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19

This is not really a biological answer, but a psychological one: One important fact to consider is that the perception of time is essentially a recollection of past experience, rather than perception of the present. Researchers who study autobiographical memory have suggested that part of this effect may be explained by the number of recallable memories ...


13

One important point that you might not be considering is the heat of vaporization. You may be aware that while it normally takes 4.18 J (1 calorie) of heat to raise 1 gram of water 1 °C, it takes around 2250 J of heat to raise 1 g of water from liquid at 99.5 °C to gas at 100.5 °C, due to the energy needed to go from a liquid to a gas. - What you may not ...


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

Flicker Fusion Threshold: The wikipedia definition: It is defined as the frequency at which an intermittent light stimulus appears to be completely steady to the average human observer. Background In 1824, Peter Mark Roget (who also wrote the famous Thesaurus) first presented the concept of "persistence of vision" to the Royal Society of London, as ...


8

I can't give a definite answer, and there's nothing in the literature about this specifically, but perhaps some relevant information and a suggested behavioural experiment will help. Background Firstly, I assume you are talking about sodium hypochlorite (which is usually what people mean by bleach)? If so, there are several compounds your cat could be ...


7

First of all one should tell that one can attribute the activation of certain brain zones with some indepent events only when the activation takes place along the signal input (receptors, sensory pathways towards the cortex and the sensory areas in cortex) or motor action (=output) (along the motox cortex => motor neuron => target organ). Those zones in ...


7

There are numerous examples of visual attraction in animals. An absolute classic of an experiment, taught to most/all evolutionary biology students, is the widowbird tail length experiment by Andersson. He experimentally manipulated the tail lengths of male widowbirds at random. Some tails were made longer and some shorter. From this experiment Andersson ...


7

There are strong connections between the auditory cortex and the limbic system, which includes such structures as the hippocampus and the amygdala. A recent paper [1] builds on earlier notions of emotional "significance" of music without any lyrics. It adds in lyrics, so giving a perspective of which portions of the brain are reacting to which component of ...


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 ...


6

One way we can get evidence qualia are the same or very similar for different people is by reactions to it, beyond just the word. For example, beyond the word "pain", we have other strong reactions to pain. So nobody suspects other people might experience pain as pleasure and vice versa. Obviously not! There are no obvious signs for colour qualia, so it ...


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

This phenomena has nothing to do with any different kinds of receptors. When we are wet, we have lots of water on our surface. The evaporation of water causes cooling. Blowing wind tends to make evaporation faster. So, even if wind blows at normal temperature, we feel cold. If we are not wet, there is some water on our body surface. This water is low in ...


5

Absolutely. Quality by appearance is sometimes a big part of mate selection and sometimes it is not. The size and cognitive capacity brain is probably important but not always. Primates are closest to us and have most similar tastes to us, have varying levels of interest in mate appearance. Most primates have a troupe dominance where a dominant male ...


5

The basis of this question is a common misconception, and unfortunately the accepted answer by @CHM is also based on this common misconception. The misconception is based on the homunculus falacy and the tendency for people to think that the image that lands on the retina is somehow 'assembled' and presented for something (the 'consciousness') to view. This ...


5

There may be some clues in neurobiology. A possibility may be that a person's general emotional state may affect their perception of the passage of time, as argued in this article and references within. Studies of people with damage to their orbitofrontal cortex (prefrontal cortex region) can experience sustained altered emotional states when compared to ...


5

Yes, color and shading can certainly affect depth perception, as explained by wikipedia: Aerial perspective – Due to light scattering by the atmosphere, objects that are a great distance away have lower luminance contrast and lower color saturation. Due to this, images seem blurry the farther they are away from a person's point of view. In computer ...


5

See this link. It provides a great overview. The answer you want is in the otolith section. To paraphrase, it states that our otolith organs are designed to help us lean forward while running to maintain our center of gravity when in motion; however, in a plane this reflex can backfire by causing a pilot to believe he is going straight when in actuality he ...


5

Earwax, also called cerumen, is slightly acidic (1), with a pH of about 6, and acidic foods or substances taste sour. The composition of earwax, upon which its taste depends, is related to its functions. Earwax aids in cleaning and lubrication of the ear canal and has an antimicrobial effect. The antimicrobial effect is in part attributed to its acidity, ...


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

Short answer Temperature differences of 0.02 degrees Celcius can be distinguished, dependent on various factors including experimental conditions and bodily location. Background The ability to discriminate temperature differences depends on whether it is a cooling or heating pulse, the skin temperature, the duration of the temperature stimulus, age, bodily ...


5

As other answers and comments have stated the reason that you feel cooler when the wind is blowing (wind chill factor often gets talked about on the news) is because evaporation is speed up by the wind. The reason that this evaporation causes cooling (explained in more detail here) is because when water evaporates, that water takes its energy with it. That ...


4

Perception of time can change drastically during an emergency. When we are younger, much like during an emergency, the brain hasn't activated very many filters for sensory data. The young have much to learn about the world and more detail is needed for the brain to make appropriate decisions. Sensory information is recorded in great detail, making time ...


4

According to the link you provided, the phenomenon Haidinger's Brush seems to be associated with the macula of the retina. The yellow color of the macula may explain the yellowness of Haidinger's Brush. This suggests to me that the brush may be an artifact of the structure of the eye, and others have claimed that Haidinger's brushes probably do not have any ...


4

It may be because, when we move our shoulders towards our the body, also know as abduction (Fig 1.) gives the central part of the body an elevation. when we rotate our arms more upwards (Adduction), the elevation will be lost. So in other words, when we are making snow angels, Start Normal position (hands near thighs) = Back and shoulders on ground ...


4

As far as I know there are 5 receptors for far-red and red light which are the phytochroms(phyA-phyE) Its all about the ratio between red and far-red light. Each phytochrom has an inactive(PR) and an active(PFr) conformation. phyA is the only phytochrom which is activated by far-red light, so its active state is PR. (Only if the ratio between red and ...


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

There are limits to what a sensory system can detect, which is called the detection threshold. To determine the detection threshold psychophysical methods can be used. A straightforward way to determine the detection threshold is with a yes/no task, where the subject receives stimuli with various intensities. An arbitrary point, mostly the 50% correct-rate, ...


3

Auditory information is routed to cerebral hemispheres via the brainstem and midbrain. Structures in the midbrain receive information from both ears and combine it (including differencing it for spatial location) before sending the combined information on to both cerebral hemispheres. Usually only the left hemisphere interprets the sound for language ...


3

Response of the gustatory receptor neurons can be measured using standard electrophysiological techniques, under different conditions(exposure to substances). For example see this article. However, it is difficult to say if a person feels sweetness or not or how the substance produces complex taste perceptions in some people.



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