Look into my eyes, baby
Babies use primarily the eyes of another to allow themselves to be guided in their surroundings.
Babies are exposed to a flood of stimuli. From very early on, they turn themselves towards other people who show them specific things in their surroundings. Until now, it has been unclear which signals infants use to do this. Scientists at the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in Leipzig and the University of Heidelberg have now discovered that the eyes of another are crucial to allow themselves to be guided. An especially important characteristic seems to be the light–dark contrast between the dark iris and the white background.
Little Paul*, only four months old, looks at the screen in front of him. Two eyes gaze at him, two white ovals each with a black dot in the middle. Suddenly, the gaze of the pair of eyes moves to one side to a stack of building blocks. Paul follows it attentively. The eyes do not look at the colourful rattle on the other side. Likewise, Paul ignores it. When both objects emerge on the screen again, the boy’s attention seems to be drawn to the rattle.
“According to novelty preference, babies look longer at things which are new to them. In this case the eyes obviously did not focus on the rattle, and hence, at the beginning, neither did the baby’s”, says study leader Christine Michel. The movement of the black dots seems to direct babies’ attention to surrounding objects in the same manner as another person’s gaze direction.
But does it only work with dots that resemble real eyes? To investigate, the researchers again showed the young study participants two moving circles which direct their gaze to one side— though in this case with white dots on a black background. It emerged that Paul seemed to follow these unreal reversed eyes in a less targeted manner. When both toys appeared again, he did not pay more attention to one of them. Rather, he seemed to be familiar with both objects. Accordingly, his attention had swung back and forth between the two objects, independently from the direction of the moving circles.
The children appear to follow and concentrate more on the gaze direction of the black artificial pupils than the white ones”, the neuroscientist explains. “Consequently, they learn especially well from moving black dots on a white background. They seem to react particularly sensitively to the contrast of real eyes.
Up to now it has been unknown if the capability to recognise signals communicated by the eyes is inborn or if it is learnt by children during the first months of life. “Some scientists assume that there is a module in the brain which specifically responds to the gaze direction of other people. It would therefore recognise the direction in which a person looks and then influence our interactions with him or her”, says Christine Michel. In apes, these specially targeted neurons have already been explored.
“In contrast, others believe that this ability to follow another person’s gaze does not exist at birth. Infants consequently learn during their development that it is worth following eyes”, Michel adds. They become sensitive to the characteristic of the light–dark contrast. According to the neuroscientist, because the babies in this study were already four months old, further studies are needed to show which explanation proves to be true.
However, one thing is certain: The results show how important direct eye contact is when dealing with babies, especially in the first months. If you look at them intentionally before showing them something, you can direct their attention in a targeted manner”, says Stefanie Hoehl, senior author of the underlying study, which has been published in the renowned magazine Scientific Reports. “Other options can be used to draw a baby’s attention to something which they understand much later in their development.” For instance, only at the end of the first year of life are they able to follow a request to focus on an object if somebody points at it—rather than looking at it.
* Name changed by the editors