ILLUSION OF MACH BANDS

The illusion of Mach's bands You can make shadows where there are no, or that some areas look darker or clear than they are actually.

The discovery of this important visual effect is due to the physicist of Austrian origin, Ernst Mach, who was also an outstanding philosopher of science, whose works in the field of optics are still part of the most notable in the area. He was also interested in wave dynamics and other phenomena.

The illusion of Mach's bands was discovered in the 1860s And, since then, it has become a reference, not only within the diversity of incredible optical illusions that exist, but also for its implications at the medical level.

The illusion of Mach's bands, what is it?

The illusion of Mach's bands You can make, among the limits of gray -tonalities, we think we see an area that looks darker than it is, or clearer.

One of the explanations that has predominated most to try to understand the illusion of Mach's bands has been that of lateral inhibition, which occurs when a cell inhibits the growth or activity of another that is adjacent.

Lateral inhibition is what allows us to discriminate a stimulus in front of another. In the case of the eye, this inhibition stops the excitation signal process in the retina to facilitate the transmission of margins in the contrasts.

However, after the lateral inhibition theory, focused at the ocular level, others that are broader have emerged, such as the assumption that the effect occurs due to the experiences learned about the light patterns of the surfaces.

In any case, when we observe Mach's bands, we can appreciate a gradient, that is, a band that, on the light edge seems darker, and on the dark edge it seems clearer, when Actually there is nothing more dark or clearer.

Why is the optical illusion of Mach bands so?

The study on Mach's bands has been very relevant to the medical area, then, specialists often enc from their confidence in tomography and radiographs. But, these can also reflect shadows or objects that are not present.

That is to say, In certain cases, radiographs show shadows or artifacts that could induce an erroneous diagnosis. Well, who analyzes the results, would be providing data from an effect on visual perception, and with it, for example, suggest that there are pathological injuries that are not present.

Ravesh Panikkath researcher, in his study on Mach's bands, presented the case of a 63 -year -old patient who was diagnosed with pneumopericardium.

However, this woman did not present other symptoms that confirmed the diagnosis, so she had more chest radiographs, and after the follow -up, in no one could demonstrate that there was air around the heart.

It was, then, a shadow that simulated a pneumopericardio, That is, it was nothing more than the illusion caused, possibly, by light receptors in the retina. In other words, the woman did not suffer from the pathology, but the effects of Mach's band were appreciated.

From there, the great importance of this effect in the medical area, then, the indicated author also emphasizes that Mach's band can make a pneumothorax, and even non -existent fractures appreciate.

Therefore, the concern arises that, when this phenomenon occurs, a radiologist could do a misinterpretation. Inclusive, I might believe that a true shadow is just the effect of Mach's band and ignore it.

When the edge of certain objects is more curved, the illusion of Mach's bands becomes more prominent. The eye enhances them and makes the edge of a dark object look lighter, and the edge of a clear, darker object.

As we can notice, optical illusions are more than entertainment, then, in some areas, such as doctor, it can mean a diagnosis that compromises health.

Bibliography

• Emilce Cely, F. The influence of Eciriocriticism of E. Mach at the Foundation of Psychology.
• Melo, p., & Escaffi, J. TO. (2010). Machology Bands in Radiology. Chilean Radiology Magazine, 16 (2), 86-89.
• Panikkath, r. and Panikkath, D. (2014). Mach band sign: an optical illusion. Proceedings (Baylor University. Medical Center), 27 (4), 364-365. https: // www.Tandfonline.com/DOI/ABS/10.1080/08998280.2014.11929161
• Ribeiro, d. (2014). Ernst Mach. Count, 7.