Inter-trial priming does not affect attentional priority in asymmetric visual search

Attentional priming in Go No-Go search tasks

Go/No-Go responses in visual search yield different estimates of the operation of visual attention than more standard present versus absent tasks. Such minor methodological tweaks have a surprisingly large effect on measures that have, for the last half-century or so, formed the backbone of prominent theories of visual attention. Secondly, priming effects in visual search have a dominating influence on visual search, accounting for effects that have been attributed to top-down guidance in standard theories. Priming effects in visual search have, however, never been investigated for searches involving Go/No-Go present/absent decisions. Here, Go/No-Go tasks were used to assess visual search for an odd-one-out face, defined either by color or facial expression. The Go/No-Go responses for the color-based task were very fast for both present and absent trials and notably, they resulted in negative slopes of RT and set size. Interestingly "Go" responses were even faster for the target absent case. The "Go" responses were, on the other hand, much slower for expression and became higher with increased set-size, particularly for the target-absent response. Priming effects were considerable for the feature search, but for expression, the target absent priming was strong, but did not occur for target present trials, arguing that repetition priming for this search mainly reflects priming of context rather than target features. Overall, the results reinforce the point that Go/No-Go tasks are highly informative for theoretical accounts of visual attention and are shown here to cast a new light on attentional priming.

Selection history influences an attentional decision bias toward singleton targets

Selection history effects are ubiquitous findings that show how implicitly encoding a target's feature or location on a trial can facilitate target activation on the following trial. Although the target-defining feature (e.g., color) is usually unpredictable, it is often relevant to determining the target on a given trial. The present study used a feature priming task, like the three-item oddball search task, but varied the target-defining feature (shape) orthogonal to the priming feature (color) that could influence target activation. On any trial the target could be a color singleton or not, and the target's feature could repeat or switch between trials. Larger priming effects were seen when the current target was a color singleton than a nonsingleton. Importantly, diffusion analyses showed that pretrial selection bias contributed to these larger priming effects. The results suggest selection history facilitates target activation through an attentional decision bias to select the object with the most recently attended color, and this attentional decision is easier when the current target is also distinct.

Eye-specific attentional bias driven by selection history

Attention helps in selection among competing stimuli, but attentional selection also biases subsequent information processing as a prior experience. Previous studies have demonstrated that intertrial repetition of target features or locations facilitates perceptual processing as selection history guides attention. In the current study, we found that eye selection history in binocular rivalry induces eye-specific attentional bias. In four experiments, participants responded to the target presented at one of the locations on either eye. The results showed that the target was detected faster when presented to the same eye as in the previous trial under binocular rivalry. However, the effect of eye repetition was not observed when the interocular conflict was reduced by presenting stimuli to only one eye on each trial. Our result indicates that eye selection history can affect eye dominance during binocular rivalry as attention amplifies selected information among competing inputs. These findings suggest that prior experience of attentional deployment modulates subsequent information processing owing to the residual effect of attentional amplification.

Does feature intertrial priming guide attention? The jury is still out

Our search performance is strongly influenced by our past experience. In the lab, this influence has been demonstrated by investigating a variety of phenomena, including intertrial priming, statistical learning, and reward history, and collectively referred to as selection history. The resulting findings have led researchers to claim that selection history guides attention, thereby challenging the prevailing dichotomy, according to which top-down and bottom-up factors alone determine attentional priority. Here, we re-examine this claim with regard to one selection-history phenomenon, feature intertrial priming (aka priming of pop-out). We evaluate the evidence that specifically pertains to the role of feature intertrial priming in attentional guidance, rather than in later selective processes occurring after the target is found. We distinguish between the main experimental rationales, while considering the extent to which feature intertrial priming, as studied through different protocols, shares characteristics of top-down attention. We show that there is strong evidence that feature intertrial priming guides attention when the experimental protocol departs from the canonical paradigm and encourages observers to maintain the critical feature in visual working memory or to form expectations about the upcoming target. By contrast, the current evidence regarding the standard feature intertrial priming phenomenon is inconclusive. We propose directions for future research and suggest that applying the methodology used here in order to re-evaluate of the role of other selection history phenomena in attentional guidance should clarify the mechanisms underlying the strong impact of past experience on visual search performance.

Target activation and distractor inhibition underlie priming of pop-out: A response to Dent (this issue)

Visual search is faster when the target and distractors features repeat than when they switch on successive trials, a phenomenon known as priming of pop-out (PoP). In previous work, we suggested that two mechanisms, each indexed by a repetition benefit and a switch cost underlie PoP: target activation and distractor inhibition. Consistent with this account, we reported strong correlations between the benefit and cost indexing each mechanism and concluded that there are stable individual differences on target-activation and distractor-inhibition processes. In subsequent work, we noted flaws in our baseline for benefits and costs and suggested a different baseline. Yet, we did not explore the implications of these flaws for our previous conclusions - a gap that Dent (this issue) filled in a large-scale replication of our study. He found our reported correlations to entirely vanish when the corrected baselines are used, whereas repetition benefits were correlated and so were switching costs. He concluded that his findings invalidate the activation-inhibition account of PoP and proposed a hybrid account, according to which repetition effects reflect activation and inhibition, whereas switch costs index a conflict-resolution process. Here, we claim that failure to observe correlations between indices of the same components invalidates the claim that there are stable individual differences on these components but does not challenge the idea that target-activation and distractor inhibition underlie PoP. We reanalyzed the data from four published experiments. As Dent (this issue), we find no correlations between indices of the same component. However, we show that novel predictions of the activation-inhibition components account are supported, whereas the predictions of the conflict-resolution account are disconfirmed.

Feature singletons attract spatial attention independently of feature priming

People perform better in visual search when the target feature repeats across trials (intertrial feature priming [IFP]). Here, we investigated whether repetition of a feature singleton's color modulates stimulus-driven shifts of spatial attention by presenting a probe stimulus immediately after each singleton display. The task alternated every two trials between a probe discrimination task and a singleton search task. We measured both stimulus-driven spatial attention (via the distance between the probe and singleton) and IFP (via repetition of the singleton's color). Color repetition facilitated search performance (IFP effect) when the set size was small. When the probe appeared at the singleton's location, performance was better than at the opposite location (stimulus-driven attention effect). The magnitude of this attention effect increased with the singleton's set size (which increases its saliency) but did not depend on whether the singleton's color repeated across trials, even when the previous singleton had been attended as a search target. Thus, our findings show that repetition of a salient singleton's color affects performance when the singleton is task relevant and voluntarily attended (as in search trials). However, color repetition does not affect performance when the singleton becomes irrelevant to the current task, even though the singleton does capture attention (as in probe trials). Therefore, color repetition per se does not make a singleton more salient for stimulus-driven attention. Rather, we suggest that IFP requires voluntary selection of color singletons in each consecutive trial.

Attentional capture by irrelevant emotional distractor faces is contingent on implicit attentional settings

Although expressions of facial emotion hold a special status in attention relative to other complex objects, whether they summon our attention automatically and against our intentions remains a debated issue. Studies supporting the strong view that attentional capture by facial expressions of emotion is entirely automatic reported that a unique (singleton) emotional face distractor interfered with search for a target that was also unique on a different dimension. Participants could therefore search for the odd-one out face to locate the target and attentional capture by irrelevant emotional faces might be contingent on the adoption of an implicit set for singletons. Here, confirming this hypothesis, an irrelevant emotional face captured attention when the target was the unique face with a discrepant orientation, both when this orientation was unpredictable and when it remained constant. By contrast, no such capture was observed when the target could not be found by monitoring displays for a discrepant face and participants had to search for a face with a specific orientation. Our findings show that attentional capture by emotional faces is not purely stimulus driven and thereby resolve the apparent inconsistency that prevails in the literature on the automaticity of attentional capture by emotional faces.