Attention: Tracking, shifting, capture

Talk Session: Sunday, May 19, 2024, 2:30 – 4:15 pm, Talk Room 1
Moderator: Anna Nobre, Yale University

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Talk 1, 2:30 pm, 34.11

Spatiotemporal processing drives the contralateral delay activity in a dual working memory and attentional tracking task

Piotr Styrkowiec^1,2 (), William Ngiam¹, William Epstein¹, Ron Gneezy¹, Edward Awh¹, Edward Vogel¹; ¹University of Chicago, USA, ²University of Wroclaw, Poland

Recent work has suggested that storage in visual working memory (VWM) occurs through the assignment of spatiotemporal pointers to the to-be-remembered items (Thyer et al., 2022). Thus, VWM capacity limits may not be set by the stimulus content exactly, but rather by attentional processes that define the spatiotemporal pointers for item-based storage. We examined whether this is the case in the contralateral delay activity (CDA), an event-related potential long known to track VWM load. The CDA has been shown to track the number of targets in multiple-object tracking (Drew and Vogel, 2008), but also the number of to-be-remembered colors (Vogel and Machizawa, 2004). To directly contrast the effects of attentional tracking load and stimulus content load on working memory, we developed a novel dual-task paradigm. Participants track either one or two moving discs (attentional tracking load), with either two or four colors displayed across each of the discs (working memory load). Participants completed a ‘tracking only’ condition, where they would need to monitor the moving target discs like in a multiple-object tracking task, and a ‘tracking plus memory’ condition, where they would track the discs and remember all displayed colors like in a multiple-identity tracking task. The key question was whether or not CDA amplitude would be determined by the number of individuated items tracked, or by the number of distinct colors associated with the currently tracked items. Strikingly, CDA amplitude was determined almost entirely by the number of items tracked, with no reliable effect of variations in the number of colors per tracked item. These findings suggest the CDA largely reflects the maintenance of spatiotemporal pointers for moving objects, not the number of feature values associated with those objects.

Talk 2, 2:45 pm, 34.12

One at a time in the mind’s eye: Serial versus parallel mental simulation of moving objects

Halely Balaban¹ (), Tomer Ullman²; ¹The Open University of Israel, ²Harvard University

Our everyday environment is highly dynamic, and this creates great challenges for any cognitive system. Decades of research using the Multiple Object Tracking paradigm has shown that when people view moving objects, they can only track a handful of them at a time. But people’s real-world tracking extends beyond direct perception: we can also keep track of occluded bodies, as well as imagine the yet-unseen future paths of objects (e.g., in order to estimate where a thrown ball will land). In this work, we examined the capacity limitations of tracking items in imagination, rather than perception. Across 4 experiments, participants (N=136 total) watched short 2D animations of balls moving under gravity. Animations paused mid-motion, and participants were asked to continue the scene in their mind’s eye, and indicate when each ball hits the ground in their imagination. Responses were compared with the true impact time, which was extracted from simulated physics. With a single ball, people’s imagination-based responses closely matched the true impact time (Exp. 1). However, once another ball was introduced, performance was significantly altered (Exp. 2), and followed the predictions of a computational model of serial simulation, which only moves a single object forward at a time. The serial pattern was not due to response requirements (Exp. 3), and was reduced, but not fully eliminated, by introducing extremely strong grouping cues that even allowed relying on heuristics (Exp. 4). Together, our results show that tracking objects in imagination is, at least under certain conditions, a serial process that operates on a single-object basis. More broadly, examining ‘imagination tracking’ highlights previously unexplored capacity limits in mental simulation, calling for an updating of current models of how humans make intuitive predictions of physical outcomes.

Talk 3, 3:00 pm, 34.13

Less Salient, More Capture: The Curious Case of Abrupt Onsets

Han Zhang¹ (), Kane York¹, John Jonides¹; ¹University of Michigan

Abrupt onsets are commonly assumed to capture attention due to their high physical salience. Using a technique recently introduced by Stilwell et al. (2023), we directly compared the salience level of a color singleton, an abrupt onset, and a color singleton + abrupt onset item. We then assessed the magnitude of capture by these items in a visual search task, in which these items served as distractors. In an oddball-detection task, 26 participants reported the presence or absence of the critical item among four heterogeneous shapes. Applying the exact algorithm from Stilwell et al. (2023), we determined the exposure threshold for each item type. Abrupt onsets exhibited a significantly larger exposure threshold (61 ms), indicating lower salience, compared to color singletons (25 ms; t(25) = 5.41, p < .001) and color singleton + abrupt onset items (22 ms; t(25) = 5.92, p < .001). Next, another group of 30 participants completed a visual search task with the same display. Surprisingly, only the pure onset distractor elicited a capture effect, as indicated by response time differences (23.5 ms, t = 5.46, p < .001). In contrast, we found suppression effects for both the color singleton distractor (29.1 ms, t = 5.28, p < .001) and the color singleton + abrupt onset distractor (26.3 ms, t = 3.45, p < .001). The interaction between distractor presence and distractor type was highly significant, F(2, 58) = 30.15, p < .001. Finally, these findings were replicated when the same group of participants (N = 26) completed both tasks. Overall, individuals could suppress an abrupt onset distractor with high salience but not with lower salience. These results suggest that abrupt onsets maintain a privileged status in the visual system and tend to capture attention, despite their relatively low salience.

Acknowledgements: This work was supported by the National Science Foundation [grant number: 1658268] and the National Institute of Mental Health (Unique Federal Award Identification Number (FAIN): R21MH129909).

Talk 4, 3:15 pm, 34.14

Susceptibility to attentional capture by target-matching distractors predicts high visual working memory capacity

Zhe Qu¹ (), Yulong Ding²; ¹Sun Yat-sen University, ²South China Normal University

Introduction: It is well known that the ability of distractor suppression has a close relation to visual working memory (VWM). Recent event-related potential (ERP) studies (e.g., Gaspar et al., 2016) showed that individuals with high working memory capacity could call on an early suppression (indexed by Pd component) to salient-but-irrelevant distractors whereas those low-capacity ones could not. However, it remains unclear whether such an early suppression mechanism applies to nonsalient distractors that possess the target-defining feature. The main purpose of the present study is to investigate the relation between the VWM capacity and the attentional process of feature-matched distractors. Methods: Fifty-one healthy young adults participated in this study. Like previous studies (e.g., Gaspar et al., 2016), individual VWM capacity was measured by the K-score of change detection task. In the ERP experiment, we adopted a central rapid serial visual presentation (RSVP) task in which distractors with or without the target-defining feature were presented peripherally. Participants were informed to identify a digit of a specified color in the central RSVP stream. We focus on two distractor-elicited ERP components (i.e., N2pc and Pd) that would reflect two distractor-related attentional processes (i.e., attentional capture and attentional suppression), respectively. Results: Surprisingly, we revealed that high-capacity individuals would be captured more attention (reflected by a larger distractor-N2pc emerging in less than 200 ms) compared to low-capacity ones, meaning that they are less able to ignore such distractors in early visual processing. Although feature-matched distractors captured more attention for high-capacity individuals, they received stronger suppression soon afterwards, indexed by a larger distractor-Pd. Conclusion: Compared to low-capacity individuals, high-capacity ones would first be captured more attention by feature-matched distractors, then enact more inhibition to those distractors. Our findings support that, high-capacity individuals could exhibit more flexible ways of attentional processing when dealing with different kinds of distractors.

Talk 5, 3:30 pm, 34.15

Cued Suppression and Learned Suppression Rely on Separate Mechanisms

Nancy Carlisle¹ (), Matthieu Chidharom^1,2; ¹Lehigh University, ²University of Chicago

In recent years, two forms of attentional suppression have been identified. In cued suppression, participants avoid certain distractor features which are cued on each trial. In learned suppression, participants gradually learn to ignore bottom-up features, which would normally capture attention, through repeated exposure. Although both types of suppression are well established, it is not clear if both types of suppression rely on the same underlying mechanisms. To address this question, we examined correlations (N=54) between cued suppression and learned suppression, as well as WM capacity and a real-world inattentive trait questionnaire. If cued and learned suppression rely on similar mechanisms, we expect correlated amounts of suppression across individuals. Instead, we found that cued and learned suppression were not correlated. Cued suppression was correlated with WM capacity, in line with the idea that these tasks relied on cognitive control. Learned suppression was correlated with the real-world inattentive trait questionnaire, suggesting that reductions in learning to suppress may create distractibility both inside and outside the lab. These results suggest that cued and learned suppression are separable forms of attentional guidance, not two ways of activating the same suppression mechanism.

Acknowledgements: 1R15EY030247

Talk 6, 3:45 pm, 34.16

Continuous psychophysics reveals a temporal cost of real-time distractor suppression during ensemble perception

Kevin Ortego¹, Viola Stoermer¹; ¹Dartmouth College

Ensemble perception plays a fundamental role in how our visual system represents complex scenes. It is commonly studied by briefly presenting sets of stimuli to participants and having them report the average across the feature dimension of interest (e.g. orientation). In real scenes, however, multiple feature sets are often present at the same time, and their inputs to the visual system change continuously, due to variability in the environment or eye and head movements of the observer. Here, we developed a new task to test how participants track feature summaries continuously and how irrelevant distractor features affect the precision and time course of ensemble estimates. During 45-second long tracking trials, participants viewed a set of oriented lines that continuously changed orientations, and concurrently rotated a joystick to reproduce the average orientation of those lines. Following previous work using continuous psychophysics (Bonnen et al., 2015), we computed the cross-correlation between the mean target orientation and the response time series, with the peak amplitude of the resulting cross-correlogram reflecting perceptual sensitivity and the peak latency reflecting processing time. We first validated that our novel task produces results that parallel findings from traditional ensemble tasks: the precision of orientation estimates increased when more items were present (p=0.003), and decreased with higher variability of the orientation set (p<0.001). Next, we examined the impact of distractors on tracking performance by adding differently-colored distractor lines. We found lower precision (p=0.001) and a temporal cost of ~100ms (p=0.025) when distractors were present. Together, these results suggest that the presence of distractors in ensemble processing impairs and delays the extraction of relevant feature summaries, and demonstrate the utility of continuous tasks by revealing a temporal cost that may not be captured by traditional reaction time measures.

Talk 7, 4:00 pm, 34.17

Separating rhythms of sensory and motor preparation

Sage E.P. Boettcher¹, Anna-Katharina Bauer², Berit Hartjen³, Sabine Kastner³, Anna C. Nobre⁴; ¹University of Oxford, ²Royal Holloway University of London, ³Princeton University, ⁴Yale University

Covert attention enhances the processing of relevant stimuli within our environment without the need for overt eye movements. Recent work has demonstrated that our covert attentional system rhythmically samples the environment approximately 3 to 8 times per second. Our sensory system must work in tandem with our motor system to produce fluent natural behaviour. That is, once we perceive a task-relevant stimulus, we must execute the appropriate response. Although past work has shown an important role for actions in resetting perceptual sampling, it remains unclear to what extent motor preparation is itself rhythmically modulated. To investigate whether motor preparation follows a similar rhythmic sampling as found in perception, we designed a task that orthogonalized sensory and motor preparation. Compound cues indicated both the most likely location of an upcoming target stimulus (left or right visual field) and the most likely motor response (left or right button press). Both sensory and motor predictions of cues were valid in a majority of trials. However, in a minority of trials, predictions could be invalid in only the sensory domain, only the motor domain, or both domains with equal likelihood. The interval between the cue and target varied between 300 and 1100 ms. This manipulation allowed us to interrogate the effects of valid sensory vs. motor cues orthogonally time. Consistent with previous work we found that sensory cues modulated behaviour in a range between 3 and 8 Hz. In contrast, interestingly, motor preparation showed little evidence of rhythmic modulation.

Acknowledgements: Support by Wellcome Trust Award (104571/Z/14/Z) and JSMF Award (220020448) to A.C.N. As well as an EPS Postdoctoral fellowship awarded to S.E.P.B. The WIN centre is supported by the Wellcome Trust (203139/Z/16/Z). The work is supported by the NIHR Oxford Health Biomedical Research Centre.