Lee, Yen Ju, Princess Hearns, and Harold Greene
“Basic” cognitive and perceptual processes such as causal reasoning, and attention are generally reported as similar for all humans. However, recent research suggests that East Asians tend to be more holistic than North Americans(see Nisbett et.al, PR 2001). As well, East Asians are more likely to utilize background information during scene viewing tasks (Masuda et al., PSPB 2008). The underlying mechanism may be differences in the allocation of attention when viewers from different cultures process visual information.
Oculomotor indices provide a window on where attention is allocated. Attempts to demonstrate cultural differences in attention allocation have provided conflicting results. Whereas Chua et al. (PNAS 2005) reported differences in oculomotor control between Chinese and North American scene viewers, subsequent studies have found no difference (Rayner et al.,VisRes 2009). A potential limitation may be that scene viewing is “open ended” and is influenced by many cognitive preferences. In contrast, during visual search, the goal is clear: “find the target”.
In our visual search study, eye-gaze-contingent scotomas (i.e. blindspots) were presented in the horizontal and vertical parafoveal field of Taiwanese and North American students at UDM. The measure of interest was the probability of directing saccades in the visual field when a scotoma was present. We have found (i) no main effect of the scotomas, and (ii) that most saccades were directed horizontally. Interestingly, whereas the interaction between scotoma and saccade direction was not significant for the Taiwanese sample (p= .83), it was for the North American sample (p= .01). The interaction indicates an asymmetry in processing within the parafoveal visual field for the North American sample.
The results (i) call into question assumptions about the universality of basic perceptual processes, and (ii) lend support to the claim (e.g. Chua et al., PNAS 2005) that cultural differences can influence oculomotor control.