Inhibition of return (IOR) refers to the longer reaction times (RTs) to targets presented at previously cued, fixated or attended locations. It has been suggested that there are two distinct forms of IOR. The input form, generated when the reflexive oculomotor system is suppressed, affects the sensory/perceptual processing. The output form, generated when the reflexive oculomotor system is not suppressed, biases responding. It has been demonstrated, using the locus of slack logic associated with the psychological refractory period (Pashler, 1998),that the input form of IOR operates on a pre-bottleneck stage of processing, Kavyani et al. (2017). Using the same logic, Klein et al. (2020) demonstrated that the output form of IOR operates at or after the bottleneck. Building on the methods of Klein et al. the present study used PRP paradigm to determine whether the output form of IOR operates at or after the bottleneck. The output form of IOR was generated by an initial saccade from a peripheral location to a central fixation point. Task 1 consisted of a manual response indicating the location (right/left) of a subsequent visual stimulus. Task 2 required participants to discriminate the frequency (high/low) of an auditory stimulus and make a key-press response with their other hand. The targets (T1 and T2) for the two tasks were presented in close succession with 200, 400 and 800ms target-target onset asynchronies (TTOAs). Responses to T1 were delayed by IOR and responses to T2 were substantially delayed when the TTOA was brief. Statistical analysis of the amount of carry over of the IOR effect experienced by Task 1 onto the RTs for Task 2 strongly suggest that the output form of IOR operates after the bottleneck. Nevertheless, aspects of the results could be interpreted to support a weaker influence of IOR operating also at the bottleneck stage of processing.

We conducted a cued target localization experiment to examine inhibition of return (IOR) in a computer-simulated three-dimensional (3D) environment. Cues and targets were presented either on the same or different depth planes, and on the same or opposite sides. In trials where cues and targets were at different depths, they were positioned either within a single object extending across depth or across two distinct objects separated along the depth axis. IOR was reduced when the cue appeared farther than the subsequent target (a far-to-near switch), compared to when both appeared at the same depth. Notably, this depth-specific reduction in IOR only emerged when the cue and target appeared between different objects, not when they were part of the same object. By contrast, no such effect was found for near-to-far depth switches. These findings suggest that IOR can be modulated by both depth and object structure, but only under specific spatial configurations-particularly when attention shifts from a farther to a nearer location across separate objects.

The cueing task is a robust experimental paradigm for investigating attention. A centrally presented valid cue, correctly indicating the location of an upcoming target stimulus, leads to quicker responses than an invalid cue. A feature of this paradigm is that increasing the delay between a peripheral cue and a target reverses this effect, where responses become slower for a valid cue, a phenomenon termed inhibition of return (IOR). Using GEMS, a system that utilises genetic programming techniques, we generated potential strategies underlying the facilitation and IOR effects in the cueing paradigm. Models were generated for three experiments differing in their experimental designs, all with good fit to behavioural data. Our approach helps address current issues in the field of attention regarding how it is defined and what mechanisms underlie it. Additional benefits and limitations of this method are discussed.

Numerous studies adopting Posner peripheral cueing paradigms have shown that exogenous attentional orientation (EAO) to a salient-but-irrelevant stimulus involves two opposing attentional processes: early attentional capture and late attentional suppression. Recent evidence has indicated that long-term perceptual learning can induce involuntary attentional capture by nonsalient shapes. However, it remains unclear whether a well-trained nonsalient shape could exhibit a biphasic pattern of EAO similar to that observed with physically salient stimuli, including both an early exogenous attentional shift and a late inhibition of return (IOR). Through both a perceptual learning task and a classic peripheral cueing task, the current study showed that a well-trained nonsalient shape cue could exhibit a biphasic pattern of EAO. When compared with an untrained shape, a well-trained nonsalient shape facilitated subsequent target detection at short cue-target onset asynchronies (CTOAs, 200-300ms) and deteriorated target detection at a relatively long CTOA (800ms), but not at 400- to 600-ms CTOAs. As a comparison, a detectability-matched onset cue or luminance contrast cue elicited a facilitatory effect at 200- to 300-ms CTOAs and an inhibitory effect starting from 400-ms CTOA. A control eye-tracking experiment suggested that the absence of IOR effects at 400- to 600-ms CTOAs in the trained cue task was not due to fewer eye movements during the task. Our results indicated that, as opposed to physically salient stimuli, a well-trained nonsalient shape induced delayed IOR after an evident exogenous shift of visual attention. The different patterns of EAO processes support the notion that prior experience (such as perceptual learning) plays a unique role in modulating our exogenous attention. Possible underlying mechanisms are proposed.

To examine whether children with attention-deficit/hyperactivity disorder (ADHD) can produce attentional orienting in response to gaze cues, and to identify which type of attentional orienting is impaired and why. Two experiments employed a gaze cue-target paradigm using inhibition of return (IOR) as an indicator of exogenous attentional orienting. Experiment 1 used normal upright gaze faces as cues. Experiment 2 used inverted gaze faces as cues. When normal gaze faces were used as the gaze cue, no IOR effect was observed in children with ADHD (Experiment 1); whereas when inverted gaze faces were used as the gaze cue, the IOR effect was produced in children with ADHD (Experiment 2). These results indicated that the ability to produce exogenous attentional orienting to the gaze cue is impaired in children with ADHD and that this impairment resulted from their reduced ability to exogenously orient to the intact face. These findings provide new evidence of social cognitive deficits and attentional orienting deficits in children with ADHD, and help provide support for children in educational settings.

In this narrative theoretical review, I take a closer look at the last 40 years of research on the cuing of attention and the often-related inhibition of return in the spatial senses of vision, audition, and touch. A distinction is made between perceptual versus response-based facilitation and inhibition in these two putatively related phenomena. Ray Klein has long been interested in the phenomenon of inhibition of return, though mostly from a unisensory visual perspective. This review highlights how examining these attentional and response-related phenomena outside of the visual modality (e.g., in audition and in touch), as well as crossmodally, and in a multisensory context, has helped to further our understanding of both empirical phenomena. The putative existence of attentional orienting and inhibition of return-like inhibitory phenomena outside of the spatial domain, as when attentional selection relates to a specific stimulus dimension (such as hue), semantic category, or even sensory modality, is also discussed. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Autonomous social robots aim to reduce human supervision by performing various tasks. To achieve this, they are equipped with multiple perceptual channels to interpret and respond to environmental cues in real time. However, multimodal perception often leads to sensory overload, as robots may receive numerous simultaneous stimuli with varying durations or persistent activations across different sensory modalities. Sensor overstimulation and false positives can compromise a robot’s ability to prioritise relevant inputs, sometimes resulting in repeated or inaccurate behavioural responses that reduce the quality and coherence of the interaction. This paper presents a Bioinspired Attentional System that uses Reinforcement Learning to manage stimulus prioritisation in real time. The system draws inspiration from the following two neurocognitive mechanisms: Inhibition of Return, which progressively reduces the importance of previously attended stimuli that remain active over time, and Attentional Fatigue, which penalises stimuli of the same perception modality when they appear repeatedly or simultaneously. These mechanisms define the algorithm’s reward function to dynamically adjust the weights assigned to each stimulus, enabling the system to select the most relevant one at each moment. The system has been integrated into a social robot and tested in three representative case studies that show how it modulates sensory signals, reduces the impact of redundant inputs, and improves stimulus selection in overstimulating scenarios. Additionally, we compare the proposed method with a baseline where the robot executes expressions as soon as it receives them using a queue. The results show the system’s significant improvement in expression management, reducing the number of expressions in the queue and the delay in performing them.

IntroductionThe interaction between attention and emotion is one of the key questions in schizophrenia, but the mechanisms of how emotional information affects selective attention in schizophrenia are still unclear.MethodsThe present study employed a cue-back-to-fixation procedure to manipulate the valence and emotional arousal intensity of stimuli presented at either cued locations (Experiment 1) or target locations (Experiment 2). The present study examined the impact of emotional arousal intensity on the inhibition of return (IOR)—a phenomenon characterized by faster responses to previously unattended relative to attended locations—in individuals with schizophrenia, during two distinct attentional phases: attentional disengagement and attentional reorientation.ResultsThe results showed significant IOR effects for both schizophrenia (Experiment 1a and 2a) and control groups (Experiment 1b and 2b) regardless of the emotional stimuli with different arousal intensities presented at both the cued and target locations. However, as compared with negative low arousal stimuli or neutral low arousal stimuli, significantly larger IOR effect size for control groups was found when negative high arousal stimuli were presented in cued location and for schizophrenia groups was found when negative high arousal stimuli were presented in target location.DiscussionThese results may underly the mechanism of attentional deficit for schizophrenia towards different arousal intensities of emotional stimuli. During the attentional disengagement phase, schizophrenia patients are more likely to filtered out those high-arousal stimuli that endanger life while control group participants experience enhanced perceptual processing towards them; during the attentional reorientation phase, schizophrenia patients display “hyperfocusing” on those life-threatening high-arousal stimuli while the control group manifest an “attentional blindness” phenomenon to avoid these threatening stimuli. Meanwhile, we also interpreted our findings in light of an alternative theory of salience dysregulation.

From Sound to Sight: The Cross-Modal Spread of Location-Based Inhibition of Return.

The ability to suppress an inappropriate response can be influenced by several factors, including providing information on where to pay attention. For example, the spatial prediction of the stop signal location enhances inhibitory control in a Stop Signal Task. Here, we test whether a non-predictive spatial cueing improves inhibitory control as well. In this experiment, participants observed a vertical bar moving from a central position toward one of two circles on the screen. They were asked to press a key when the bar's motion was interrupted (go signal). In 25% of the trials (stop signal trials), after a variable delay following the go signal, a visual target (stop signal) appeared in one of the circles, requiring participants to inhibit their response to the go signal. In half of these trials, the stop signal appeared on the same side as the go signal (valid condition), and in the other half, it appeared on the opposite side (invalid condition). Our results show a facilitation effect for stop trials in the invalid condition compared to the valid condition, for targets occurring from 300 ms onward the go signal. This suggests an involvement of Inhibition of Return (IOR) in affecting the stop signal detection during motor control. Our findings provide new insights into the interaction between attentional processes and motor control, highlighting a temporally focused influence of exogenous attention in shaping motor inhibition.

Action planning can bias the distribution of attention toward the anticipated consequences of the action. Human performance could be facilitated in processing stimuli appearing in locations congruent with the planned action and subsequently held in spatial working memory. This suggests that action planning has the capacity to endogenously orient attention, but this has yet to be formally investigated. In the current study, we examined whether the endogenous nature of action planning could affect exogenous attention capture. Using a virtual three-dimensional (3D) environment, participants underwent simulated driving while presented with a modified cue-target paradigm. Action planning was prompted before (Experiment 1) or during cue presentation (Experiment 2) by requiring participants to perform a lane change following their localization response at the peripheral target onset. The results showed that traditional exogenous cueing effects (inhibition of return; IOR) were revealed when action planning was not required. However, when action planning was required, the IOR effect was diminished at the action-relevant location but remained present at the action-irrelevant location. In addition, we tested that our results were not merely the effect of an induced working memory load before making the lane change (Experiment 3) and that action planning endogenously oriented attention in the absence of any exogenous cueing manipulations (Experiment 4). Collectively, these findings suggest that the endogenous shifting of attention that results from planned actions can impact the effect of exogenous orienting in dynamic stimulus interactions. Future research should continue to examine the interplay between endogenous and exogenous attention in ecologically valid settings.

Inhibition of return (IOR) refers to a phenomenon that individuals respond more slowly when the target is presented in the previously cued location in a cue-target paradigm. Although there is a large amount of evidence to support the "reorienting hypothesis" of IOR, it is still continuously challenged in the visual single-modal domain. However, it is unclear whether the occurrence of IOR under cross-modality is consistent with the reorienting hypothesis. In the present study, we used a variant of the cue-target paradigm to investigate the effect of attentional orienting as modulated by the central reorienting cue on IOR within the visual modality (Experiment 1) and across auditory-visual modalities (Experiment 2). The results showed that IOR triggered by the peripheral cue and attentional orienting triggered by the central reorienting cue directionality occurred in both the visual single-modal condition and the auditory-visual cross-modal condition, but there was no interaction between them. These results indicated that attentional reorienting may not be the cause of IOR in either single-modal or cross-modal auditory-visual conditions.

Bistable figures can generate two different percepts alternating with each other. It is suggested that eye fixation plays an important role in bistable figure perception because it helps us selectively focus on certain image features. We tested how the shift of percept is related to the eye-fixation pattern and whether inhibition of return (IOR) plays a role in this process. IOR refers to the phenomenon where, after attention remains at the same image location for a period, the inhibition to the mechanisms supporting that location increases. Consequently, visual attention shifts to a new location, and reallocation to the original location is suppressed. We used an eye tracker to record the observers' eye movements during observation of the duck/rabbit figure and the Necker cube while recording their percept reversals. In Experiment 1, we showed there were indeed different eye fixation patterns for different percepts. Also, the fixation shifted across different regions that occurred before the percept reversal. In Experiment 2, we examined the influence of inward bias on the duck/rabbit figure and found that it had a significant effect on the first percept but that this effect diminished over time. In Experiment 3, a mask was added to the attended region to remove the local saliency. This manipulation increased the number of percept reversals and fixation shifts across different regions. That is, the change in local saliency can cause a fixation shift and thus reverse our perception. Our result shows that what we perceive depends on where we look.

This study systematically explored the impact of the spatial metaphor of time on attentional bias using visual order stimuli. Three experiments were conducted. Experiment 1, comprising Experiments 1a and 1b, investigated how the spatial metaphor of time shaped attentional bias across five disorder levels. Experiment 1a examined horizontal orientations, while Experiment 1b focused on vertical orientations. Experiment 2 compared attentional biases toward stimuli with the same disorder level in both orientations. The key distinction between the stimuli was that one represented short-term memory, while the other did not involve memory. Building on the findings of Experiment 2, Experiment 3 compared attentional biases between fully ordered structures (intact Gestalt structures) as non-memory representations and partially disordered structures in short-term memory. The results revealed a significant preference for future-related information, particularly on the right side in horizontal orientations. Short-term memory representations enhanced attentional attraction and triggered inhibition of return (IOR), while fully ordered structures attracted attention as effectively as partially disordered structures, thereby neutralizing attentional biases. Overall, this study contributes to a deeper understanding of the cognitive mechanisms underlying visual attention and the influence of temporal metaphors.

It is known that individuals with autism spectrum disorders (ASD) exhibit impairments in shifting attention. However, previous studies have primarily focused on school-aged children and adults with ASD. It remains unclear whether attentional shifting impairments emerge at an early age. Additionally, it is uncertain which specific process-engagement or disengagement-is affected in individuals with ASD. This study investigated the time course of attentional shifting in preschool-aged children with ASD using a Posner cue-target paradigm. The cue-target onset asynchrony was systematically manipulated to reveal both the early facilitation effect of attentional capture (i.e., engagement) and the later inhibitory aftereffect, commonly referred to as inhibition of return (IOR). Results showed an early facilitation effect in both ASD and typically developing (TD) children, indicating that ASD children engaged attention to salient spatial locations. In contrast to TD children, no reliable IOR effect was observed in ASD children, suggesting difficulties in disengaging attention. These findings indicate a selective impairment in attentional disengagement among preschool-aged children with ASD and support the need for early intervention programs focusing on attentional shifting.

Inhibition of return (IOR) refers to a location repetition cost typically observed when signaling the detection of or localizing sequentially presented stimuli repeating or changing their location. In discrimination tasks, however, IOR is often reduced or even absent; here, effects of binding and retrieval are thought to take place. Information is bound into an event file, which upon feature repetition causes retrieval, leading to partial repetition costs. It is assumed that the presence of retrieval-based effects masks the observation of IOR. Yet, some evidence suggests that long intervals between stimuli can lead to IOR in tasks in which usually mostly binding effects are observed. We hypothesized that with an increasing interval between prime response and probe onset (response stimulus interval, RSI), event files will decay and decreasingly mask IOR. In turn, IOR should be strongest at longest intervals. In the current study, participants discriminated the color of stimuli repeating or changing their location. Crucially, we varied the RSI from 500 ms to 3000 ms, trial-wise (Experiment 1) and block-wise (Experiment 2). We observed overall binding effects that were reduced with increasing RSI; these effects were slightly stronger when presented block-wise. IOR was overall absent (Experiment 1) or weak (Experiment 2) and did not emerge with increasing RSI. While event file decay took place, it did not unleash IOR. Rather, these results suggest that retrieval-based effects do not simply mask but overwrite IOR when manually responding. The observations of IOR with long intervals are discussed in the context of overall fast responding.

We present an extensive review of the repetition effect aiming to understand a simple experimental fact: why the repetition of a stimulus leads to reduced neural activity as compared to unrepeated stimuli. Previous attempts to understand this fact were connected mainly with the application of the mechanisms of local models (synchrony, facilitation and sharpening). We show that the Neurolocator model earlier proposed for the explanation of neural memory, focused attention, and Pavlovian conditioning can also successfully explain most difficult cases of repetition effects. The Supplement Material includes wide range of related effects such as habituation and sensitization, negative priming, inhibition of return, whole brain segregation and integration. All of them need an additional works to build specific models in each case, but we believe that their successful modeling will be closely connected with the Neurolocator model.

Exogenous spatial attention attenuates audiovisual integration (AVI). Previous studies on the effects of exogenous spatial attention on AVI have focused on the inhibition of return (IOR) effect induced by visual cues and the facilitation effect induced by auditory cues, but the differences between the effects of exogenous spatial attention (induced by visual and auditory cues) on AVI remain unclear. The present study used the exogenous spatial cue-target paradigm and manipulated cue stimulus modality (visual cue, auditory cue) in two experiments (Experiment 1: facilitation effect; Experiment 2: IOR effect) to examine the effects of exogenous spatial attention (evoked by cues in different modalities) on AVI. The results of Experiment 1 showed that the AVI effect at valid cue locations was significantly lower than that at invalid cue locations in both visual and auditory cue conditions, suggesting that the exogenous spatial facilitation effect evoked by both visual and auditory cues attenuated AVI. Further analysis showed that the facilitation effect induced by visual cues attenuated AVI to a greater extent than that induced by auditory cues. In Experiment 2, the AVI effect was significantly lower at valid cue locations than at invalid cue locations in the visual cue condition, whereas there was no significant difference in AVI effect between valid and invalid cue locations in the auditory cue condition, suggesting that the exogenous spatial IOR effect evoked by visual cues attenuated AVI, while the IOR effect evoked by auditory cues had no significant effect on AVI. Taken together, these results may suggest that exogenous spatial attention induced by visual cues has a greater effect on AVI than that induced by auditory cues.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children. Previous studies have shown that children with ADHD have impaired processing of emotional stimuli, but it is unclear whether their ability to integrate multimodal emotional stimuli is impaired and at which processing pathway this impairment exists. The present study investigated the ability of children with ADHD to integrate emotional audiovisual stimuli under different emotional conditions, and the effect of audiovisual integration on IOR to reveal the impaired processing pathway of their emotional audiovisual integration. Fifty-eight school-age children (29 with ADHD and 29 matched typically developing (TD) children) performed an emotional valence discrimination task with a cue-target paradigm. The results showed that children with ADHD did not exhibit audiovisual integration of emotional stimuli in all experimental conditions. In addition, the IOR effect was significantly smaller for audiovisual targets than for visual targets under the negative but not the neutral emotion condition in children with ADHD, whereas this effect was present in all emotion conditions in TD children. These results indicate that the ability to integrate emotional audiovisual information is impaired in children with ADHD and this impairment exists in both bottom-up and top-down pathways. Additionally, although presenting emotional auditory stimuli at the same time as emotional faces reduced IOR both in children with ADHD and TD, the manner of reduction differed. These findings provide new evidence of emotional processing deficits and multimodal integration deficits in children with ADHD, and help provide support for children in educational settings.

Parkinson's disease (PD) may affect not only motor functions, but also cognitive processes such as attention. While past research has examined PD impact on spatial attention, it has not addressed how the key functions of attentional orienting and alerting in PD are mediated by cueing format, an ecologically relevant parameter. We assessed how exogenous and endogenous orienting cue modes affect PD patients' visuospatial attention expressed as dorsal attention network orienting benefits, ventral attention network reorienting costs, and alerting abilities. Ninety PD patients and 72 healthy comparison participants performed a spatial attention task in an engaging game format which required selection of a target location without prior cueing, or with temporal, valid spatial, or invalid spatial exogenous or endogenous cueing. PD patients differed from healthy participants only in response time benefits in orienting under endogenous probabilistically predictive cue processing. They did not exhibit greater reorienting costs, differences in inhibition of return, or alerting deficits, irrespective of modes of cueing. These results suggest that fundamental orienting and alerting functions might be intact in PD, with challenges emerging only if additional cognitive processes, including those related to motor preparation, are required to utilize cue information. (PsycInfo Database Record (c) 2024 APA, all rights reserved).