Metacognitive Control of Action: Preparation for Aiming Reflects Knowledge of Fitts's Law

Article excerpt

Metacognitive control has been studied in intellectual skills but has not yet been studied in perceptual-motor skills. To probe metacognitive control in a perceptual-motor context, we developed a task in which participants chose the position of a cursor relative to two targets. One of the two targets was randomly erased. Participants tried to move the cursor into the remaining target within a limited amount of time. The target widths were varied, making the difficulty of moving to either target dependent on the chosen cursor position. Predictions were based on the assumption that participants could use an analogue of Fitt's law to choose optimal positions. The fit between observed and predicted positions was excellent, suggesting that participants used information about movement speed-accuracy trade-offs to guide movement preparation. The findings suggest that metacognition applies to both perceptual-motor skills and intellectual skills, and that these two domains are more similar than traditionally assumed.

The past several years have witnessed growing interest in metacognition-in how people's knowledge of their own cognitive abilities affects the way they prepare for and perform intellectual tasks (Nelson, 1996). People can, for example, assign confidence ratings to their ability to recall recently learned information, and these ratings are predictive of subsequent test performance (Koriat & Goldsmith, 1996; Nelson & Dunlosky, 1991, 1992). Similarly, people allocate more time to learning more difficult study items than to learning less difficult study items (Metcalfe & Kornell, 2003). The ability to reflect on one's own cognitive abilities appears to be a defining feature of human cognition (Nelson & Narens, 1994).

Research on metacognition has focused on intellectual skills such as verbal fact retrieval and study time allocation but has not been concerned with perceptual-motor skills such as reaching for targets. Nonetheless, there has been a growing appreciation of similarities between intellectual skills and perceptual-motor skills. For example, learning rates for both kinds of skills can be approximated by power functions (Logan, 1992; Newell, Liu, & Mayer-Kress, 2001; but see Heathcote, Brown, & Mewhort, 2000), and skill development in both domains follows similar progressions from controlled to automatic stages (Anderson, 1982; Fitts & Posner, 1967). Reviewing studies that revealed such similarities, Schmidt and Bjork (1992) and Rosenbaum, Carlson, and Gilmore (2001) concluded that the psychological substrates of intellectual and perceptual-motor skills are more alike than different, a view that accords with the embodied-cognition approach to the study of mind and behavior (Clark, 1997).

If intellectual and perceptual-motor skills rely on similar mechanisms, one would expect metacognition to apply to the guidance of perceptual-motor skills, just as it does to the guidance of intellectual skills. At a general level, this conjecture is not controversial. People with ambulatory difficulties know that they need canes, swimmers make conscious decisions about how close they should stay to shore, and so on. Furthermore, there is evidence that metacognitive control governs the selection and maintenance of high-level intentions and strategies (Gollwitzer & Schaal, 1998). But what about more fine-grained aspects of perception and performance? Does metacognitive control extend to subtler, quantitative aspects of perceptual-motor skill?

To explore the metacognitive control of perceptual-motor performance in a situation relevant to Fitts's law, we developed a variant of the prototypical manual aiming task (see Figure 1). Participants saw a video display consisting of two rings connected by a straight line. The participants positioned a cursor along the line between the two rings, knowing that after choosing the cursor position, one of the two rings, whose identity was unpredictable, would be erased. …