Inhibition of return for objects and locations in static displays

When orienting attention, inhibition mechanisms prevent the return of attention to previously examined stimuli. This inhibition of the return of attention (IOR) has been shown to be associated additively with location- and object-based representations. That is, when static objects are attended, IOR is associated with both the object and the location cued, and hence IOR is larger than when only spatial location is attended. Recently McAuliffe, Pratt, and O'Donnell (2001) failed to observe such additive effects except under a narrow set of conditions (at short cue-target intervals and using mixed blocks in which object- and pure location-based effects were probed in the same display). The present study shows that additive IOR effects are observed under conditions that violate all of these boundary conditions. The results also show that IOR is modulated by internal structural properties of objects. These findings are cosistent with the hypothesis that IOR operates over functionally independent object- and location-based frames of reference.     

动态范式中基于客体的返回抑制 ——是客体抑制还是空间抑制的动态更新？

对动态范式中基于客体的返回抑制进行了考察。实验1在双侧客体改变和不改变条件下考察了返回抑制效应,结果表明,在双侧客体改变条件下返回抑制仍然存在。实验2采用单侧客体变化技术对动态范式中基于客体的返回抑制进行了测量,结果发现,在有效线索化条件下,单侧客体改变和不改变条件下对靶子的反应时没有显著差异（p > 0.90）。这些结果表明动态范式中基于客体的返回抑制的机制是空间抑制的动态更新,而不是客体表征受到抑制     

Object- and location-based inhibition of return in younger and older adults

When a cued object moves to new spatial coordinates, inhibition of return (IOR) with younger adults is found at the original cued location (location-based IOR) and at the current location of the object (object-based IOR). Older adults, however, show only location-based IOR. To determine whether this pattern of results represents a general age-related deficit in object-based IOR, the authors used static displays in which the placeholders (i.e., objects) were either present (location-based IOR+object-based IOR) or absent (location-based IOR only). Both age groups showed location-based IOR, but the older adults failed to show object-based IOR, consistent with age-related differences in visual pathways.     

Inhibition of return in static and dynamic displays

Inhibition of return (IOR) causes people to be slower to return their attention to a recently attended object (object-based IOR) or location (location-based IOR). In attempts to separately measure the two components, moving stimuli have been used that permit the dissociation of the attended object from its location when it was attended. The implicit assumption has been that both object- and locationbased components of IOR will operate whenever the cued object and cued location are identical. We show here that although this assumption may be true in a static display, it appears to be unwarranted when moving stimuli are involved: Very little IOR is observed when a cued object moves away from, and then subsequently returns to, its initial location. Thus, the processes that underlie IOR operate very differently in static versus dynamic scenes.     

工作记忆对动态范式中基于客体的返回抑制的影响

采用双任务干扰范式探讨了工作记忆对动态范式中基于客体的返回抑制的影响。三个实验分别考察了在言语、空间和视觉工作记忆负载条件下基于客体的返回抑制效应,结果发现只有在空间工作记忆负载条件下,动态范式中的返回抑制才受到损害。这表明空间工作记忆不但在静态范式中的IOR信息的维持和更新中起着重要的作用,在动态范式中的IOR信息的维持和更新中同样起着重要的作用。同时也为动态范式中基于客体的返回抑制的空间抑制动态更新说提供了新的证据     

Age-related differences in object- and location-based inhibition of return of attention

Four experiments examined age-related differences in inhibition of return (IOR) of visual attention. Using static stimuli, both young and older adults were slower to detect targets in previously cued objects, showing equivalent IOR. With objects that moved after they had been cued, young adults were slower to detect targets in the cued object (compared with uncued ones), revealing object-based IOR, but older adults were faster to detect targets in such objects, failing to demonstrate object-based IOR. Both age groups were slower to detect targets at the initially cued location (location-based IOR). The results show that age has a differential effect on IOR depending on the frame of reference of the inhibition: Inhibition for objects breaks down with age, but that for location does not. This pattern of results is consistent with the view that there are specific inhibitory deficits in old age.     

Examining the effect of practice on inhibition of return in static displays

In a recent article, Weaver, Lupiáñez, and Watson (1998) reported that both object-based and location-based inhibition of return effects were reduced with practice. The present study was conducted to (1) replicate the reduction of inhibition of return with practice in single-session experiments with a variety of displays and responses and (2) to examine the notion that the reduction was, at least partly, due to habituation. However, no evidence for practice-related changes in the size of the inhibitory effect were found over a series of different inhibition of return experiments using static displays (using various numbers of target locations, types of keypress responses, and number of trials). Overall, the results suggest that inhibition of return is a robust phenomenon and may not, with static displays, be especially sensitive to practice effects.     

Examining the effect of practice on inhibition of return in static displays.

In a recent article, Weaver, Lupiá?ez, and Watson (1998) reported that both object-based and location-based inhibition of return effects were reduced with practice. The present study was conducted to (1) replicate the reduction of inhibition of return with practice in single-session experiments with a variety of displays and responses and (2) to examine the notion that the reduction was, at least partly, due to habituation. However, no evidence for practice-related changes in the size of the inhibitory effect were found over a series of different inhibition of return experiments using static displays (using various numbers of target locations, types of keypress responses, and number of trials). Overall, the results suggest that inhibition of return is a robust phenomenon and may not, with static displays, be especially sensitive to practice effects.     

Objects and their locations in exogenous cuing.

Anatomical, physiological, and behavioral studies provide support for separate object- and location-based components of visual attention. Although studies of object-based components have usually involved voluntary attention, more recent evidence has suggested that objects may play an independent role in reflexive exogenous orienting, at least at long stimulus onset asynchronies (SOAs). In the present experiments, the role of objects in reflexive attentional orienting was investigated by developing a task in which location and object cuing could be separately examined for both short and long SOAs. Typical location cuing effects were obtained, indicating facilitation at short cue-target intervals and inhibition of return (IOR) at longer intervals. In contrast, object cuing resulted in facilitation for cued objects at long cue-target intervals and no object-based IOR. Interestingly, object cuing primarily affected targets at cued locations, and not those at uncued locations. Together, the experiments examine the interactive nature of objects and locations in exogenous orienting and seem most consistent with a location-mediated view of object-based orienting.     

中央线索化对动态范式中基于客体的返回抑制的影响

采用3×2×3的混合实验设计,考察了三种线索-靶子呈现时间间隔条件下,中央线索化对动态范式中“基于客体的返回抑制”的影响。结果表明,在外周方框旋转同时或旋转停止后中央线索化时,出现了“基于客体的返回抑制”效应,但在外周方框旋转之前中央线索化时,“基于客体的返回抑制”效应却消失了。这说明中央线索化对动态范式中的“基于客体的返回抑制”有着重要的影响,也为动态范式中“基于客体的返回抑制”的空间位置抑制动态更新说提供了新的证据。     

Objects and their locations in exogenous cuing

Anatomical, physiological, and behavioral studies provide support for separate object- and locationbased components of visual attention. Although studies of object-based components have usually involved voluntary attention, more recent evidence has suggested that objects may play an independent role in reflexiveexogenous orienting, at least at long stimulus onset asynchronies (SOAs). In the present experiments, the role of objects in reflexive attentional orienting was investigated by developing a task in which location and object cuing could be separately examined for both short and long SOAs. Typical location cuing effects were obtained, indicating facilitation at short cue—target intervals and inhibition of return (IOR) at longer intervals. In contrast, object cuing resulted in facilitation for cued objects at long cue—target intervals and no object-based IOR. Interestingly, object cuing primarily affected targets at cued locations, and not those at uncued locations. Together, the experiments examine the interactive nature of objects and locations in exogenous orienting and seem most consistent with a location-mediated view of object-based orienting.     

Examining location-based and object-based components of inhibition of return in static displays

Tipper and Colleagues (e.g., Jordan & Tipper, 1998; Tipper, Driver, & Weaver, 1991; Tipper, Weaver, Jerreat, & Burak, 1994) have provided support for inhibition of return (IOR) being composed of a location-based and an object-based component. They were able to separate out the effects of locationbased and object-based IOR by using complex displays and displays that involved moving the cued object. The present study was designed to further examine the object- and location-based components of IOR in static displays. Three experiments were conducted that looked at the presence or absence of placeholder boxes on IOR. The first experiment was designed to replicate the results of Jordan and Tipper by presenting both objects and no-objects in the same display. In the second experiment, trials were blocked, and in the third experiment trials were presented in a random order. Overall, the results are inconsistent with the notion that independent object-based and location-based IOR components combine to produce the overall IOR effect and that additive effects are realized due to the context in which the trials are presented. We propose that a single inhibitory mechanism can account for the data.     

The impact of monetary stimuli on object-based attention

Previous research has implied that monetary reward to target location (a reward for spatial properties) can affect object-based attention, but no study has directly investigated the influence of monetary objects (a reward for object properties) on object-based attention. Thus, it is unclear whether and how monetary objects can affect object-based attention. To experimentally investigate this problem, this study adapted the well-established two-rectangle paradigm. In Experiment 1, either two 100-yuan notes or two 1-yuan notes were presented to participants. We found an object-based effect with faster responses to targets at an uncued position on the cued object compared to those at an equidistant position on the uncued object; the effect was similar in 100-yuan and 1-yuan note trials. In Experiment 2, two notes (one 100-yuan and one 1-yuan) were simultaneously presented to participants, and cue location (100-yuan, 1-yuan) was manipulated. We found a greater object-based effect when the cue appeared on the 100-yuan note than on the 1-yuan note. These results suggest that the rewarding property of objects can affect object-based attention by means of altering object salience.     

Examining location-based and object-based components of inhibition of return in static displays

Tipper and Colleagues (e.g., Jordan & Tipper, 1998; Tipper, Driver, & Weaver, 1991; Tipper, Weaver, Jerreat, & Burak, 1994) have provided support for inhibition of return (IOR) being composed of a location-based and an object-based component. They were able to separate out the effects of location-based and object-based IOR by using complex displays and displays that involved moving the cued object. The present study was designed to further examine the object- and location-based components of IOR in static displays. Three experiments were conducted that looked at the presence or absence of placeholder boxes on IOR. The first experiment was designed to replicate the results of Jordan and Tipper by presenting both objects and no-objects in the same display. In the second experiment, trials were blocked, and in the third experiment trials were presented in a random order. Overall, the results are inconsistent with the notion that independent object-based and location-based IOR components combine to produce the overall IOR effect and that additive effects are realized due to the context in which the trials are presented. We propose that a single inhibitory mechanism can account for the data.     

Scene-based and object-centered inhibition of return: evidence for dual orienting mechanisms

We investigated whether inhibition of return (IOR) could be observed in location-based, scene-based, and object-centered frames of reference. IOR was found to move both with a separate cued object (scene-based) and with a location within a single rotating object (object-centered). Importantly, however, IOR was also associated with the environmental location cued when cuing was of a separate object (scene-based), whereas facilitation of the cued location was found when cuing was of a component within an object. These results suggest that location is of central importance to scene-based representations of separate objects, which appear to be encoded in viewer-centered coordinates, whereas environmental locus is of little relevance when attention orients within a single object. The results also provide further evidence for the coexistence of both excitation and inhibition associated with uninformative exogenous cues.     

Shifting attention into and out of objects: evaluating the processes underlying the object advantage

Visual cuing studies have been widely used to demonstrate and explore contributions from both object- and location-based attention systems. A common finding has been a response advantage for shifts of attention occurring within an object, relative to shifts of an equal distance between objects. The present study examined this advantage for within-object shifts in terms of engage and disengage operations within the object- and location-based attention systems. The rationale was that shifts of attention between objects require object-based attention to disengage from one object before shifting to another, something that is not required for shifts of attention within an object or away from a location. One- and two-object displays were used to assess object-based contributions related to disengaging and engaging attention within, between, into, and out of objects. The results suggest that the "object advantage" commonly found in visual cuing experiments in which shifts of attention are required is primarily due to disengage operations associated with object-based attention.     

Attentional spreading in object-based attention

The authors investigated 2 effects of object-based attention: the spread of attention within an attended object and the prioritization of search across possible target locations within an attended object. Participants performed a flanker task in which the location of the task-relevant target was fixed and known to participants. A spreading attention account predicts that object-based attention will arise from the spread of attention through an attended object. A prioritization account predicts that there will be a small, if any, object-based effect because the location of the target is known in advance and objects are not required to prioritize the deployment of attentional search. The results suggested that object-based attention operates via the spread of attention within an object.     

Object-based attention with endogenous cuing and positional certainty

Previous studies have concluded that object-based attention does not always arise if attention is cued endogenously (Macquistan, 1997) or if the target location is known with certainty (Shomstein & Yantis, 2002). In the Experiments reported here, we found object-based attention even when the locations of the two targets were known with certainty due to presentation of an endogenous cue. However, object-based attention can be prevented by limiting the exposure time of the object stimuli. These findings provide additional evidence against a search prioritization account of object-based attention. They lead to a fuller view of the role of object boundaries in directing attention. Object-based attention is frequently used spontaneously, even when the object boundaries are irrelevant to the task. However, object segmentation is not necessary for all tasks, because attention can be allocated before the stimulus has been segregated into objects.     

Mixed reference frames for dynamic inhibition of return

Reference frames mediating inhibition of return (IOR) in dynamic displays were investigated by comparing the effects of a cue in simple versus extended objects. Experiment 1 replicated S. P. Tipper, B. Weaver, L. M. Jerreat, and A. L. Burak's (1994) finding of location- and object-based IOR for boxes rotating about fixation. In Experiments 2 and 3, the boxes were replaced by two boomerang-shaped objects. Response times were slowed to all target locations across a cued object. They were also slowed to locations vacated by the uncued region of the cued object-evidence for a representation the authors call the "perceptual footprint." Whereas an object served as the medium for location-based IOR for B. S. Gibson and H. Egeth (1994), the environment served as the medium for object- and location-based IOR in Experiments 2 and 3. This suggests that (a) frames of reference may be considered hierarchically and (b) nesting of frames is context dependent.     

Frames of reference in unilateral neglect and visual perception: a computational perspective

Neurological patients with unilateral neglect fail to orient and respond to stimuli on one side, typically the left. A key research issue is whether neglect is exhibited with respect to the left side of the viewer or of objects. When deficits in attentional allocation depend not merely on an object's location with respect to the viewer but on the object's intrinsic extent, shape, or movement, researchers have inferred that attention must be operating in an object-based frame of reference. Simulations of a view-based connectionist model of spatial attention prove that this inference is not logically necessary: Object-based attentional effects can be obtained without object-based frames. The model thus explains away troublesome phenomena for view-based theories of object recognition.