Attending and intending.

children insert an extra wh-word in the middle of a question ('What do you think what pigs eat? ') thus creating a construction that is acceptable in German. These errors reflect the limit of the POS: as there is no German input, the error must arise from children's own innate expectations. Crain and Pietroski also engage the empiricist arguments on their own ground. They consider carefully various claims about the richness of the input, and defend the argument that the presence of a rich input does not guarantee that children can make appropriate use of it. There is no denying that empiricist approaches to language and language acquisition have made great strides in recent years. Crain and Pietroski ask us to step back for a moment and reconsider what motivates the nativist approach. The POS is a real problem in language acquisition; the arguments and data reviewed here make clear how far empiricists will have to go truly to undermine the nativist position. The presentation of a central visual cue can be used to orient subjects' attention in space (known as covert orienting). In the now classic Posner task, a cue can be a valid or invalid predictor of the location at which an event subsequently occurs. The difference in the time taken to detect the target when its location is validly cued (i.e. in the location where it actually appears), as opposed to invalidly cued, is one index of the effect of attention on information processing. Neuropsychological and neuroimaging studies have revealed the posterior parietal cortex to have a crucial role in covert orienting, and the involvement of this same area in the planning of eye movements has led to the suggestion that covert orienting and eye-movement planning are closely related processes. Applying the same logic to other regions of the parietal cortex, areas known to be involved in forming limb-centred, rather than eye or head centred spatial representations might also be involved in mediating covert attention to motor responses. In a recent TMS study, Rushworth et al. compared these two types of covert attention: orienting in a Posner-type task, where attention is directed to a visual dimension (spatial location), and an analogous motor task where attention is directed to a motor response 1. Rushworth hypothesized that the posterior parietal cortex would be involved only in visual attention whereas more anterior parietal sites might be crucial for motor intention. …