Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [sensation]

Sensation is dealing with the processing of the senses, including the traditional senses vision, hearing, taste, smell and touch, but also sense experiences such as vestibular and pain. It typically involves the higher-level cortical brain areas associated with the conscious experience of physical stimuli.

81
votes
3answers
14k views

Is there an RGB equivalent for smells?

Millions of colors in the visible spectrum can be generated by mixing red, green and blue - the RGB color system. Is there a basic set of smells that, when mixed, can yield all, or nearly all ...
29
votes
3answers
5k views

Can one see flickering of a light bulb at 50 Hz?

Yesterday I had a BBQ with some friends. The sun had already set and the only light source left (besides some ambient light from the world around) was a low energy light bulb. After a while I started ...
24
votes
1answer
2k views

Can we taste electrons?

Why does licking a 9-Volt battery elicits a taste sensation? Can taste be stimulated by electrical stimulation?
21
votes
1answer
6k views

Why does my room suddenly look 'reddish'? My eyes seem to adapt to color

To get the context of this question clear, I would like you to walk through some parts of my house. We'll start with one of my rooms as it appears normally - As evident, this part of my house has a ...
21
votes
4answers
3k views

Could we transmit smells electronically?

We can encode sound and images in radio waves and send them, but presumably there's some physiological reason that we can't easily make a picture or video of a smell. Could we realistically break ...
20
votes
3answers
3k views

How statistically significant was the “sweaty T-shirt” experiment?

An Overview of the Experiment. In 1995 there was an experiment that involves young people smelling T-shirts worn by another gender and rating their preference. The researchers found that people ...
15
votes
1answer
4k views

Why does black and yellow indicate danger?

It is a well-known fact that combination of black and yellow indicates danger or poisonousness. In western society it seems obvious this comes from bees and wasps, but it seems like many tropical ...
14
votes
2answers
828 views

Why can you not tickle yourself?

It's the age old question, why can't we tickle ourselves? If you rub your fingers along your skin, sure there's sensation but you don't break down into a laughing fit (at least I don't :P), if someone ...
13
votes
1answer
318 views

Why does getting certain chemicals in cuts hurt?

More specifically, shampoo. What are the mechanics of detecting a noxious chemical stimulus in terms of which receptors recognise what, how do they do it, and how is this information relayed to the ...
13
votes
1answer
588 views

Are there specific features of birds that cats/small predators are attracted to?

I've recently heard a podcast, in which a professor describes one of the theories as to why we like abstract art. In his talk, he mentions an experiment with seagull chicks, in which the seagull ...
13
votes
1answer
208 views

What portions of the brain have drastic changes in activation when we “sense” someone is there?

I was watching an old Arnold Schwarzenegger movie ("Commando") where he plays an elite soldier (surprise). An enemy tries to sneak up on him, and Arnold says that he smelled the other guy approaching....
13
votes
0answers
2k views

Why do we experience temperatures below 37 degrees Celsius as 'hot'? [duplicate]

We always prefer to be in 20-25° C, although our core temperature is about 37°? Why is our skin temperature lower than our core temperature?
12
votes
1answer
39k views

Why can cats interpret things on a monitor/tv, but dogs cannot?

E.g. you can see a lot of videos where cats are smashing some mouse or spider on an ipad, but I have never seen it with a dog. I have a dog myself and I know that he sometimes responds to the sounds ...
12
votes
3answers
5k views

How do ants sense imminent rainfall?

I have always been told to watch to see if ant-hole mounds are built up as a sign of imminent rainfall. My questions are, if what I have always been told is true, then by what mechanism do ants '...
11
votes
3answers
28k views

Why do I smell flowers after sneezing? [closed]

Often when I sneeze, I smell flowers for a few seconds afterwards. I've done some searching on the internet, and apparently it's something that is at least not entirely uncommon, although the exact ...
11
votes
3answers
3k views

How are our senses dimmed during sleep?

Our senses are not as sensitive during sleep compared to wake. There is an arousal threshold during sleep that only when it is overcome will it wake a person up. My question is how is this arousal ...
10
votes
2answers
3k views

Why dogs move their noses when smelling?

I read on Wikipedia that: The wet nose, or rhinarium, is essential for determining the direction of the air current containing the smell. Cold receptors in the skin are sensitive to the cooling of ...
10
votes
1answer
467 views

Dogs bark at familiar person in Santa costume. Why? Don't dogs trust smell over vision?

Last night 10 humans and 2 dogs spent Christmas together. At some point, one human dissappears for a few minutes and comes back wearing a full Santa outfit. Upon respawning, the dogs start barking ...
10
votes
1answer
2k views

Evolutionary reasons why you cannot tickle yourself but masturbate

There are obviously good reasons that explain why you cannot tickle yourself (see e.g. here). This got me thinking why it is possible to masturbate... Wouldn't it make more sense to not being able to ...
9
votes
1answer
705 views

Can frogs see clearly under and above water?

If humans attempt to see underwater, the image is blurred due to refractive differences in air and water that disrupt the normal refractive effect of the lens in the eye. A diving mask overcomes this ...
8
votes
3answers
6k views

Can a human smell through the ears?

The title does, prima facie, appear absurd. Performing a swallowing action whilst pinching the nostrils shut gives the impression of listening through a bucket filled with water around the head; ...
8
votes
2answers
647 views

Do animals exist which have good vision, but see only grayscale?

In computer vision the color information is often discarded, as most object recognition tasks seem to work just as well on the greyscale image (even better, because there is less unnecessary ...
8
votes
2answers
7k views

Can ants sense food from a long distance?

I recently had ants find and then swarm to a food container that I put down on a desk. I'm curious as to whether an ant would have needed to get lucky (i.e., discovering the food after crawling up the ...
8
votes
2answers
1k views

Do butterflies see behind?

Butterflies, like many other insects, understand that I am getting near from behind. How do they feel this - through vision, hearing, or some other sense?
8
votes
2answers
4k views

Why do I still see a bright light after looking directly at it?

When you look directly at a bright light, maybe accidentally when looking at the sun, the shape of the image may persistently be perceived even after you look away. Does this image persistence have ...
8
votes
1answer
2k views

What is the smallest touch sensation that a human can feel?

What is smallest touch (pressure) sensation that a normal, healthy person (not hypersensitive nor insensitive) can feel on the palm of the hand?
8
votes
1answer
5k views

Does the human ear adapt to noise levels?

I have noticed lately that if I go to sleep, when I have my radio running, it is on lowest volume, I still consider it kind of loud. In the morning, when being on the edge of waking up, I hear the ...
8
votes
1answer
357 views

Do blind people learn Braille equally fast as the sighted?

The visually deprived brain undergoes extensive remodeling due to cross-modal plasticity. This leads to increased areas of the cortex being available for other purposes such as tactile processing. Now ...
8
votes
1answer
2k views

How can flies sense mirrors?

I've noted that flies in my house have no problem landing on even perfectly clean mirrors. Why don't they fly straight into them? Can they sense that there is a surface there, even though they can't ...
8
votes
1answer
393 views

Do ants feel acceleration?

The organ we have to provide us with current acceleration information is quite complicated. Because an ant queen didn't seem to notice when I picked up the bottle she was in, I have a suspicion that ...
7
votes
1answer
245 views

Perception of white in the absence of rods

If the retina would not have any cones, one would be color blind. If white is the presence of all colors (in the matter of color mixture, not addition), then what would white look like without rods?
7
votes
1answer
1k views

How can bats hear such high frequencies?

I attended a talk that glossed over some biology as it was talking about a certain protein. The speaker mentioned humans can hear up to, often less than 20kHz frequencies, whereas bats can hear up to ...
7
votes
1answer
231 views

Is bad tasting food more likely to cause harm?

Taste is often referred to as subjective. For example certain foods taste bad to me, such as oranges, grapefruit, grapes, raisins, and sweet potatoes. However the wiki article on taste explains that ...
7
votes
0answers
78 views

Cold water sour taste

Recently I underwent a wisdom tooth extraction, and while there is still numbness I have observed something peculiar. If I drink cold water, it tastes sour, however the same effect is not observed ...
7
votes
3answers
9k views

Why do we squint when tasting very sour things?

Sometimes while tasting a very sour thing (like tamarind, lemon etc.) our eyes squint immediately and involuntarily for a second, but a little later becomes normal again. Why, and how, does this ...
6
votes
1answer
560 views

What would happen if you “rewired” your eyes with your nose?

The nose sends sensory input through transduction of chemicals in the air via the olfactory nerves/tracts to the primary olfactory cortex. The eyes send sensory input through transduction of light ...
6
votes
1answer
12k views

Why does ear wax taste sour?

Why does ear wax taste sour? I am interested in both the physiochemical mechanisms and the evolutionary reasons behind the sour taste of earwax.
6
votes
1answer
8k views

How precisely can we sense temperature differences?

We have thermoreceptors, thus we can sense temperature (both warm and cold). I'm interested in the sensitivity of our thermoreceptors - What is the smallest temperature difference that we can sense? ...
6
votes
1answer
1k views

What is the biochemical explanation for tingling and burning sensation in brain due to certain food?

Consumption of mustard (spicy English Mustard), wasabi and horseradish based food dressings usually result in a burning, tingling or freezing sensation in the brain/scalp and nostrils as the vapour ...
6
votes
1answer
69 views

What is mold detection threshold in humans?

I managed to find primary taste detection thresholds, e.g. for sweetness it's 1 part in 200 of sucrose in solution. Recently I've noticed that I can detect mold smell/taste even if there are no signs ...
6
votes
1answer
373 views

Do ants use something similar to the honey bee “waggle dance” to instruct the rest of the colony where to find a food source?

In the 20 years since we built our home, we've just recently had our first ant infestation. I'm familiar with the fact that ants leave scent trails to find their way back and forth between the ...
5
votes
4answers
890 views

Why do humans not have a powerful sense of smell?

It seems like a useful ability to be able to detect many different things about, say, another organism. A lot of mammals have this ability. Why not humans? Did we evolve it out or never develop it?
5
votes
3answers
1k views

Why can humans feel electricity?

What evolutionary process has provided humans with the ability of feeling electric current? Besides lightning and electric eel, what natural hazards include electricity that poses a threat to humans?
5
votes
1answer
413 views

Are similar smells usually based on similar chemicals?

Building off of this question: Why does freshly cut grass smell like a watermelon?, is it usually the case that things that we perceive as having similar smells are, in fact, the same or a similar ...
5
votes
2answers
132 views

How can bobcats feel the mice under the snow?

I've just seen the Planet Earth II's second episode "Mountains" where they shock us with these North American bobcats that can feel mice from the distance of several meters, sneak to them and kill ...
5
votes
1answer
219 views

What is the biological limit on hearing resolution?

I sometimes wonder how many different individual musical scales could be perceived by human ears. I define a musical scale as a collection of notes that relate to some fundamental frequency by ...
5
votes
1answer
946 views

How are smell and taste in fish differentiated?

The senses of taste and smell in different fish classes are described as two distinct senses; smell is mediated by the nasal openings, and taste by epithelial taste buds. They are both forms of ...
5
votes
1answer
76 views

Can nociceptors die because of too much mechanical stress?

In martial art people hit their body (e.g., with small bean bags) to become more insensitive to pain. Can the sensory neurons die during this procedure? I think this is just an urban legend. Instead, ...
5
votes
3answers
645 views

Why do human ears have a lower boundary for the lowest energy perceivable signal than eyes?

I am currently hearing a lecture about human machine interaction. The lecturer is not a biologist (neither am I, we are both computer scientists), but he makes some statements about biology which I ...
5
votes
2answers
2k views

What's the frequency resolution of the human ear?

I was thinking about audio compression (namely mp3), that "filters" out sound that we would not likely hear. The MP3 lossy audio data compression algorithm takes advantage of a perceptual ...