Chapter 4-Summary
Consciousness is the basic awareness of both internal and external stimuli. Internal awareness can range from feelings of hunger or pain to even thoughts and emotions. External stimuli are generally more physical and include detection of light, the feeling of temperature, or even listening during a conversation.
As humans we experience various states of consciousness and our levels of awareness differ in many case. From being fully awake to a state of deep sleep, our levels of awareness are continuously changing. Sleep for instance is a state marked by relatively low physical activity as well as a reduced sense of awareness. Wakefulness encompasses relatively higher levels of sensory awareness, thought activity, and behavior. To demonstrate these differences, you can imagine times of being sleepy in comparison to being fully alert and awake. What sorts of thought or behavior patterns differ between these states? Perhaps you demonstrate a more wakeful state in the early afternoon versus early in the morning.
These states are delegated through internal rhythms of biology activity also known as biological rhythms. Biological rhythms encompass all cyclical patterns of bodily change ranging from fluctuation of body temperature to an individual’s menstrual cycle. Keep in mind levels of alertness can also be associated with these bodily fluctuations. All these fluctuations take place every day for a period of about 24 hours and are a prime example of our circadian rhythm, the biological rhythm that cycles every 24 hours. Because our sleep patterns are generally dictated by natural light-dark cycles, bodily changes during these fluctuations are some of the more obvious examples of circadian rhythm. Throughout these changes homeostasis, or the tendency towards equilibrium within our biological system, is maintained. A sense of time is maintained I the part of the hypothalamus known as the suprachiasmatic nucleus and acts as a clock of a sorts within the brain. Despite continued maintaining of equilibrium between states; various instances, like sleep deprivation, can throw off our circadian rhythms. To maintain any irregularities, an endocrine structure known as the pineal gland releases a hormone known as melatonin to regulate our sleep-wake cycles.
Sleep itself is not present in a single state; rather it is composed of 5 stages divided by differentiating brain wave activity. Entirely, sleep can be divided into two general phases: rapid eye movement (REM) and non-REM (NREM). REM can be characterized by actual rapid eye movements under closed eyelids as well as similar brain wave activity to that of being awake. In contrast, non-REM sleep is makes up the majority of the sleep stages and can be categorized into 4 stages, each with differentiating intensity of brain wave activity.
Despite all bodily functions set in maintaining scheduled sleep, issues such as disorders or substance uses create altered states of consciousness that can disrupt and interfere with sleep. Disorders such as insomnia, sleep apnea, or sleepwalking are just a few of the more common instances preventing sleep. Solutions such as cognitive-behavioral therapy, a type of psychotherapy focusing on cognitive processes as well as problem behaviors can be used to possibly remedy these sleep disorders.
Substance ranging from stimulants to hallucinogens can also play a role in sleep deprivation. Uses of substances encompass disorders primarily on addiction. Compulsive use can result in a physical dependence, involving changes in bodily functions, or a psychological dependence, regarding emotional cravings in contrast to physical needs. Even in discontinuing the substance, withdrawal is a possible result and includes a variety of negative symptoms as a result of unsatiated addictions.
Although states of consciousness shift between wakefulness and sleep, we have the ability to alter our states of consciousness ourselves. Hypnosis for example, is a state of extreme self-focus, often utilizing powerful forms of suggestion to the individual by a clinician. Another form of altered consciousness is meditation, which also increased focus to heighten temporal awareness.