The distinction between living and inanimate objects is based on an innate predisposition that can be observed from the age of four months, according to the CNRS work published in PNAS and supported by the European Commission and the Fyssen Foundation. This categorization of objects would allow moving from simple vision to an understanding of the objects that make up the world around us.
It is useless to see an object without recognizing it
When you see a tall wooden beam sticking out of the ground with a green crown, you immediately put it in its category: it’s a tree. “By recognizing an object as a member of a category, we understand what that object is and find its visible properties‘, like the shape of the leaves informing you that it is an olive tree, ‘as well as its invisible properties‘, for example that at the right time of year there will likely be olives, the researchers explain in the publication. This process is essential to reasoning. “Someone who only sees colors, shapes, textures without recognizing the object cannot do anything with it“, explains Liuba Papeo, Lead author of this new work, from the Institut Marc Jeannerod in the Lyon region. “Recognizing an object is one of the most important operations for any cognitive process.”
Animated/inanimate, artificial/natural… These innate categories form our vision of the world
The distinction between living and inanimate objects is based on an innate predisposition that can be observed from the age of four months, according to the CNRS work published in PNAS and supported by the European Commission and the Fyssen Foundation. This categorization of objects would allow moving from simple vision to an understanding of the objects that make up the world around us.
It is useless to see an object without recognizing it
When you see a tall wooden beam sticking out of the ground with a green crown, you immediately put it in its category: it’s a tree. “By recognizing an object as a member of a category, we understand what that object is and find its visible properties‘, like the shape of the leaves informing you that it is an olive tree, ‘as well as its invisible properties‘, for example that at the right time of year there will likely be olives, the researchers explain in the publication. This process is essential to reasoning. “Someone who only sees colors, shapes, textures without recognizing the object cannot do anything with it“, explains Liuba Papeo, Lead author of this new work, from the Institut Marc Jeannerod in the Lyon region. “Recognizing an object is one of the most important operations for any cognitive process.”
Animated/inanimate, artificial/natural… These innate categories form our vision of the world
This categorization can theoretically encompass an infinite number of parameters, but some are fundamental and universal to the human race. They can even be observed in our brains by functional MRI. “When adults look at pictures neurons activated in the visual cerebral cortex are more similar for two objects of the same category than for two objects of different categories“, explains Jean-Rémy Hochmann, Co-Author. So looking at a cat and a pony, two animated “objects,” will activate a much more similar population of neurons in your brain than looking at a cat and a closet. This brain organization also allows us to distinguish the cat much faster than the cupboard in the middle of a piece of furniture: “People distinguish and find a target among objects in a different visual category more quickly than among objects in the same visual category‘ the researchers explain in the publication.
These categorizations animate/inanimate, human/non-human, face/body, naturally inanimate/artificially inanimate, and large/small (inanimate) are found even in other primates, suggesting that they “biologically important for the survival of the species” and “selected during evolution“, explains Liuba Papeo. In other words, this ability to categorize objects that we have not necessarily already encountered in reality based on visual characteristics such as shape, texture, or color would be innate. But beware, “innate does not necessarily mean it is an ability immediately at birth, it may take time and learning to manifest‘ the researcher explains. But how long exactly?
4-month-old babies are already categorizing objects
This is the main result of the study: From the age of 4 months, babies can distinguish between animate and inanimate objects. To come to this conclusion, the four scientists from the institute, together with their colleagues Céline Spriet and Etienne Abassi, observed 97 babies aged 4, 10 and 19 months. The experiment consisted of following the children’s gaze as they showed them sequences of pairs of images on a screen. What is the relationship between the categorization of an object and the time we spend looking at it? “The idea is very simple: if you look at an object A and an object B, the more similar the objects are, the more similar the gaze time for the two objects. It’s the difference that counts“, explains Liuba Papeo. For example, when babies were shown a volcano and a crocodile, the time they spent looking at each image differed much more than when a giraffe replaced the volcano.
For each pair of images, similarities and differences in infant gaze time were compared to similarities and differences in neural activity observed in FIG brain scan from 15 adult volunteers. The presented images were selected for testing visual categories that are already well established in adults. Researchers then observe that babies’ gazes are anything but random. “The older babies are, the more the organization of their gaze matches the organization of the visual cortex in adults.’ summarizes Jean-Rémy Hochmann. “This suggests that as babies age, they use much of the information encoded in the visual cortex to visualize the world..”
A process that becomes more complex with age
However, the researchers observe a big difference between babies aged 4 and 10 months. With the youngest, it is possible to manipulate their gaze time: they prefer larger or more colorful images. “They can tell the difference between animate and inanimate objects, but they place more value on the physical properties of objects (color, size, shape…).“, reports Liuba Papeo. Therefore, by 10 months, babies begin to detach themselves from colors or shapes in order to categorize objects more according to their identity.
Between 10 and 19 months, a second stage of the categorization process takes shape. Still after their gaze times babies start making”Distinctions (which) are becoming more and more precise and subtle‘ notes Liuba Papeo. So you distinguish the categories inanimate/animate, but also human/animal within animate objects or between natural/artificial objects (e.g. between a chair and a tree). This work completes previous findings that the categorization of objects was significantly accelerated at the time of language acquisition from 18 months, enabling them to name objects.
The secret of babies’ brains
Several mysteries remain to be explored. The difference in categorization between babies aged 4 and 10 months is important: When does the changeover take place? After recent complementary experiments, the researchers are already finding that babies at 6 months are more or less responsive than at 4 months. “Is it between 6 and 8 months, or more likely between 8 and 10 months, that children begin to favor the object’s identity over its visual appearance?‘ asks Liuba Papeo.
The drivers of this changed perception of the environment also remain unclear. Is it about the physiological maturation of the brain or the duration of the viewing experience? – so age – Of the child? There is a way to find out. “We would like to reproduce these experiments with premature babies, for example two months premature. At 8 months, these babies’ brains are as mature as a term baby’s at 6 months, but they have a good 8 months of visual experience.“, explains Jean-Rémy Hochmann. This new line of research is being developed with the HFME Maternity Hospital des Hospices Civils de Lyons.