Visuomotor preparation of discrete finger responses

Adam, J. J.
Department of Movement Sciences, University of Maastricht, The Netherlands

Human skilled behavior requires preparatory processes that selectively make sensory and motor systems more efficient for perceiving the upcoming stimulus and performing the correct action. I review the literature concerning these preparatory processes as studied by response-cuing paradigm, and propose a model that accounts for the major findings. According to the Grouping Model (Adam, Hommel, & Umilta, 2003), advance or precue information directs a dynamic process of subgroup making—that is, a process of stimulus- and response-set reconfiguration—whereby the internal representation of the task is simplified. The Grouping Model assigns a critical role to the unit of selection, with Gestalt factors and interresponse dependencies mediating the formation and strength of stimulus and response subgroups. Moreover, the Grouping Model assigns a critical role to the mode of selection by distinguishing between fast, automatic subgroup selection and slow, effortful subgroup creation. I present the results of several experiments that manipulated perceptual and motoric grouping factors. Also, I present the results of an fMRI study that investigated the neural activation patterns associated with the rapid visuomotor preparation of discrete finger responses. Our imaging results revealed a large-scale distributed network of neural areas involved in fast visuomotor preparation, including specific areas in the frontal cortex (middle frontal gyrus, premotor and supplementary motor cortex), the parietal cortex (intra-parietal sulcus, inferior and superior parietal lobe) and the basal ganglia.