10 Hz rhythmic stimulation modulates electrophysiological, but not behavioral markers of suppression.

We investigated the role of alpha in the suppression of attention capture by salient but to-be-suppressed (negative and nonpredictive) color cues, expecting a potential boosting effect of alpha-rhythmic entrainment on feature-specific cue suppression. We did so by presenting a rhythmically flickering visual bar of 10 Hz before the cue - either on the cue's side or opposite the cue -while an arrhythmically flickering visual bar was presented on the respective other side. We hypothesized that rhythmic entrainment at cue location could enhance the suppression of the cue. Testing 27 participants ranging from 18 to 39 years of age, we found both behavioral and electrophysiological evidence of suppression: Search times for a target at a negatively cued location were delayed relative to a target away from the cued location (inverse validity effects). In addition, an event-related potential indicative for suppression (the Distractor Positivity, Pd) was observed following rhythmic but not arrhythmic stimulation, indicating that suppression was boosted by the stimulation. This was also echoed in higher spectral power and intertrial phase coherence of EEG at rhythmically versus arrhythmically stimulated electrode sites, albeit only at the second harmonic (20 Hz), but not at the stimulation frequency. In addition, inverse validity effects were not modulated by rhythmic entrainment congruent with the cue side. Hence, we propose that rhythmic visual stimulation in the alpha range could support suppression, though behavioral evidence remains elusive, in contrast to electrophysiological findings.

Top-down suppression of negative features applies flexibly contingent on visual search goals.

Visually searching for a frequently changing target is assumed to be guided by flexible working memory representations of specific features necessary to discriminate targets from distractors. Here, we tested if these representations allow selective suppression or always facilitate perception based on search goals. Participants searched for a target (i.e., a horizontal bar) defined by one of two different negative features (e.g., not red vs. not blue; Experiment 1) or a positive (e.g., blue) versus a negative feature (Experiments 2 and 3). A prompt informed participants about the target identity, and search tasks alternated or repeated randomly. We used different peripheral singleton cues presented at the same (valid condition) or a different (invalid condition) position as the target to examine if negative features were suppressed depending on current instructions. In all experiments, cues with negative features elicited slower search times in valid than invalid trials, indicating suppression. Additionally, suppression of negative color cues tended to be selective when participants searched for the target by different negative features but generalized to negative and non-matching cue colors when switching between positive and negative search criteria was required. Nevertheless, when the same color - red - was used in positive and negative search tasks, red cues captured attention or were suppressed depending on whether red was positive or negative (Experiment 3). Our results suggest that working memory representations flexibly trigger suppression or attentional capture contingent on a task-relevant feature's functional meaning during visual search, but top-down suppression operates at different levels of specificity depending on current task demands.

New Evidence for Retrospectively Cued Perception.

Past research suggests a continuity between perception and memory, as reflected in influences of orienting of spatial attention by cues presented after a visual target offset (post-target cues) on target perception. Conducting two experiments, we tested and confirmed this claim. Our study revealed an elevated reliance on post-target cues for target detection with diminishing target visibility, leading to better performance in validly versus invalidly cued trials, indicative of contrast gain. We demonstrated this post-target cueing impact on target perception without a postcue response prompt, meaning that our results truly reflected a continuity between perception and memory rather than a task-specific impact of having to memorize the target due to a response prompt. While previous studies found an improvement in accuracy through valid compared to invalid cues using liminal targets, in Experiment 1, we further showed an influence of attention on participants' response time by the post-target cues with cues presented away from a clearly visible target. This suggests that visual interactions at the target location provided no better explanation of post-target cueing effects. Our results generalize prior research with liminal targets and confirm the view of a perception-memory continuum so that visual target processing is not shielded against visuospatial orienting of attention elicited by events following the offset of the visual target.

Swift attenuation of irrelevant features through feature consistency: Evidence from a capture-probe version of the contingent-capture protocol.

In the present two experiments, we explore the possibility of swift attenuation of capture by irrelevant features in the contingent-capture protocol. Some prior research suggests that feature attenuation might be most efficient for fixed, anticipated irrelevant features and that varying irrelevant features from trial to trial can undermine their successful attenuation. Here, we exploited this dependence of attenuation on feature certainty to test if attenuation contributed to contingent-capture effects in a capture-probe version of the contingent-capture protocol. In line with the swift attenuation of irrelevant features, salient but target-dissimilar singleton cues that were consistently coloured diminished recall of probes at their locations. This was in comparison to inconsistently coloured target-dissimilar singleton cues. Nonetheless, probe-recall was still better at target-dissimilar cue locations than at non-singleton locations in the cueing display, indicating attenuation of task-irrelevant features rather than their complete suppression.

The influence of hatha yoga on stress, anxiety, and suppression: A randomized controlled trial.

Engaging in yoga may mitigate stress and anxiety in individuals while potentially enhancing one's capacity to manage distractions. Our research aimed to explore the relation between these two outcomes: Can an eight-week yoga program foster distraction suppression, thereby reducing stress and discomfort? To answer this question, we used Hatha Yoga, the most commonly practiced form of yoga. We tested if the intervention improved participants' ability to suppress distractions and selectively decrease self-reported stress and stress reactivity. In Addition, we investigated whether such an intervention would increase participants' mindfulness. Our study included 98 healthy yoga novices between 18 and 40 years who were randomly assigned to either an experimental or a waitlist condition, with each participant completing pre- and post-intervention assessments, including questionnaires, as well as electrophysiological and behavioral measures. After eight weeks of yoga practice, significant reductions in self-reported stress and stress reactivity levels, as well as increased mindfulness, were observed among those participating in the intervention relative to those in the waitlist control group. There were, however, no significant changes in state or trait anxiety due to the intervention. Changes in stress measures could not be explained by changes in participants' ability to suppress distractors, which was not affected by the intervention. Overall, our findings suggest that regular participation in Hatha Yoga can improve mental health outcomes without impacting cognitive functioning directly related to distractor suppression. CLINICAL TRIAL REGISTRATION NUMBER: NCT05232422.

Visual attentional guidance during smooth pursuit eye movements: Distractor interference is independent of distractor-target similarity.

In the current study, we used abrupt-onset distractors similar and dissimilar in luminance to the target of a smooth pursuit eye-movement to test if abrupt-onset distractors capture attention in a top-down or bottom-up fashion while the eyes track a moving object. Abrupt onset distractors were presented at different positions relative to the current position of a pursuit target during the closed-loop phase of smooth pursuit. Across experiments, we varied the duration of the distractors, their motion direction, and task-relevance. We found that abrupt-onset distractors decreased the gain of horizontally directed smooth-pursuit eye-movements. This effect, however, was independent of the similarity in luminance between distractor and target. In addition, distracting effects on horizontal gain were the same, regardless of the exact duration and position of the distractors, suggesting that capture was relatively unspecific and short-lived (Experiments 1 and 2). This was different with distractors moving in a vertical direction, perpendicular to the horizontally moving target. In line with past findings, these distractors caused suppression of vertical gain (Experiment 3). Finally, making distractors task-relevant by asking observers to report distractor positions increased the pursuit gain effect of the distractors. This effect was also independent of target-distractor similarity (Experiment 4). In conclusion, the results suggest that a strong location signal exerted by the pursuit targets led to very brief and largely location-unspecific interference through the abrupt onsets and that this interference was bottom-up, implying that the control of smooth pursuit was independent of other target features besides its motion signal.

Response time concealed information test using fillers in cybercrime and concealed identity scenarios.

The Response Time Concealed Information Test (RT-CIT) can reveal that a person recognises a relevant item (e.g., a murder weapon) among other control items, based on slower responses to the former compared to the latter ones. To date, the RT-CIT has been predominantly examined only in the context of scenarios that are very unlikely in real life, while sporadic assessment has shown that it suffers from low diagnostic accuracy in more realistic scenarios. In our study, we validated the RT-CIT in the new, realistic, and very topical mock scenario of a cybercrime (Study 1, n = 614; Study 2; n = 553), finding significant though moderate effects. At the same time (and expanded with a concealed identity scenario; Study 3, n = 250), we assessed the validity and generalizability of the filler items presented in the RT-CIT: We found similar diagnostic accuracies when using specific, generic, and even nonverbal items. However, the relatively low diagnostic accuracy in case of the cybercrime scenario reemphasizes the importance of assessments in realistic scenarios as well as the need for further improving the RT-CIT.

Which processes dominate visual search: Bottom-up feature contrast, top-down tuning or trial history?

Previous research has identified three mechanisms that guide visual attention: bottom-up feature contrasts, top-down tuning, and the trial history (e.g., priming effects). However, only few studies have simultaneously examined all three mechanisms. Hence, it is currently unclear how they interact or which mechanisms dominate over others. With respect to local feature contrasts, it has been claimed that a pop-out target can only be selected immediately in dense displays when the target has a high local feature contrast, but not when the displays are sparse, which leads to an inverse set-size effect. The present study critically evaluated this view by systematically varying local feature contrasts (i.e., set size), top-down knowledge, and the trial history in pop-out search. We used eye tracking to distinguish between early selection and later identification-related processes. The results revealed that early visual selection was mainly dominated by top-down knowledge and the trial history: When attention was biased to the target feature, either by valid pre-cueing (top-down) or automatic priming, the target could be localised immediately, regardless of display density. Bottom-up feature contrasts only modulated selection when the target was unknown and attention was biased to the non-targets. We also replicated the often-reported finding of reliable feature contrast effects in the mean RTs, but showed that these were due to later, target identification processes (e.g., in the target dwell times). Thus, contrary to the prevalent view, bottom-up feature contrasts in dense displays do not seem to directly guide attention, but only facilitate nontarget rejection, probably by facilitating nontarget grouping.

Evidence for top-down suppression of negative features in the target feature dimension.

While searching for a goal-relevant object, an internal representation of the features necessary to identify the to-be-searched-for object (i.e., target) guides attention towards visual stimuli with matching properties. Recent evidence suggests that features that negatively define a target (i.e., negative features) also bias attentional allocation through top-down suppression. Since humans usually know what to look for, it will rarely, if ever, be the case that a negative feature defines a goal-relevant object alone. Thus, to better understand the relevance of top-down suppression, our participants searched for a target conjunctively defined by a positive (e.g., a blue bar) and a negative feature (e.g., a nonred bar) with both features realized within the same dimension (color in Experiments 1, 3 and 4, orientation in Experiment 2). Experiments 1 and 2 showed that reaction times were slower if cues with a negative feature preceded the target at the same versus a different position (i.e., validly vs. invalidly cued targets), indicating suppression. In contrast, cues with a task-irrelevant different-dimension feature elicited no significant reaction time difference between validly cued and invalidly cued trials. In addition, Experiment 3 showed that while negative cues were top-down suppressed, cues with a positive feature captured attention. This finding indicated that both positive and negative features guide visual attention through capture and suppression, respectively, during the search for a target defined by the presence of one and the absence of another feature from the same dimension. However, suppression seems to apply to the negative and all nontarget features in the task-relevant dimension. This was shown in Experiment 4, in which participants suppressed cues with a task-irrelevant color similarly to cues with a negative color.

Top-down knowledge surpasses selection history in influencing attentional guidance.

Visual attention is influenced by the characteristics of the stimuli (bottom-up), their task relevance (top-down), and prior experience (e.g., selection history and learning). However, it is largely unclear how learning and selection history interact with top-down attentional guidance. We combined trial-and-error learning with a spatial cueing protocol to test whether previously learned target-defining features continued to capture attention if participants were instructed to search for a new target feature (Experiment 1) or had to learn a new target feature (Experiment 2). It turned out that the previously learned feature quickly stopped capturing attention when the target feature changed (Experiment 1; even before participants learned the new target-defining feature, in Experiment 2). Finally, in Experiment 3, in which participants learned to search for targets defined by two redundant features (color and orientation), we found possible reasons for the dominance of the instructed feature over learning. Participants reported using only the target color for their search. Consequently, only cues with a target color captured attention. The unused target orientation only captured attention in participants aware of both target-defining features (13 out of 23) and only if the orientation was presented in the target color. We conclude that knowledge of target-defining features and their use as search criterion is critical for attentional guidance, while previously learned target features either influence attentional guidance only contingent on such deliberately selected top-down based attentional control settings or may influence visual search but not attentional guidance.

The good, the bad, and the red: implicit color-valence associations across cultures.

Cultural differences-as well as similarities-have been found in explicit color-emotion associations between Chinese and Western populations. However, implicit associations in a cross-cultural context remain an understudied topic, despite their sensitivity to more implicit knowledge. Moreover, they can be used to study color systems-that is, emotional associations with one color in the context of an opposed one. Therefore, we tested the influence of two different color oppositions on affective stimulus categorization: red versus green and red versus white, in two experiments. In Experiment 1, stimuli comprised positive and negative words, and participants from the West (Austria/Germany), and the East (Mainland China, Macau) were tested in their native languages. The Western group showed a significantly stronger color-valence interaction effect than the Mainland Chinese (but not the Macanese) group for red-green but not for red-white opposition. To explore color-valence interaction effects independently of word stimulus differences between participant groups, we used affective silhouettes instead of words in Experiment 2. Again, the Western group showed a significantly stronger color-valence interaction than the Chinese group in red-green opposition, while effects in red-white opposition did not differ between cultural groups. Our findings complement those from explicit association research in an unexpected manner, where explicit measures showed similarities between cultures (associations for red and green), our results revealed differences and where explicit measures showed differences (associations with white), our results showed similarities, underlining the value of applying comprehensive measures in cross-cultural research on cross-modal associations.

Novel tests of capture by irrelevant abrupt onsets: No evidence for a mediating role of search task difficulty during color search.

According to the attentional dwelling hypothesis, task-irrelevant abrupt-onset cues capture attention in a stimulus-driven way by eliciting spatial shifts and further dwelling at cue position until target onset. Consequently, search can be facilitated for targets at cued locations relative to uncued locations. Critically, effects of stimulus-driven capture can go undetected in mean reaction times and error rates when search is too easy. In contrast, according to the priority accumulation framework (PAF), cueing effects for task-irrelevant cues differ from cueing effects by task-relevant cues. Most critically, cueing effects by irrelevant cues do not necessarily index spatial shifts and more dwelling but rather retrieval of cueing information. We used both behavioral measures (i.e., cueing effects and distractor compatibility effects) and event-related potentials on direct visual orienting activity elicited by the cue (Experiment 2) as well as consequences on target processing (Experiment 1) to investigate whether task-irrelevant abrupt onsets elicited attention shifts and led to further dwelling. We found behavioral support for attentional effects of task-irrelevant cues, surprisingly, however, only when search displays remained on-screen until response. We found no support for the attentional dwelling hypothesis or for PAF in the size of cueing effects as a function of search difficulty. Critically, lateralized ERPs revealed that salience of abrupt onsets per se is not sufficient to elicit spatial shifts during color search. Finally, neurophysiological evidence demonstrates that choices toward the implementation of experimental protocols can dramatically alter behavioral results on attentional effects of salient, but task-irrelevant abrupt onsets and conclusions drawn from them.

Testing the role of temporal selection for stimulus-driven capture of attention.

Stimulus-driven and top-down dependent capture of attention can be observed under very similar conditions, raising the question of the decisive factors for whether one or the other effect is seen. In the current study, we tested the role of temporal selectivity. Studies showing less evidence of stimulus-driven attention by salient color singletons often used sequences of displays, in which the first display contained an irrelevant color cue that could easily be ignored by timed allocation of attention, as the relevant target was consistently presented in a second display only. In contrast, studies showing more evidence of stimulus-driven attention used distractors presented simultaneously with the targets, making it more difficult to simply ignore additional salient distractors at the point in time where the target was presented. Here, we therefore tested stimulus-driven capture under two conditions: with temporal certainty that the first display could safely be ignored and without temporal certainty that the first display could be ignored. Results showed that this manipulation had no significant influence on stimulus-driven capture of attention by irrelevant but salient cues preceding the targets, although the same participants showed more distractor interference by a target-concomitant and salient color singleton. Thus, temporal selection was seemingly not the decisive factor for the amount of stimulus-driven capture of attention.

Cross-modal attentional effects of rhythmic sensory stimulation.

Temporal regularities are ubiquitous in our environment. The theory of entrainment posits that the brain can utilize these regularities by synchronizing neural activity with external events, thereby, aligning moments of high neural excitability with expected upcoming stimuli and facilitating perception. Despite numerous accounts reporting entrainment of behavioural and electrophysiological measures, evidence regarding this phenomenon remains mixed, with several recent studies having failed to provide confirmatory evidence. Notably, it is currently unclear whether and for how long the effects of entrainment can persist beyond their initiating stimulus, and whether they remain restricted to the stimulated sensory modality or can cross over to other modalities. Here, we set out to answer these questions by presenting participants with either visual or auditory rhythmic sensory stimulation, followed by a visual or auditory target at six possible time points, either in-phase or out-of-phase relative to the initial stimulus train. Unexpectedly, but in line with several recent studies, we observed no evidence for cyclic fluctuations in performance, despite our design being highly similar to those used in previous demonstrations of sensory entrainment. However, our data revealed a temporally less specific attentional effect, via cross-modally facilitated performance following auditory compared with visual rhythmic stimulation. In addition to a potentially higher salience of auditory rhythms, this could indicate an effect on oscillatory 3-Hz amplitude, resulting in facilitated cognitive control and attention. In summary, our study further challenges the generality of periodic behavioural modulation associated with sensory entrainment, while demonstrating a modality-independent attention effect following auditory rhythmic stimulation.

Does language rule perception? Testing a radical view of linguistic relativity.

To investigate whether language rules the visual features that can be discriminated (a radical assumption of linguistic relativity), we examined crosslinguistic differences between native Korean and German speakers during liminal perception of a target disk that was difficult to perceive because its visibility suffered from masking by a ring that followed and enclosed the target disk (metacontrast-masking). Target-mask fit varied, with half of the masks tightly and the other half loosely encircling the targets. In Korean, such tight versus loose spatial relations are semantically distinguished and thus highly practiced, whereas in German, they are collapsed within a single semantic category, thus are not distinguished by language. We expected higher sensitivity and greater attention to varying spatial target-mask distances in Korean than in German speakers. This was confirmed in Experiment 1, where Korean speakers consistently outperformed German speakers in discriminating liminal metacontrast-masked stimuli. To ensure that this effect was not attributable to generic differences in attention capture or by language-independent differences between participant groups, we investigated stimulus-driven attention capture by color singletons and conducted a control experiment using object-substitution masking, where tightness of fit was not manipulated. We found no differences between Korean and German speakers regarding stimulus-driven attention capture or perceptual sensitivity. This was confirmed in Experiment 3, where we manipulated types of masking within participants. In addition, we validated the tightness-of-fit manipulation in a language-related task (Experiment 4). Overall, our results are consistent with linguistic relativity, namely its assumed generalized language influences in nonlinguistic perceptual tasks. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Motor-induced oscillations in choice response performance.

Recently, numerous studies have revealed 4-12 Hz fluctuations of behavioral performance in a multitude of tasks. The majority has utilized stimuli near detection threshold and observed related fluctuations in hit-rates, attributing these to perceptual or attentional processes. As neural oscillations in the 8-20 Hz range also feature prominently in cortical motor areas, they might cause fluctuations in the ability to induce responses, independent of attentional capabilities. Additionally, different effectors (e.g., the left versus right hand) might be cyclically prioritized in an alternating fashion, similar to the attentional sampling of distinct locations, objects, or memory templates. Here, we investigated these questions via a behavioral dense-sampling approach. Twenty-six participants performed a simple visual discrimination task using highly salient stimuli. We varied the interval between each motor response and the subsequent target from 330 to 1040 ms, and analyzed performance as a function of this interval. Our data show significant fluctuations of both RTs and sensitivity between 12.5 and 25 Hz, but no evidence for an alternating prioritization of left- versus right-hand responses. While our results suggest an impact of motor-related signals on performance oscillations, they might additionally be influenced by perceptual processes earlier in the processing hierarchy. In summary, we demonstrate that behavioral oscillations generalize to situations involving highly salient stimuli, closer to everyday life. Moreover, our work adds to the literature by showing fluctuations at a high speed, which might be a consequence of both low task difficulty and the involvement of sensorimotor rhythms.

Linguistic Skill and Stimulus-Driven Attention: A Case for Linguistic Relativity.

How does the language we speak affect our perception? Here, we argue for linguistic relativity and present an explanation through "language-induced automatized stimulus-driven attention" (LASA): Our respective mother tongue automatically influences our attention and, hence, perception, and in this sense determines what we see. As LASA is highly practiced throughout life, it is difficult to suppress, and even shows in language-independent non-linguistic tasks. We argue that attention is involved in language-dependent processing and point out that automatic or stimulus-driven forms of attention, albeit initially learned as serving a linguistic skill, account for linguistic relativity as they are automatized and generalize to non-linguistic tasks. In support of this possibility, we review evidence for such automatized stimulus-driven attention in language-independent non-linguistic tasks. We conclude that linguistic relativity is possible and in fact a reality, although it might not be as powerful as assumed by some of its strongest proponents.

Art and Perception: Using Empirical Aesthetics in Research on Consciousness.

Understanding consciousness is a major frontier in the natural sciences. However, given the nuanced and ambiguous sets of conditions regarding how and when consciousness appears to manifest, it is also one of the most elusive topics for investigation. In this context, we argue that research in empirical aesthetics-specifically on the experience of art-holds strong potential for this research area. We suggest that empirical aesthetics of art provides a more exhaustive description of conscious perception than standard laboratory studies or investigations of the less artificial, more ecological perceptual conditions that dominate this research, leading to novel and better suited designs for natural science research on consciousness. Specifically, we discuss whether empirical aesthetics of art could be used for a more adequate picture of an observer's attributions in the context of conscious perception. We point out that attributions in the course of conscious perception to (distal) objects versus to media (proximal objects) as origins of the contents of consciousness are typically swift and automatic. However, unconventional or novel object-media relations used in art can bring these attributions to the foreground of the observer's conscious reflection. This is the reason that art may be ideally suited to study human attributions in conscious perception compared to protocols dedicated only to the most common and conventional perceptual abilities observed under standard laboratory or "natural"/ecological conditions alone. We also conclude that art provides an enormous stock of such unconventional and novel object-media relations, allowing more systematic falsification of tentative conclusions about conscious perception versus research protocols covering more conventional (ecological) perception only. We end with an outline of how this research could be carried out in general.

Do Subliminal Fearful Facial Expressions Capture Attention?

In two experiments, we tested whether fearful facial expressions capture attention in an awareness-independent fashion. In Experiment 1, participants searched for a visible neutral face presented at one of two positions. Prior to the target, a backward-masked and, thus, invisible emotional (fearful/disgusted) or neutral face was presented as a cue, either at target position or away from the target position. If negative emotional faces capture attention in a stimulus-driven way, we would have expected a cueing effect: better performance where fearful or disgusted facial cues were presented at target position than away from the target. However, no evidence of capture of attention was found, neither in behavior (response times or error rates), nor in event-related lateralizations (N2pc). In Experiment 2, we went one step further and used fearful faces as visible targets, too. Thereby, we sought to boost awareness-independent capture of attention by fearful faces. However, still, we found no significant attention-capture effect. Our results show that fearful facial expressions do not capture attention in an awareness-independent way. Results are discussed in light of existing theories.

Unseeing the white bear: Negative search criteria guide visual attention through top-down suppression.

In three spatial cueing experiments, we investigated whether a negative search criterion (i.e., a task-relevant feature that negatively defines the target) can guide visual attention in a top-down manner. Our participants searched for a target defined by a negative feature (e.g., red if the target was a nonred horizontal bar). Before the target, a peripheral singleton cue was shown at the target position (valid condition) or a nontarget position (invalid condition). We found slower reaction times in valid than invalid trials only with singleton cues matching the negative feature. Importantly, we ruled out that participants searched for target-associated features instead of suppressing the negative feature (Experiment 1). Furthermore, we demonstrated that suppression of cues with a negative feature was stronger than mere ignorance of singleton cues with a task-irrelevant feature. Finally, cue-target intervals of 60 ms and 150 ms elicited the same suppression effects for cues matching the negative feature. These findings suggest that the usage of a negative search criterion elicited feature-selective proactive suppression (Experiments 2 and 3). Thus, our results provide first evidence of top-down attentional suppression dependent on current task goals as a strategy operating in parallel to the goal-directed search for target-defining features (Experiment 2). (PsycInfo Database Record (c) 2022 APA, all rights reserved).