In this paper, I make a case for the modularity of the motor system. I start where many do in discussions of modularity, by considering the extent to which the motor system is cognitively penetrable, i.e., the extent to which its processing and outputs are causally influenced, in a semantically coherent way, by states of central cognition. I present some empirical findings from a range of sensorimotor adaptation studies that strongly suggest that there are limits to such influence under certain (...) conditions. These results cry out for an explanation. In the remainder of the paper, I provide one: The motor system is cognitively penetrable, but nonetheless modular along broadly Fodorian lines, insofar as it is informationally encapsulated. This means that its access is limited to its own proprietary database in computing its function from input to output, which does not include the information stored in central cognition. I then offer a model of action control, from distal intention to action outcomes, that further helps to illustrate this picture and can accommodate the target empirical findings. (shrink)

Can we think of a task in a distinctively practical way? Can there be practical concepts? In recent years, epistemologists, philosophers of mind, as well as philosophers of psychology have appealed to practical concepts in characterizing the content of know-how or in explaining certain features of skilled action. However, reasons for positing practical concepts are rarely discussed in a systematic fashion. This paper advances a novel argument for the psychological reality of practical concepts that relies on evidence for a distinctively (...) productive kind of reasoning. (shrink)

In this commentary, I contend that a representative sample of the arguments in the target article miss the mark. In particular, the interface problem provides no warrant for positing similarities between representational formats, and the evidence from neurocognitive, animal, and behavioral studies is inconclusive at best. Finally, I raise doubts about whether the authors' central hypothesis is falsifiable.