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Health and medicine
Course: Health and medicine > Unit 9
Lesson 3: Sleep and consciousnessStates of consciousness
Created by Carole Yue.
Want to join the conversation?
- I think semantics get me lost here, because there are 2 meanings for “consciousness”: one is measurable, like the frequencies mentioned in the video (excellent job btw), and another one that is subjective, that we tend to use whenever we want to differentiate, for example, a New-York broker from a hunter-gatherer living in Papua New Guinea. They both are contemporary, but there’s clearly something that sets them apart. Dr. Clare Graves, in its Spiral Dynamic’s study, differentiates them using the term “levels of consciousness”, and by doing so, one can say that the New-York broker is “more conscious” than the tribe man. This is very intuitive. But also very different from the “levels of consciousness” described in the film. Is it just semantics?(8 votes)
- What do you mean by "light" or "deep" meditation?(6 votes)
- It is similar to light sleep and deep sleep. An analogy might be to say how intensely you are in you meditative state.(4 votes)
- Are those states in order? I mean, in order to achieve sleep, you need to experience drowsiness and in order to achieve drowsiness you have to experience daydreaming?(3 votes)
- I don't think that is the case. One could (for example) become drowsy without daydreaming before. However, I think that there is a high chance that through the span of a day, a person will experience all 4 stages, though not in a particular order.(2 votes)
- What about lucid dreaming? Is this what she means at? 2:02(1 vote)
- She isn't really talking about lucid dreaming here, just the normal dream state. Lucid dreaming is a different state of consciousness than either awake or dreaming, because you are aware that you are dreaming yet you are still asleep. That awareness means that it is not a state of unconsciousness, it is something else.(5 votes)
- If the minimum for beta waves is 12 hertz and the max for alpha is 13 how do you know if a 12.5 hertz wave is alpha or beta?(2 votes)
- Does caffeine intake affect beta waves () ? If so, how does that work on a neuro level? 2:31(2 votes)
- at about 3 min she talks about experiencing heightened alertness "for too long" thus increasing beta levels, stress, anxiety. Does anyone know how long is "too long"?(2 votes)
- Job interview
So, why are you interested In this job?
Oops! Sorry, I gotta daydream in four seconds before I...
Wait... Was I daydreaming? Where am I?
FIRED(2 votes)
- If you are 12.5 hz will you have beta alpha waves?(1 vote)
- yes u will surely have every part of the brain and of course the rest release beta alpha waves.any hz waves are enough(1 vote)
- what drugs are released during sleep(1 vote)
- What about gamma waves? Why don't I ever hear people speaking about gamma waves?(1 vote)
- Gamma band activity has a frequency around 40Hz. It is shown to be appearing during challenging cognitive tasks. Yet there is no agreement on the theory. There are still some neurophysiologists argue that an activity with such high frequency is a confusion with the high frequency electromyographic activity instead of a cognitive one.(1 vote)
Video transcript
Voiceover: What is consciousness? Well that's not something
we can easily answer in one video. In general, consciousness
is usually defined as awareness of our selves
and our environment. We can have different
states of consciousness meaning different levels of awareness and they can occur naturally or be induced by external factors such as drugs or internal factors such
us our own mental efforts. These states range from alertness to sleep and everything in between. Alertness is what most people think of when they think about being conscious. When you're alert, you are awake, aware of who you are, where you are, and what's going on in your environment. You can focus your attention, encode information and memory, engage in conversation, all the stuff you normally do when you're awake and aware of the world. That's alertness. We've all had the
experience of daydreaming or being awake but not really aware of
the world around you. Maybe you've had that experience in class or during this video. You may feel more relaxed but you're not as focused as you are during normal awareness. Daydreaming occurs naturally. Sometimes you'll find yourself daydreaming when you didn't mean to. Some people can induce a similar state through light meditation. Moving into the less conscious
states of consciousness, we have drowsiness. That state when you're almost asleep but still semi aware of the world. You might feel this way
just before falling asleep or maybe just as you're waking up. In all those drowsiness
also comes naturally just like daydreaming, some people can induce
this state of consciousness through deep meditation. Finally we have sleep, it's a little strange to call
this a state of consciousness because it's really more of
a state of unconsciousness. You're not aware of yourself
or the world around you when you're asleep. Even though you might be
aware of a dream world. One thing that's pretty cool is that even though you might not be aware of when you shift from one state
of consciousness to another your brain knows. You have sets of neurons
that fire rhythmically in your central nervous system leading to neural oscillations or just those rhythmic patterns of firing that we can measure. There's a machine called
an electroencephalogram or EEG which measures
those neural oscillations more commonly called brainwaves. There are four main types of brainwaves that we associate with different
states of consciousness. Alpha, beta, delta, and theta. Each of these types of brainwaves oscillates at a different frequency and is associated with a
particular state of consciousness. For example, beta waves which oscillate at about 12 to 30 hertz
which is pretty fast. It means that it's going at about 12 to 30 cycles per second. Those are associated with
normal waking consciousness and concentration. If you maintain this heightened alertness for too long though your beta levels get really high and you might experience increase stress, anxiety, and restlessness. Just sort of this
constant awaken alertness. Alpha waves though are common during relaxed awake states such as daydreaming or light meditation. As you might expect an alpha waves have a lower frequency than beta waves. Alpha waves are about eight to 13 hertz. Although alpha waves
disappear as you become drowsy they can reappear later
when you're in deep sleep. When you do get drowsy or
you're in deep meditation an EEG would show theta waves which are even slower than alpha waves. They're like four to seven hertz. You also see this pattern right after you first fall asleep, when you're sleeping very lightly. Sleep as a state of consciousness is surprisingly complex and involves multiple phases of it's own and different cycles of brainwaves including the delta waves, which we haven't talked about yet. The next video, is going to
focus on the stages of sleep and what your brain does
during those stages.