Human brain activation elicited by the localization of sounds delivering at attended or unattended positions: an fMRI/MEG study

The visual meridian effect, as a consequence of programming the necessary ocular movements for visual object localization (Rizzolatti et al. 1987), was interpreted as an evidence of a supramodal network for visual attention to space, which may be critical for reorienting the focus of attention toward stimuli appearing at unattended locations. This hypothesis was confirmed in a behavioural study also for auditory and for bimodal audio–visual stimulation (Ferlazzo et al. 2001). The present study is aimed at observing: the cerebral circuit underling the auditory meridian effect; whether this circuit is related with the network involved in reorienting the focus of attention toward stimuli appearing at an unattended location; whether a functional temporal dynamics can be defined in these areas.