Final answer:
Normal waking consciousness differs from an altered state of consciousness in that it involves higher levels of sensory awareness and control over thoughts and behaviors, whereas an altered state often features reduced sensory awareness and diminished control, as demonstrated during sleep.
Step-by-step explanation:
Contrasting Normal Waking Consciousness and Altered States of Consciousness
One characteristic that contrasts normal waking consciousness with an altered state of consciousness is the level of sensory awareness and control over one's thoughts and behaviors. During normal waking consciousness, individuals experience high levels of sensory awareness, thought, and behavioral control. In contrast, an altered state of consciousness, which may be induced by sleep, meditation, hypnosis, or the influence of psychoactive drugs, often features reduced sensory awareness and a diminished ability to regulate one's thoughts and actions.
For example, while in the depths of sleep, a form of altered consciousness, our sensory awareness to the external world is substantially decreased and our control over thoughts is largely relinquished, as evidenced by the uncontrollable nature of dreaming.
Biological rhythms and the brain's circadian rhythms, regulated by the suprachiasmatic nucleus (SCN), play a crucial role in the transitions between various states of consciousness throughout the day and night.