What people with superpowers can do: a gift from nature
With vision, people are relatively lucky. Our Pets-cats and dogs-see a very poor color scheme. They are dichromates. This means that the retina of their eyes has only two types of cones — light-sensitive cells responsible for color perception. People are characterized by trichromatism, that is, we have three different types of cones, or rather, cones can contain one of three types of light-absorbing protein-opsin. As a result, some cells become sensitive to light in the violet-blue part of the spectrum, others — in the green-yellow, and others-in the yellow-red. Cones of each type are able to distinguish about a hundred shades in their range, and thus, in the aggregate, the human eye will distinguish 100 to the third degree, that is, a million color combinations. This is a lot, although a person might be a little envious of some birds and insects that have a cone on the retina with opsin of the fourth type-sensitive to radiation in the ultraviolet range.
This, unfortunately, is not available to us, and not only because there is no suitable cone. Light in the UV range is blocked by the lens and cornea, and only people who suffer from a serious disorder of the optical system of the eye-aphakia, are able to perceive rays located in the near-ultraviolet part of the spectrum.
Watch the video on the topic
Daughters of color-blind
On the other hand, there are serious grounds to believe that the real tetrachromatic people still sometimes occur. The first suspicions appeared in the Dutch scientist de Vries, who in 1948 studied a case of color blindness. The man had cones of two normal types, and the third type probably underwent a mutation, resulting in a colorblind person who could not distinguish between green and red colors. De Vries had the idea to study the man's daughters, and he found that they could distinguish between red and green perfectly, but in the test, where it was necessary to combine the two colors to get a normal yellow, for some reason they wanted to add more red. More than is necessary from the point of view of an ordinary person. Then it turned out that the women had normal cones of all three types on the retina, and a fourth, mutated type.
De Vries suggested that the daughters of colorblind people were not satisfied with the usual composition of red and green, not because they saw worse than others, but because they saw more than others. And if this assumption is correct, then the person with tetrachromatic able to discern not one million and one hundred million tones. The Dutchman did not find experimental confirmation of his assumptions, but his experiments were recalled in the 1980s at the University of Cambridge. Neuroscientists John Mellon and Gabriela Jordan began to look for women with tetrachromatic among female relatives of men who are color blind. The search and experiments dragged on for decades, and only in 2007, Jordan, already working at the University of Newcastle, was able to confirm the presence of real tetrachromatic in a subject who (in order to comply with medical secrecy) was assigned the code cDa29. In an experiment with three color spots, the shade of one of which was slightly different from the color of the other two (a normal eye would not have seen the difference), the woman accurately identified the "stranger". There is an assumption that different X-chromosomes of the female pair XX may store genes responsible for one type of opsin, but encoding it slightly differently, from where the fourth type of cones arises. This explains why tetrachromats, you should probably only look for in women: in men, X chromosome is known to only one.
The world of familiar notes
Although it is believed that the hearing aid Homo sapiens ultrasound is not available, some people claim that they still respond to sounds beyond the upper threshold of audibility. Explanations for this phenomenon have been tried to find, and there are two hypotheses on this topic. According to one of them, ultrasound still affects the hair cells in the cochlea of the inner ear, according to another — the brain directly resonates with ultrasound, modulating these sounds to an audible range. However, much more interesting is such an unusual property of a few of us, as the possession of absolute hearing. This phenomenon is clearly somewhere on the border of physiology and culture. A person with absolute hearing is able to remember the absolute pitch of notes (without comparison with another sound of a known pitch) and recognize them. When you hear a car horn on the street, the "absolute" will say, for example: "Oh! the Salt of the second octave!".
Research on the phenomenon was conducted, in particular, at the University of California (San Francisco). Scientists were interested in what is more in absolute hearing-pedagogy or genetics? It turned out that pedagogy is important because most of the "absolutes" who took part in the study began to learn music systematically at the age of seven. But it was not without genetics. Even among those who were tormented by piano lessons in kindergarten, absolute hearing developed 15 times more often if there were older relatives with the same abilities in the family. In addition, it was possible to identify a link with the development of absolute hearing in four different parts of the human genome. Thus, the gene for absolute hearing does not exist — it is determined by a combination of genes, which determines the rarity of such a phenomenon.
Everything is too salty!
The fact that along with super-hearing there is also a super-taste, thought back in the 1930s when researchers at The DuPont chemical Corporation found out that different people evaluate the taste of the same substances differently — for example, in the range from tasteless to bitter. Scientists decided to test whether there is a difference in taste sensations from the contact of the tongue with the synthetic substance 6-n-propylthiouracil (PROP), used to treat thyroid disorders. It turned out that a certain minority did not taste it at all, the majority considered it bitter, and another small group experienced a strong sense of bitterness in the mouth.
The latter, apparently, belonged to people with hypersensitive taste. In 1991, the American physiologist Linda Bartoszuk studied people with a strong reaction to PROP and noticed that their tongues were much thicker than those of an ordinary person, covered with mushroom-shaped papillae that contain taste receptors and thermoreceptors. It is now believed that people with superbugs have one or two dominant alleles of the TAS2R28 gene. In contrast to absolute hearing, superbug gives its owners more trouble than joy. They distinguish subtle nuances of taste scales, but at the same time, many ordinary foods and drinks seem too salty, bitter, or spicy.
I remember when I was young…
Memory needs to be trained. To learn something by heart, use the mnemonic rules. But this is if we are talking about an ordinary person. However, there are cases when memory is so helpful that even without any training, it stores a huge amount of information, without bringing its owner any benefit. Scientists have described up to 50 reliable cases of hyperthymesia, or autobiographical memory. This syndrome manifests itself in the fact that a person is literally fixated on his past and is able to recall every day of his life in the smallest detail, starting from childhood.
The term "hyperthymesia" was first used in 2006 in the work of American neuroscientist James Mcgaw and co-authors. The article was devoted to the analysis of the case of A. J.-a woman who was interviewed by researchers at the University of California, Irvine.: "Since February 5, 1980, I remember everything. It was Tuesday." The psychological and physiological basis of this memory is not completely clear. One of the assumptions is that there is a failure of the so-called episodic memory (it stores the past as a set of circumstances). Using episodic memory, the brain can not stop, and each memory by Association causes the next. There is also an assumption about the connection of the phenomenon with obsessive-compulsive disorder, in which a person is haunted by various kinds of obsessions. In this case, memories of the past become an obsession.
Another type of unusual memory is called eidetic, sometimes this phenomenon is not exactly called photographic memory. The essence of elitism is the ability to retain memory visual, but also tactile, motor, olfactory impressions as if the factors that caused them to continue to act on the senses. After seeing a photo, a person with eidetic memory can turn away and continue describing the picture in detail, as if it is still in front of their eyes. In its purest form, eidetic occurs in children, but its manifestations in adults are extremely rare. Sometimes phenomenal memory based on various mnemonic strategies is taken for eidetic. In this case, the person does not" photograph " reality, but remembers a large amount of information, linking it with various logical and associative transitions. For example, the ability of high-class chess players to keep the placement of pieces on the Board in their head and play, as they say, with their eyes closed is known. But are we talking about eidetic memory? Dutch chess player and psychologist Adrian de Groot conducted experiments at the time, suggesting that chess masters remember the placement of pieces on the boards. In cases where the composition of the pieces did not resemble a real game, the ability of grandmasters to remember the placement fell sharply. That is, if there was no logic in the arrangement, no "photographing" took place.
Orange songs sing orange…
A mixture of feelings called "synesthesia" is observed in one form or another in many people. Confusion occurs when the stimulation of one sense organ causes parallel sensations characteristic of another sense organ. Synesthesia is manifested in the form of such phenomena as color hearing (for example, a musician feels the color of individual notes or sound ranges), auditory synesthesia (visual images give rise to sounds in the brain), taste synesthesia (images, words, symbols create parallel taste sensations), and so on. Color hearing refers to the most common cases, along with the assignment of color to letters or symbols. The cause of synesthesia is rooted in the complex structure of our brain: the areas responsible for processing signals from different sensory organs, however, "communicate" with each other through a network of neural connections. When for one reason or another this communication becomes redundant, there is a "confusion of feelings", and, although synesthesia itself is not considered a mental disorder, it sometimes occurs as a result of brain lesions of different natures.