Senses that shut down when you sleep

Factual Questions
1

The question relates to deep sleep and not the time when you are in the zone when you are not fully asleep.

The sense of sight is obviously shut down whilst the sense of hearing is not, or else we would never hear that alarm.

But are there some people whose sense of hearing is also shut down during sleep. What is that condition called.

What about the sense of touch or smell?

Do they shut down completely and for all humans during deep sleep.

Any evolutionary significances to why some senses are shut down and others not?

2

I don’t think that our senses are completely shut off while we are sleeping, but they are diminished considerably. For example, if there are wolves howling on my property I hear them and wake up. So my hearing must be functioning and my brain is able to respond, even though I was fully asleep at the time. I am not by any means a light sleeper.

As far as the alarm goes, I think our sleep cycles during the night and usually the alarm is going off when I am in my lightest sleep pattern, so it’s not too surprising that I hear it and can react to it.

3

There have been plenty of people saved from house fires because the smell of smoke woke them up.

And at least some of the senses of touch must still be working, because you can wake someone by touching them, and people often wake up from being too cold or warm.

4

The sensor for the level in my bladder doesn’t shut down, thank goodness. It’s better than an alarm clock.

5

I don’t believe your senses “shut down” in any sense during sleep, your brain just focuses less on them because it’s doing other things.

I used to work in a film lab and I quickly learned that I functioned much better in the darkroom with my eyes closed. Closing my eyes helped me to mentally visualize my tasks better. By shutting off that sense, I was able to make brain stop trying to use it.

I think sleep is like that, your brain simply focuses less on your senses, allowing it to “concentrate” on sleep.

6

I would think there’d be significant evolutionary pressure not to shut down sensors. If you don’t hear the lion roaming around you won’t live long to pass on your genes.

7

The sense of sight is not shut down, or else parents would never be able to wake up their teenage children by turning on the lights after the children don’t respond to the alarm and repeated calls to get up.

8

I don’t think any of the primary five “shut down,” although of course you mostly tune them out. Senses don’t have an ‘off’ switch. That said, the brain is really good at filtering sensory data, which is why it can sometimes be fooled into missing important stuff. If something happens that shoves you out of that comfort zone, the brain starts your waking cycle. Sometimes very fast if you hear a loud noise or someone shove you off the bed.

9

I always thought the sense of smell stayed active during sleep, but I have nothing to base that on.

10

Had a dream one Halloween night where I thought I was smelling chocolate. It woke me up it was so strong. Found out my Rottie pup had eaten all but two of the mini chocolate bars that were not taken by Trick or Treaters and was laying on the bed next to me! My sense of smell sure didn’t shut down while sleeping then.

11

I don’t think very much about this is actually know in detail. If it were, the nature of the modern internet would have turned the information into a “viral” something or other.

The nature of sleep itself, although under study for centuries now, is still a mystery for the most part. We know that it appears to be necessary, but only to MOST people. How people experience sleep varies tremendously from one person to the next, and varies tremendously from one experience of it to another, within the life of each individual.

The phenomenon know as “sleep paralysis” is no doubt related to this. It isn’t well understood either, and there are lots of intriguing experiences that various people have had with it.

I have informally studied my own sleep experiences for six decades now, and I KNOW that none of my senses are “shut off.” What does happen, is that my mind can and does make specific decisions about what to attend to. I know, because although I only dream some of the time, that if outside stimuli occur WHILE I am dreaming, that whatever version or portion of my mind is actively deciding what to attend to and how, will incorporate the external stimuli into my dreams.

I’ve taken to referring to that portion of my mind as “the Dream Guy,” who is in charge of running “me” while I am asleep. He has his own ideas as to whether to allow me to wake up for things. One of my favorite illustrative experiences, was a dream I had which was lots of fun, and very involving, in which I was sort of a classic James Bond sort of person, in the middle of a mission. At a critical moment, as I was trying to work out a serious concern in the dream, a loud ringing sound began. My dream “narrator” explained that there was a phone ringing, but that it wasn’t for me, since I was in someone’s office, trying to gather information, so I should ignore it. But the ringing went on without stopping and starting, so my dream character said “wait, that doesn’t SOUND like a phone!” But the narrator rushed back into action and adjusted the dream, to report that “it is a phone ringing, and it’s not for you, but this particular phone is defective, so it rings continuously instead of intermittently, so you should still ignore it.” Finally, another part of my mind stepped up, and actually still within the dream, stated firmly that no, this sound was probably my alarm clock, and that I should set the dream aside for another time, and get up for work.

Lots of physical sensations have similarly been explained away within dreams, which is why SOMETIMES it takes only a light touch to wake me, and SOMETIMES it takes something close to an earthquake.

Clearly, this all means that sleep is not at all purely mechanical. Also, that consciousness isn’t a binary state, it is a continuum.