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.
126
questions
18
votes
1
answer
3k
views
Why is loud music much louder after pausing and resuming it?
If I pause a sufficiently loud song (in headphones) for several seconds, then resume it, I perceive it as deafeningly loud, even painfully. Yet, if I first lower the volume, resume, and then gradually ...
27
votes
3
answers
6k
views
Did predators evolve eyes first?
I'm an engineer and biology is my weakest point, so please forgive if this question is dumb.
Lately I've been wondering, "Why do animals that have eyes tend to have exactly 2 of them?" The ...
- 379
3
votes
0
answers
74
views
Happiness from sunlight is from IR or UV?
I found this study that shows that UV light makes our skin release feel-good endorphins. This is the pop-sci writeup.
On the other hand, it seems like IR is what causes the sense of warmth in the skin ...
- 39
1
vote
0
answers
63
views
How does the central nervous system create the feeling of physical sensation in our consciousness? [closed]
I know sensory neurons that respond to light and physical sensations (pressure, temperature) exist throughout our body, giving us information about our surroundings.
For instance, when I push the tip ...
- 19
3
votes
2
answers
503
views
What determines the maximum frequency limit that humans can hear?
I learned that the human ear doesn't hear sounds outside the range of 20-20,000 Hz.
I can understand that sounds below this range are so weak that they don't affect the ear.
But why do sounds above ...
1
vote
1
answer
104
views
how do we feel electricity on skin even though merkel cells are pressure sensitive only?
Note: Here I am not talking about electric shock (one feels when a lot of electricity passes through), I am talking about smaller sensations one feel directly on the skin.
Note: I am not able to find ...
- 21
3
votes
2
answers
58
views
What role does the eardrum and ossicles play in hearing, versus cilia?
Modern electronic sound recording equipment employs a physical membrane that triggers the piezoelectric effect in a metallic element, to transform sound waves into electric signals.
I had always ...
- 1,387
1
vote
1
answer
147
views
How does this small brown crescent-headed land planarian(?) "look around" and sense its envirnoment?
This 2-3 cm long, thin brown worm with a wide "anchor" or hammer or crescent shaped head was seen in northern Taiwan slowly moving along a damp tile outdoor surface. It moved by contraction/...
- 5,094
2
votes
2
answers
368
views
Are sensory mechanoreceptors and mechanical nociceptors the same type of neurons or are they different?
I always supposed the neurons / receptors which transmitted touch and pain were the same, since they react to stimulus which are the same but with different intensity, and they just sent a stronger ...
- 2,787
33
votes
1
answer
5k
views
Are drugs made bitter artificially to prevent being mistaken for candy?
All drugs I remember tasting (with the notable exception of Aspirin) have bitter taste. Is the taste due to the active substance, or is a bittering agent added to them, perhaps to prevent overdose?
...
- 883
4
votes
2
answers
142
views
Book request: biology of sensation and perception
I’m interested in learning about the biological and chemical basis of human sensation and perception (on both a microscopic and macroscopic level). This includes
The mechanisms underlying our “five ...
5
votes
1
answer
149
views
Are there people blind to touch?
There are people who completely blind or deaf. Are there people who are completely blind to touch in a particular area or in the entirety of their body? If not, are there people in whom the ...
- 51
0
votes
1
answer
681
views
Why do coliform bacteria smell so bad?
I have done multiple cultures of E. coli bacteria and related species over the course of my education. Almost every time, they had this revolting smell. However, other organisms used for genetics ...
- 231
1
vote
1
answer
354
views
Why are eyes more sensitive to flicker in periphery — contradictory answers
In terms of the perception of flickering by CRT monitors, This answer suggests that peripheral vision has faster response and is thus more sensitive to flicker due to being provided by rod cells.
...
- 395
3
votes
1
answer
144
views
Why/how does exposure to noise cause cochlear hair-cell loss?
I am trying to understand why listening to loud music - e.g. concerts or earphones at high volume damages hearing.
According to the National Institute on Deafness the cause is physical.
Most ...
- 133
5
votes
2
answers
432
views
Understanding the "Waterfall Illusion"
Motion after-effect illusions, such as the waterfall illusion, refer to illusions where fixating a screen which shows stimuli moving in a particular direction elicits the perception of motion in the ...
- 53
6
votes
2
answers
159
views
Are there gaps in what our ears can hear?
I know about the hair cells in our Cochlea and it is the movement of the fluid that makes them vibrate. And it is this that activates the transmission of electrical signals to the brain that become ...
- 77
-3
votes
1
answer
37
views
A speculative question about sensation
I know this is rather speculative and I am not a biologist, but I have womdered about this for a long time.
I have always been able to pinpoint the central line of any part of my body exactly as if ...
- 101
1
vote
1
answer
439
views
Multiple numbers in the Ishihara test?
When I was in high school (30 years ago), I took a biology class, and the instructor showed us an Ishihara color test for color-blindness. (This is the "hidden numbers" test.)
What I thought I saw ...
2
votes
1
answer
104
views
How do we feel sensations from a tooth surface that is made up of enamel?
If enamel does not have any sensory receptors, how do we feel the tactile sensations when we touch our teeth with an object/finger nail?
- 502
2
votes
0
answers
42
views
How many "primary colors" can we smell? [duplicate]
There are many more that three visible wavelength in the visible EM spectrum, and yet we can model any color using only three primary RGB wavelength. Perception of an arbitrary color is equivalent of ...
- 161
2
votes
0
answers
108
views
How can we usually "trust a fart" not to be liquid or solid?
Jack Nicholson's character Edward Cole in the movie The Bucket List said ...and never trust a fart, and a search for Al Roker leakage White House will clear up any doubts what that's all about.
How ...
- 5,094
4
votes
1
answer
288
views
Why is peripheral vision not bleached by daylight?
In daylight, rods are known to be bleached: we have to wait some time after going into darkness before scotopic vision becomes effective. But, as I understand, peripheral vision is also mostly due to ...
- 395
1
vote
1
answer
173
views
How are sound waves amplified while traveling within the cochlea?
How are sound waves amplified while traveling from the basal membrane to apical membrane within the cochlea? Are they amplified by the movement of the stapes?
- 11
30
votes
3
answers
9k
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 ...
- 419
2
votes
1
answer
901
views
What is the signal conversion from hair cells to cochlear nerve cells?
If I understood correctly, inner hair cells generates a graded potential (receptor potential), this potential maps the stereocilia deflection. On the other hand, the cochlear nerve cells transmit ...
- 113
0
votes
2
answers
73
views
why do we tighten out muscles against cold?
When I'm in shower and I want to open the cold water on myself suddenly I make my muscles so tight before I open the water and that helps so much in being able to handle the shock. Why does tightening ...
- 258
1
vote
1
answer
164
views
What is an "Alternative Sensation"?
As far as I know, alternative sensation it's a sensation to distract people from the original stimuli, for example when you have to get an injection, the nurse will pinch you in the other arms so your ...
- 387
3
votes
2
answers
4k
views
What is the direction of the processing of light by the (human) retina and how does it happen?
Quoting Textbook of Medical Physiology by Guyton and Hall, 2016, page 647,
...the functional components of the retina, which are arranged in layers from the outside to the inside as follows:
(...
- 265
4
votes
1
answer
128
views
Pitch perception - why is the missing fundamental not directly detected in the cochlea?
I'm learning about pitch perception, and learned about the case of the missing fundamental.
In the main image in that wikipedia page, it seems like the bottom graph, with the fundamental frequency ...
- 143
25
votes
1
answer
32k
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 ...
- 477
3
votes
1
answer
179
views
Is the masking effect of sound related to action potentials or to mechanical aspects of hearing?
I am an applied mathematics / signal processing engineer who wants to learn more and I have a question that has been bugging me for some time. It is known in audio coding circles that human hearing is ...
- 189
-3
votes
1
answer
59
views
Are there organisms sensing conformations, which we humans can't sense directly? [closed]
Are there organisms which can sense the conformations, which we humans can't sense directly, i.e. without using any equipment?
If there are organisms which can sense conformations ("the shape or ...
- 137
0
votes
2
answers
118
views
Are resonances the reason receptors work?
From Visual phototransduction - Wikipedia:
When struck by a photon, 11-cis retinal undergoes photoisomerization to all-trans retinal which changes the conformation of the opsin GPCR leading to ...
- 578
3
votes
1
answer
268
views
What causes Pseudomonas fragi to smell sweet?
I am working with Pseudomonas fragi and I could not help but notice that it smells sweet, which probably explains its species name 'fragi' from 'fragum', strawberry in Latin.
Does anybody know what ...
- 901
1
vote
1
answer
162
views
Is it the theory of the 5 senses obsolete? [closed]
An enigmatic topic in traditional science was labelled as the mystery of the 5 senses, and how to best group senses by type.
Is that theory now meaningless?
Do Scientists still agree that that ...
- 10.3k
0
votes
3
answers
140
views
How do our sensory organs work automatically without our conscious effort? [closed]
I wonder how our different sensory organs (e.g., eyes, nose, ears, etc.) work automatically without our conscious efforts or without our command. We don't have to tell our eyes how to see, our ears ...
- 19
2
votes
0
answers
31
views
Sensitivity Along Digestive Tract [closed]
Suppose you swallowed a little capsule with a blunt poker which had
some impulse of force applied every few seconds. What would be the
sensitivity ordering (of lips, mouth, throat, esophagus, stomach,...
- 313
8
votes
1
answer
462
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 ...
- 425
1
vote
1
answer
2k
views
How greater magnitude implies greater frequency of action potential?
Greater the magnitude of receptor potential, greater is the rate of discharge of action potentials in the nerve fibre.1
Now consider a case where stimulus ( strength ) is large , so there is more ...
- 4,786
2
votes
0
answers
2k
views
Does Rüppell's Griffon Vulture Have Greatest Vision Acuity? (Small Carrion Spotted at 10 km+?)
Synopsis:
Some sources seem to imply the Rüppell's (griffon) vulture (Gyps rueppelli) can see objects at a distance in excess of 10 km -- roughly three times the ...
- 169
4
votes
4
answers
2k
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?
- 151
2
votes
0
answers
54
views
What digitally encoded smell formats exist?
Is there a defacto format for storing and transmitting smell digitally? Where can I obtain samples of such smell encodings? What reference dataset exists against which I can compare my smell sample to ...
- 121
6
votes
1
answer
92
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 ...
- 161
10
votes
1
answer
2k
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 ...
- 594
8
votes
2
answers
11k
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 ...
- 660
8
votes
1
answer
4k
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?
- 323
6
votes
1
answer
939
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 via ...
- 29.7k
84
votes
3
answers
15k
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 ...
- 935
2
votes
0
answers
62
views
Sensing weather conditions through bodily reactions (e.g. dry hands, arthritic pains)
Two fairly known examples of the effect of certain weather conditions on the body are dry hands due to decreased air humidity around us (more commonly in the winter, as described here), and flaring of ...
- 474