Final answer:
Hypnosis is a psychological state where attention is altered and an individual is highly receptive to suggestions, often used in therapy and associated with global changes in brain function. It is part of the universal drive to experience altered states of consciousness, which can also occur naturally or through meditation and psychoactive drugs.
Step-by-step explanation:
The psychological state of altered attention and expectation, in which the individual is unusually receptive to suggestions, is commonly referred to as hypnosis. Hypnosis is characterized by a state of extreme self-focus and minimal attention to external stimuli. In this state, individuals can experience changes in perception, emotion, thought, or behavior as a result of directed suggestions. Clinical applications involve using relaxation and suggestion to alter a patient's thoughts and perceptions. Brain imaging studies have shown that hypnosis is associated with global changes in brain function, indicating that the hypnotic state is more than just a subjective experience. It is important to note that the desire to experience altered states of consciousness is not unique to humans; it appears to be a universal drive that is also observable in animals. Examples include animals consuming fermented fruit to become intoxicated or cats' responses to catnip. Altered consciousness can also be achieved through meditation, use of psychoactive drugs, and even natural transitions such as from wakefulness to sleep.