Abstract
Previous studies have shown that attention can increase low-level adaptation (e.g., shapes). For high-level face adaptation, Rhodes et al. (2011) also found increased face identity aftereffects by attention. However, for facial expression adaptation, most studies focus on the necessity of awareness (e.g., Yang, et al., 2010; but Adams, et al., 2010) but not attentional modulation. In the current study, we investigated how task-driven attentional allocation modulates facial expression adaptation and examined the attentional shift via the microsaccade pattern. Three types of attentional allocation were included during adaptation: when the adapting sad face was shown right to the fixation cross for 2 s, participants had to count how many times a target appeared left to the fixation ("decreasing-attention condition"), or judge whether a brightness change occurred in the left or right part of the adapting face ("increasing-attention condition"), or do nothing ("free-attention condition"). A baseline condition without any adaptor was also included. The test face, randomly selected from a face set with varying facial expression from sad to happy, was presented at the same location as the adapting face for 200 ms. We found similar facial expression aftereffects in free-attention and increasing-attention conditions. This indicates no enhancement on facial expression adaptation by increasing attention to the adapting face. However, these aftereffects were both significantly larger than that in the decreasing-attention condition (both p's <.05). This suggests decreasing attention to the adaptor reduces facial expression adaptation. Therefore, we found asymmetric attentional modulation effects on facial expression adaptation. Moreover, eye movement pattern analysis revealed more right-oriented microsaccades in both free-attention and increasing-attention conditions than those in the decreasing-attention condition (both p's <.05). This provides evidence for the attentional shift and further supports the behavioral findings. Taken together, our current findings provide new insights for the top-down mechanism in facial expression adaptation.
Meeting abstract presented at VSS 2014