Inhibition of return affects contrast sensitivity

When the time interval between two peripheral stimuli is long enough, reaction times (RTs) to targets presented at previously stimulated locations are longer than RTs to targets presented at new locations. This effect is widely known as Inhibition of Return (IOR). The effect is usually explained as an inhibitory bias against returning attention to previously attended locations. Thus, attentional disengagement is considered to be a necessary condition to observe IOR . We report data from three experiments with 2 different paradigms in which we show that IOR can be dissociated from the endogenous disengagement of spatial attention. Two main results are reported: 1) IOR is observed at an endogenously attended location in some situations, and 2) even after the endogenous disengagement of attention, facilitation instead of IOR is observed in other situations. We conclude that the endogenous disengagement of attention is neither sufficient nor necessary for IOR to be observed. However, by presenting an intervening event between the cue and the target, an IOR effect occurred in all conditions, indicating the importance of attentional segregation processes (exogenous disengagement) for generating IOR. These results are interpreted on the basis of cue-target event integration and segregation processes (Lupiáñez, 2010), which constitute our dynamical perceptual experience. IOR is explained as a cost in detecting the appearance of new attention-capturing information (i.e., the target) at locations where attention has been already captured by previous events (the cue).

Brain Research, 2009

We investigate early (P1) and late (P3) modulations of event-related potentials produced by endogenous (expected vs. unexpected location trials) and exogenous (cued vs. uncued location trials) orienting of spatial attention. A 75% informative peripheral cue was presented 1000 ms before the target in order to study Inhibition of Return (IOR), a mechanism that produces slower responses to peripherally cued versus uncued locations.

Philosophical Transactions of the Royal Society B: Biological Sciences, 2013

Perception & Psychophysics, 2006

Vision Research, 2006

We investigated the mechanisms underlying the effects of sustained and transient covert attention on contrast sensitivity. The aim of this study was twofold: (1) Using a zero-noise display, we assessed whether sustained (endogenous) attention enhances contrast sensitivity via signal enhancement, and compared the magnitude of the effect with that of transient (exogenous) attention.

Acta Psychologica, 2018

Studies of endogenous and exogenous attentional orienting in spatial cueing paradigms have been used to investigate inhibition of return, a behavioral phenomenon characterized by delayed reaction time in response to recently attended locations. When eye movements are suppressed, attention is covertly oriented to central or peripheral stimuli. Overt orienting, on the other hand, requires explicit eye movements to the stimuli. The present study examined the time course of slowed reaction times to previously attended locations when distractors are introduced into overt and covert orienting tasks. In a series of experiments, manual responses were required to targets following central and peripheral cues at three different cue-target intervals, with and without activated oculomotor systems. The results demonstrate that, when eye movements are suppressed, behavioral inhibition is reduced or delayed in magnitude by the presence of a distractor relative to conditions without distractors. However, the time course of behavioral inhibition when eye movements are required remains similar with or without distractors.

The Quarterly Journal of Experimental Psychology, 2006

Psychology, 2012

In the cueing paradigm, an abrupt onset of the cue brings about both the facilitation effect and inhibition of return (IOR) depending on the cue-target interval. Previous studies showed that physical properties of the cue such as duration affect the occurrences of facilitation effect and IOR. However, other study indicated that cue duration did not affect these two effects. The first aim of this study was to clarify how cue duration affects the facilitation effect. The results showed that the temporal properties of the cue influenced the facilitation effect. The second aim of this study was to examine the relationship between the magnitude of the facilitation effect and that of IOR with the results in Experiments 1 and 2. There were four findings that suggested discrepancies in the effect of spatial cueing between the facilitation effect and IOR. In conclusion, these two processes were driven by distinct mechanisms.

Journal of Experimental Psychology: Human Perception and Performance, 2012

Canadian Journal of Experimental Psychology/Revue canadienne de psychologie expérimentale, 2005

The ability to efficiently direct visual attention to salient features in the environment is a critical function of the visual system. The finding that people are slower to detect a target that appears at a previously cued location is thought to reflect a mechanism known as inhibition of return (IOR). Past research has shown that difficult target discriminations result in a greater amount of time needed to inhibit previously attended locations (i.e., a delayed onset of inhibition), suggesting that task difficulty plays a critical role in the allocation of attention. In this study, IOR was measured at a wide range of SOAs while participants detected either a perceptually degraded target or a standard, high luminance target. When responses were made to a perceptually degraded target, the time course of IOR was delayed by approximately 250 ms (relative to the control group), suggesting that the difficulty in detecting targets also influences the allocation of attention. The results are consistent with the notion that IOR is not simply a reflexive subcortical mechanism but rather involves top-down attentional control settings.

Experimental Brain Research, 2006

Vision research, 2009

Exogenous spatial attention can be automatically engaged by a cue presented in the visual periphery. To investigate the effects of exogenous attention, previous studies have generally used highly salient cues that reliably trigger attention. However, the cueing threshold of exogenous attention has been unexamined. We investigated whether the attentional effect varies with cue salience. We examined the magnitude of the attentional effect on apparent contrast . Attention alters appearance. Nature Neuroscience, 7(3), 308-313.] elicited by cues with negative Weber contrast between 6% and 100%. Cue contrast modulated the attentional effect, even at cue contrasts above the level at which observers can perfectly localize the cue; hence, the result is not due to an increase in cue visibility. No attentional effect is observed when the 100% contrast cue is presented after the stimuli, ruling out cue bias or sensory interaction between cues and stimuli as alternative explanations. A second experiment, using the same paradigm with high contrast motion stimuli gave similar results, providing further evidence against a sensory interaction explanation, as the stimuli and task were defined on a visual dimension independent from cue contrast. Although exogenous attention is triggered automatically and involuntarily, the attentional effect is gradual.

Perception & Psychophysics, 1999

Perception & Psychophysics, 1999

Conventional wisdom holds that a nonpredictive peripheral cue produces a biphasic response time (RT) pattern: early facilitation at the cued location, followed by an RT delay at that location, The latter effect is called inhibition ofreturn (lOR). In two experiments, we report that lOR occurs at a cued location far earlier than was previously thought, and that it is distinct from attentional orienting. In Experiment 1, lOR was observed early (i.e., within 50 msec) at the cued location, when the cue predicted that a detection target would occur at another location. In Experiment 2, this early lOR effect was demonstrated to occur for target detection, but not for target identification. Weconclude that previous failures to observe early lOR at a cued location may have been due to attention being directed to the cued location and thus "masking" lOR. A central goal ofattention research is to understand how we prepare for and select stimulus information from the environment. Typically, we attend to visual information by executing an overt shift of the head and eyes. However, attention can also be allocated covertly, without any overt movements. The effects of covert orienting on visual performance have been explored with a spatial precuing paradigm in which a response stimulus is preceded by a visual event that summons attention to a particular location (

Cognitive Neuropsychology, 2006

In the present series of experiments, peripheral informative cues were used in order to dissociate endogenous and exogenous orienting of spatial attention using the same set of stimuli. For each block of trials, the cue predicted either the same or the opposite location of target appearance. Crucially, using this manipulation, both expected and unexpected locations could be either cued or uncued. If one accepts the hypothesis that inhibition of return (IOR) is an attentional effect that inhibits the returning of attention to a previously attended location , one would not predict an IOR effect at the expected location, since attention should not disengage from the location predicted by the cue. Detection and discrimination tasks were used to examine any potential difference in the mechanism responsible for IOR as a function of the task at hand. Two major results emerged: First, IOR was consistently observed at the expected location, where, according to the traditional "reorienting" hypothesis, IOR is not supposed to occur. Second, a different time course of cueing effects was found in detection versus discrimination tasks, even after controlling for the orienting of attention. We conclude that IOR cannot be accounted for solely by the "reorienting of attention" hypothesis. Moreover, we argue that the observed time course differences in cueing effects between detection and discrimination tasks cannot be explained by attention disengaging from cues later in discrimination than in detection tasks, as proposed by . The described endogenous -exogenous dissociation is consistent with models postulating that endogenous and exogenous attentional processes rely on different neural mechanisms.