Attentional Repulsion Research Articles

Investigating mechanisms of the attentional repulsion effect: A diffusion model analysis.

This article investigates the decisional and attentional drivers of the attentional repulsion effect (ARE) using the diffusion decision model (DDM). The ARE is a phenomenon in which a subjective expansion of space is experienced outside the focus of attention. It is thought to occur due to changes in the functioning of visual cell receptive fields. The DDM is a model of the decision-making process that assumes responses are selected by sequentially sampling an encoded representation of a stimulus until sufficient evidence has been accumulated favoring one response alternative over the other. The model decomposes observed choice and response times into different latent variables corresponding to the rate of evidence accumulation, response caution, response bias, and the time course of stimulus encoding and response execution. In this article, we interpret changes in the rate of evidence accumulation as primarily reflecting perceptual-driven changes in stimulus representation. We interpret changes in response bias as primarily reflecting decision-level changes. We utilize the DDM's ability to estimate these variables independently to explore how they are each affected by cueing manipulations to clarify whether the ARE emerges due to attentional or decisional drivers, or some combination of the two. The results of this study could shed light on the mechanisms underlying the ARE, and has implications in our understanding of spatial attention.

The size of attentional focus modulates the perception of object location

The present study examined how the size of attended area affects the repulsion of perceived object location from the focus of attention reported previously (attentional repulsion effect). We induced sustained changes in the size of attentional focus and tested the impact of this experimental variation on the perception of object location. The results of three experiments revealed reliable repulsion effects for each size of attentional focus. However, the magnitude of the effect decreased substantially with an increase in focus size. This outcome extends the knowledge about how spatial attention affects visual perception.

Endogenous shifts of attention cause distortions in the perception of space: Reviewing and examining the attentional repulsion effect

ABSTRACT The functioning of spatial attention and its effects on visual processing are typically studied using chronometric and accuracy measures of behaviour. However, a growing body of literature has studied the attentional repulsion effect (ARE). Simply put, when attention is focused on one location in the visual field, stimuli appearing nearby the attended location are perceived as being located further away from the attended location than they physically are. The ARE is particularly compelling, as it is best explained by considering the receptive field properties of visual cells, thus allowing for more direct comparisons between behaviour and neural functioning. Nonetheless, most research testing the ARE has manipulated spatial attention exogenously. Furthermore, for studies that have explored endogenous attention and the ARE, empirical evidence is conflicting. Therefore, the aim of the current study was to address this inconsistency by testing the effect of voluntary attention on spatial repulsion using an optimal operationalization of endogenous attention. Centrally presented, highly informative double-cues were used to shift attention, and placeholders were included in the display to help anchor attention. Overall, we observed strong spatial repulsion effects when attention was shifted endogenously, providing compelling evidence that voluntary deployments of attention can cause perceptual distortions of space.

Microsaccade dynamics in the attentional repulsion effect

A briefly flashed peripheral cue has been shown to repulse the perceived position of a subsequently presented foveal probe - a bias called the Attentional Repulsion Effect (ARE). While this bias has originally been assumed to reflect attentional capturing by the cue, its attentional nature has recently been questioned. To investigate the ARE’s attentional properties, we recorded microsaccades as an attentional marker in the ARE paradigm. Microsaccades, small fixational eye movements performed during fixation, have previously been described to reflect the dynamics of spatial attention deployment. Our results favor an attentional explanation for the ARE: In trials in which an ARE was found, microsaccades were directed more often toward the cue, presumably reflecting the covert shift of attention. In contrast, more cue-incongruent microsaccades were observed in trials in which no ARE was found. Therefore, both repulsion as well as measured microsaccade modulations, are most likely an outcome of the preceding shifts of covert attention.

Attentional repulsion effects produced by feature-guided shifts of attention.

Attention shifts to particular objects in the visual field can distort perceptual location judgments. Visual stimuli are perceived to be shifted away from the current focus of attention (the attentional repulsion effect [ARE]). Although links between repulsion effects and stimulus-driven exogenous attentional capture have been demonstrated conclusively, it remains disputed whether AREs can also be elicited as a result of feature-guided attention shifts that are controlled by endogenous task sets. Here we demonstrate that this is indeed the case. Color singleton cues that appeared together with equiluminant gray items triggered repulsion effects only if they matched a current task-relevant color but not when their color was irrelevant. When target-color and nontarget-color singleton cues appeared in the same display, AREs emerged relative to the position of the target-color cue. By obtaining independent behavioral measures of perceptual repulsion and electrophysiological measures of attentional capture by target-color cues, we also showed that these two phenomena are correlated. Individuals who were more susceptible to attentional capture also produced larger AREs. These results confirm the existence of links between task-set contingent attentional capture and AREs. They also provide the first direct demonstration of the attentional nature of these effects with online brain activity measures: perceptual repulsion arises as the result of prior feature-guided attention shifts to specific locations in the visual field.

Vertical and horizontal meridian modulations suggest areas with quadrantic representations as neural locus of the attentional repulsion effect.

The attentional repulsion effect (ARE) is a perceptual bias attributed to a covert shift of attention toward a peripheral cue, which, in turn, repulses the perceived position of a subsequently presented probe (Suzuki & Cavanagh, 1997). So far, probes were mainly presented around the vertical meridian. Other studies of perceptual biases reported disruptions when stimuli were presented across the vertical meridian. These disruptions were explained by separate representations of the left and right visual hemifields, projecting to opposite anatomical hemispheres. As the ARE is typically examined through two-alternative, forced-choice tasks in which the estimation of the probe's position is based on the cue's effectiveness to repulse the probe across the vertical meridian, no such asymmetry has been reported. To test for similar meridian disruptions in the ARE, we collected absolute estimations (computer mouse responses) of the perceived probe positions (Experiment 1a). As absolute estimations of memorized positions are associated with overestimated distances in reproduction, results had to be compared to a no-cue baseline condition (Experiment 1b). Through this new methodological approach, we found the ARE to be strongest when the attentional capturing cue and the subsequently presented probe were displayed in the same hemifield (Experiment 2a). In a further experiment (Experiment 2b), we observed that the ARE is not only disrupted at the vertical, but also at the horizontal meridian. These disruptions at both meridians suggest the involvement of visual neural areas with quadrantic representations, such as V2 and/or V3 in the generation of the ARE.

Examining the Role of Attention and Sensory Stimulation in the Attentional Repulsion Effect.

It has been suggested that visual attention warps space, such that stimuli appearing near its locus are perceived as farther away than they actually are. This is known as the attentional repulsion effect (ARE). Recent data challenge the role of attention as the sole factor responsible for the ARE, suggesting instead that the ARE is, at least in part, a product of low level sensory interactions between a peripheral orienting cue and the Vernier target stimulus used to measure the effect. Here, we directly test whether attentional orienting, without a cue in peripheral vision to guide attention, is sufficient for generating an ARE. In Experiment 1, attention was guided to the visual periphery by a central symbolic cue that reliably indicated the locations of to-be-identified targets in peripheral vision. On a subset of trials, we probed for an ARE with Vernier targets. Reaction time (RT) data revealed that the cue guided attention but there was no trace of an ARE. In Experiment 2, we ensured that the Vernier targets were sensitive to the ARE by using the standard spatially uninformative peripheral cue to guide attention instead of the central symbolic cue. RT data again revealed that the cue guided attention, while the Vernier targets revealed an ARE. Collectively, these data suggest that attentional orienting without peripheral sensory stimulation is not sufficient for generating an ARE.

The attentional repulsion effect and relative size judgments.

Rapid shifts of involuntary attention have been shown to induce mislocalizations of nearby objects. One pattern of mislocalization, termed the Attentional Repulsion Effect (ARE), occurs when the onset of peripheral pre-cues lead to perceived shifts of subsequently presented stimuli away from the cued location. While the standard ARE configuration utilizes vernier lines, to date, all previous ARE studies have only assessed distortions along one direction and tested one spatial dimension (i.e., position or shape). The present study assessed the magnitude of the ARE using a novel stimulus configuration. Across three experiments participants judged which of two rectangles on the left or right side of the display appeared wider or taller. Pre-cues were used in Experiments 1 and 2. Results show equivalent perceived expansions in the width and height of the pre-cued rectangle in addition to baseline asymmetries in left/right relative size under no-cue conditions. Altering cue locations led to shifts in the perceived location of the same rectangles, demonstrating distortions in perceived shape and location using the same stimuli and cues. Experiment 3 demonstrates that rectangles are perceived as larger in the periphery compared to fixation, suggesting that eye movements cannot account for results from Experiments 1 and 2. The results support the hypothesis that the ARE reflects a localized, symmetrical warping of visual space that impacts multiple aspects of spatial and object perception.

Attentional Repulsion Effect: the influence of response mode and microsaccades

Attentional Repulsion Effect: the influence of response mode and microsaccades

Near complete interocular transfer of the attentional repulsion effect

During a brief period following attention capture by an abrupt-onset cue, a briefly presented item in the vicinity appears to be displaced away from the focus of attention. This effect, termed the attentional repulsion effect (ARE), can be induced with various ways of focusing attention (e.g., color pop-out, an auditory cue, voluntary focusing), and can be measured in various ways (e.g., as a vernier offset, shape deformation, action error). While most prior results on ARE have confirmed its close relationship with attention mechanisms, DiGiacomo and Pratt Vision Research 64 (2012) 35–41 reported no interocular transfer of ARE, placing ARE’s operational locus at the level of monocular processing in V1 and/or LGN. DiGiacomo's and Pratt’s result is surprising because even local pattern adaptation effects thought to be mediated by V1 show 50%–80% of interocular transfer. How could it be that a strongly attention-dependent effect is exclusively mediated by monocular processes? It was thus important to replicate DiGiacomo’s and Pratt’s surprising results using a transient-free mirror-based stereoscope and a broader method where ARE was measured with both vertical and horizontal vernier offsets. Our results demonstrate a nearly complete interocular transfer of ARE, with stronger ARE obtained with horizontal than with vertical verniers, implying that ARE may be hemifield dependent. We speculate that the null ARE result reported by DiGiacomo and Pratt in their dichoptic condition may be due to a statistical anomaly or to a potential visual artifact generated by the eye shutters that were used to present dichoptic stimuli.

On spatial attention and its field size on the repulsion effect.

We investigated the attentional repulsion effect—stimuli appear displaced further away from attended locations—in three experiments: one with exogenous (involuntary) attention, and two with endogenous (voluntary) attention with different attention-field sizes. It has been proposed that differences in attention-field size can account for qualitative differences in neural responses elicited by attended stimuli. We used psychophysical comparative judgments and manipulated either exogenous attention via peripheral cues or endogenous attention via central cues and a demanding rapid serial visual presentation task. We manipulated the attention field size of endogenous attention by presenting streams of letters at two specific locations or at two of many possible locations during each block. We found a robust attentional repulsion effect in all three experiments: with endogenous and exogenous attention and with both attention-field sizes. These findings advance our understanding of the influence of spatial attention on the perception of visual space and help relate this repulsion effect to possible neurophysiological correlates.

Examining the locus of the attentional attraction effect.

Our spatial perception is not always veridical. Indeed, systematic distortions in localization have been found to result from orienting of attention. Distorted localization is inferred from tasks wherein the subject reports the location of centrally presented parallel (vernier) line stimuli. Particularly, prior to the presentation of the lines, a shift of attention toward peripheral cues produces a mislocalization of the line stimuli away from the cues (termed the attentional repulsion effect [ARE]). However, if the shift of attention is induced after target presentation, by reversing the order of stimulus presentation, a substantial mislocalization toward the cues (attentional attraction effect [AAE]) is found. The purpose of this study was to identify whether the AAE arises from the modulation in the same processes as the ARE. While an interocular presentation of cues to one eye and vernier lines to the other was previously shown to eliminate the ARE, the AAE persists across both the interocular and monocular conditions (both the cues and vernier lines are presented to the same eye). Considering Ono and Watanabe's (2011) suggestion that memory traces may be involved in generating the AAE, this prospect was examined by having participants delay their response for a short (100 ms) or long (1,000 ms) period of time. The magnitude of AAE was larger with a longer delay, consistent with the involvement of visual memory. Next, to directly examine the role of spatial working memory, the attentional attraction task was embedded within either a spatial memory task (remembering the locations of one or three squares) or a color memory task (remembering the color of one or three squares). Only high spatial memory load reduced the magnitude of AAE. Our results suggest the AAE relies on changes to different visual processes than does the ARE and involves spatial working memory.

Examining the Locus of the Attentional Attraction Effect

Our spatial perception is not always veridical. Indeed, systematic distortions in localization have been found to result from orienting of attention. Distorted localization is inferred from tasks wherein the subject reports the location of centrally presented parallel (vernier) line stimuli. Particularly, prior to the presentation of the lines, a shift of attention toward peripheral cues produces a mislocalization of the line stimuli away from the cues (termed the attentional repulsion effect [ARE]). However, if the shift of attention is induced after target presentation, by reversing the order of stimulus presentation, a substantial mislocalization toward the cues (attentional attraction effect [AAE]) is found. The purpose of this study was to identify whether the AAE arises from the modulation in the same processes as the ARE. While an interocular presentation of cues to one eye and vernier lines to the other was previously shown to eliminate the ARE, the AAE persists across both the interocular and monocular conditions (both the cues and vernier lines are presented to the same eye). Considering Ono and Watanabe’s (2011) suggestion that memory traces may be involved in generating the AAE, this prospect was examined by having participants delay their response for a short (100 ms) or long (1,000 ms) period of time. The magnitude of AAE was larger with a longer delay, consistent with the involvement of visual memory. Next, to directly examine the role of spatial working memory, the attentional attraction task was embedded within either a spatial memory task (remembering the locations of one or three squares) or a color memory task (remembering the color of one or three squares). Only high spatial memory load reduced the magnitude of AAE. Our results suggest the AAE relies on changes to different visual processes than does the ARE and involves spatial working memory.

Depth Modulation of Attentional Repulsion and Attraction Effects

Depth Modulation of Attentional Repulsion and Attraction Effects

Examining the Locus of the Attentional Attraction Effect

The orienting of attention is known to distort regions of visual space. For example, a shift of attention towards peripheral cues causes the mislocalization of central vernier line targets away from the focus of attention (the attentional repulsion effect). However, by reversing the order of presentation of the vernier lines and cues, a substantial attraction effect is found (i.e., the vernier lines are now mislocalized toward the attended peripheral locations). The purpose of this study was to identify the locus of this attentional attraction effect. Participants were asked to judge the location of the top vernier line relative to the bottom line, with any attraction effect being computed as the tendency to perceive the top line as closer to the location of the cue. Unlike the repulsion effect, the attraction effect was found in an interocular display condition in which the vernier lines were presented to one eye and the peripheral cues were presented to the other eye, using LCD goggles. This result suggests that the attentional attraction effect is a higher order process as compared to the repulsion effect, and likely requires visual short term memory. To test this, we inserted either a spatial memory load task (remembering the locations of one or three squares) or color memory load task (remembering the colors of one or three squares) before the attentional attraction effect task (i.e., vernier line targets followed by peripheral cues). The results showed that occupying spatial memory reduced the magnitude of the attraction effect while the color memory load had no effect. Overall, these results indicate that the attentional attraction effect is quite different from the attentional repulsion effect, as it involves higher order visual processes that require spatial working memory. Meeting abstract presented at VSS 2013

Depth Modulation of the Attentional Repulsion Effect

Shifts of attention can cause mislocalisation of visual objects. Abriefcue that attracts attention can cause a shift in the perceived location of a subsequently presented visual object--specifically, moving it away from the focus of attention (attentional repulsion). In the present study we investigated whether depth would influence the magnitude of attentional repulsion by presenting peripheral visual cues in different depth planes from the target or fixation. In experiment 1 the results showed that the magnitude of the attentional repulsion was larger when the cue was presented at the depth plane farther away from the target and fixation. In experiment 2 we presented the fixation point in the same depth plane as the nearest cues and found larger repulsion effects when the cues were presented in depth planes farther away from the fixation. In experiment 3 no depth modulation was observed when the fixation was presented in the same depth plane with the farthest cues. Taken together, when the cues were presented in the depth plane farther away from the fixation, the magnitude of the attentional repulsion effect increased. It is speculated that the residual coarser spatial representation in the space farther from the fixation plane or the enhanced attentional process for the space closer than the fixation may be responsible for the larger attentional repulsion effect.

Spatial distortion induced by imperceptible visual stimuli

Previous studies have explored the effects of attention on spatial representation. Specifically, in the attentional repulsion effect, a transient visual cue that captures attention has been shown to alter the perceived position of a target stimulus to the direction away from the cue. The effect is also susceptible to retrospective influence, that attention appears to attract the target when the cue appears afterwards. This study examined the necessity of visual awareness of the cue in these phenomena. We found that when the cues were rendered invisible by backward visual masks, both repulsion and attraction effects were weakened but still observed. The results suggest that the effects possibly depend on processes that are not necessarily associated with conscious visual awareness of the cues. We conjecture that attentional shift produced by the weak, invisible cues may play a role in spatial distortion; but other possible accounts including non-attentional ones are also discussed.

Misperceiving space following shifts of attention: Determining the locus of the attentional repulsion effect

The Attentional Repulsion Effect (ARE) is a spatial consequence of allocating attention to peripheral locations. Specifically, a shift in attention to the periphery produces an error in the localization of visual objects in the opposite direction of the shift. Suzuki and Cavanagh proposed three possible mechanisms to account for the neural basis of the repulsion effect; surround suppression, RF shrinking, and RF recruitment. The purpose of the present experiment was to begin to investigate the ARE mechanism by determining its locus. This was achieved by assessing both monocular and binocular vision, and then by examining AREs in a condition that assesses interocular transfer, where the cue is only presented to one eye and the target is only presented to the other eye. Importantly, this latter test allowed for a direct verification of the ARE’s locus. Given that the magnitude of the repulsion effect was nearly identical in the two vision conditions, and that the effect disappeared in the interocular condition, the current findings indicate that the ARE occurs early in visual processing, prior to or in the input layers of V1 and before binocular vision dominates.

Attentional repulsion effect despite a colour-based control set

A salient distractor can have a twofold effect on concurrent visual processes; it can both reduce the processing efficiency of the relevant target (e.g., increasing response time) and distort the spatial representation of the display (e.g., misperception of a target location). Previous work has shown that knowledge of the key feature of visual targets can eliminate the effect of salient distractors on processing efficiency. For instance, knowing that the target of interest is red (i.e., having an attentional control set for red) can eliminate the cost of green distractors on the speed of response to the target. The present study shows that the second mark of irrelevant salient distractors, i.e., distortions in spatial representation, is resistant to such top-down control. Using the attentional repulsion effect, we examined the influence of salient distractors on target localization. Observers had a colour-based control set and the distractors either matched or mismatched with the control set. In the first two experiments, we found systematic mislocalization of targets away from the peripheral distractors (i.e., an attentional repulsion effect). Critically, the effect was caused by distractors that both matched and mismatched the control set. A third experiment, using the same stimuli, found that processing efficiency was perfectly resistant to distractors that did not match the control set, consistent with previous work. Together, the present findings suggest that although top-down control can eliminate the cost of a salient distractor on processing efficiency, it does so without eliminating the distractor's influence on the spatial representation of the display.

Mislocalization of Visual Stimuli: Independent Effects of Static and Dynamic Attention

Shifts of visual attention cause systematic distortions of the perceived locations of visual objects around the focus of attention. In the attention repulsion effect, the perceived location of a visual target is shifted away from an attention-attracting cue when the cue is presented before the target. Recently it has been found that, if the visual cue is presented after the target, the perceived location of the target shifts toward the location of the following cue. One unanswered question is whether a single mechanism underlies both attentional repulsion and attraction effects. We presented participants with two disks at diagonal locations as visual cues and two vertical lines as targets. Participants were asked to perform a forced-choice task to judge targets' positions. The present study examined whether the magnitude of the repulsion effect and the attraction effect would differ (Experiment 1), whether the two effects would interact (Experiment 2), and whether the location or the dynamic shift of attentional focus would determine the distortions effects (Experiment 3). The results showed that the effect size of the attraction effect was slightly larger than the repulsion effect and the preceding and following cues have independent influences on the perceived positions. The repulsion effect was caused by the location of attnetion and the attraction effect was due to the dynamic shift of attentional focus, suggesting that the underlying mechanisms for the retrospective attraction effect might be different from those for the repulsion effect.