The dynamic adjustment of visual spatial attention scale by 'two-level cues' paradigm

The visual attention mechanism in the brain was studied among 16 young subjects through the precue-target visual search paradigm by ERP technique, with the attentive ranges cued by different scales of Chinese characters. The results showed the amplitudes of P1 and N1 components of event-related potentials increased with the reduction of the cue scale. These results indicated that the spot light effect happened at the early selected attention period. The results also showed that there existed separation in P2 effect. The separation indicated that the attentive processing of the cue range mainly happened in the left hemispher