Consciousness: Levels, Sleep, and Theories

This chapter focuses on states of consciousness, including sleep, dreams, psychoactive drugs, hypnosis, and meditation.
Psychoactive drugs induce altered states of consciousness.
Hypnosis and meditation are also covered as they relate to altered states of consciousness.
Sensitive Topic Disclaimer: The class will discuss sensitive topics such as drugs (addiction, withdrawal, tolerance) and, later, eating disorders (in the motivation and emotion chapter). Students are encouraged to step out or take a break if any topic causes discomfort.

Consciousness Defined: An individual's awareness of external events and internal sensations which occur under conditions of arousal.
- It has two main components: awareness and arousal.
Awareness:
- Defined as a subjective state of being conscious about what is going on around you.
- It is a subjective state, meaning it is not the same for everyone, not easily defined, and can vary greatly from person to person.
- Neural Basis for Awareness: The feeling of awareness originates from the Global Brain Workspace ( $GBW$ ).
  - The $GBW$ involves multiple brain structures, primarily the cerebral cortex and specifically the prefrontal cortex.
  - This makes sense as these areas are responsible for higher-order executive functions like thinking, planning, reasoning, and personality.
Arousal:
- Defined as a physiological state of being engaged with the environment; also referred to as a biological state.
- This includes physical engagement like breathing, being awake, walking, moving, and actively interacting with the environment.
- Connection to Sympathetic Nervous System: Arousal was previously discussed in relation to the sympathetic nervous system, which elicits the