CONSCIOUSNESS

CONSCIOUSNESS: Your personal and immediate awareness of:

  • mental activity

  • internal sensations

  • external stimuli & the world around you

  • planning or active problem solving

-most psychologists today consider consciousness an important area of research, as did early researchers

    -Willaim James described it as a “stream”/ “river” unified and unbroken.

→ ATTENTION THE MINDS SPOTLIGHT

ATTENTION: capacity to selectively focus senses and awareness on particular stimuli or aspects of the moment.

—> CHARACTERISTICS OF ATTENTION:

  • attention has a limited capacity

  • attention is selective

  • attention can be blind and deaf    

        - misdirect magicians exploit the limited, selective natures of attention

        -inattentional blindness: one doesn’t notice some significant object or event that is in clear field of vision

    -inattentional deafness: failing to hear an auditory message when attention is elsewhere


→Perils of Multitasking

  • multitasking can refer to doing two or more things at once

  • multitasking involves the division of attention

  • → CELL PHONE RISKS

        -driving was more impaired when drivers were driving on a cell phone than when the same drivers were legally drunk.

        -using a headset or Bluetooth device while driving does not improve safety.


→     Biological and Environmental “clocks” that regulate consciousness

  • many body functions, including, mental alertness, are regulated by circadian rhythms, which systematically vary over a 24-hour period

  • circadian combines the latin words “about” and “day”

  • circadian rhythm refers to a biological or psychological process that systematically varies over the course of each day.

  • process affected includ:

    • body temp

    • cortisol secretion

    • sleep and wakefulness

    • secretion of melatonin

    • release of growth hormone

      • Examples of Human Circadian Rhythm

        • peak mental alertness and memory: 2: 9AM and 9PM

        • lowest body temp: 97 degrees around 4PM

        • highest body temp: 99 around 4PM

        • peak hearing, visual, taste, and smell sensitivity: 2: 3AM and 6PM

        • lowest sensitivity to pain: 4PM

        • peak sensitivity to pain: 4PM

        • peak degree of sleepiness: 2: 3AM and 3PM

        • peak melatonin hormone in blood: between 1AM and 3 AM


→ Suprachiasmatic Nucleus

    (SCN)

    -cluster of neurons in the hypothalamus that governs the timing of circadian rhythms

Melatonin: hormone of the pineal gland that produces sleepiness

  • bright light, especially sunlight, helps regulate the sleep-wake cycle and other circadian rhythms

  • light detected by special photoreceptor signals the SCN in the hypothalamus

    • Pineal Gland

      • first thing in the morning

      • shortly after light exposure

      • later in the day

  • Role of Sunlight

    • sunset each day detected by the SCN through its connections with the visual system

    • SCN triggers an increase in MELATONIN

    • increased blood levels of melatonin make you sleepy and reduce activity levels

      • CIRCADIAN RHYTHMS AND SUNLIGHT

        • The 24.2-hour day

        • Internal body clock drifts to its natural-or intrinsic rhythm. Interestingly, our intrinsic circadian rhythm is abt 24.2 hours, or slightly longer than a day.

        • when deprived of all environmental time cues, sleep-wake, body temp, and melatonin circadian rhythms become desynchronized

        • jet lagged: circadian rhythms are out of synchronization with daylight and darkness cues; thinking, concentration, and memory get fuzzy

        • blind people can experience desynchronized melatonin, body temp, and sleep-wake circadian cycles

  • Sleep and Modern Sleep Research

    • modern sleep research began with the invention of electroencephalography and the discovery that sleep is marked by distinct physiological processes and stages

    • electroencephalograph

      • invented by German psychiatrist Hans Berger in the 1920’s

      • uses electrodes placed on the scalp tom measure and record brain’s electrical activity

      • EEG (electroencephalogram) graphic record of brain activity produced by electroencephalograph

    • Brain remains active during sleep

    • pattern of activity differs from waking state- some areas active, others not.

      • TWO basic types of sleep

        • REM (rapid eye movement) associated with dreaming

        • NREM (non-rapid eye movement) divided into four stages


→ The Onset of Sleep and Hypnagogic Hallucinations

Brain Wave Patterns When Awake

  • Beta brain waves- brain wave patter associated with aler wakefulness

  • alpha brain waves- brain wave pattern associated with relaxed wakefulness and drowsiness

Brain Wave Patterns When Drowsiness Sets In

-hypnagogic hallucinations- vivid sensory phenomena that occur during the onset of sleep

INCLUDE:

  • sensation of falling, accompanies by a myoclonic jerk (most common)

  • daily activities and preoccupations

  • floating, flying, or seeing kaleidoscopic patterns or an unfolding landscape


—The First 90 minutes of sleep and beyond

  • enter NREM sleep four-stage progression

    • STAGE 1 NREM: some hypnagogic imagery, easy to regain consciousness, less vivid mental imagery

    • STAGE 2 NREM: slight muscle twitches, sleep spindles, k complex

    • STAGE 3 AND STAGE 4 NREM: slow wave sleep, heart rate and respiration drops, sleeper oblivious to world, sleepwalking, takes a long time to regain consciousness.

      • upon reaching stage 4 after abt 80-100 minutes of total sleep time, sleep lightens, returns through stages 3 and 2

      • REM sleep emerges, characterized by EEG patterns that resemble beta waves of alter wakefulness

        • brain more active, generating smaller and faster brain waves

        • visual and motor neurons activate

        • muscles most relaxed

        • rapid eye movements occur

        • sexual arousal occurs in both sexes

        • dreams occur

      • four or five sleep cycles occur in a typical night’s sleep; less time is spent in slow-wave, more is spent in REM

      • first REM period is about 5 to 15 minutes; length extends in later periods


→ Why Do We Sleep?

        sleep is important in:

            -maintaining immune function learning and memory mood regulation

  • animals with natural predators sleep as much as 15 hours a day

  • grazing animals, such as cattle and horses, sleep in short bursts- about 4 hours per day

  • hibernation patterns coincide with periods during which food is scarce and environmental conditions pose threats