Visual-Tactile Bottom-Up and Top-Down Attention

Bottom-Up And Top-Down Visual Attention

In a recent attention study (Uncapher, Hutchinson, & Wagner, 2011), subjects were scanned while incidentally encoding a series of visually presented objects in a variant of the Posner cueing paradigm. A triangular arrow cue was preceded on a paper screen by projector, pointing either to the left or the right side of the screen. After the presentation of the target, subjects pressed a button to indicate they had identified a real object, regardless of whether the item appeared in the validly or invalidly cued location (Figure 1).

Figure 1.

Top-down and bottom-up experiment task in the previous study

Recent brain imaging studies using functional magnetic resonance imaging (fMRI) found a frontal-parietal network in top-down attentional control. They used an event-related experimental paradigm and a specially designed visual-spatial attentional-cueing paradigm. In the first 400 ms post cue, attention-directing and control cues elicited similar general cue-processing activity, corresponding to the more lateral subregions of the frontal-parietal network identified by fMRI. These results suggest that voluntary attentional orienting is initiated by medial portions of the frontal cortex, which then recruit medial parietal areas. Together, these areas then implement biasing of the region-specific visual-sensory cortex to facilitate the processing of upcoming visual stimuli (Grent-'t-Jong & Woldorff, 2007) .