention systems act as a filter, which means a mind may hold far more than it is focusing on.
Where it lives in the brain is contested. The Stockholm neuroscientist Bjorn Merker argues that the brain stem supports a basic form of awareness, citing infants born with hydranencephaly, and that only higher forms such as self-awareness need the cortex, a claim that challenges definitions of brain death based on cortical silence. Detection of faint images also varies from one attempt to the next, partly because shifts in ongoing alpha-wave activity bias what the sensory cortex picks up. Gregory Bateson, approaching from systems theory, described mind as the dynamics of self-organisation.
Source: Awareness
