Table 2.

An overview of common visual search experiments.

Task properties	Inference	Sample scheme	Reference
B: solid white D: colored oriented lines T: colored or (and) oriented line Diff: orientation or (and) color	Binding happens in early stages of visual processing. But the relationship between features are represented in lateral areas.		Wolfe and Cave, 1999
B: solid black D: gray-oriented lines with wave-like homogenous pattern T: oriented line Diff: orientation, intensity, or both	Contrast in feature of target and its local background induces saliency.		Nothdurft, 1993
B: solid black D: gray squares T: gray square Diff: size, intensity, or both	Size and intensity are functionally related.		Huang and Pashler, 2005
B: solid black D: regular vertical colored line array (a column of lines are more salient than others in color or intensity) T: vertical broken line Diff: intensity or color with respect to the background except for the column in which the target is placed	It is easier to find the target on the part of image that is salient due to color and intensity but not orientation.		Jingling et al., 2013
B: grating D: circular gratings T: circular grating Diff: intensity, spatial frequency, and orientation	Background properties (in addition to distractors) affect saliency.		De Vries et al., 2013
B: surface texture D: not used T: small circle Diff: smoothness	Proposing surface texture to study low-level features in attention		Clarke et al., 2008
B: pixels with random color from two colors (R-G or B-Y) D: not used T: solid squares Diff: color which is chosen from one of two colors used in the background	Yellowish targets in bluish background are more salient than other combinations.		Wool et al., 2015
B: solid gray D: not used T: colored circles with various intensity Diff: hue and intensity	Blue is the least salient color in gray background and needs more fixations to be detected.		Etchebehere and Fedorovskaya, 2017
B: solid gray D: colored bars with various frequency T: colored bars with various frequency Diff: orientation and frequency	Orientation attracts more attention than spatial frequency.		Phillips et al., 2006

B, D, T, and Diff stand for background, distractors, target, and difference between target and distractors, respectively.