Auditory what, where, and when: a sensory somatotopy in lateral premotor cortex.

Recent findings have demonstrated that attention to visual events engages the lateral premotor cortex even in the absence of motor planning. Here, we used functional magnetic resonance imaging to explore acoustically triggered activations within the lateral premotor cortex. Temporal (when), object-related (what), and spatial (where) auditory patterns were to be monitored for violations in a serial prediction task. As a result, we found a modality-dependent modulation for auditory events within the inferior ventrolateral premotor cortex, an area engaged in vocal plans. In addition, however, auditory activations were distributed within the entire premotor cortex depending on which stimulus property was attended to. Attention to where patterns was found to engage fields for gaze and reaching (dorsolateral premotor cortex), what patterns to engage fields for hand movements (superior ventrolateral premotor cortex), and when patterns to engage fields for vocal plans. Together, the findings confirm the idea of a sensory somatotopy in lateral premotor cortex, according to which a perceptual pattern triggers representations within that motor effector which would be most appropriate to generate it as an action effect.