6 There’s actually a blind spot in our vision, but our brain fills the gap. 

The blind spot is a very common phenomenon among vertebrates. It is because the light-detecting photoreceptor cells are absent in the area where the optic nerve passes through the retina. Because of that, the corresponding field of vision becomes invisible as no light is detected from there by our eyes. The phenomenon was first discovered in the 1600s by Edme Mariotte in France. Until then, the point where the optic nerve enters the eye was thought to be the most photosensitive part of the eye. (source)

7 Our brain filters out quite a lot of sensory information it receives. Your nose, for example, is something your eyes always see but your brain just ignores it.

Sensory “gating” or filtering is a neurological process which filters out all the unnecessary or redundant information from the environmental stimuli we receive in our brain. Information such as the blinking of your eyes, the clothes on your skin, breathing, swallowing, or your tongue moving to a comfortable position in your mouth without any conscious input from you, is always filtered out unless you are consciously trying to experience them to prevent overload in the higher cortical centers of the brain. All this filtering work is done by the tiny part of our brain known as the “thalamus”, which is the point from where the sensory and motor neurons relay signals and which also is thought to be involved in a person’s consciousness.(1, 2)

8 At the beginning of a dangerous or stressful situation, your blood thickens. The body does this to encourage clotting in case of any physical injury. This is why stress often causes heart attacks. 

At the onset of anxiety and stress, a varied set of responses begins in our body to help us deal with the situation. Among them is the activation of blood coagulation. A study was conducted a few years ago involving a group of people suffering from anxiety disorder and a group of healthy people. After taking a round of blood samples from these people, they were asked to take a number of tests on the computer. A second round of blood samples was taken upon finishing the tests. What the scientists found was that the group with an anxiety disorder had a much more highly activated coagulation system. The scientists believe that this could explain why anxiety patients have a statistically higher risk, three to four times higher, of dying from heart diseases. (source)

9 Human skin is actually covered in stripes called Blaschko’s Lines. They cover our body from head to toe. We just can’t see them. 

In the early 1900s, German dermatologist Alfred Blaschko found that the rashes and moles on the skin of many of his patients followed specific patterns. Those patterns, however, did not follow the nerves, blood vessels or any other known body system. He traced these patterns on the body. However, it was later found that they are far more extensive than the number Blaschko had thought. These patterns are a result of how the embryonic cells migrate to accommodate for the formation of new cells on the skin of a quickly growing body. They follow a “V” shape over the back, “S” shaped whirls over the chest and sides, and wavy shapes on the head. (1, 2)

10 It takes around thirteen milliseconds for your brain to perceive images after they actually happen. So, you are basically always living in the past. 

During an MIT research project, many subjects were shown a series of six to twelve images, each image lasting for thirteen to eighty milliseconds, gradually decreasing the exposure period from eighty to thirteen milliseconds. They were asked to look for a particular type of image among them. Professor Mary Potter, one of the researchers in the study, conducted a similar study previously and found that humans could recognize images that were seen for as little time as one hundred milliseconds. But, in the new study, she found that the brain can recognize them for as less as thirteen milliseconds, which was the fastest rate at which the computer monitor they used could display the images. (source)