Monday, 22 April 2024 ------------------------ Hello. All is well. In chapter four, we discuss states of consciousness, mainly focusing on sleep. Consciousness is the awareness of stimuli, external and internal stimuli. The experience of consciousness is a continuum dependent on brain activity (sensory and motor signals). As said, brain waves represent its overall electrical activity, having two properties: frequency and amplitude. When we're awake, our brain's waves are primarily beta waves. High frequency, low amplitude. We measure frequency in hertz (Hz). Beta waves have a frequency of 13-30 Hz. Sleep is a state with low levels of brain activity, but it's not a constant level, instead having four stages. Stages of sleep can be split into two groups. NREM (non-rapid eye movement) sleep and REM (rapid eye movement) sleep. NREM sleep takes place first, containing three stages. Stage one is a transitional phase from wakefulness to sleep, primarily with alpha waves (8-12 Hz) and a few theta waves (4-7 Hz). Transition to sleep is associated with heart rate and breathing slowing down, muscle tension and body core temperature lowering. If awoken during the first stage, we'd not feel as we'd fallen into sleep yet. Stage two is primarily theta waves. During this stage we can have sleep spindles, short bursts of high frequency waves, possibly having applications for learning and memory. Stage three is known as deep sleep or low-wave sleep, consisting of mainly delta waves (>3 Hz). If higher frequency waves are had during this stage (alpha waves), you'll not feel refreshed after sleep regardless of time spent sleeping. Finally, we enter the last stage, REM sleep, having similar brain wave frequency as when we're awake. Our motor system, except for circulation and respiration, is paralyzed, and we have dreams during this stage. Also, with closed eyelids, our eyes move around, hence the name I suppose. We have biological rhythms, cyclical patterns of bodily changes. The circadian rhythms are 24-hour cycles affecting biological conditions like body temperature and arousal. This regulation is a homeostatic process governed by the hypothalamus, specifically the suprachiasmatic nucleus (SCN) known as our biological clock. This 24-hour cycle is different from person to person, but has generalizable patterns we call chronotypes. Some people are more alert in the early-morning, while others are more alert late-evening. It's not merely based on preference but on our underlying biology. When we lack sleep, we more easily fall asleep (sleep rebound). Hence, sleep is a homeostatic regulation. This also applies to REM sleep specifically, as we'll tend to enter REM sleep more quickly if we lack it (REM rebound). I imagine that's why we fall into a dream again after waking up in the middle of a dream. The pituitary gland secretes the hormone melatonin, responsible for regulating sleep. During sleep, the pituitary and pineal gland secretes hormones (can't be bothered to name them) regulating growth and the reproductive system. Why we sleep is not fully understood (e.g. some fish never sleep), there are hypotheses for adaptive functions such as energy restoration and minimizing activity during periods with heightened predatory risk. For cognitive function, we believe sleep to aid function of learning and memory. When we're sleep deprived, our cognitive function is greatly reduced, comparable to states of intoxication. Being well-rested has been shown to improve learning and creativity. Regarding dreaming, Sigmund Freud believed it gave insight to the unconscious mind, and Carl Jung believed it to give access to a collective unconscious mind shared by all. More recent research suggests it's primarily a reflection of life events, having empirical support from studies. There's a theory that dreaming is a state of proto-consciousness, a sort of prototype model for waking consciousness or something. Today, I did not take any stimulant medication, only coffee. The effect I feel by this is mainly a resistance to depth in reading and writing. For fun, I'll skip medication for the remainder of this month. It could be interesting to see how this affects my writing. I don't really experience any major withdrawal effects. I've done this before with no significance. Related to sleep deprivation, I have never succeeded in reaching a state where I'm intoxicated from alcohol before I have to throw up. Perhaps I'm just in a constant state of intoxication, ha. I wonder if my lifetime deliberate control of mind and behavior has allowed me to better detach from deviations in my state of mind, whatever that means. I can be distressed but seem perfectly fine from outward. At times, I don't think I'm aware of the distress myself. I think this can have consequences, like poor regulation by ignoring signals. For example, the feeling of coldness I can largely ignore. I wear the same clothing all year round, for upper body, a t-shirt and a light jacket. It could perhaps be better to listen and appropriately respond to signals. It's a balance. While I enjoy the flexibility, it can become irresponsible or be plain idiocy. Funnily, I think I prefer the nuisance of feeling cold versus the overwhelm I experience from having more clothing to make sense of. This is boring.