Feature saliency affects delayed matching of an attended feature

Abstract

We examined how top-down attentional modulation and bottom-up stimulus saliency interact with feature memory. Experiment 1 used a delayed-matching-to-sample (DMS) task to examine the relative saliency between features by observing the relative accuracy of recognition at different stimulus durations. Feature salience decreased according to the following order: colour, form, and texture. In a modified DMS task (Experiments 2 and 3), participants were required to attend to one of three features and ignore the others. After a delay, they were required to choose which of the two test stimuli matched the reference stimulus on the attended feature, disregarding other task-irrelevant features. The target was either identical to the reference stimulus or mismatched the reference stimulus on one of the irrelevant features. The results showed that colour matching was affected neither by a form change nor by a texture change. Form matching was affected by a colour change, and texture matching was affected by a colour or form change. These results are consistent with the relative saliency hypothesis. Even when all features of an attended object are maintained, a relatively more salient task-irrelevant feature can interfere with the delayed recognition of a less salient feature.

Keywords:

• Attentional modulation
• Delayed-matching-to-sample task
• Feature saliency

Acknowledgements

This work was supported by grants from National Science Council to C.-T. Yang (NSC 92-2815-C-002-070-H and NSC 98-2410-H-006-118-MY2) and to Y.-Y. Yeh (NSC 96-2413-H-002-007-MY3). We thank S.-H. Lin and Y.-J. Chen for their assistance in stimulus generation and C.-J. Wu for her assistance in figure production. Parts of the results were presented at the 15th meeting of Object, Perception, Attention, and Memory in Long Beach, CA.

Notes

¹Vogel et al. (2006; Woodman & Vogel, 2008) found that orientation was better memorised than shape, whereas Lamberts et al. (2002; Lamberts & Kent, 2008) found the opposite result. These inconsistent findings may have occurred because different stimuli were used to test the memory of features. The former studies used orientation bars and geometric shapes to test participants’ memory of different features, whereas the latter studies used a real object (i.e., hot air balloon). The difficulty in delayed recognition of orientation and shape is different across the two series of studies.

²Although memory of colour, form, orientation, and motion have been extensively investigated, texture, surprisingly, has not been explored, even though texture is an important visual cue regarding surface property; in addition, texture discrimination contributes to object identification and scene perception (Bergen & Landy, 1991; Julesz, 1981). Thus, this study investigated memory of the colour, form, and texture of an object.

³We used the following abbreviation rule to simplify the names of the conditions; the first letter of the alphabet denoted the attended feature dimension (i.e., C: colour; F: form; and T: texture) and the second letter of the alphabet denoted the target type (i.e., I: identical; C: change in colour; F: change in form; and T: change in texture).