One-year-old babies capable of complex reasoning: Study

Last Updated: May 27, 2011, 00:00 AM IST

Washington: Babies as young as one year old are capable of making judgements about the probability of an event they have never seen before, a new study has claimed.

Using a computer model, a team at the Massachusetts Institute of Technology (MIT) in the US were able to predict accurately what a baby would know about a particular event if given certain information.

The model may be useful in engineering artificial intelligence that reacts appropriately to the world, said Josh Tenenbaum, a cognitive scientist at MIT who led the research.

"The deeper thing that this shows is that infants` knowledge of objects is not a gut feeling.
They`re actually doing some kind of rational, probabilistic reasoning," he told.

Past studies have shown that babies grasp all sorts of information and can even tell the difference between an angry and a friendly dog. These studies typically rely on a method called "violation in expectation" in which researchers monitor babies` gazes as they look at normal and atypical scenarios.

But Tenenbaum and his colleagues wanted to go further quantifying how "surprising" a given event is based on the probability of it happening. Then they wanted to see if the level of babies` surprise matched the improbability of a given situation.

The researchers, who detailed their findings in the journal Science, showed a number of tricky videos to their one-year-old subjects and gauged how long they would look at animated scenarios that were more or less consistent with their knowledge of objects` normal behaviour.

In one case, the babies were shown four objects --three blue, one red -- bouncing around a container. After some time, the scene would be covered and one of the objects would be removed from the container through an opening.

Based on prior research showing that infants look longer at unexpected events, the study demonstrated they would be surprised if the object farthest from the opening disappeared when the scene was blocked very briefly, for 0.4 seconds. With a two-second interval, they showed surprise only if the red object disappeared first.

The computational model correctly predicted how long babies would look at the same exit event under a dozen different scenarios and varying number of objects, positions and time delays.

This suggests infants reason by mentally simulating possible scenarios and figuring out which outcome is most likely based on a few physical principles, Tenenbaum said.

"Even young infants` brains, before they`re able to walk and talk, they are building coherent, rational models about what is happening out there in the world," he said, adding, "We actually think that at 12 months, they know more than this model does."

Tenenbaum said he hopes to do more experiments to refine the model, adding in concepts that babies might grasp such as friction and gravity.