What's the science?

There are many benefits to predictable learning. For example, when something is predictable there is time to build expectations and better understand when those expectations have been violated. In toddlers, there is mixed evidence for the benefits of both predictable and unpredictable learning. It is still unclear which method of learning is ideal for toddlers during development. Recently in Current Biology, Benitez and colleagues test whether toddlers learn words better in predictable versus unpredictable situations.

How did they do it?

Toddlers were presented with a series of boxes that would open in a sequence to reveal a series of objects. The timing and location of box opening was predictable (always clockwise), however, the object to be revealed was unknown. This sequence exposure experiment was repeated 5 times. Then, a second labelling experiment was performed, where boxes would open either in the predictable sequence or in an unpredictable (i.e. an unexpected box would open that was different from the previously learned sequence) pattern to reveal an image paired with a recorded voice announcing what the object was. The authors used an eye tracking system to track how the toddlers attended to the objects and to rule out potential confounding effects of visual attention. They then tested, in a learning phase, whether the toddlers retained object-label pairs better for predictable vs. unpredictable events. They tested this using a “looking-while-listening” method where the object-label pair was presented and they were to look to the correct object.

What did they find?

Reaction times were greater for unpredictable events than predictable events in both the object revealing and labelling experiments suggesting that toddlers were tracking the sequence of events. They also demonstrated anticipatory looks towards a box where an object was about to be revealed meaning the toddlers developed expectations about the sequence of events. Toddlers were found to look at the correct object-label pair for a greater proportion of time than the incorrect object for the predictable events compared to the unpredictable events. Toddlers were also more accurate at looking to the object-label pair during predictable events.