Valence versus motivation: The different impact of emotion on space- and object-based attention.

Numerous studies have indicated that both the broaden-and-build model and the motivational dimensional model emphasize the impact of emotion on spatial attention by altering the attentional scope. However, no prior research has investigated the impact of emotional valence and motivational intensity on spatial attention within the same paradigm. Furthermore, object-based attention, characterized by distinct neural mechanisms from space-based attention and also susceptible to attentional scope, represents a major pattern of selective attention. Nevertheless, it is still unclear whether and how emotional valence and motivation play a role in object-based attentional selection. Therefore, the present study aimed to explore these areas. Using a two-rectangle paradigm, Experiment 1 found that motivational intensity modulated space-based effects, whereas emotional valence modulated object-based effects. Experiment 2 used a traditional spatial cueing paradigm to further study the stability of modulating effect of motivation intensity on space-based attention, yielding results consistent with those of Experiment 1. The present study indicated that the broaden-and-build model and motivational dimensional model were not either one or the other, but both played a role in object- and space-based attention. This study provides crucial empirical evidence for theoretical complementation and integration of emotional attention.

Context matters: The interactive effect of introvert-extrovert personality traits and object valence on object-based attention.

Previous research has independently investigated the impact of individual personality traits and object valence on different patterns of attentional selection. However, the interactive role of individual personality traits and object valence in different patterns of attentional selection in both same and different emotional contexts remains unclear. To address the above issues, the present research used a variant of the two-rectangle paradigm, preselected individuals as introverts and extroverts, and simultaneously presented two faces with same or different emotions. Accordance to the result, in the same emotional context, personality traits and object valence did not interact to modulate both space-based effect (SBE) and object-based effect (OBE). However, in the different emotional context, personality traits and object valence interacted to modulate OBE. Specifically, for the extroverts, OBE existed no difference among negative, neutral and positive conditions. In contrast, for the introverts, the OBE was larger in the negative condition compared to those in the positive and neutral conditions. This research provides the first evidence suggesting that object-based attention can be impacted by the interaction between individual characteristics and object properties, and further proposes a preliminary framework called "context-dependent attentional selection hypothesis."

The Impact of Reward Object on Object-Based Attention.

Reward has been shown to influence selective attention, yet previous research has primarily focused on rewards associated with specific locations or features, with limited investigation into the impact of a reward object on object-based attention (OBA). Therefore, it remains unclear whether objects previously associated with rewards affect OBA. To address this issue, we conducted two experiments using a paradigm that combined a reward training phase with a modified two-rectangle paradigm. The results indicate that a reward object modulates both space-based attention (SBA) and OBA. When cues appear on a reward object, the effects of both SBA and OBA are amplified compared to when cues appear on a no-reward object. This finding supports the value-driven attentional capture (VDAC) theory, which suggests that a reward object gain enhanced saliency to capture attention, thereby providing a theoretical support for the treatment of conditions such as drug addiction.

Allocation of Space-Based Attention is Guided by Efficient Comprehension of Spatial Direction.

Spatial navigation is supported by visual cues (e.g., scenes, schemas like arrows, and words) that must be comprehended quickly to facilitate effective transit. People comprehend spatial directions faster from schemas and words than scenes. We hypothesize that this occurs because schemas and words efficiently engage space-based attention, allowing for less costly computations. Here, participants completed a spatial cueing paradigm, and we calculated cue validity effects - how much faster participants responded to validly than invalidly cued locations - for each cue format. We pre-registered Experiment 1 and found significant cue validity effects with schemas and words, but not scenes, suggesting space-based attention was allocated more efficiently with schemas and words than scenes. In Experiment 2, we explicitly instructed participants to interpret the scenes from an egocentric perspective and found that this instruction manipulation still did not result in a significant cue validity effect with scenes. In Experiment 3, we investigated whether the differential effects between conditions were due to costly computations to extract spatial direction and found that increasing cue duration had no influence. In Experiment 4, significant cue validity effects were observed for orthogonal but not non-orthogonal spatial directions, suggesting space-based attention was allocated more efficiently when the spatial direction precisely matched the target location. These findings confirm our hypothesis that efficient allocation of space-based attention is guided by faster spatial direction comprehension. Altogether, this work suggests that schemas and words may be more effective supports than scenes for navigation performance in the real-world.

The space paradox in graphic representation.

The negative space drawing technique refers to drawing the transparent space around and between objects, rather than drawing the objects themselves. This space-based instruction is thought to attenuate object-specific visual attention and to enhance perception of a spatial expanse. Developmentally, it is equivalent to the Piagetian dichotomic space concept of filled and empty space. A sample of 96 children from 5 to 12 years of age and 24 adults (N = 120) drew on a computer tablet a real-life model spacebox placed in front of the participant, with three cubes placed inside the model. Children followed two instructions, a Visual Realism (VR) Instruction "Please draw the three cubes and the box as you can see them" and a Negative Space (NSp) Instruction "Please draw the space around the objects," with the sequence counterbalanced. NSp outline drawings began to show from 9 years onwards. A positive effect of the NSp technique showed for occlusion drawing because of the depiction of common contour of objects which could create a cohesive scene feature such as a horizon. The VR instruction focused attention toward the space box and enhanced 3D drawing of both the spacebox and the cubes. Thus, it could be concluded-rather paradoxically-that drawing in 3D is better based on object- than on space-based attention, while drawing occlusion is better based on space-based than object-based attention. We suggest, however, that a better definition of VR as attention to object appearances is that VR unifies objects and spatial context into one global plane.

Automatic object-based spatial selection depends on the distribution of sustained attention.

Several space-based and object-based attention studies suggest these selection mechanisms may be voluntarily deployed, depending on task parameters and the attentional scope of the observer. Here, we sought to elucidate factors related to involuntary deployment of object-mediated space-based attention through two experiments. Experiment 1 used a modified flanker task where a target and nearby distractor were presented within the same or different object frames, such that an object-based attentional spread should be detrimental to performance. Results showed the presence of a flanker effect with no significant difference in magnitude between grouping conditions, indicating participants may have uniformly used a diffused attentional spotlight regardless of object segmentation. In a second experiment, we manipulated the extent of the observer's sustained attentional scope via an inducer task to determine whether object-based selection depends on the initial spotlight size. The results revealed object-based effects solely when attention narrowly encompassed the target, but not when it was widened to include the distracting flanker. This suggests the deployment of object-based attention may occur when spatial attention is initially focused narrowly. Because selecting the whole object frame directly interfered with task goals, we conclude that object-based attention may not always fully conform to relevant task goals or operate in a goal-oriented manner. We discuss these results in the context of existing literature while proposing a reconciliation of previously inconsistent findings of object-based selection.

The modulation of object-based attentional selection by facial expressions.

Human beings can show preferentially attentional bias to different facial expressions. However, it is unclear whether the modulation of selective attention by facial expressions is based on the face itself (object-based attention) or its location (space-based attention). This study aimed to test this problem by using faces with different emotional valences in the two-rectangle paradigm across three experiments. We found that there was no significant difference in space-based effect among the positive, neutral, and negative conditions. However, the object-based effect was larger for the negative condition than for the neutral and positive ones, because of its slower reaction times for the invalid different-object trials. The results indicated that the object-based attentional selection was modulated by facial expressions, and that faces expressing negative emotions hamper the disengagement of attention from the whole object (i.e., the face), instead of the certain location. Our study can further add support to the attentional prioritisation hypothesis over attentional spreading hypothesis.

Phasic pupillary responses modulate object-based attentional prioritization.

Visual attention studies have demonstrated that the shape of space-based selection can be governed by salient object contours: when a portion of an enclosed space is cued, the selected region extends to the full enclosure. Although this form of object-based attention (OBA) is well established, one continuing investigation focuses on whether this selection is obligatory or under voluntary control. We attempt to dissociate between these alternatives by interrogating the locus coeruleus-norepinephrine (LC-NE) system - known to fluctuate with top-down attention - during a classic two-rectangle paradigm in a sample of healthy human participants (N = 36). An endogenous spatial pre-cue directed voluntary space-based attention (SBA) to one end of a rectangular frame. We manipulated the reliability of the cue, such that targets appearing at an uncued location within the frame occurred at low or moderate frequencies. Phasic pupillary responses time-locked to the cue display served to noninvasively measure LC-NE activity, reflecting top-down processing of the spatial cue. If OBA is controlled analogously to SBA, then object selection should emerge only when it is behaviorally expedient and when LC-NE activity reflects a high degree of top-down attention to the cue display. Our results bore this out. Thus, we conclude that OBA was voluntarily controlled, and furthermore show that phasic norepinephrine may modulate attentional strategy.

Single stimulus location for two inputs: A combined brain-computer interface based on Steady-State Visual Evoked Potential (SSVEP).

Brain-computer interfaces (BCI) help severely paralyzed people communicate with the outside world. One type of BCI depends on eye movements and has high information transfer (ITR) but is tiring for users and not applicable to people with eye dyskinesia. Conversely, independent BCIs enable attention shifts across visual stimuli without eye movement, but at the cost of a lower ITR. Steady-state visual evoked potential (SSVEP) is an oscillatory brain response and typically used as BCI signal sources because of high signal-to-noise ratio (SNR). Considering the effect of attentional modulation on the SSVEP, we proposed the novel concept of one-to-two BCI to optimize existing problems, wherein the target and other stimuli shared the same location. Specifically, two spatially overlapping stimuli were displayed in the center-of-view field, as in the independent BCI, and participants were required to divide their attention between the right and left visual fields, as in the dependent BCI. Using three different design schemes in two experiments, we aimed to provide a new framework for BCI design by exploring the feasibility of a combined BCI that can realize a single stimulus location for two inputs. The results strongly demonstrated that, even when the targets and distractors overlapped spatially, the former evoked stronger SSVEP responses. Notably, the BCI scheme based on the object-based attention could achieve a recognition rate as high as 83.2% and an ITR of 12.5 bits per minute. The feasibility of a one-to-two BCI design, which simplified the keyboard layout, reduced the attention shift, and relieved user fatigue, was established.

Target frequency modulates object-based attention.

Decades of research have provided evidence that object representations contribute to attentional selection. However, most evidence for object-based attentional allocation is drawn from studies employing the two-rectangle paradigm where the target distribution is biased towards the cued object. It is thus unclear whether object-based attentional selection is from object representations or a consequence of spatial attention based on statistical imbalances. Here, we investigate the extent to which target frequency modulates object-based attention by systematically manipulating the frequency of target appearance in a particular spatial location within objects to equate spatial allocation, bias specific spatial locations, or bias objects. In four experiments, participants were presented with a variant of the two-rectangle paradigm in which one end of a rectangle was cued and performed a target discrimination task. Critically, the target location probabilities were parametrically manipulated. The target could appear equally in all ends within the objects (valid, invalid within-object, invalid between-object, diagonal) (Experiment 1) or with overall equality between objects but biased towards the invalid locations (Experiment 2). The target could also appear in three locations (valid, invalid within-object, invalid between-object) distributed equally between objects but biased towards the invalid between-object location (Experiment 3) or with an overall bias towards the invalid between-object location (Experiment 4). We observed that while objects bias attention, spatial biases are prioritized over object representations. Combined results suggest that object-based contribution to attentional guidance is the result of both spatial probabilities and object representations.

Wholist-analytic cognitive styles modulate object-based attentional selection.

Previous studies have shown that individual difference plays an important role in the object-based cueing effect observed in experiments on attentional selection. A wide range of studies have also used the theory of cognitive style to explain individual strategies in most cognitive processes. However, the characteristics of individuals that modulate object-based attentional selection are still unclear. To investigate the modulation of object-based attention by cognitive style, this study used a classic two-rectangle paradigm and compared space-based effects and object-based effects for individuals who had been preselected as wholists or analysts in terms of cognitive style. The results revealed that a space-based effect was obtained for both wholist and analytic individuals. However, an object-based effect was obtained only for analysts and not wholists, regardless of object orientation. The results further indicated that a wholist versus analytic cognitive style can modulate object-based attention by way of perceptual grouping. Our study provides the first evidence that object-based attention can indeed be influenced by individual characteristics and extends traditional model of cognitive style by indicating that wholist individuals tend to group two or more objects in a scene into one larger gestalt.

Increased overt attention to objects in early deaf adults: An eye-tracking study of complex naturalistic scenes.

The study of selective attention in people with profound deafness has repeatedly documented enhanced attention to the peripheral regions of the visual field compared to hearing controls. This finding emerged from covert attention studies (i.e., without eye-movements) involving extremely simplified visual scenes and comprising few visual items. In this study, we aimed to test whether this key finding extends also to overt attention, using a more ecologically valid experimental context in which complex naturalistic images were presented for 3 s. In Experiment 1 (N = 35), all images contained a single central object superimposed on a congruent naturalistic background (e.g., a tiger in the woods). At the end of the visual exploration phase, an incidental memory task probed the participants' recollection of the seen central objects and image backgrounds. Results showed that hearing controls explored and remembered the image backgrounds more than deaf participants, who lingered on the central object to a greater extent. In Experiment 2 we aimed to disentangle if this behaviour of deaf participants reflected a bias in overt space-based attention towards the centre of the image, or instead, enhanced object-centred attention. We tested new participants (N = 42) in the visual exploration task adding images with lateralized objects, as well as images with multiple object or images without any object. Results confirmed increased exploration of objects in deaf participants. Taken together our novel findings show limitations of the well-known peripheral attention bias of deaf people and suggest that visual object-centred attention may also change after prolonged auditory deprivation.

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.

Object-based biased competition during covert spatial orienting.

Biased-competition models assert that spatial attention facilitates visual perception by biasing competitive interactions in favor of relevant input. In line with this view, past work has shown that the benefits of covert spatial attention are greatest when targets must compete with interfering stimuli. Here we propose a boundary condition for the resolution of interference via exogenous attention: Attention resolves visual interference between targets and distractors, but only when they can be individuated into distinct representations. Thus, we propose that biased competition may be object-based. We replicated previous observations of larger attention effects when targets were flanked by irrelevant distractors (interference-present displays) than when targets were presented alone (interference-absent displays). Critically, we then showed that this amplification of cueing effects in the presence of interference is eliminated when strong crowding hampers individuation of the targets and distractors. Likewise, when targets were embedded within a noise mask that did not evoke the percept of an individuated distractor, the attention effects were equivalent across noise and lone-target displays. Thus, we conclude that exogenous spatial attention resolves interference in an object-based fashion that depends on the perception of individuated targets and distractors.

Precues' elevation of sensitivity is not only preattentive, but largely monocular.

Visual sensitivity can be heightened in the vicinity of an appropriate precue. Experiments with multiple, noninformative precues suggest that this facilitation should not be attributed to focal attention. The number of simultaneously appearing precues seems to be irrelevant; contrast thresholds are lowest for targets that appear in a precued position. Here we report that precues become less effective when they and the target are delivered to different eyes. We conclude that the mechanism responsible for such heightened sensitivity has largely monocular input.

Feature integration in basic detection and localization tasks: Insights from the attentional orienting literature.

Once presumed to be intimately related, feature integration and the consequences of attentional orienting are now often studied separately. Yet the paradigms used to study each can be highly similar; participants respond to a stimulus, which is then followed by a second stimulus, matching or mismatching the first on some feature(s). Given the similarities between the methods, it seems likely that these fields each could gain insights regarding their own work by looking at the other. Here we note a peculiarity of feature integration research: It relies on paradigms that require or encourage participants to identify the nonspatial features of a stimulus in order to make the correct response. This leaves open the question of whether feature integration effects can be found in tasks that do not require stimulus identity (e.g., color or shape) processing. To answer this question, we reviewed attentional orienting studies that manipulated whether stimulus identity repeated but that required only detection or localization responses, irrespective of stimulus identity. With one exception, feature integration effects were absent from those experiments. Furthermore, we attempted to replicate the exception and found no feature integration effects. Our review shows that detection and localization paradigms are particularly useful for studying the consequences of attentional orienting in the absence of integration effects, and that these same tasks provide a baseline to understand the sources of feature integration effects with only slightly variations in the basic task.

Spatial attention is necessary for object-based attention: Evidence from temporal-order judgments.

Attentional selection is a dynamic process that relies on multiple types of representations. That object representations contribute to attentional selection has been known for decades; however, most evidence for this contribution has been gleaned from studies that have relied on various forms of spatial cueing (some endogenous and some exogenous). It has thus remained unclear whether object-based attentional selection is a direct result of spatial cuing, or whether it still emerges without any spatial marker. Here we used a novel method-the temporal-order judgment (TOJ)-to examine whether object-based guidance emerges in the absence of spatial cuing. Participants were presented with two rectangles oriented either horizontally or vertically. Following a 150-ms preview time, two target stimuli were presented on the same or on different objects, and participants were asked to report which of the two stimuli had appeared first. The targets consisted of stimuli that formed a percept of a "hole" or a "hill." First, we demonstrated that the "hill" target was indeed processed faster, as evidenced by a positive perceived simultaneity (PSS) measure. We then demonstrated that if two targets appeared with equal probabilities on the same and on different objects, the PSS values, although positive, were not modulated by the objects. In a subsequent set of experiments, we showed that objects can modulate attentional allocation-however, only when they are biased by a spatial (endogenous) cue. In other words, in the absence of a spatial cue or bias, object representations do not guide attentional selection. In addition to providing new constraints for theories of object-based attentional guidance, these experiments introduce a novel paradigm for measuring object-based attentional effects.

Target-object integration, attention distribution, and object orientation interactively modulate object-based selection.

The representational basis of attentional selection can be object-based. Various studies have suggested, however, that object-based selection is less robust than spatial selection across experimental paradigms. We sought to examine the manner by which the following factors might explain this variation: Target-Object Integration (targets 'on' vs. part 'of' an object), Attention Distribution (narrow vs. wide), and Object Orientation (horizontal vs. vertical). In Experiment 1, participants discriminated between two targets presented 'on' an object in one session, or presented as a change 'of' an object in another session. There was no spatial cue-thus, attention was initially focused widely-and the objects were horizontal or vertical. We found evidence of object-based selection only when targets constituted a change 'of' an object. Additionally, object orientation modulated the sign of object-based selection: We observed a same-object advantage for horizontal objects, but a same-object cost for vertical objects. In Experiment 2, an informative cue preceded a single target presented 'on' an object or as a change 'of' an object (thus, attention was initially focused narrowly). Unlike in Experiment 1, we found evidence of object-based selection independent of target-object integration. We again found that the sign of selection was modulated by the objects' orientation. This result may reflect a meridian effect, which emerged due to anisotropies in the cortical representations when attention is oriented endogenously. Experiment 3 revealed that object orientation did not modulate object-based selection when attention was oriented exogenously. Our findings suggest that target-object integration, attention distribution, and object orientation modulate object-based selection, but only in combination.

Object-based selection is contingent on attentional control settings.

The visual system allocates attention in object-based and location-based modes. However, the question of when attention selects objects and when it selects locations remains poorly understood. In this article, we present variations on two classic paradigms from the object-based attention literature, in which object-based effects are observed only when the object feature matches the task goal of the observer. In Experiment 1, covert orienting was influenced by task-irrelevant rectangles, but only when the target color matched the rectangle color. In Experiment 2, the region of attentional focus was adjusted to the size of task-irrelevant objects, but only when the target color matched the object color. In Experiment 3, we ruled out the possibility that contingent object-based selection is caused by color-based intratrial priming. These demonstrations of contingent object-based attention suggest that object-based selection is neither mandatory nor default, and that object-based effects are contingent on simple, top-down attentional control settings.