Researchers have found that the 34-week-old fetus responds better to objects that look like human faces than others. The experimental results can be useful in clinical practice.

It is known that newborn babies are more interested in the faces of the people around them than other objects. Scientists at Lancaster University went even further and tried to understand whether this applies to unborn children. The results were presented in the journal Current Biology.
The authors of the experiment used 4D ultrasound, which allows you to see a volumetric image in real time. As you know, external light enters the uterus through a layer of maternal tissue 30 mm thick. Images consisting of three points of infrared light arranged in a triangle were projected onto its wall. One configuration vaguely resembled a human face ("eyes" and "mouth"), while the other was specially inverted: in this case, there was no longer any similarity. The projection was placed so that the fetus could see it, and then moved to the side 5 cm at a speed of 1 cm per second. The reaction of the embryos was studied using ultrasound. In total, 39 fetuses at the age of 34 weeks were involved in the experiment.

Infrared light points used / © Current Biology
Experts found that unborn babies more often turned their heads towards normal “faces” rather than upside-down ones. Researchers see this as strong evidence that embryos are beginning to define human faces while still in the womb. If they just paid attention to everything new, there would be no difference between the reaction to the "correct" and inverted pictures.
Most likely, we are talking about a predisposition to learning. The peculiarity of fetal perception is generated by visual information hitting the walls of the uterus, and he receives the first experience even before birth. There is another version: the ability to recognize faces may be innate.
However, it should be noted that only red light penetrates into the uterus, and the results of the experiment cannot say that the embryo sees external objects through the mother's tissues under normal conditions.
Be that as it may, the experience gained will be useful in clinical practice. With its help, it will be possible to better assess the condition of the fetus. Scientists also want to improve light sources and understand whether an unborn child can distinguish the number of certain objects. But experts do not recommend conducting such experiments at home, so as not to expose the fetus to additional stress.