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Developmental psychology When do children perceive faces?
The perception and the recognition of faces are important pillars of social coexistence for people. For this reason, people are experts in the perception of faces. However, the ability to develop what happens in children in a gradual learning process must first be developed, reports the Ruhr-Universität Bochum (RUB).
People do not have the faculty of facial perception at birth. From what age children are capable of perceiving certain thing and faces, developmental psychologists have examined many times in the past, but so far without clear results. "There are two camps with different opinions among the scientists", reports Prof. Dr. med. Sarah Weigelt from the RUB. In the process, one camp assumes that by the age of five, everything has already gone and people are only getting better at recognizing faces, because attention and memory would become more efficient. "Other researchers think that humans are so attuned to recognizing faces that the brain continuously increases its performance in this area until the age of 32," Weigelt continued.
The age at which face recognition is fully developed in children remains a matter of debate. (Image: lassedesignen / fotolia.com) Deviating ideas about the development of facial perception
The scientist of the RUB explains that the faculty of facial recognition in the brain is not simply switched on, but refines as the process progresses. Over time, for example, people learn to distinguish "very similar-looking people and to recognize people after they have cut and colored their hair," the RUB report in a statement on the current study results. Whether the development in the brain areas, the faces process, at the age of five years is already completed, but remains controversial. In principle, the question as to when people can perceive faces can not be answered with an age statement, the RUB continues. The RUB Development Neuropsychologist Prof. Dr. med. Sarah Weigelt and PhD student Marisa Nordt now find out when children are equal to adults in the face are equal. To do so, they looked at facial recognition at five to ten-year-olds.
Activity in the brain when looking at faces examined
With the help of so-called functional magnetic resonance imaging, the researchers analyzed what happens when looking at faces in the brain of adults and children. On the basis of the imaging procedure, it became clear how strongly the brain areas were active at a certain time. "The researchers focused their analysis on the so-called fusiform facial area, a small area in the temporal lobe, which is specialized in the perception of faces," reports the RUB. They showed the participating children photos of faces, with six pictures in a row showing each other within twelve seconds. After a short break, followed by a new twelve-second block with six photos, followed by another break and another photo block. The children were presented with three types of image sequences: Either with six identical photos within a block or with six photos of the same person, but on different shots, or with six photos of different people.
Habituation effect in adults
The aim was to check the habituation effect that occurs in brain areas when they are repeatedly confronted with the same stimulus. So activity in certain brain areas decreases as we look at the same image of a person again and again. Adults had shown a strong habituation effect in the facial area of the brain in previous studies when they saw six identical photos in succession. In pictures of different people, the effect was not observed. Particularly interesting for the current investigation were the image sequences with six different photos of the same person, the researchers continue. Here, too, a habituation effect has been shown in earlier studies in adults; which, however, was less severe than when they looked at identical photos of a person.
Children show deviations in the habituation effect
The scientists have now examined what the situation looks like in a seven-year-old child when looking at the different image sequences. A total of 15 children participated in the study, according to RUB's announcement. Looking at six identical photos, they showed the same habituation effect as adults, the researchers report. This effect did not occur when they got to see photos of different people. Accordingly, there were no relevant deviations from the adults. However, the results were exciting for the sequences with different photos of the same person, Weigelt emphasizes.
The children also have slight habituation effects when looking at the photos of identical people in different poses, but "if you take a closer look, you realize that the results are different for children," said Prof. Weigelt. Although the averaged values showed a similar habituation effect as with adults. But the detailed analysis made it clear that the children in principle had an either-or-decision. Thus, the children showed either a full habituation effect or none at all. "When children see different photos of the same person, they either seem to say: That's the same person. Or: these are different people, "explains Weigelt. There is nothing in between. Seven-year-olds can recognize faces, but according to the researchers, this ability is not yet fully developed. Accordingly, a longer-term, gradual learning process can be assumed. (Fp)