Effects of cue validity on attentional selection

Abstract

Visual attention can be allocated to locations or objects, leading to enhanced processing of information at the specific location (space-based effects) or specific object (object-based effects). Previous studies have observed object-based effects to be smaller and less robust than space-based effects, with large individual differences in their temporal occurrence. Studies on space- and object-based effects are often based on a two-rectangle paradigm in which targets appear at cued locations more often than uncued locations. It is, however, unclear whether and how the target's spatial probability affects the temporal occurrence of these effects. In three experiments with different cue validities (80%, 50% and 33%), we systematically changed the interval between the cue and the target from 50 to 600 ms. On a group level and for individuals, we examined how cue validity affects the occurrence of object- and space-based effects. We observed that the magnitude and the prevalence of space-based effects heavily decreased with reduced cue validity. Object-based effects became even more sparse and turned increasingly negative with decreasing cue validity, representing a different-object rather than a same-object advantage. These findings indicate that changes in cue-validity affect both space- and object-based effects, but it does not account for the low prevalence and magnitude of object-based effects.

Variability in the temporal dynamics of object-based attentional selection

“…Recent research has shown effects of object-based attention are smaller and less prevalent than effects of space-based attention, which are only found in a small subset of participants [8,10]. In the current study, we systematically changed the intervals between the cue and the target, varying from 50 to 600 milliseconds.…”

“…Stimuli and procedure were similar as in the discrimination task from Pilz et al [10] and Lou et al [8]. The stimulus display was composed of two white rectangles (each 1.6 × 8.2 degrees visual angle) and a white fixation cross (0.45 × 0.45 degrees visual angle) located in the center of the screen.…”

“…Interestingly, however, object-specific advantages are commonly shown by faster responses on the same-compared to different-object trials, which indicates that attention spreads along the object. This paradigm, and modified versions of it, have been widely used to study space-and object-based attentional selection [4][5][6][7][8][9][10].…”

“…In general, object-based effects have been found to be smaller and not as robust as spacebased effects [8,9,11,12], and are affected by changes to the paradigm, including the probability of targets appearing at the cued location [6,8,9,13] and the duration of the interval between the cue and the target [6,14,15]. Testing 240 participants, Pilz et al [10] investigated the strength of space-and object-based effects on the level of individual participants.…”

“…Therefore, it is reasonable to assume that the cue-to-target interval at which maximal object-based effects occurs, is not consistent across individuals. To test our hypothesis, we adopted the commonly used two-rectangle discrimination task described above [8,10]. Instead of a consistent cue-to-target interval of 200 ms, we systematically changed intervals from 50 ms to 600 ms to assess object-based effects over time.…”