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Oculomotor research shows that eye movements are primed toward the midpoint of an array of visual stimuli, such that an eye movement to a visual target is executed most rapidly when it appears near the midpoint of an earlier array. At longer intervals between the prime and target, this facilitatory effect can reverse to become inhibitory — such that eye movements are slower when made toward the midpoint – but the source of this inhibition is unclear. One of our prior studies suggests a global source: target proximity to the midpoint determines inhibition, consistent with the notion that oculomotor activation is responsible for the effect and the original definition of inhibition of return. A later study suggests a local source: target proximity to the nearest array element determines inhibition, consistent with the notion that repeat stimulation of an input pathway is responsible. To resolve the ambiguity we systematically test whether timing differences between studies altered the source of the inhibition. We find that both previously observed patterns are reproducible depending on the prime offset – target onset asynchrony. We also resolve the discrepancy by showing that when this asynchrony is less than 200 ms, target proximity to the array’s midpoint and its proximity to any given array element can jointly determine inhibition, whereas when the asynchrony is approximately 200 ms, inhibition is robust at the midpoint of the array. At longer asynchronies, all inhibitory effects rapidly dissipate.

During scene perception our eyes generate complex sequences of fixations. Predictors of fixation locations are bottom-up factors like luminance contrast, top-down factors like viewing instruction, and systematic biases like the tendency to place fixations near the center of an image. However, comparatively little is known about the dynamics of scanpaths after experimental manipulation of specific fixation locations. Here we investigate the influence of initial fixation position on subsequent eye-movement behavior on an image. We presented 64 colored photographs to participants who started their scanpaths from one of two experimentally controlled positions in the right or left part of an image. Additionally, we computed the images' saliency maps and classified them as balanced images or images with high saliency values on either the left or right side of a picture. As a result of the starting point manipulation, we found long transients of mean fixation position and a tendency to overshoot to the image side opposite to the starting position. Possible mechanisms for the generation of this overshoot were investigated using numerical simulations of statistical and dynamical models. We conclude that inhibitory tagging is a viable mechanism for dynamical planning of scanpaths., 34 pages with 10 figures submitted to Vision Research. Reviews Received on June 8th, 2016 (Minor Revision). Updated Version will be uploaded within the year 2016

Inhibition of Return (IOR) refers to slower reaction time to a target presented at the same location as a preceding stimulus. Here, we examine reflexive attention orienting via the saccadic IOR using a shift in gaze direction (i.e. from averted to direct) in faces presented as a peripheral cue, in upright and inverted orientations, in adults with Autism Spectrum Disorder (ASD) and typically developed comparison participants. While both groups showed an IOR in the inverted face condition, this effect was reduced in participants with ASD in the upright face condition, as compared to comparison participants, suggesting that moving eyes do not trigger reflexive exogenous orienting in individuals with ASD. Impaired reflexive orienting to eye gaze might severely compromise the later development of social functions in ASD, such as joint attention, face emotion recognition and mindreading. Fil: Zalla, Tiziana. Ecole Normale Supérieure; Francia Fil: Fernandez, Laura Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ecole Normale Supérieure; Francia. Centro de Investigación y Transferencia en Acústica; Argentina Fil: Pieron, Marie. Ecole Normale Supérieure; Francia Fil: Seassau, Magali. Eye Brain; Francia Fil: Leboyer, Marion. Fondation FondaMental; Francia. Inserm; Francia. Universidad Paris-Est Créteil; Francia

There is an extensive literature on the phenomenon of inhibition of return (IOR): When attention is drawn to a peripheral location and then removed, response time is delayed if a target appears in the previously inspected location. Recent research suggests that non-spatial attribute repetition (i.e., if a target shares a feature like color with the earlier, cueing, stimulus) can have a similar inhibitory effect, at least when the target appears in the previously cued location. What remains unknown is whether location- and feature-based inhibitory effects can be dissociated. In the present study, we used a multiple cueing approach to investigate the properties of location- and feature-based repetition effects. In two experiments (detection, and discrimination), location-based IOR was absent but feature-based inhibition was consistently observed. Thus, the present results indicate that feature- and location-based inhibitory effects are dissociable. The results also provide support for the view that the attentional consequences of multiple cues reflect the overall center of gravity of the cues. We suggest that the repetition costs associated with feature and location repetition may be best understood as a consequence of the pattern of activation for object files associated with the stimuli present in the displays.

Inhibition of return (IOR) most often describes the finding of increased response times to cued as compared to uncued targets in the standard covert orienting paradigm. A perennial question in the IOR literature centers on whether the effect of IOR is on motoric/decision-making processes (output-based IOR), attentional/perceptual processes (input-based IOR), or both. Recent data converge on the idea that IOR is an output-based effect when eye movements are required or permitted whereas IOR is an input-based effect when eye movements are monitored and actively discouraged. The notion that the effects of IOR may be fundamentally different depending on the activation state of the oculomotor system has been challenged by several studies demonstrating that IOR exists as an output-, or output- plus input-based effect in simple keypress tasks not requiring oculomotor responses. Problematically, experiments in which keypress responses are required to visual events rarely use eye movement monitoring let alone the active discouragement of eye movement errors. Here, we return to an experimental method implemented by Ivanoff and Klein (2001) whose results demonstrated that IOR affected output-based processes when, ostensibly, only keypress responses occurred. Unlike Ivanoff and Klein, however, we assiduously monitor and discourage eye movements. We demonstrate that actively discouraging eye movements in keypress tasks changes the form of IOR from output- to input-based and, as such, we strongly encourage superior experimental control over or consideration of the contribution of eye movement activity in simple keypress tasks exploring IOR.

We investigated the influence of attentional inhibition on the perceived duration of a brief visual event. Although attentional capture by an exogenous cue is known to prolong the perceived duration of an attended visual event, it remains unclear whether time perception is also affected by subsequent attentional inhibition at the location previously cued by an exogenous cue, an attentional phenomenon known as inhibition of return. In this study, we combined spatial cuing and duration judgment. After one second from the appearance of an uninformative peripheral cue either to the left or to the right, a target appeared at a cued side in one-third of the trials, which indeed yielded inhibition of return, and at the opposite side in another one-third of the trials. In the remaining trials, a cue appeared at a central box and one second later, a target appeared at either the left or right side. The target at the previously cued location was perceived to last shorter than the target presented at the opposite location, and shorter than the target presented after the central cue presentation. Therefore, attentional inhibition produced by a classical paradigm of inhibition of return decreased the perceived duration of a brief visual event.

The present study develops an explicit and predictive computational model of neonate saccades based on the interaction of several simple mechanisms, including the tendency to fixate towards areas of high contrast, and the decay and recovery of a world-centered contrast representation simulating a low-level inhibition of return mechanism. Emergent properties similar to early visual behaviors develop, including the externality effect (or tendency to focus on external then internal features). The age-associated progression of this effect is modulated by the decay period of the model’s contrast representation, where the high-level behavior of either scanning broadly or locally is modulated by a single decay parameter.

The current study investigated whether subliminal spatial cues can affect the oculomotor system. In addition, we performed the experiment under monocular viewing conditions. By limiting participants to monocular viewing conditions, we can examine behavioral temporal-nasal hemifield asymmetries. These behavioral asymmetries may arise from an anatomical asymmetry in the retinotectal pathway. The results show that even though our spatial cues were not consciously perceived they did affect the oculomotor system: relative to the neutral condition, saccade latencies to the validly cued location were shorter and saccade latencies to the invalidly cued location were longer. Although we did not observe an overall inhibition of return effect, there was a reliable effect of hemifield on IOR for those observers who showed an overall IOR effect. More specifically, consistent with the notion that processing via the retinotectal pathway is stronger in the temporal hemifield than in the nasal hemifield we found an IOR effect for cues presented in the temporal hemifield but not for cues presented in the nasal hemifield. We conclude that unconsciously processed spatial cues can affect the oculomotor system. In addition, the observed behavioral temporal-nasal hemifield asymmetry is consistent with retinotectal mediation. © 2010 Elsevier Ltd. All rights reserved.

This study used a classic exogenous cueing task in which an abrupt onset cue indicated the target location at chance level. When there was a delay between the cue and the target, observers responded slower and less accurate to the target presented at cued than at uncued locations, signifying the occurrence of inhibition-of-return (IOR). On some trials, instead of a manual response, participants had to move their eyes to a location in space. Our findings show no saccade deviation away from the location that was inhibited due to IOR unless participants had to process the target letter presented at the inhibited location. Our findings are consistent with the notion that inhibition resulting in IOR does not occur at the saccade map level but IOR seems to reduce the input of signals going into the saccade map. We show that the strength of saccade deviation is an important measure which can reveal the amount of attentional processing taking place at any particular location in time. © 2008 Elsevier Ltd. All rights reserved.

This study examined the relationship between inhibition of return (IOR) in covert orienting and microsaccade statistics. Unlike a previous study [Galfano, G., Betta, E., & Turatto, M. (2004)], IOR was assessed by means of a target–target paradigm, and microsaccade dynamics were monitored as a function of both the first and the second visual event. In line with what has been reported with a cue-target paradigm, a significant directional modulation was observed opposite to the first visual event. Because participants were to respond to any stimulus, this rules out the possibility that the modulation resulted from a generic motor inhibition, showing instead that it is peculiarly coupled to the oculomotor system. Importantly, after the second visual event, a different response was observed in microsaccade orientation, whose direction critically depended of whether the second visual event appeared at the same location as the first visual event. The results are consistent with the notion that IOR is composed of both attentional and oculomotor components, and challenge the view that covert orienting paradigms engage the attentional component in isolation.

A series of experiments were conducted to examine the inhibitory effect of a visual distracter on saccadic eye movements. Participants were presented with a sequence of two critical displays. In one display a red target was presented together with a green distracter. This was followed by a display with a new red target presented in isolation at one of three locations with respect to the previous display. The lone target was presented either at the location of the recent target, the location of the recent distracter, or a new location. Participants were instructed to fixate the target in both displays and to ignore the green distracter. Experiment 1 revealed a significant increase in saccadic reaction times (SRTs) when the target was presented at the location of the recent distracter. Experiment 2 revealed that SRTs increased only in the conditions where the new target was presented at the location of the recent distracter, irrespective of its colour. Experiment 3 found that the inhibitory effect lasted for at least 2s. In Experiment 4 the inhibitory effect was abolished when a lone distracter (i.e., anti-target) was presented without a target. Experiments 5 and 6 revealed that inhibition at the location of the recent target (‘inhibition-of-return’) also emerged with a shorter inter-display interval and when the distracter was removed from the recent display. These results distinguished between inhibition of a recent distracter and ‘inhibition-of-return’ and are consistent with models of competitive interactions which generate inhibitory effects on the spatial representation of a distracter.

The ability to search and scan the environment effectively is a prerequisite for spatial behavior. A longstanding theory (Posner M. I., & Cohen, Y. (1984). Components of visual orienting. In H. Bouma, & D. Bouwhuis (Eds.), Attention and performance X (pp. 531–556). London: Erlbaum) proposes that inhibition of previously attended loci (Inhibition of return; IOR) serves to facilitate exploration by increasing the likelihood to inspect new areas instead of returning to locations that have been inspected before. In this eye movement study we tested whether we could find evidence in favor of this hypothesis. Here we report that IOR does occur during search and free viewing, because we found increased fixation times preceding return saccades (eye movements that return to previously fixated locations). Meanwhile we observed no influence of IOR on the search strategy. Rather than the predicted low number we found many return saccades. Therefore, IOR does not serve as a foraging facilitator in saccadic search and free viewing. We hypothesize that IOR is an intrinsic aspect of shifting attention and gaze direction and furthermore that it is not always advantageous to prevent return saccades.

Disappearance phenomena, in which salient visual stimuli do not register consciously, have been known to occur. Recovery from such phenomena typically occurs through change in some visual attribute, such as increase in luminance contrast or stimulus duration. Thus far, there have been no reports of cross-modal modulation of disappearance phenomena. In particular, what effect a cross-modal attentional cue has on sensory suppression is unknown. Here, we show that an adapted, flickered visual target that is synchronous with a brief sound appears more vivid than a similarly adapted, otherwise identical, visual target that is offset in time by more than 200 ms from the auditory cue. We argue that the brief auditory stimuli momentarily boost the concurrent signal of the adapted visual stimulus at a site downstream of the visual adaptation, thus causing the transient recovery from the visual adaptation. Repetitive visual cues cause significantly less recovery from visual adaptation than repetitive auditory cues, implying that there are functions a cross-modal cue can perform that a cue of the same modality cannot. Moreover repetitive auditory cues selectively prevent synchronous visual targets from undergoing visual adaptation. Ours is the first report of cross-modal modulation of a disappearance phenomenon.

We present a neural model of the frontal eye fields. It consists of several retinotopic arrays of neuron-like units that are recurrently connected. The network is trained to make memory-guided saccades to sequentially flashed targets that appear at arbitrary locations. This task is interesting because the large number of possible sequences does not permit a pre-learned response. Instead locations and their priority must be maintained in active working memory. The network learns to perform the task. Surprisingly, after training it can also select targets in visual search tasks. When targets are shown in parallel it chooses them according to their salience. Its search behavior is comparable to that of humans. It exhibits saccadic averaging, increased reaction times with more distractors, latency vs accuracy trade-offs, and inhibition of return. Analysis of the network shows that it operates like a queue, storing the potential targets in sequence for later execution. A small number of unit types are sufficient to encode this information, but the manner of coding is non-obvious. Units respond to multiple targets similar to quasi-visual cells recently studied [Exp. Brain Res. 130 (2000) 433]. Predictions are made that can be experimentally tested.

We examined the characteristics of readers’ eye movements as they read sentences or short passages of text and compared the durations of eye fixations preceding two types of saccades: (a) saccades to words that were fixated on the prior fixation (return saccades) and (b) saccades in which the eyes moved about the same distance but did not land on a word fixated on the prior fixation (non-return saccades). Consistent with research from much simpler attention or oculomotor tasks, we found what could be considered an inhibition of return effect: fixations preceding return saccades were longer than those preceding non-return saccades.

Inhibition-of-return is the process by which visual search for an object positioned among others is biased toward novel rather than previously inspected items. It is thought to occur automatically and to increase search efficiency. We examined this phenomenon by studying the facilitative and inhibitory effects of location cueing on target-detection response times in a search task. The results indicated that facilitation was a reflexive consequence of cueing whereas inhibition appeared to depend on cue informativeness. More specifically, the inhibition-of-return effect occurred only when the cue provided no information about the impending target’s location. We suggest that the results are consistent with the notion of two levels of visual processing. The first involves rapid and reflexive operations that underlie the facilitative effects of location cueing on target detection. The second involves a rapid but goal-driven inhibition procedure that the perceiver can invoke if doing so will enhance visual search performance.

Inhibition of return (IOR) refers to the performance disadvantage when detecting a target presented at a previously cued location. The current paper contributes to the long-standing debate whether IOR is caused by attentional processing or perceptual processing. We present a series of four experiments which varied the cue luminance in mixed and blocked conditions. We hypothesised that if inhibition was initialized by an attentional process the size of IOR should not vary in the blocked condition as participants should be able to adapt to the level of cue luminance. However, if a perceptual process triggers inhibition both experimental manipulations should lead to varying levels of IOR. Indeed, we found evidence for the latter hypothesis. In addition, we also varied the target luminance in blocked and mixed condition. Both manipulations, cue luminance and target luminance, affected IOR in an additive fashion suggesting that the two stimuli affect human behaviour on different processing stages.

In recent years, many studies have explored the conditions in which irrelevant visual distractors affect saccades trajectories. These previous studies mainly focused on the low-level stimulus characteristics and how they affect the magnitude of curvature. The present study explored the possible effect of high level semantic information on saccade curvature. Semantic saliency was manipulated by presenting irrelevant peripheral taboo versus neutral cue words in a spatial cuing paradigm that allowed for the measurement of trajectory deviations. Findings showed larger saccade trajectory deviations away from taboo (versus neutral) cue words when making a saccade towards another location. This indicates that due to their high semantic saliency, more inhibition was necessarily applied to taboo cue locations to effectively suppress their competing as saccade targets. © 2011 Elsevier Ltd.

Although spatial working memory has been shown to play a central role in manual IOR (Castel, Pratt, & Craik, 2003), it is so far unclear whether spatial working memory is involved in saccadic IOR. The present study sought to address this question by using a dual task paradigm, in which the participants performed an IOR task while keeping a set of locations in spatial working memory. While manual IOR was eliminated, saccadic IOR was not affected by spatial working memory load. These findings suggest that saccadic IOR does not rely on spatial working memory to process inhibitory tagging.

Studies that followed the covert and overt probe-following-search paradigms of Klein (1988) and Klein and MacInnes (1999) to explore inhibition of return (IOR) in search are analyzed and evaluated. An IOR effect is consistently observed when the search display (or scene) remains visible when probing and lasts for at least 1000 ms or about four previous inspected items (or locations). These findings support the idea that IOR facilitates foraging by discouraging orienting toward previously examined regions and items. Methodological and conceptual issues are discussed leading to methodological recommendations and suggestions for experimentation.

Recent studies have shown that the saccade trajectory often curved away from an object that was previously attended but irrelevant to the current saccade goal. We investigated whether such curved saccades occur during serial visual search, which requires sequential saccades possibly controlled by inhibition to multiple locations. The results show that the saccade trajectories were affected by at least three previous fixations. Furthermore, the effect of the previous fixations on saccade trajectories decreased exponentially with time or the number of intervening saccades. The relationship between the curved saccade trajectory and inhibition of return during serial visual search was discussed.

Recent research has suggested that inhibition of return (IOR) develops more quickly when subjects must respond with an eye movement than when they make a manual response to the target (Perception and Psychophysics 62 (2000) 1512–1524). Four spatial cueing experiments were conducted where subjects had to indicate the location of visual targets. Within each of the oculomotor and manual modalities, responses could be either directed towards the target (saccade or pointing) or had a more complex stimulus–response (S–R) mapping. For both saccadic and manual responses, IOR onset was delayed as the required S–R mapping became more indirect. This finding further emphasizes the role of response-related processes in spatial attention. Possible explanations for this pattern of results are considered, including the notion that activity in prefrontal cortex, needed for execution of such abstract S–R mappings, may influence the time course of reflexive spatial cueing effects.

Tasks such as reading or visual search consist of series of saccades. We have investigated to what extent saccades that are made within a series of self-paced movements are influenced by preceding movements. The present paper concerns an analysis of the duration of the fixations preceding saccades. We tested human subjects in a paradigm where they had to fixate two to four targets in a fixed order as fast as they could. We found that fixations before so-called ‘return saccades’ (saccades returning to the previously fixated position) are considerably longer (up to 40%) than other fixations. This phenomenon, which we call ‘Inhibition of Saccade Return’ (ISR), is present when return and regular saccades are mixed in one trial, and seems to be reset after each saccade. ISR is strongest at the previously fixated target, and decreases gradually from there. The radius of the area where ISR is found is about 4°. The relation between ISR and ‘Inhibition of Return’ of spatial attention [Posner & Cohen, 1984] is discussed, as well as the neurophysiological basis of ISR.

Reaction time in a detection or a location discrimination task was longer when a target appeared at the same location as in the previous trial (inhibition of return; IOR). However, it became shorter when the task was color or orientation discrimination (facilitation of return: FOR). This dichotomy was observed in the single target as well as in the popout displays. In additional experiments, vernier, size, and luminance discriminations all led to FOR, whereas eye-movement and arm-reaching tasks led to IOR. Moreover, identical stimuli could lead to the opposite patterns of result depending on the nature of the task: inhibition in global location tasks, and facilitation in feature analysis tasks. These may correspond to “where” vs “what” or “action” vs “recognition” pathways neurophysiologically. Copyright © 1996 Elsevier Science Ltd.

A recent study illustrating the importance of sensory influences on inhibition of return (IOR) found stimuli biased towards the parvocellular (P) pathway produced greater IOR while stimuli biased towards the magnocellular (M) pathway produced less IOR (Brown, 2009; Guenther & Brown, 2007). The present study used a different sensory manipulation (temporal onset/offset) to further explore this relationship. Greater M activity was expected when stimuli were presented abruptly (M-biased) compared to when stimuli were ramped on and off (P-biased). Consistent with our recent findings, greater location-based IOR was found under ramped vs. abrupt conditions. The results showed location-based IOR is influenced by the nature of stimulus presentation (ramped vs. abrupt) providing convergent evidence of an IOR mechanism sensitive to M- and P-biased stimuli.

Inhibition of return (IOR) is an orienting phenomenon characterized by slower behavioral responses to spatially cued, relative to uncued targets, when the cue-target onset asynchronies (CTOAs) are long enough that cue-elicited attentional capture has dispersed. Here, we implement a short-term depression (STD) account of IOR within a neuroscientifically based dynamic neural field model (DNF) of the superior colliculus (SC). In addition to the prototypical findings in the cue-target paradigm (i.e., the biphasic pattern of behavioral enhancement at short CTOAs and behavioral costs at long CTOAs), a variety of findings in the literature are generated with this model, including IOR in averaging saccades and the co-existence of IOR and endogenous orienting at the same location. Many findings that cannot be accommodated by this model could be accounted for by incorporating cortical contributions.

Inhibition of return (IOR) is an attention mechanism that expedites the search of an object in our environment. Results in different studies support either a perceptual or motor account of IOR. One problem with the perceptual account is that IOR has not been observed in temporal order judgment. Here we demonstrate that IOR can be observed in a temporal order saccade task where eye movement instead of manual response is used to select the target. The result suggests the importance of monitoring eye movement in studies of IOR.

In two experiments, we investigated the effects of exogenous cueing on visual motion processing. The first experiment shows that the typical pattern of reaction time (RT) effects, namely early facilitation and later inhibition of return (IOR), can be obtained using a color change as exogenous cue and a direction change as target. In the second experiment, we manipulated the validity of the cue independently with respect to location and feature using transparent motion stimuli. Facilitation of RTs with short cue-target interstimulus-intervals (ISIs) was only evident for targets with both the valid location and the valid feature. Furthermore, at longer cue-target intervals, RTs were prolonged for targets at the cued location, irrespective of the cued feature. These results demonstrate spatial and feature-based components of early facilitation and purely spatial IOR.

It was found [Vision Res. 36 (1996) 2125] that reaction times for repeated targets were longer in detection and location discrimination tasks (inhibition of return; IOR) and shorter in color and orientation discrimination tasks (facilitation of return; FOR). The present experiment, using a more detailed analysis, shows that both IOR and FOR can be found in the discrimination tasks. Overall, the results are inconsistent with the notion that IOR and FOR effects reside in separate visual pathways. Rather, the results are accounted for by repetition priming and IOR that occur with specific combinations of target features and task demands.