Zooming in and zooming out of the attentional focus: an FMRI study.

Visuospatial attention can either be "narrowly" focused on (zooming in) or "widely" distributed to (zooming out) different locations in space. In the current functional magnetic resonance imaging study, we investigated the shared and differential neural mechanisms underlying the dynamic "zooming in" and "zooming out" processes while potential distance confounds from visual inputs between zooming in and zooming out were controlled for. When compared with zooming out, zooming in differentially implicated left anterior intraparietal sulcus (IPS), which may reflect the functional specificity of left anterior IPS in focusing attention on local object features. By contrast, zooming out differentially activated right inferior frontal gyrus, which may reflect higher demands on cognitive control processes associated with enlarging the attentional focus. A conjunction analysis between zooming in and zooming out revealed significant shared activations in right middle temporal gyrus, right superior occipital gyrus, and right superior parietal cortex. The latter result suggests that the right posterior temporal-occipital-parietal system, which is known to be crucial for the control of spatial attention, is involved in updating the internal representation of the spatial locations that attentional processing is associated with.