Object-based Attention Research Articles

The impact of task-irrelevant reward on object-based attentional selection in conflict contexts.

Previous research has demonstrated the influence of task-irrelevant reward on object-based attention in non-conflict contexts. However, it remains unclear whether object-based attention emerged and how task-irrelevant reward guide object-based attention in conflict contexts. Therefore, the present study adopted a variant of two-rectangle paradigm to investigate the impact of task-irrelevant reward on object-based attention in conflict contexts across three experiments. Experiment 1 observed object-based effects when combing the two-rectangle paradigm with the Stroop task. Experiment 2 used color character as target and found object-based effects in the incongruent-unrewarded condition, not in the incongruent-rewarded condition. The difference can be due to faster response in the incongruent-unrewarded condition for invalid same-object trials. Experiment 3 adopted monetary objects as target and observed reversed object-based effects in the incongruent-high-rewarded condition, not in the incongruent-low-rewarded condition. This was due to faster response in the incongruent-low-rewarded condition than in the incongruent-high-rewarded condition for invalid same-object trials. These findings demonstrated that task-irrelevant reward can affect the object-based attention in conflict contexts, and different types of rewards may share a common mechanism in their impact on object-based attention. Ultimately, this study provided further support for the attentional spreading theory.

Spreading and Shifting of Attention: The Role of Object

Object-based attention (OBA) is a selective attention mechanism that suggests that attention selects an object as a processing unit. This mechanism has been widely studied using the double-rectangle paradigm (Egly et al.), with shorter reaction times (RTs) in the within-object than in the between-object conditions as the OBA effect. However, this paradigm could not distinguish whether this OBA effect reflects a within-object benefit or a between-object cost. To address this issue, the present study employed the single-rectangle paradigm to disentangle the processes of spreading and shifting attention within an object, within space, and across an object’s boundary. In Experiments 1 and 2, attention was encouraged to spread by using a two-target comparison task. The results revealed that spreading attention within an object is faster than within space, but the object boundary can impede this spreading. In Experiment 3, a detection task was used to encourage attentional shifts. Results showed that shifting attention across an object boundary incurs a cost, whereas shifting within an object provides no advantage over shifting within space. These findings, largely replicated with briefly disappeared objects, suggest that the OBA effect involves both a within-object benefit and a between-object cost, providing insights into how object influences attentional shifting and spreading.

Invalid Trials Are Not Required to Observe Neural Correlates of Object-based Attention in Retinotopic Visual Cortex.

A central debated question in the study of object-based attention (OBA) is whether attention to the object-mediated deployment of attention is obligatory and automatic [Chen, Z., & Cave, K. R. Reinstating object-based attention under positional certainty: The importance of subjective parsing. Perception & Psychophysics, 68, 992-1003, 2006] or whether the pattern of results is driven by other non-obligatory factors, such as prioritization of invalid target locations [Shomstein, S., & Yantis, S. Object-based attention: Sensory modulation or priority setting? Perception & Psychophysics, 64, 41-51, 2002]. However, virtually all behavioral measures attributed to OBA are based on examining performance on invalid-cue trials, the inclusion of which confounds the assessment of the automaticity hypothesis. Our approach to resolve this issue is to determine whether effects of OBA can be observed in a 100% valid cueing paradigm. In this article, we investigate the obligatory nature of OBA by leveraging the spatial specificity of fMRI and the retinotopic organization of early visual cortex. We aimed to identify potential neural correlates of OBA in the complete absence of invalid trials. Participants perform a version of the classic two-rectangle OBA paradigm while simultaneously measuring changes in BOLD signals arising from retinotopically organized cortical areas V1, V2, and V3. In the first half of the experiment, we used the classic two-rectangle OBA paradigm except that the cue was 100% valid. In the second half, we reduced cue validity to more closely match standard OBA paradigms (runs containing invalid trials). We analyzed BOLD signals arising from our ROIs in V1, V2, and V3 according to their topographic correspondences with the ends of the rectangles in the visual field and compared these. We then compared responses in each ROI according to where the cue had occurred (cued, uncued-same-object, uncued-other-object location). We replicated this procedure in Experiment 2, but changed the layout of the two rectangles from a vertical to a horizontal configuration. Critical result: We observed statistically significant effects of OBA in V3 (Experiment 1) and V1-2 (Experiment 2) in both the 100% valid runs and in runs containing invalid trials. Moreover, the effects of OBA were no smaller in the 100% runs compared with runs containing invalid trials. Conclusion: We see BOLD modulation at the uncued locations consistent with neural correlates of OBA.

A robotics-inspired scanpath model reveals the importance of uncertainty and semantic object cues for gaze guidance in dynamic scenes.

The objects we perceive guide our eye movements when observing real-world dynamic scenes. Yet, gaze shifts and selective attention are critical for perceiving details and refining object boundaries. Object segmentation and gaze behavior are, however, typically treated as two independent processes. Here, we present a computational model that simulates these processes in an interconnected manner and allows for hypothesis-driven investigations of distinct attentional mechanisms. Drawing on an information processing pattern from robotics, we use a Bayesian filter to recursively segment the scene, which also provides an uncertainty estimate for the object boundaries that we use to guide active scene exploration. We demonstrate that this model closely resembles observers' free viewing behavior on a dataset of dynamic real-world scenes, measured by scanpath statistics, including foveation duration and saccade amplitude distributions used for parameter fitting and higher-level statistics not used for fitting. These include how object detections, inspections, and returns are balanced and a delay of returning saccades without an explicit implementation of such temporal inhibition of return. Extensive simulations and ablation studies show that uncertainty promotes balanced exploration and that semantic object cues are crucial to forming the perceptual units used in object-based attention. Moreover, we show how our model's modular design allows for extensions, such as incorporating saccadic momentum or presaccadic attention, to further align its output with human scanpaths.

Attention modulates human visual responses to objects by tuning sharpening

Visual stimuli compete with each other for cortical processing and attention biases this competition in favor of the attended stimulus. How does the relationship between the stimuli affect the strength of this attentional bias? Here, we used functional MRI to explore the effect of target-distractor similarity in neural representation on attentional modulation in the human visual cortex using univariate and multivariate pattern analyses. Using stimuli from four object categories (human bodies, cats, cars, and houses), we investigated attentional effects in the primary visual area V1, the object-selective regions LO and pFs, the body-selective region EBA, and the scene-selective region PPA. We demonstrated that the strength of the attentional bias toward the target is not fixed but decreases with increasing target-distractor similarity. Simulations provided evidence that this result pattern is explained by tuning sharpening rather than an increase in gain. Our findings provide a mechanistic explanation for the behavioral effects of target-distractor similarity on attentional biases and suggest tuning sharpening as the underlying mechanism in object-based attention.

Attention modulates human visual responses to objects by tuning sharpening.

Visual stimuli compete with each other for cortical processing and attention biases this competition in favor of the attended stimulus. How does the relationship between the stimuli affect the strength of this attentional bias? Here, we used functional MRI to explore the effect of target-distractor similarity in neural representation on attentional modulation in the human visual cortex using univariate and multivariate pattern analyses. Using stimuli from four object categories (human bodies, cats, cars, and houses), we investigated attentional effects in the primary visual area V1, the object-selective regions LO and pFs, the body-selective region EBA, and the scene-selective region PPA. We demonstrated that the strength of the attentional bias toward the target is not fixed but decreases with increasing target-distractor similarity. Simulations provided evidence that this result pattern is explained by tuning sharpening rather than an increase in gain. Our findings provide a mechanistic explanation for the behavioral effects of target-distractor similarity on attentional biases and suggest tuning sharpening as the underlying mechanism in object-based attention.

Space- and object-based attention in patients with a single hemisphere following childhood resection.

The neural processes underlying attentional processing are typically lateralized in adults, with spatial attention associated with the right hemisphere (RH) and object-based attention with the left hemisphere (LH). Using a modified two-rectangle attention paradigm, we compared the lateralization profiles of individuals with childhood hemispherectomy (either LH or RH) and age-matched, typically developing controls. Although patients exhibited slower reaction times (RTs) compared to controls, both groups benefited from valid attentional cueing. However, patients experienced significantly higher costs for invalid trials-reflected by larger RT differences between validly and invalidly cued targets. This was true for invalid trials on both cued and uncued objects, probes of object- and space-based attentional processes, respectively. Notably, controls showed no significant RT cost differences between invalidly cued locations on cued versus uncued objects. By contrast, patients exhibited greater RT costs for targets on uncued versus cued objects, suggesting greater difficulty shifting attention across objects. We explore potential explanations for this group difference and the lack of difference between patients with LH or RH resection. These findings enhance our understanding of spatial and object-based attention in typical development and reveal how significant neural injury affects the development of attentional systems in the LH and RH.

An audiovisual cognitive optimization strategy guided by salient object ranking for intelligent visual prothesis systems

Objective.Visual prostheses are effective tools for restoring vision, yet real-world complexities pose ongoing challenges. The progress in AI has led to the emergence of the concept of intelligent visual prosthetics with auditory support, leveraging deep learning to create practical artificial vision perception beyond merely restoring natural sight for the blind.Approach.This study introduces an object-based attention mechanism that simulates human gaze points when observing the external world to descriptions of physical regions. By transforming this mechanism into a ranking problem of salient entity regions, we introduce prior visual attention cues to build a new salient object ranking (SaOR) dataset, and propose a SaOR network aimed at providing depth perception for prosthetic vision. Furthermore, we propose a SaOR-guided image description method to align with human observation patterns, toward providing additional visual information by auditory feedback. Finally, the integration of the two aforementioned algorithms constitutes an audiovisual cognitive optimization strategy for prosthetic vision.Main results.Through conducting psychophysical experiments based on scene description tasks under simulated prosthetic vision, we verify that the SaOR method improves the subjects' performance in terms of object identification and understanding the correlation among objects. Additionally, the cognitive optimization strategy incorporating image description further enhances their prosthetic visual cognition.Significance.This offers valuable technical insights for designing next-generation intelligent visual prostheses and establishes a theoretical groundwork for developing their visual information processing strategies. Code will be made publicly available.

Priming the distractor can eliminate the Stroop interference effect.

The Stroop interference effect-the slower response to color in an incongruent Stroop stimulus (e.g., ) relative to a neutral Stroop stimulus (e.g., ) is usually highly robust. The present study investigated the role of selective attention in the Stroop task by priming the distractor word. Replicating previous studies using the verbal (color-naming) task, priming the distractor word produced a substantial speedup of response to the color in a Stroop stimulus in our manual Stroop task. Importantly, priming the distractor completely eliminated the Stroop interference effect (Incongruent = Neutral, e.g., ), and brought about a sizable facilitation effect (Congruent < Neutral, e.g., ) that was absent in the standard (control-primed) Stroop trials. RT distribution analysis showed that the pattern of facilitation and interference effects was changed radically by priming the distractor: In the standard Stroop task, the Stroop interference effect increased across quantiles, and the facilitation effect was absent throughout the quantiles; in contrast, in the distractor-primed Stroop task, the interference effect was eliminated, and the large facilitation effect that emerged remained constant across the quantiles. We interpret these results in terms of a "Trojan horse" account that suggests that in a Stroop stimulus, color and word form are integrated into an object; hence, when object-based attention is deployed to attend to the color, the word form "sneaks in." Priming the distractor breaks this integration, allowing attention to disengage from the irrelevant word dimension and eliminating Stroop interference.

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.

The role of binocular disparity and attention in the neural representation of multiple moving stimuli in the visual cortex.

Segmenting visual scenes into distinct objects and surfaces is a fundamental visual process, with stereoscopic depth and motion serving as crucial cues. However, how the visual system uses these cues to segment multiple objects is not fully understood. We investigated how neurons in the middle-temporal (MT) cortex of macaque monkeys represent overlapping surfaces at different depths, moving in different directions. Neuronal activity was recorded from three male monkeys during discrimination tasks under varying attention conditions. We found that neuronal responses to overlapping surfaces showed a robust bias toward the binocular disparity of one surface over the other. The disparity bias of a neuron was positively correlated with the neuron's disparity preference for a single surface. In two animals, neurons preferring near disparities of single surfaces (near neurons) showed a near bias for overlapping stimuli, while neurons preferring far disparities (far neurons) showed a far bias. In the third animal, both near and far neurons displayed a near bias, though the near neurons showed a stronger near bias. All three animals exhibited an initial near bias across neurons relative to the average of the responses to the individual surfaces. Although attention modulated neuronal responses, the disparity bias was not caused by attention. We also found that the effect of attention was consistent with object-based, rather than feature-based attention. We proposed a model in which the pool size of the neuron population that weighs the responses to individual stimulus components can be variable. This model is a novel extension of the standard normalization model and provides a unified explanation for the disparity bias across animals. Our results reveal how MT neurons encode multiple stimuli moving at different depths and present new evidence of response modulation by object-based attention. The disparity bias allows subgroups of neurons to preferentially represent individual surfaces of multiple stimuli at different depths, thereby facilitating segmentation.

Three theories of object-based attention implemented in deep neural network models

Three theories of object-based attention implemented in deep neural network models

Behavioral and neural signatures of object-based attention in the human visual system

Behavioral and neural signatures of object-based attention in the human visual system

Attention Modulates Human Visual Responses to Objects by Tuning Sharpening.

Visual stimuli compete with each other for cortical processing and attention biases this competition in favor of the attended stimulus. How does the relationship between the stimuli affect the strength of this attentional bias? Here, we used functional MRI to explore the effect of target-distractor similarity in neural representation on attentional modulation in the human visual cortex using univariate and multivariate pattern analyses. Using stimuli from four object categories (human bodies, cats, cars and houses), we investigated attentional effects in the primary visual area V1, the object-selective regions LO and pFs, the body-selective region EBA, and the scene-selective region PPA. We demonstrated that the strength of the attentional bias towards the target is not fixed but decreases with increasing target-distractor similarity. Simulations provided evidence that this result pattern is explained by tuning sharpening rather than an increase in gain. Our findings provide a mechanistic explanation for behavioral effects of target-distractor similarity on attentional biases and suggest tuning sharpening as the underlying mechanism in object-based attention.

Auditory objects in working memory include task-irrelevant features

Object-based attention operates both in perception and visual working memory. While the efficient perception of auditory stimuli also requires the formation of auditory objects, little is known about their role in auditory working memory (AWM). To investigate whether attention to one object feature in AWM leads to the involuntary maintenance of another, task-irrelevant feature, we conducted four experiments. Stimuli were abstract sounds that differed on the dimensions frequency and location, only one of which was task-relevant in each experiment. The first two experiments required a match–nonmatch decision about a probe sound whose irrelevant feature value could either be identical to or differ from the memorized stimulus. Matches on the relevant dimension were detected more accurately when the irrelevant feature matched as well, whereas for nonmatches on the relevant dimension, performance was better for irrelevant feature nonmatches. Signal-detection analysis showed that changes of irrelevant frequency reduced the sensitivity for sound location. Two further experiments used continuous report tasks. When location was the target feature, changes of irrelevant sound frequency had an impact on both recall error and adjustment time. Irrelevant location changes affected adjustment time only. In summary, object-based attention led to a concurrent maintenance of task-irrelevant sound features in AWM.

HyperSOR: Context-Aware Graph Hypernetwork for Salient Object Ranking.

Salient object ranking (SOR) aims to segment salient objects in an image and simultaneously predict their saliency rankings, according to the shifted human attention over different objects. The existing SOR approaches mainly focus on object-based attention, e.g., the semantic and appearance of object. However, we find that the scene context plays a vital role in SOR, in which the saliency ranking of the same object varies a lot at different scenes. In this paper, we thus make the first attempt towards explicitly learning scene context for SOR. Specifically, we establish a large-scale SOR dataset of 24,373 images with rich context annotations, i.e., scene graphs, segmentation, and saliency rankings. Inspired by the data analysis on our dataset, we propose a novel graph hypernetwork, named HyperSOR, for context-aware SOR. In HyperSOR, an initial graph module is developed to segment objects and construct an initial graph by considering both geometry and semantic information. Then, a scene graph generation module with multi-path graph attention mechanism is designed to learn semantic relationships among objects based on the initial graph. Finally, a saliency ranking prediction module dynamically adopts the learned scene context through a novel graph hypernetwork, for inferring the saliency rankings. Experimental results show that our HyperSOR can significantly improve the performance of SOR.

Unraveling the mechanism of semantic object-based attention: The role of top-down search strategies.

There is an ongoing debate between the sensory enhancement account and the attentional prioritization account concerning the mechanism underlying object-based attention. This debate remains unresolved because of the predominant use of geometric objects in previous studies, which made it difficult to experimentally dissociate the two accounts due to the prominent boundaries of these objects. The current study investigated the mechanism underlying semantic object-based attention by utilizing Chinese two-character words with different word frequencies and the event-related potentials (ERPs) technique to elucidate the ongoing debate. The behavioral results showed that the semantic object effect was observed only in the high-frequency condition. The ERP results revealed the following: (1) the N1 component was larger for the high-frequency condition compared with the low-frequency condition. However, there was no significant difference in amplitude between the N1 component elicited by invalid same object locations and invalid different object locations, irrespective of whether it occurred in high- or low-frequency conditions. (2) The P3 component elicited by invalid same object locations was larger than that elicited by invalid different object locations only in the high-frequency condition. (3) The N400 amplitude elicited by invalid same object locations was smaller than that elicited by invalid different object locations only in the high-frequency condition. These results suggest that in the absence of obvious object boundaries, the production of object-based attention is primarily driven by search strategies. Attentional prioritization, rather than sensory enhancement, is the dominant mechanism underlying object-based attention.

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.

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."

Vaporized Δ9-tetrahydrocannabinol exposure in utero has negative effects on attention in a dose- and sex-dependent manner

Vaporized Δ9-tetrahydrocannabinol exposure in utero has negative effects on attention in a dose- and sex-dependent manner