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18

Anything related to mint usually contains menthol. What does it do? It triggers the TRPM8 ion channels, causing your skin's cold receptor to become sensitive, and causing it to overfire. This causes the brain (receiving cold signals from skin) to feel cold, and that's why you feel cold. I have summarised it in a few sentences, but as with any scientific ...


12

First recall that pink is white minus green, more or less. Now, your perception can be explained by adaptation: Neurons try to control their gain (amplification factor) to have roughly the same range of output. So if there's a lot of stimuli they like, they will reduce their gain, and vice versa. It can be thought of as a form of fast time-scale homeostasis ...


9

Short answer Action potentials generated to different colors are indeed similar throughout the nervous system and do not encode color as such. Instead, the different color- sensitive cells in the retina are connected to different neurons and these color-specific signals are kept segregated up until the higher visual cortical areas. Background Action ...


8

Mixing up input from different senses is actually a known neurological phenomenon called synesthesia. Synesthetes (ie. adults experiencing synesthesia) might see numbers in colors for example. Some may even "taste" colors as you say. Now do all infants have synesthesia before some stage in development is another question. It is actually a rather old ...


8

Short Answer: Though the concept of development of perception in children is known (Vernon et al, 1961), the process of differentiation between different senses is largely innate, though some disorders related to sensory processing may be acquired during infancy. Background: The processes involved here are sensory processing and sensory integration. Sensory ...


7

There are two different aspects to or drivers of thirst, osmolality and hypovolemia, with plasma osmolality elevation being the more potent stimulus of thirst. As stated by @arboviral (and supported by his link), not a lot is known about the mechanisms of immediate thirst satiety. Much more is known about the mechanisms causing thirst, and the mechanisms of ...


7

This is a good question. The first thing to note is that human colour vision is very complex and still poorly understood. If you visit the wikipedia page on RGB, you will find that this correctly mentions that the S, M and L cones are most responsive to violet, green and yellow wavelengths respectively (which answers your first question - calling the cones ...


7

Given your questions taken together and your comment It would be interesting to know how much delay the brain can handle in understanding causality and associating events I think you are interested in intersensory asynchrony. A well-known example where two stimulus modalities are perceived as separate while they are in fact coming from the same event is a ...


7

This is a really interesting set of questions and I'll try to answer all yet keep it compact. So first of all let's see the nerve classes and conduction speed from this and this wikipedia pages: Peripherial nerves can be classified into three groups A, B, and C (based on their diameter). Group A are the thickest (largest in diameter), are myelinated and ...


7

To explain the neurophysiological background to the existing answers I would like to add the following: The effect you are describing (pinkish appearance of white) is generally referred to as a negative after image and it is a direct reflection of the color opponency in the retina. The effect is caused by adaptation of the (in this case green) cones in the ...


7

"Rewiring" the brain isn't quite that simple: simply splicing a nerve to another doesn't necessarily mean the axons of that nerve will then grow into area. I am unaware of any studies that cross these specific pathways but as I am writing this answer I see you have already updated your question to ask about other modalities! So, with that in mind... ...


7

Humans' poor sense of smell is a myth, borne of 19th century speculation rather than actual data. This is described in an excellent recent paper in Science , "Poor human olfaction is a 19th-century myth" by John P. McGann. Quoting from a recent blog post of mine, The myth dates to the work of the pioneering and hugely influential anatomist and ...


7

Yes Many echolocating bats use the stapedius muscle to separate the inner ear bones when they emit their call so they are not deafened by their own call. Their ears are highly sensitive to the very frequency they are making so they need a way to protect against it. They are only deafened for 2-8ms but that is enough to protect their hearing while still ...


6

Short answer Humans sense temperature differences. Background (Including edits based upon comments) Because the question is "Do humans perceive temperature or heat-flux?", I will answer the answer from a psychophysical perspective, i.e., by dealing with sensory awareness. Just as with many other sensory systems, temperature sensors in the human body ...


6

Short answer As far as I can see, there are no animalia with high-sensitivity infrared photoreceptors in their retinae. Instead, infrared is detected at low thresholds with a dedicated sensory system in some species - the pit organ. This organ is separate from the retinae and its output does not merge with the retinal image. However, red cones, and even ...


6

There are several factors in human. we are upright, which brings the nose just about as far away for scents as it can get, you want your nose as close to the ground as possible for the most efficient use scent. This is not in and of itself a deal breaker but it is an important factor which made smell less important for us. Our large brain is competing for ...


6

Tot start of with your definition: Sensory substitution, when one of sensory modality changes into another sensory modality to help someone restore the ability to perceive defective sensory using a working sensory modality. I personally like to use a more subtle definition of sensory substitution (Stronks et al., 2015): [T]he process of obtaining ...


5

Short answer Echolocating bats have relatively large sensory epithelia in their inner ear, that may correlate with their high upper frequency limit of up to 200 kHz. The basilar membrane is thinner and stiffer, possibly allowing it to decode higher frequencies. Background In terms of the place theory of hearing, the cochlea acts as a frequency transformer, ...


5

On the contrary, your olfactory epithelium - the bit that does the smelling up at the top of your nasal cavity - doesn't absorb smells. The olfactory receptors bind small molecules reversibly. However, the olfactory epithelium has a coating of mucus, and so small molecules dissolve in the mucus in order to meet the receptors. Molecules will also evaporate ...


5

This is the modified answer in response to the discussion: Facts: There are warmth and cold receptors in the body at two places: The Peripheral receptors and the Central Receptors The peripheral receptors are present in skin and the central receptors in the body core at multiple sites the notable site being the hypothalamus The Temperature receptors have ...


5

Yes, Mantis shrimp have 12 photo-receptors and can detect the low-end of IR. In H. trispinosa one of the photoreceptors, R3P, detects right at the edge of 'deep red' light and would detect infrared (700+ nm). Although this study didn't explicitly measure infrared detection, by the shape of the curve it's not a huge leap that they detect infrared at ...


4

Flux is defined as amount of heat transferred per unit area per unit time. Our body does not perceive heat flux. It perceives temperature and tries to adjust heat exchange mechanisms until thermal homeostasis is achieved (in all warm blooded animals). This is a feedback controlled process. If it were to measure heat flux then the body cannot sense if it ...


4

Senses in general adapt to continuous stimulation due to various processes. One such process is simply the exhaustion of the reserves of a receptor, or secondary neuron, due to a depletion of neurotransmitters. Entering a room activates a fresh pool of chemical receptors, thereby generating a clear sense of smell. However, this dims due to adaptation. ...


4

Short Answer Yes, plants are alive! How to define life? It is up to anyone to define what is living and what is not. In other words, the definition of what is living is arbitrary. Viruses are a common limit case (see the post why-isnt-a-virus-alive?). What are plants able to do? Now coming to plants, everyone seem to agree quite well on whether plants ...


4

The eye really on can sense 3 colors, or to be more precise it only has three types color sensitive each of which detects a large range of wavelengths with no way to distinguish between them within the same cone. We only determine color by the different levels of activation between the different cone cells. This means we need a lot of light to see color and ...


4

Electrocommunication is used by weakly electric fish only and it is limited to aquatic environments where the electrical conductivity of the medium allows to transmit electric signals. The best studied fish species that use this communication method are The African Mormyriformes (which comprise the Mormyridae or elephantfish and the Gymnarchidae with ...


4

The strawberry-like odour that you perceived is mainly attributed to three ethyl esters, namely the ethyl esters of butyric, hexanoic and 3-methylbutanoic acid. There are other odour-active volatiles produced by Pseudomonas fragi, about 26, which are said to add to the richness and complexity of the odour of the three aforementioned main compounds. Source: ...


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