The Science of Sleep: Understanding What Happens When We Drift Off

[atjta]

OK I have a few questions about sleep. What do you feel when you sleep? I read somewhere that being asleep is different from being dead or under anaesthesia so what do you feel? Like do you perceive passage of time or something. I read somewhere that you do and it sort of makes sense since when I wake up I am aware of a time gap, but it's a bit difficult to imagine. Also is it true that you still perceive sensory info but your brain doesn't make sense of it? Like when people talk in the background you hear what they say but your brain doesn't make sense of it, and you start ignoring it after awhile. Also does that mean that if you were perpetually in the same environment you would fall asleep and not wake up?
Wasn't sure what forum to put it so I put it in general.

 

[Drakkith]

All of your senses still function when you are asleep. You still feel pain, hear things, ETC. Since your are asleep your brain simply doesn't allow you to conciously experience them for the most part. If something excites your senses enough it will cause you to wake up. (Such as a loud noise near you wakes you up, or sunlight shining into your eye can wake you up) Each person has different things that will wake them up. For example, I can sleep through someone mowing the lawn outside my window, but I will wake up instantly to my phone, alarm, or doorbell going off. (Usually) Like my dad says about himself, I tend to wake up when something unusual happens or when something happens that I know I need to wake up for. Like getting the door, answering the phone, ETC.

I know I have some perception of time passed AFTER I wake up. I can tell when I wake up after abour 3-4 hours that it has only been about that long compared to waking up after 7-8 hours. Whether that is due to actually having a sense of time or because of the way I feel when I wake up I don't know for sure.

Also does that mean that if you were perpetually in the same environment you would fall asleep and not wake up?

No. You will wake up after your brain and body have rested long enough. Sleep, after all, is induced because your body and brain need to rest.

 

[atjta]

Another question, are plants, bacteria, etc similar to people sleeping in that they can perceive, but don't have consciousness?

 

[Drakkith]

Another question, are plants, bacteria, etc similar to people sleeping in that they can perceive, but don't have consciousness?

No. Plants and bacteria literally do NOT posess a nervous system. Bacteria act just like individual cells in our body do. They both respond to chemical and other signals in their environment, but neither "sleep" or have consciousness. That would require a complex nervous system.

Sleeping people are perceiving things, but the "conscious" part of your brain simply isn't aware of them. The unconscious part is however.

Plants "may" act differently during the night than they do in the day, but it is a result of different environmental effects on the plant, such as sunlight and temperature. Plants do not have a nervous system but their cells do respond to various stimuli.

 

[hypatia]

Also is it true that you still perceive sensory info but your brain doesn't make sense of it?

A purely anecdotal story. I was once in a house fire, sound asleep. I conceived the sound of pop corn popping, which woke me to a lighter stage of sleep. Once my brain told me it was just pop corn, I fell deeper into sleep again. It was neighbors breaking the glass window to my room that woke me. I was lucky to get out unharmed. My brain seemed to have tried to make sense, of the sound of wood popping and burning. I have never felt comfortable sleeping sense then.

 

[Proton Soup]

it's possible to have enough sense of time to awaken without an alarm.

another pure anecdote, sometimes when my bladder is really full, i'll dream that I'm relieving myself, and that will get the attention of my conscious mind that i need to get up and go to the bathroom.

 

[atjta]

QUestion: if you "unconsciously perceive" something in sleep can you remember it when you wake up?

 

[Drakkith]

QUestion: if you "unconsciously perceive" something in sleep can you remember it when you wake up?

I think so. Sometimes I'll wake up and KNOW that the doorbell just rang, but I was deep asleep when it happened.

 

[lisab]

I think so. Sometimes I'll wake up and KNOW that the doorbell just rang, but I was deep asleep when it happened.

Yeah, but sometimes I wake up and KNOW something heavy just fell down with a huge bang, but no such thing actually happened.

For me, that's common enough that anything I perceive in that twilight sleep state, no matter how real it seems, I just assume it was a dream.

 

[Drakkith]

Yeah, but sometimes I wake up and KNOW something heavy just fell down with a huge bang, but no such thing actually happened.

For me, that's common enough that anything I perceive in that twilight sleep state, no matter how real it seems, I just assume it was a dream.

Hrmm. I don't usually have that problem. If something actually happens in the real world, I will KNOW when I wake up.

 

[lisab]

Hrmm. I don't usually have that problem. If something actually happens in the real world, I will KNOW when I wake up.

Just curious, do you sleep walk? I do. I sometimes have very vague memories of doing it, but most of the time the only way I find out about it is by finding evidence of what I did when I was asleep.

 

[atjta]

Also do you still perceive time when asleep/unconscious? Because whenever I wake up from anything, it always seems like SOME time has passed.

 

[atjta]

^bump

 

[atjta]

Can some1 reply please?

 

[Drakkith]

Also do you still perceive time when asleep/unconscious? Because whenever I wake up from anything, it always seems like SOME time has passed.

I believe you DO perceive time on an unconscious level, but not conscious. I will almost always wake up about 1-5 minutes before my alarm goes off, so my body has some perception of time. Could you imagine having an 8 hour dream where time flowed normally? That would be FOREVER lol.

 

[Ryan_m_b]

I have never not-perceived time but my perception of time does change. Sometimes a dream seems very, very long (I have become trapped in dreams before and literally just sat down in the dream waiting for my alarm clock to wake me up and save me) and sometimes they seem quick. Time is always there though!

 

[atjta]

Is the unconscious perception feeling but not thinking about like organisms without brains (or simpler brains) do or do you just not feel anything?

 

[Ryan_m_b]

An organism without a brain has no "you". You are an emergent property of your central nervous system.

 

[atjta]

Well organisms without a brain DO perceive. That's what makes them organisms, amirite

 

[Ryan_m_b]

Well organisms without a brain DO perceive. That's what makes them organisms, amirite

I think you are confusing perceive and react. Take a single cell; it reacts to it's environment mainly through the chemistry of the environment causing certain reactions to occur within it/on its surface. The action of these reactions drives other reactions that cause appropriate reactions. An example would be the establishment of an action potential across a membrane; gate proteins respond to the local electrical gradient, they open allowing the movement of ions. These ions change the local electrical gradient and thus close the gates. There is no perception here, merely reaction

 

[atjta]

I read somewhere that bacteria actually perceive light for example, and same with plants.

 

[Ryan_m_b]

I read somewhere that bacteria actually perceive light for example, and same with plants.

It depends on your definition. Rod cells in our eyes sense light (in similar ways to bacteria and plants; light causes a specific chemical reaction that leads to a series of chemical reactions leading to a behaviour) but I would not say they perceive it. Perception implies conscious awareness of the environment.

 

[atjta]

But you don't always think about what you perceive.

 

[Ryan_m_b]

But you don't always think about what you perceive.

Yes but this does not imply that perception is just sensing. An analogy would be that standing on the pavement my senses sense the passing car through it's light, sound and smell of its exhaust. My brain then crunches all this data and compares it to previous memories so that I perceive a car passing rather than a series of random sensations. I could then think "oh a car" or I could be thinking about something else entirely.

In an organism with no central nervous system there is no perception, merely sensation directly leading to reaction

 

[atjta]

I used to think that perception is merely sensation/feeling.
Also does that mean you don't perceive when you sleep (except lucid dreams)

 

[Drakkith]

I used to think that perception is merely sensation/feeling.
Also does that mean you don't perceive when you sleep (except lucid dreams)

What is different about lucid dreams compared to normal dreams when talking about perceiving?

I would say that sensing refers to the physical act of your bodies senses getting data about the environment while perceiving is the gathering of this data in your brain. But that's just my view.

 

[candydude357]

I have a question, does perception/feeling continue in any type of unconsciousness except death? Even a coma? So being in a dreamless sleep is different from your perspective than being dead (even if you don't realize/think about the difference)?
Because one thing that's worrying me is that if you are your consciousness, if you become unconscious you wouldn't be you when you wake up, ie, when your conscious experience ends, the conscious experience that follows is experienced by a different consciousness. Or are there always gaps in conscious experience in daily life as well?

 

[Ryan_m_b]

I have a question, does perception/feeling continue in any type of unconsciousness except death? Even a coma? So being in a dreamless sleep is different from your perspective than being dead (even if you don't realize/think about the difference)?
Because one thing that's worrying me is that if you are your consciousness, if you become unconscious you wouldn't be you when you wake up, ie, when your conscious experience ends, the conscious experience that follows is experienced by a different consciousness. Or are there always gaps in conscious experience in daily life as well?

When you are unconscious your brain is still receiving input, there is just no consciousness there to perceive it. If you become unconscious of course you are the same person when you wake up, of course this really depends on what your definition of identity is. For all useful purposes it is still you, nothing has changed you have just been unconscious for a while. Death is different because death is an absence of everything, conscious/unconscious the lot.

 

[candydude357]

Do sleeping people (or bacteria) feel anything?
Do all organisms without a brain feel/not feel anything?

 

[DaveC426913]

Do sleeping people (or bacteria) feel anything?
Do all organisms without a brain feel/not feel anything?

Sleeping people can and do feel things. The unconscious mind may ignore it or may cause the mind to come out of a deep sleep to process the sensation.

'Feel' is a tricky word, like perceive. It almost certainly does not apply to lower/simpler organisms, They may react, but that is often a fairly direct reaction that doesn't involve any processing or decision-making.

For example, a moth does not choose to fly around a light at night. They have photo receptors (I believe in their wings). when light hits them at a certain angle, it causes the wings to change configuration, steering the moth toward the light. There is no thought involved.

Simple organisms may exhibit seemingly complex or thoughtful behaviour when in reality it is far more simple and direct than it seems.

All organisms respond to the world around them (it's one of the definitions of life), but 'feeling' something is generally assumed to require a complex nerve network where signals and the reaction rules masy be complex (even contradictory) and so must be processed and prioritized before being acted upon.

 

[candydude357]

But I always thought that moths do perceive light, but don't think about it?
Like there's some sort of feeling, but they don't think about it?
For example when you hear a conversation but don't process what they're talking about, you hear everything (so you perceive it) but don't think/process it.

 

[DaveC426913]

But I always thought that moths do perceive light, but don't think about it?
Like there's some sort of feeling, but they don't think about it?
For example when you hear a conversation but don't process what they're talking about, you hear everything (so you perceive it) but don't think/process it.

Again, that depends on your definition of 'perceive'. They have photosensors, yes. Is that perception?

This is a semantic discussion, since we're just discussing our ideas of words, not the actual facts of what's going on.


Going back to feeling and pain for a moment:

... a scalpel... cuts into the head and exposes the insect’s brain.

“There’s no anesthesia. Isn’t it unbearably painful?”

“Not at all ... Insects have no pain receptors, nor do they have the cognitive traits needed to experience pain the way we do. The experience of pain is created in the brain. Insects don’t have a system that can convey information about pain,”...

http://Earth'sky.org/biodiversity/inside-a-moths-brain

 

[Drakkith]

Wait, insects don't have pain receptors? I never knew that...

 

[Ryan_m_b]

I can not complete my sleep and often take sleeping pills for the sound sleep.
Is it a healthy way for he sound sleep?, Please give me some healthy suggestions

Take it up with your doctor.

 

[DaveC426913]

Seconded.

Needing to take sleeping pills regularly is a sure alert to get to your doctor.