May 29, 2011

Infants Have Sophisticated Expectations Of Situations

An international team of researchers found that infants can use their knowledge of the physical world to form sophisticated expectations of how novel situations unfold.

The scientists developed a computational model of infant cognition that accurately predicts the infants' surprise at events that violate their conception of the physical world.

The model calculates the probability of a particular event, given what it knows about how objects behave. 

MIT's Josh Tenenbaum, co-leader of the study, said the close correlation between the model's predictions and the infants' actual responses to these events suggests that infants reason in a similar way.

"Real intelligence is about finding yourself in situations that you've never been in before but that have some abstract principles in common with your experience, and using that abstract knowledge to reason productively in the new situation," he said in a statement.

The team developed a computational model to predict how long infants would look at animated scenarios that were more or less consistent with their knowledge of objects' behavior.

The model begins with abstract principles of how objects can behave in general, then runs multiple simulations of how objects could behave in a given situation.

The scene would be covered, and one of the objects would exit the container through an opening.

The computational model accurately predicted how long babies would look at the same exit event under a dozen different scenarios, varying number of objects, spatial position and time delay.

"We don't yet have a unified theory of how cognition works, but we're starting to make progress on describing core aspects of cognition that previously were only described intuitively. Now we're describing them mathematically," Tenenbaum said in a statement.

He said he plans to further refine this model by adding other physical principles that babies appear to understand, such as gravity or friction.

"We think infants are much smarter, in a sense, than this model is," he said in a statement. "We now need to do more experiments and model a broader range of the existing literature to test exactly what they know."

He is also developing similar models for infants' "intuitive psychology." 

"We have to understand more precisely what the normal case is like in order to understand how it breaks," Tenenbaum says.

The study was published in the May 27 issue of Science.


On the Net: