Are babies super? Performance, competence and infant habituation

Are babies really more competent than we give them credit? (No.)

Developmental psychology is filled with studies that claim to show the hidden abilities of babies. The claim is that babies come pre-packaged with all kinds of knowledge and skills that provides them with the foot in the door they need to learn about the world. Babies are limited in their ability to demonstrate this knowledge, however, because of their immature bodies and inability to control these well. In the language of the field, there is hidden competence concealed by problems with performance, and researchers (such as Liz Spelke and Renee Baillargeon) are interested in finding ways to reveal this hidden competence.

At IU we referred to such studies as 'super baby' studies, because they purported to show that infants were remarkably competent and knowledgeable about the world. Besides the rampant dualism of 'mind' being concealed by 'body', these studies are good examples of a common problem (the psychologist's fallacy) in psychological research, one that a rigorous application of embodied cognition helps fix.

Embodied solutions to neural delays: Information and Network Motifs

One of the bugbears of direct perception is the fact of neural delays. The transmission of signals through the nervous system takes time, and this means that there is a lag between something happening (at, say, the retina) and that event having consequences in cortex, let alone behaviour. In control theory terms, delays in a system can lead to instability in that system's behaviour as you are forced to make corrections that are then incorrect and must themselves be corrected.

It's typically suggested in psychology that these delays are compensated for via computational predictions; the nervous system 'perceives the present' by taking the lagged input and using it as the basis of a guess about what's going on now (e.g. Changizi et al, 2008, plus see this post from a while back). This is a problematic idea: if the perceptual control of actions is based on a guess compensating for a variable time lag, then the stability issue remains, not to mention the consequences for mis-predicting the future. Regardless, it's not really an option for a theory of direct perception, and I want to discuss a couple of options.

Internal representation or behavioural dynamics?

More on Gibson later, but I wanted to get to this today. Yesterday I saw a talk about eye tracking, and how people control smooth pursuit movements (the tracking movements your eyes can make when you’re following something continuously). Tracking performance is a quandary for cognitive folks, because we are often very good at it. For instance, if you ask people to track a moving stimulus and record their eye movements, they will successfully foveate the target with almost no lag or erratic need to play catch up (foveating means using the fovea, the densely packed high resolution region on the retina we rely on for precise visual perception). The lack of ‘catch-up’ is the interesting bit, and cognitive psychology thinks that it is evidence of prediction by the system. Prediction requires a predictor, which for cognitive psychology is always a representation.

The main thing I learned from this talk is this: I am a rampant ego-maniac who is convinced I am right and other people are wrong, but at least I am capable of entertaining the idea that there is another way to conceive of the task. This speaker (and at least one other person in the room) was completely unaware that their perspective entailed assumptions about the underlying mechanism and simply couldn’t conceive of another way to describe the task: for them, prediction was clearly required and therefore internal representation was clearly required.