Functional organization of the lateral premotor cortex: fMRI reveals different regions activated by anticipation of object properties, location and speed

Previous studies have provided evidence that the lateral premotor cortex (P MC) is involved in representations triggered by attended sensory events. Ho wever, while the functional specificity of subregions of this large cortica l structure has been intensively investigated in the monkey, little is know n about functional differences within human lateral premotor areas. In the present study, functional magnetic resonance imaging was used to investigat e if attending to object-specific (O), spatial (S), or temporal (T) propert ies of the same sensory event, i.e. moving objects, involves different prem otor areas. We found a frontoparietal 'prehension network' comprising the p re-supplementary motor area (preSMA), the ventral PMC, and the left anterio r intraparietal sulcus (aIPS) to be activated independently of the attended stimulus property, but most intensively during object-related attention. M oreover, several areas were exclusively activated according to the attended stimulus property. Particularly, different PMC regions responded to thr Ob ject (O) task (left superior ventrolatelal PMC), the Spatial (S) task (dors olateral PMC), and the Timing (T) task (frontal opercular cortex (FOP)). Th ese results indicate that the representation of different stimulus dimensio ns engage distinct premotor areas and, therefore, that there is a functiona l specificity of lateral premotor subregions. (C) 2001 Elsevier Science B.V . All rights reserved.