Learning Cue Combination, 2016-2020

This collection includes data from a series of laboratory behavioural experiments. The experiments investigate aspects of perception, action and decision-making. The experiments are described in full in journal articles. Because each dataset is already deposited elsewhere, the collection here serves as a pointer to these deposited data sources.People often have to deal with multiple streams of information at once. For example, imagine you are on a walk out in the woods trying to find a kind of rare bird. You hear a bird call (audio information) and turn towards it. You can see some leaves moving around in a tree (visual information). Neither stream of information is perfectly reliable -- you will tend to make some error one way or another when you try to pinpoint the sound location, and you don't know exactly which leaf the bird was behind -- but both are useful pieces of information. What we see in the lab when we give these kinds of tasks to adults is called 'optimal cue combination'. Adults tend to combine all the different 'cues' available in an 'optimal' way that gets them as close as possible to the right location. To do this, they have to take into account how reliable each cue is, weight each cue by its reliability, and then take a weighted average. Developmental Psychologists have found that children don't begin doing this until they are about 10 or 11 years old; before that, they seem to just ignore one cue or the other (e.g. Nardini, Bedford & Mareschal, 2010). This is surprising because in these studies, children have all the information they need to make more accurate judgments. They are just failing to combine the information in the right way. We want to know why. What is changing at 10-11 years old that allows them to start doing optimal cue combination? We are going to examine two big ideas that might provide good answers to this puzzle. First, children at 10-11 might gain a new ability. They might first develop the ability to learn how to put cues together at this age. The second idea is that it might come down to the quality of the individual cues that children are trying to average together. It's generally a bad idea to do 'optimal cue combination' with a cue that is strongly biased (systematically incorrect) -- in that case, it makes more sense to ignore the biased cue. Even if a cue is not strictly-speaking biased, it might also be so noisy that it is hard to learn how it works. It could be that children under 10-11 years don't show optimal cue combination because the individual cues that they have available are all too biased or noisy. To test these ideas, we will test several predictions that they make. For example, we should be able to train children at 7-9 years as much as we want and they should never learn cue combination; we should be able to prevent adults from learning cue combination with a new cue by inducing child-like biases. It is possible that both of these big ideas might be correct -- it could be that children need a new ability and that the individual cues also have to improve. This work will be made possible by a combination of methods newly developed in our lab especially for this project, including testing and training children's abilities to combine the senses, and to learn a completely "new" sense, in immersive virtual reality. The work will be interesting to cognitive scientists, especially those interested in development and education. It will help us design better future interventions to teach additional senses to children with sensory loss. It will give us a better understanding of how the use of multiple cues responds to training in childhood, which is of interest to safety-oriented organizations since so many behaviours like safe road crossing can rely on multiple senses (seeing and hearing traffic). It will also be of interest to people who design educational tests since we will continue to develop our new test of a major sensory milestone and show people how similar efficient tests can be designed in other areas of education.