How the size of exogenous attentional cues alters visual performance: From response gain to contrast gain

The normalisation model of attention (NMoA) predicts that the attention gain pattern is mediated by changes in the size of the attentional field and stimuli. However, existing studies have not measured gain patterns when the relative sizes of stimuli are changed. To investigate the NMoA, the present study manipulated the attentional field size, namely, the exogenous cue size. Moreover, we assessed whether the relative rather than the absolute size of the attentional field matters, either by holding the target size constant and changing the cue size (Experiments 1-3) or by holding the cue size constant and changing the target size (Experiment 4), in a spatial cueing paradigm of psychophysical procedures. The results show that the gain modulations changed from response gain to contrast gain when the precue size changed from small to large relative to the target size (Experiments 1-3). Moreover, when the target size was once again made larger than the precue size, there was still a change in response gain (Experiment 4). These results suggest that the size of exogenous cues plays an important role in adjusting the attentional field and that relative changes rather than absolute changes to exogenous cue size determine gain modulation. These results are consistent with the prediction of the NMoA and provide novel insights into gain modulations of visual selective attention.