Investigating the suitability of online eye tracking for psychological research: Evidence from comparisons with in-person data using emotion-attention interaction tasks.

The future is bound to bring rapid methodological changes to psychological research. One such promising candidate is the use of webcam-based eye tracking. Earlier research investigating the quality of online eye-tracking data has found increased spatial and temporal error compared to infrared recordings. Our studies expand on this work by investigating how this spatial error impacts researchers' abilities to study psychological phenomena. We carried out two studies involving emotion-attention interaction tasks, using four participant samples. In each study, one sample involved typical in-person collection of infrared eye-tracking data, and the other involved online collection of webcam-based data. We had two main findings: First, we found that the online data replicated seven of eight in-person results, although the effect sizes were just 52% [42%, 62%] the size of those seen in-person. Second, explaining the lack of replication in one result, we show how online eye tracking is biased toward recording more gaze points near the center of participants' screen, which can interfere with comparisons if left unchecked. Overall, our results suggest that well-powered online eye-tracking research is highly feasible, although researchers must exercise caution, collecting more participants and potentially adjusting their stimulus designs or analytic procedures.

Emotional dissociations in temporal associations: opposing effects of arousal on memory for details surrounding unpleasant events.

Research targeting emotion's impact on relational episodic memory has largely focused on spatial aspects, but less is known about emotion's impact on memory for an event's temporal associations. The present research investigated this topic. Participants viewed a series of interspersed negative and neutral images with instructions to create stories linking successive images. Later, participants performed a surprise memory test, which measured temporal associations between pairs of consecutive pictures where one picture was negative and one was neutral. Analyses focused on how the order of negative and neutral images during encoding influenced retrieval accuracy. Converging results from a discovery study (N = 72) and pre-registered replication study (N = 150) revealed a "forward-favouring" effect of emotion in temporal memory encoding: Participants encoded associations between negative stimuli and subsequent neutral stimuli more strongly than associations between negative stimuli and preceding neutral stimuli. This finding may reflect a novel trade-off regarding emotion's effects on memory and is relevant for understanding affective disorders, as key clinical symptoms can be conceptualised as maladaptive memory retrieval of temporal details.

Oh, the number of things you will process (in parallel)!

We highlight the importance of considering the variance produced during the parallel processing stage in vision and present a case for why it is useful to consider the "item" as a meaningful unit of study when investigating early visual processing in visual search tasks.

Trial history effects in the ventral attentional network.

The ventral attentional network (VAN) is thought to drive "stimulus driven attention" [e.g., Asplund, C. L., Todd, J. J., Snyder, A. P., & Marois, R. A central role for the lateral prefrontal cortex in goal-directed and stimulus-driven attention. Nature Neuroscience, 13, 507-512, 2010; Shulman, G. L., McAvoy, M. P., Cowan, M. C., Astafiev, S. V., Tansy, A. P., D' Avossa, G., et al. Quantitative analysis of attention and detection signals during visual search. Journal of Neurophysiology, 90, 3384-3397, 2003]; in other words, it instantiates within the current stimulus environment the top-down attentional biases maintained by the dorsal attention network [e.g., Kincade, J. M., Abrams, R. A., Astafiev, S. V., Shulman, G. L., & Corbetta, M. An event-related functional magnetic resonance imaging study of voluntary and stimulus-driven orienting of attention. The Journal of Neuroscience: The Official Journal of the Society for Neuroscience, 25, 4593-4604, 2005]. Previous work has shown that the dorsal attentional network is sensitive to trial history, such that it is challenged by changes in task goals and facilitated by repetition thereof [e.g., Kristjánsson, A., Vuilleumier, P., Schwartz, S., Macaluso, E., & Driver, J. Neural basis for priming of pop-out during visual search revealed with fMRI. Cerebral Cortex, 17, 1612-1624, 2007]. Here, we investigate whether the VAN also preserves information across trials such that it is challenged when previously rejected stimuli become task relevant. We used fMRI to investigate the sensitivity of the ventral attentional system to prior history effects as measured by the distractor preview effect. This behavioral phenomenon reflects a bias against stimuli that have historically not supported task performance. We found regions traditionally considered to be part of the VAN (right middle frontal gyrus, inferior frontal gyrus and right supramarginal gyrus) [Shulman, G. L., McAvoy, M. P., Cowan, M. C., Astafiev, S. V., Tansy, A. P., D' Avossa, G., et al. Quantitative analysis of attention and detection signals during visual search. Journal of Neurophysiology, 90, 3384-3397, 2003] to be more active when task-relevant stimuli had not supported task performance in a previous trial than when they had. Investigations of the ventral visual system suggest that this effect is more reliably driven by trial history preserved within the VAN than that preserved within the visual system per se. We conclude that VAN maintains its interactions with top-down stimulus biases and bottom-up stimulation across time, allowing previous experience with the stimulus environment to influence attentional biases under current circumstances.

Relative contributions of task-relevant and task-irrelevant dimensions in priming of pop-out.

Intertrial effects such as priming of pop-out (PoP) often occur for task-irrelevant dimensions as well as task-relevant dimensions, though to a weaker extent. Here we test the hypothesis that increased priming for task-relevant dimensions is due to greater passive build-up of priming for the task-relevant dimension rather than to an active filtering of task-irrelevant dimensions; if this is the case, then we should observe a positive correlation between the magnitude of task-relevant and task-irrelevant priming. We tested this hypothesis using a pop-out search task in which the task-relevant dimension was orientation and the task-irrelevant dimension was color. We found a strong, positive association between task-relevant and task-irrelevant priming across a large group of participants (N = 100); additionally, we observed increased priming over consecutive repetitions for the task-relevant dimension, whereas task-irrelevant priming was constant across multiple repetitions. As further evidence against an active filtering account, task-irrelevant priming showed no systematic relationship with visual short-term memory capacity, which has been shown to correlate with filtering ability. Together, our results suggest that task-irrelevant dimensions are co-selected rather than filtered out during target search. Further, increased task-relevant priming may reflect an enhanced representation of the task-relevant dimension that is reinforced over consecutive repetitions.

Feelings of control restore distorted time perception of emotionally charged events.

Humans perceive time with millisecond precision. However, when experiencing negative or fearful events, time appears to slow down and aversive events are judged to last longer than neutral or positive events of equal duration. Feelings of control have been shown to attenuate increases in arousal triggered by anxiety-provoking events. Here, we tested whether feelings of control can go as far as influencing people's perception of the world, by modulating the perceived duration of aversive events. Observers judged the duration of images depicting positive or negative content, and we manipulated the amount of control experienced by participants. Crucially, participants never had any real control over events. All control was illusory. Results showed that when participants experienced low levels of control, negative images were judged as lasting longer than positive images. However, when participants illusorily experienced high levels of control, they no longer experienced aversive negative images as lasting longer than positive images.

Complex background information slows down parallel search efficiency by reducing the strength of interitem interactions.

In the laboratory, visual search is often studied using uniform backgrounds. This contrasts with search in daily life, where potential search items appear against more complex backgrounds. In the present study, we examined the effects of background complexity on a parallel visual search under conditions where objects are easily segregated from the background. Target-distractor similarity was sufficiently low such that search could unfold in parallel, as indexed by reaction times that increase logarithmically with set size. The results indicate that when backgrounds are relatively simple (sandy beach with water elements), search efficiency is comparable to search using a solid background. When backgrounds are more complex (child bedroom or checkerboard), logarithmic search slopes increase compared to search on solid backgrounds, especially at higher levels of target-distractor similarity. The results are discussed in terms of different theories of visual search. It is proposed that the complex visual information occurring in between distractors slows down individual distractor rejection times by weakening the strength of interitem interactions. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Making waves in the stream of consciousness: entraining oscillations in EEG alpha and fluctuations in visual awareness with rhythmic visual stimulation.

Rhythmic events are common in our sensory world. Temporal regularities could be used to predict the timing of upcoming events, thus facilitating their processing. Indeed, cognitive theories have long posited the existence of internal oscillators whose timing can be entrained to ongoing periodic stimuli in the environment as a mechanism of temporal attention. Recently, recordings from primate brains have shown electrophysiological evidence for these hypothesized internal oscillations. We hypothesized that rhythmic visual stimuli can entrain ongoing neural oscillations in humans, locking the timing of the excitability cycles they represent and thus enhancing processing of subsequently predictable stimuli. Here we report evidence for entrainment of neural oscillations by predictable periodic stimuli in the alpha frequency band and show for the first time that the phase of existing brain oscillations cannot only be modified in response to rhythmic visual stimulation but that the resulting phase-locked fluctuations in excitability lead to concomitant fluctuations in visual awareness in humans. This entrainment effect was dependent on both the amount of spontaneous alpha power before the experiment and the level of 12-Hz oscillation before each trial and could not be explained by evoked activity. Rhythmic fluctuations in awareness elicited by entrainment of ongoing neural excitability cycles support a proposed role for alpha oscillations as a pulsed inhibition of cortical activity. Furthermore, these data provide evidence for the quantized nature of our conscious experience and reveal a powerful mechanism by which temporal attention as well as perceptual snapshots can be manipulated and controlled.

The impact of focused attention on emotional evaluation: An eye-tracking investigation.

Emotional well-being depends on the ability to successfully engage a variety of coping strategies to regulate affective responses. Most studies have investigated the effectiveness of emotion regulation (ER) strategies that are deployed relatively later in the timing of processing that leads to full emotional experiences (i.e. reappraisal and suppression). Strategies engaged in earlier stages of emotion processing, such as those involved in attentional deployment, have also been investigated, but relatively less is known about their mechanisms. Here, we investigate the effectiveness of self-guided focused attention (FA) in reducing the impact of unpleasant pictures on the experienced negative affect. Participants viewed a series of composite images with distinguishable foreground (FG, either negative or neutral) and background (BG, always neutral) areas and were asked to focus on the FG or BG content. Eye-tracking data were recorded while performing the FA task, along with participants' ratings of their experienced emotional response following the presentation of each image. First, proving the effectiveness of self-guided FA in down-regulating negative affect, focusing away from the emotional content of pictures (BG focus) was associated with lower emotional ratings. Second, trial-based eye-tracking data corroborated these results, showing that spending less time gazing within the negative FG predicted reductions in emotional ratings. Third, this reduction was largest among subjects who habitually use suppression to regulate their emotions. Overall, the present findings expand the evidence regarding the FA's effectiveness in controlling the impact of emotional stimuli and inform the development of training interventions emphasizing attentional control to improve emotional well-being. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Rapid resumption of interrupted search is independent of age-related improvements in visual search.

In this study, 7-19-year-olds performed an interrupted visual search task in two experiments. Our question was whether the tendency to respond within 500ms after a second glimpse of a display (the rapid resumption effect [Psychological Science, 16 (2005) 684-688]) would increase with age in the same way as overall search efficiency. The results indicated no correlation of rapid resumption with search speed either across age groups (7, 9, 11, and 19years) or at the level of individual participants. Moreover, relocating the target randomly between looks reduced the rate of rapid resumption in a very similar way at each age. These results imply that implicit perceptual prediction during search is invariant across this age range and is distinct from other critical processes such as feature integration and control over spatial attention.

Predicting how surface texture and shape combine in the human visual system to direct attention.

Objects differ from one another along a multitude of visual features. The more distinct an object is from other objects in its surroundings, the easier it is to find it. However, it is still unknown how this distinctiveness advantage emerges in human vision. Here, we studied how visual distinctiveness signals along two feature dimensions-shape and surface texture-combine to determine the overall distinctiveness of an object in the scene. Distinctiveness scores between a target object and distractors were measured separately for shape and texture using a search task. These scores were then used to predict search times when a target differed from distractors along both shape and texture. Model comparison showed that the overall object distinctiveness was best predicted when shape and texture combined using a Euclidian metric, confirming the brain is computing independent distinctiveness scores for shape and texture and combining them to direct attention.

Distractor-distractor interactions in visual search for oriented targets explain the increased difficulty observed in nonlinearly separable conditions.

The linear separability effect refers to a benefit in search performance observed in a feature-search task, where target and distractor features vary along a continuous feature dimension: Search performance is best when there is a boundary in feature space that separates the distractor features from the target feature. However, the role that distractor heterogeneity plays in this effect is not well understood. Here, we reexamined this effect in the context of a new predictive procedure from Lleras et al. (2019) that quantifies the impact of distractor heterogeneity on search performance. Experiments 1A and 1B measured people's performance in homogeneous search conditions where they searched for the target among one type of distractor. The parameters observed in Experiments 1A and B were then used to predict search times in Experiments 2 and 3, where the target was presented in heterogeneous displays containing two types of distractors. The results show that total variance accounted for was 95% to 98%, without including any factor indexing the linear separability rule. The results demonstrate that heterogeneous search in orientation space is a function of target-distractor similarity and interitem interactions. The study highlights the robustness of the predictive procedure and demonstrates the generalizability of the method to estimate interitem interactions to new stimulus types. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Prioritization in visual attention does not work the way you think it does.

A common assumption in attention theories is that attention prioritizes search items based on their similarity to the target. Here, we tested this assumption and found it wanting. Observers searched through displays containing candidates (distractors that cannot be confidently differentiated from the target by peripheral vision) and lures (distractors that can be). Candidates had high or low similarity to the target. Search displays were either candidate-homogeneous (all items of same similarity) or candidate-heterogeneous (equal numbers of each similarity). Response times to candidate-heterogeneous displays were equivalent to the average of high- and low-similarity displays, suggesting that attention was allocated randomly, rather than toward the high-similarity candidates first. Lures added a response time cost that was independent of the candidates, suggesting they were rejected prior to candidates being inspected. These results suggest a "reverse" prioritization process: Distributed attention discards least target-similar items first, while focused spatial attention is randomly directed to target-similar items. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Irrelevant features of distractors in intervening visual search tasks cause active visual working memory interference - the more difficult the search task, the more interference it causes.

Visual working memory (VWM) content disrupts visual search performance when there is a singleton in the search array that is similar to the content in VWM, even when this singleton is task irrelevant. Typically, the memory-similar singleton captures attention, which results in slower search performance for memory-similar conditions compared to conditions where memory-similar content is absent. Recently, it has also been shown that VWM content may be affected when memory-similar stimuli are processed. Specifically, it appears that VWM representations bias toward memory-similar information that is processed but not memory-dissimilar information. Here, we test whether the bias caused by processing memory-similar information is an active interference process (growing with engagement with the memory-similar stimuli) or a passive interference process (indifferent to the engagement with memory-similar stimuli). To test this, observers were tasked with memorizing a single color followed by a search task. The search task was either easy or difficult, and the search items could either be memory-similar or memory-dissimilar. Critically, the target in the search task was defined by its shape, so the color of the search items was irrelevant to the search task. At the end of each trial, participants reported the color in memory using a continuous report color wheel. The results showed that VWM representations drifted towards the irrelevant color of the search items in the memory-similar conditions, and this effect was larger in the difficult search condition. The results provide evidence that VWM representations receive active interference from processing memory-similar stimuli.

Saccadic repulsion in pop-out search: how a target's dodgy history can push the eyes away from it.

Previous studies have shown that even in the context of fairly easy selection tasks, as is the case in a pop-out task, selection of the pop-out stimulus can be sped up (in terms of eye movements) when the target-defining feature repeats across trials. Here, we show that selection of a pop-out target can actually be delayed (in terms of saccadic latencies) and made less accurate (in terms of saccade accuracy) when the target-defining feature has recently been associated with distractor status. This effect was observed even though participants' task was to fixate color oddballs (when present) and simply press a button when their eyes reached the target to advance to the next trial. Importantly, the inter-trial effect was also observed in response time (time to advance to the next trial). In contrast, this response time effect was completely eliminated in a second experiment when eye movements were eliminated from the task. That is, when participants still had to press a button to advance to the next trial when an oddball target was present in the display (an oddball detection task experiment). This pattern of results closely links the "need for selection" in a task to the presence of an inter-trial bias of attention (and eye movements) in pop-out search.

Correction to: A target contrast signal theory of parallel processing in goal-directed search.

During production of the article, Figure 4 was incorrectly used twice in the initial article, so it appeared both as Figure 4 and Figure 5 in the article.

A target contrast signal theory of parallel processing in goal-directed search.

Feature Integration Theory (FIT) set out the groundwork for much of the work in visual cognition since its publication. One of the most important legacies of this theory has been the emphasis on feature-specific processing. Nowadays, visual features are thought of as a sort of currency of visual attention (e.g., features can be attended, processing of attended features is enhanced), and attended features are thought to guide attention towards likely targets in a scene. Here we propose an alternative theory - the Target Contrast Signal Theory - based on the idea that when we search for a specific target, it is not the target-specific features that guide our attention towards the target; rather, what determines behavior is the result of an active comparison between the target template in mind and every element present in the scene. This comparison occurs in parallel and is aimed at rejecting from consideration items that peripheral vision can confidently reject as being non-targets. The speed at which each item is evaluated is determined by the overall contrast between that item and the target template. We present computational simulations to demonstrate the workings of the theory as well as eye-movement data that support core predictions of the theory. The theory is discussed in the context of FIT and other important theories of visual search.

The impact of focused attention on subsequent emotional recollection: A functional MRI investigation.

In his seminal works, Endel Tulving argued that functionally distinct memory systems give rise to subjective experiences of remembering and knowing (i.e., recollection- vs. familiarity-based memory, respectively). Evidence shows that emotion specifically enhances recollection, and this effect is subserved by a synergistic mechanism involving the amygdala (AMY) and hippocampus (HC). In extreme circumstances, however, uncontrolled recollection of highly distressing memories may lead to symptoms of affective disorders. Therefore, it is important to understand the factors that can diminish such detrimental effects. Here, we investigated the effects of Focused Attention (FA) on emotional recollection. FA is an emotion regulation strategy that has been proven quite effective in reducing the impact of emotional responses associated with the recollection of distressing autobiographical memories, but its impact during emotional memory encoding is not known. Functional MRI and eye-tracking data were recorded while participants viewed a series of composite negative and neutral images with distinguishable foreground (FG) and background (BG) areas. Participants were instructed to focus either on the FG or BG content of the images and to rate their emotional responses. About 4 days later, participants' memory was assessed using the R/K procedure, to indicate whether they Recollected specific contextual details about the encoded images or the images were just familiar to them - i.e., participants only Knew that they saw the pictures without being able to remember specific contextual details. First, results revealed that FA was successful in decreasing memory for emotional pictures viewed in BG Focus condition, and this effect was driven by recollection-based retrieval. Second, the BG Focus condition was associated with decreased activity in the AMY, HC, and anterior parahippocampal gyrus for subsequently recollected emotional items. Moreover, correlation analyses also showed that reduced activity in these regions predicted greater reduction in emotional recollection following FA. These results demonstrate the effectiveness of FA in mitigating emotional experiences and emotional recollection associated with unpleasant emotional events.

What's next? New evidence for prediction in human vision.

Everyday visual experience involves making implicit predictions, as revealed by our surprise when something disturbs our expectations. Many theories of vision have been premised on the central role played by prediction. Yet, implicit prediction in human vision has been difficult to assess in the laboratory, and many results have not distinguished between the indisputably important role of memory and the future-oriented aspect of prediction. Now, a new and unexpected finding - that humans can resume an interrupted visual search much faster than they can start a new search - offers new hope, because the rapid resumption of a search seems to depend on participants forming an implicit prediction of what they will see after the interruption. These findings combined with results of recent neurophysiology studies provide a framework for studying implicit prediction in perception.

Swinging into thought: directed movement guides insight in problem solving.

Can directed actions unconsciously influence higher order cognitive processing? We investigated how movement interventions affected participants' ability to solve a classic insight problem. The participants attempted to solve Maier's two-string problem while occasionally taking exercise breaks during which they moved their arms either in a manner related to the problem's solution (swing group) or in a manner inconsistent with the solution (stretch group). Although most of the participants were unaware of the relationship between their arm movement exercises and the problem-solving task, the participants who moved their arms in a manner that suggested the problem's solution were more likely to solve the problem than were those who moved their arms in other ways. Consistent with embodied theories of cognition, these findings show that actions influence thought and, furthermore, that we can implicitly guide people toward insight by directing their actions.