Sustained attention can create an (illusory) experience of seeing dynamic change

Abstract

Recent studies speculated that two types of change detection exist, one involving the experience of seeing dynamic change (change over brief interval), the other involving detecting a completed change (change over long interval), with only the former requiring sustained attention. To examine this supposition, a flicker change detection task was conducted in which the spatial location of objects was manipulated (shift, no-shift). In shift conditions, changed image display appeared in different locations than they did in the original display. The time interval separating images was manipulated (200 or 1000 ms). Results showed that a shift led to poor change detection only in the short interval condition. The performance decline by the image shift was not attenuated even when participants knew beforehand whether or not a shift would occur. Results indicate that sustained attention, which is sustained for a brief time, is related to the experience of seeing dynamic change.

Keywords:

• Change blindness
• Dynamic change detection
• Flicker change detection task
• Spatial attention
• Sustained attention

Acknowledgements

This study was supported by a grant from the Research Fellowship of the Japan Society for the Promotion of Science for Young Scientists to RN, and by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science awarded to KY. R. N. is currently at Tohoku University as a postdoctoral researcher.

Notes

¹It may be better to record eye movement to judge whether or not attention is sustained, because eye movement correlates with attention movement in a normal scene viewing. However, we cannot determine whether or not attention maintains its state using eye movement measurements. Ariga et al. (2011) reported that observers do not maintain an attentional state during a long blank display, even though the visual stimuli were always presented at the local area where the observers can view the stimuli without eye movements. We are interested in the issue of whether or not attention can maintain its state. Therefore, we did not record observers’ eye movements in this study.

²We conducted an additional analysis to examine the effect of the image shift orientation. We divided the data of shift conditions in both ISI conditions into two groups based on the image shift (vertical shift and horizontal shift). An ANOVA revealed that only the main effect of ISI was significant, F(1, 11) = 4.89, MSE=0.99, p<.05. Neither the main effect of image shift orientation nor shift type with ISI interaction were significant, Fs < 1, MSEs > 0.9, ps>.4. We did not obtain an effect of the image shift orientation. One explanation for this is that the effect is likely to be very small because the degree of the image shift (4°) was relatively small.

³We recognize that it is easier to shift attention to a different location when participants know the direction of the shift beforehand. Although this issue is very important, we were concerned that participants’ knowledge about the shift direction might have an additional influence on change detection in this study, because this manipulation could reduce the cognitive cost of not only disengaging attention but also shifting attention to a particular direction. Thus, we did not give instructions regarding the shift direction, in order to focus on the effect of the cognitive cost of disengaging attention during a blank display. We plan to pursue this issue in future research.