In psychological experiments, participants are typically instructed to respond as fast as possible without sacrificing accuracy. How they interpret this instruction and, consequently, which speed-accuracy trade-off they choose might vary between experiments, between participants, and between conditions. Consequently, experimental effects can appear unpredictably in either RTs or error rates (i.e., accuracy). Even more problematic, spurious effects might emerge that are actually due only to differential speed-accuracy trade-offs. An often-suggested solution is the inverse efficiency score (IES; Townsend & Ashby, 1983), which combines speed and accuracy into a single score. Alternatives are the rate-correct score (RCS; Woltz & Was, 2006) and the linear-integrated speed-accuracy score (LISAS; Vandierendonck, 2017, 2018). We report analyses on simulated data generated with the standard diffusion model (Ratcliff, 1978) showing that IES, RCS, and LISAS put unequal weights on speed and accuracy, depending on the accuracy level, and that these measures are actually very sensitive to speed-accuracy trade-offs. These findings stand in contrast to a fourth alternative, the balanced integration score (BIS; Liesefeld, Fu, & Zimmer, 2015), which was devised to integrate speed and accuracy with equal weights. Although all of the measures maintain "real" effects, only BIS is relatively insensitive to speed-accuracy trade-offs.

Shielding visual search against interference from salient distractors becomes more efficient over time for display regions where distractors appear more frequently, rather than only rarely Goschy, Bakos, Müller, & Zehetleitner (Frontiers in Psychology 5: 1195, 2014). We hypothesized that the locus of this learned distractor probability-cueing effect depends on the dimensional relationship of the to-be-inhibited distractor relative to the to-be-attended target. If the distractor and target are defined in different visual dimensions (e.g., a color-defined distractor and orientation-defined target, as in Goschy et al. (Frontiers in Psychology 5: 1195, 2014), distractors may be efficiently suppressed by down-weighting the feature contrast signals in the distractor-defining dimension Zehetleitner, Goschy, & Müller (Journal of Experimental Psychology: Human Perception and Performance 38: 941-957, 2012), with stronger down-weighting being applied to the frequent- than to the rare-distractor region. However, given dimensionally coupled feature contrast signal weighting (cf. Müller J, Heller & Ziegler (Perception & Psychophysics 57:1-17, 1995), this dimension-(down-)weighting strategy would not be effective when the target and the distractors are defined within the same dimension. In this case, suppression may operate differently: by inhibiting the entire frequent-distractor region on the search-guiding master saliency map. The downside of inhibition at this level is that, although it reduces distractor interference in the inhibited (frequent-distractor) region, it also impairs target processing in that region-even when no distractor is actually present in the display. This predicted qualitative difference between same- and different-dimension distractors was confirmed in the present study (with 184 participants), thus furthering our understanding of the functional architecture of search guidance, especially regarding the mechanisms involved in shielding search from the interference of distractors that consistently occur in certain display regions.

It was shown previously that observers can learn to exploit an uneven spatial distribution of singleton distractors to better shield visual search from distractors in the frequent versus the rare region (i.e., distractor location probability cueing; Sauter, Liesefeld, Zehetleitner, & Müller, 2018). However, with distractors defined in the same dimension as the search target, this comes at the cost of impaired detection of targets in the frequent region. In 3 experiments, the present study investigated the learning and unlearning of distractor location probability cueing and the carry-over of cueing effects from same- to different-dimension distractors. All experiments involved a visual search for an orientation-defined singleton target in the presence of either a more salient color-defined (different-dimension) or orientation-defined (same-dimension) distractor singleton, and all were divided into a learning session and a subsequent test session. The present study showed that with same-dimension (but not with different-dimension) distractors, the acquired cueing effect persists over a 24-h break between the training and test session and takes several hundred trials to be unlearned when the distribution is changed to even (50%/50%) in the test session. Furthermore, the target location effect as well as (somewhat less marked) the cueing effect carries over from learning with same-dimension distractors to test with different-dimension distractors. These carry-over effects are in line with the assumption that the learned distractor suppression effects are implemented at different levels in the hierarchical architecture of search guidance: the saliency map with same-dimension distractors versus a dimension-based level below the saliency map with different-dimension distractors.

1Sometimes, salient-but-irrelevant objects (distractors) presented concurrently with a search 2 target cannot be ignored and attention is involuntarily allocated towards the distractor first. 3Several studies have provided electrophysiological evidence for involuntary misallocations of 4 attention towards a distractor, but much less is known about the mechanisms that are needed 5 to overcome a misallocation and re-allocate attention towards the concurrently presented 6 target. In our study, electrophysiological markers of attentional mechanisms indicate that (i) 7 the distractor captures attention before the target is attended, (ii) a misallocation of attention is 8 terminated actively (instead of attention fading passively), and (iii) the misallocation of 9 attention towards a distractor delays the attention allocation towards the target (rather than 10 just delaying some post-attentive process involved in response selection). This provides the 11 most complete demonstration, to date, of the chain of attentional mechanisms that are evoked 12 when attention is misguided and recovers from capture within a search display. 13

Searching for an object among distracting objects is a common daily task. These searches differ in efficiency. Some are so difficult that each object must be inspected in turn, whereas others are so easy that the target object directly catches the observer's eye. In 4 experiments, the difficulty of searching for an orientation-defined target was parametrically manipulated between blocks of trials via the target-distractor orientation contrast. We observed a smooth transition from inefficient to efficient search with increasing orientation contrast. When contrast was high, search slopes were flat (indicating pop-out); when contrast was low, slopes were steep (indicating serial search). At the transition from inefficient to efficient search, search slopes were flat for target-present trials and steep for target-absent trials within the same orientation-contrast block-suggesting that participants adapted their behavior on target-absent trials to the most difficult, rather than the average, target-present trials of each block. Furthermore, even when search slopes were flat, indicative of pop-out, search continued to become faster with increasing contrast. These observations provide several new constraints for models of visual search and indicate that differences between search tasks that were traditionally considered qualitative in nature might actually be due to purely quantitative differences in target discriminability. (PsycINFO Database Record