特征变化的连续性影响客体连续表征的维持

本研究采用客体回溯范式考察了特征变化的连续性对维持客体连续表征的作用。实验1和实验2分别探索了形状维度上的变化方式（不变、渐变、突变）和亮度维度上的变化方式（不变、渐变、随机变化）对客体预览利化效应的影响。在特征连续条件下（不变或渐变）,两个实验都获得了客体预览利化效应。而在特征不连续变化条件下（突变或随机变化）,该效应消失。这些结果说明特征变化的连续性同样影响客体连续表征的维持。     

Surface feature congruency effects in the object-reviewing paradigm are dependent on task memory demands

Perception of object continuity depends on establishing correspondence between objects viewed across disruptions in visual information. The role of spatiotemporal information in guiding object continuity is well documented; the role of surface features, however, is controversial. Some researchers have shown an object-specific preview benefit (OSPB)—a standard index of object continuity—only when correspondence could be based on an object’s spatiotemporal information, whereas others have found color-based OSPB, suggesting that surface features can also guide object continuity. This study shows that surface feature-based OSPB is dependent on the task memory demands. When the task involved letters and matching just one target letter to the preview ones, no color congruency effect was found under spatiotemporal discontinuity and spatiotemporal ambiguity (Experiments 1–3), indicating that the absence of feature-based OSPB cannot be accounted for by salient spatiotemporal discontinuity. When the task involved complex shapes and matching two target shapes to the preview ones, color-based OSPB was obtained. Critically, however, when a visual working memory task was performed concurrently with the matching task, the presence of a nonspatial (but not a spatial) working memory load eliminated the color-based OSPB (Experiments 4 and 5). These results suggest that the surface feature congruency effects that are observed in the object-reviewing paradigm (with the matching task) reflect memory-based strategies that participants use to solve a memory-demanding task; therefore, they are not reliable measures of online object continuity and cannot be taken as evidence for the role of surface features in establishing object correspondence.     

The relationship between object files and conscious perception

Object files (OFs) are hypothesized mid-level representations which mediate our conscious perception of persisting objects-e.g. telling us 'which went where'. Despite the appeal of the OF framework, not previous research has directly explored whether OFs do indeed correspond to conscious percepts. Here we present at least one case wherein conscious percepts of 'which went where' in dynamic ambiguous displays diverge from the analogous correspondence computed by the OF system. Observers viewed a 'bouncing/streaming' display in which two identical objects moved such that they could have either bounced off or streamed past each other. We measured two dependent variables: (1) an explicit report of perceived bouncing or streaming; and (2) an implicit 'object-specific preview benefit' (OSPB), wherein a 'preview' of information on a specific object speeds the recognition of that information at a later point when it appears again on the same object (compared to when it reappears on a different object), beyond display-wide priming. When the displays were manipulated such that observers had a strong bias to perceive streaming (on over 95% of the trials), there was nevertheless a strong OSPB in the opposite direction-such that the object files appeared to have 'bounced' even though the percept 'streamed'. Given that OSPBs have been taken as a hallmark of the operation of object files, the five experiments reported here suggest that in at least some specialized (and perhaps ecologically invalid) cases, conscious percepts of 'which went where' in dynamic ambiguous displays can diverge from the mapping computed by the object-file system.     

Individuation of visual objects over time

How does an observer decide that a particular object viewed at one time is actually the same object as one viewed at a different time? We explored this question using an experimental task in which an observer views two objects as they simultaneously approach an occluder, disappear behind the occluder, and re-emerge from behind the occluder, having switched paths. In this situation the observer either sees both objects continue straight behind the occluder (called "streaming") or sees them collide with each other and switch directions ("bouncing"). This task has been studied in the literature on motion perception, where interest has centered on manipulating spatiotemporal aspects of the motion paths (e.g. velocity, acceleration). Here we instead focus on featural properties (size, luminance, and shape) of the objects. We studied the way degrees and types of featural dissimilarity between the two objects influence the percept of bouncing vs. streaming. When there is no featural difference, the preference for straight motion paths dominates, and streaming is usually seen. But when featural differences increase, the preponderance of bounce responses increases. That is, subjects prefer the motion trajectory in which each continuously existing individual object trajectory contains minimal featural change. Under this model, the data reveal in detail exactly what magnitudes of each type of featural change subjects implicitly regard as reasonably consistent with a continuously existing object. This suggests a simple mathematical definition of "individual object:" an object is a path through feature-trajectory space that minimizes feature change, or, more succinctly, an object is a geodesic in Mahalanobis feature space.     

How do young children’s spatio-symbolic skills change over short time scales?

Three experiments were designed to examine how experience affects young children's spatio-symbolic skills over short time scales. Spatio-symbolic reasoning refers to the ability to interpret and use spatial relations, such as those encountered on a map, to solve symbolic tasks. We designed three tasks in which the featural and spatial correspondences between a map and its referent (a model) were systematically manipulated using a map-model paradigm. We explored how 2.5- to 5-year-olds learn to map spatial arrays when both identical and unique correspondences coexist (Experiment 1), when featural cues are absent (Experiment 2), and when object and location similarities are contradictory, thereby making both featural and spatial mapping strategies distinct (Experiment 3). Although younger children have a stronger tendency to focus on object (or featural) cues, even 2.5-year-olds can appreciate a symbol beyond the level of object similarity. With age, children are increasingly capable of learning to use spatio-relational mapping and of discovering a spatio-symbolic mapping strategy to solve more challenging map use tasks over short time scales.     

The effect of body and part-based motion on the recognition of unfamiliar objects

We investigated the role of global (body) and local (parts) motion on the recognition of unfamiliar objects. Participants were trained to categorise moving objects and were then tested on their recognition of static images of these targets using a priming paradigm. Each static target shape was primed by a moving object that comprised either the same body and parts motion; same body, different parts motion; different body, same part motion as the learned target or was non-moving. Only the same body but not the same part motion facilitated shape recognition (Experiment 1), even when either motion was diagnostic of object identity (Experiment 2). When parts motion was more related to the object's body motion then it facilitated the recognition of the static target (Experiment 3). Our results suggest that global and local motions are independently accessed during object recognition and have important implications for how objects are represented in memory.     

Effects of the orientation of moving objects on the perception of streaming/bouncing motion displays

In this study, we examined the contribution of the orientation of moving objects to perception of a streaming/bouncing motion display. In three experiments, participants reported which of the two types of motion, streaming or bouncing, they perceived. The following independent variables were used: orientation differences between Gabor micropatterns (Gabors) and their path of motion (all the experiments) and the presence/absence of a transient tone (Experiment 1), transient visual flash (Experiment 2), or concurrent secondary task (Experiment 3) at the coincidence of Gabors. The results showed that the events at coincidence generally biased responses toward the perception of bouncing. On the other hand, alignment of Gabors with their motion axes significantly reduced the frequency of bounce perception. The results also indicated that an object whose orientation was parallel to its motion path strengthened the spatiotemporal integration of local motion signals along a straight motion path, resulting in the perception of streaming. We suggest that the effect of collinearity between Gabors and their motion path is relatively free from the effect of attention distraction.     

How do humans group non-rigid objects in multiple object tracking?: Evidence from grouping by self-rotation

Previous studies on perceptual grouping found that people can use spatiotemporal and featural information to group spatially separated rigid objects into a unit while tracking moving objects. However, few studies have tested the role of objects’ self-motion information in perceptual grouping, although it is of great significance to the motion perception in the three-dimensional space. In natural environments, objects always move in translation and rotation at the same time. The self-rotation of the objects seriously destroys objects’ rigidity and topology, creates conflicting movement signals and results in crowding effects. Thus, this study sought to examine the specific role played by self-rotation information on grouping spatially separated non-rigid objects through a modified multiple object tracking (MOT) paradigm with self-rotating objects. Experiment 1 found that people could use self-rotation information to group spatially separated non-rigid objects, even though this information was deleterious for attentive tracking and irrelevant to the task requirements, and people seemed to use it strategically rather than automatically. Experiment 2 provided stronger evidence that this grouping advantage did come from the self-rotation per se rather than surface-level cues arising from self-rotation (e.g. similar 2D motion signals and common shapes). Experiment 3 changed the stimuli to more natural 3D cubes to strengthen the impression of self-rotation and again found that self-rotation improved grouping. Finally, Experiment 4 demonstrated that grouping by self-rotation and grouping by changing shape were statistically comparable but additive, suggesting that they were two different sources of the object information. Thus, grouping by self-rotation mainly benefited from the perceptual differences in motion flow fields rather than in deformation. Overall, this study is the first attempt to identify self-motion as a new feature that people can use to group objects in dynamic scenes and shed light on debates about what entities/units we group and what kinds of information about a target we process while tracking objects.     

两种时空线索条件下表面颜色特征线索对客体保持的作用*

采用客体回溯范式,以客体预览利化效应(object specific previewing benefit, OSPB)作为指标,考察表面特征线索对客体保持的作用。实验1使用双向隧道创建时空线索不明确的条件,研究表面颜色特征线索的作用。实验2使用单向隧道使时空线索明确,研究表面颜色特征线索与时空线索一致、冲突情境下的客体保持。实验1和实验2均出现了OSPB效应,且实验2冲突情境的OSPB效应低于一致情境。研究结果表明在时空线索不明确的条件下,仅凭表面颜色特征线索就能实现客体保持;在时空线索明确的条件下,时空线索是客体保持的主要线索,同时表面颜色特征线索也起一定的作用。     

Long-term retinotopic priming in object identification

An important result in perception research is that priming in an object naming task is invariant with translation and left-right reflection. A more sensitive object recognition paradigm was used in three experiments in order to investigate the extent to which priming of object identification is affected by changes in left-right orientation and position. In a prime phase, participants viewed consecutively presented object images. In a subsequent probe phase, participants identified familiar objects in rapid visual streams of nonobject distractors. In Experiment 1, images previously viewed in the same left-right orientation were primed more than images previously viewed in the opposite orientation (i.e., a left-right reflection). This reflection-sensitive priming was replicated in Experiment 2 using a brief (300-msec) prime exposure. In Experiment 3, when the retinal locations of prime and probe images matched, reflection-sensitive priming was also obtained, but when the retinal locations of prime and probe images differed, no reflection-sensitive priming was observed. These results suggest that a single prime exposure can produce long-term priming that is sensitive to left-right reflection, but that this priming is specific to a retinal location.     

The persistence of object file representations

Coherent visual experience of dynamic scenes requires not only that the visual system segment scenes into component objects but that these object representations persist, so that an object can be identified as the same object from an earlier time. Object files (OFs) are visual representations thought to mediate such abilities: OFs lie between lower level sensory processing and higher level recognition, and they track salient objects over time and motion. OFs have traditionally been studied via object-specific preview benefits (OSPBs), in which discriminations of an object's features are speeded when an earlier preview of those features occurred on the same object, as opposed to on a different object, beyond general displaywide priming. Despite its popularity, many fundamental aspects of the OF framework remain unexplored. For example, although OFs are thought to be involved primarily in online visual processing, we do not know how long such representations persist; previous studies found OSPBs for up to 1500 msec but did not test for longer durations. We explored this issue using a modified object reviewing paradigm and found that robust OSPBs persist for more than five times longer than has previously been tested-for at least 8 sec, and possibly for much longer. Object files may be the "glue" that makes visual experience coherent not just in online moment-by-moment processing, but on the scale of seconds that characterizes our everyday perceptual experiences. These findings also bear on research in infant cognition, where OFs are thought to explain infants' abilities to track and enumerate small sets of objects over longer durations.     

The negative priming effect: Inhibitory priming by ignored objects

A priming paradigm was employed to investigate the processing of an ignored object during selection of an attended object. Two issues were investigated: the level of internal representation achieved for the ignored object, and the subsequent fate of this representation. In Experiment 1 a prime display containing two superimposed objects was briefly presented. One second later a probe display was presented containing an object to be named. If the ignored object in the prime display was the same as the subsequent probe, naming latencies were impaired. This effect is termed negative priming. It suggests that internal representations of the ignored object may become associated with inhibition during selection. Thus, selection of a subsequent probe object requiring these inhibited representations is delayed. Experiment 2 replicated the negative priming effect with a shorter inter-stimulus interval. Experiment 3 examined the priming effects of both the ignored and the selected objects. The effect of both identity repetition and a categorical relationship between prime and probe stimuli were investigated. The data showed that for a stimulus selected from the prime display, naming of the same object in the probe display was facilitated. When the same stimulus was ignored in the prime display, however, naming of it in the probe display was again impaired (negative priming). That negative priming was also demonstrated with categorically related objects suggests that ignored objects achieve categorical levels of representation, and that the inhibition may be at this level.     

Are objects required for object-files? Roles of segmentation and spatiotemporal continuity in computing object persistence

Two central tasks of visual processing are (1) to segment undifferentiated retinal images into discrete objects, and (2) to represent those objects as the same persisting individuals over time and motion. Here we explore the interaction of these two types of processing in the context of object files—mid-level visual representations that “stick” to moving objects on the basis of spatiotemporal properties. Object files can be revealed by object-specific preview benefits (OSPBs), wherein a “preview” of information on a moving object speeds the recognition of that information at a later point when it appears again on the same object (compared to when it reappears on a different moving object), beyond display-wide priming. Here we explore the degree of segmentation required to establish object files in the first place. Surprisingly, we find that no explicit segmentation is required until after the previews disappear, when using purely motion-defined objects (consisting of random elements on a random background). Moreover, OSPBs are observed in such displays even after moderate (but not long) delays between the offset of the preview information and the onset of the motion. These effects indicate that object files can be established without initial static segmentation cues, so long as there is spatiotemporal continuity between the previews and the eventual appearance of the objects. We also find that top-down strategies can sometimes mimic OSPBs, but that these strategies can be eliminated by novel manipulations. We discuss how these results alter our understanding of the nature of object files, and also why researchers must take care to distinguish “true OSPBs” from “illusory OSPBs”.     

Infants’ reasoning about ambiguous motion events: The role of spatiotemporal and dispositional status information

Two experiments investigate whether 7-month-olds reason about the origin of motion events by considering two sources of causally relevant information: spatiotemporal cues and dispositional status information derived from the identification of an object as either animate (with the enduring causal property of self-initiated motion) or inanimate (requiring an external cause of motion). Infants were shown a ball, a human hand, and an animal engaged in a motion event. While dispositional status information remained constant, spatiotemporal relations varied across conditions. Based on looking time data, we conclude that infants attend flexibly to both types of information. Without spatiotemporal cues, infants rely on dispositional status information. When two objects provide dispositional cues to motion origin, but only one also provides corresponding spatiotemporal information, infants attribute the motion to the object providing both types of information. Given an ambiguous motion event with two dispositional motion originators but no additional spatiotemporal cues, infants may prefer either of the two.     

Effects of foveal priming and extrafoveal preview on object identification

The results of three different experiments suggested that the relation between an object in the fovea on fixation n and an object subsequently brought into the fovea on fixation n + 1 affects the time to identify the second object. In Experiment 1 we extended previous work by demonstrating that a previously seen related priming object speeded the time to name a target object even when a saccade intervened between the two objects. In Experiment 2 we replicated this result and further showed that the benefit on naming time was due to facilitation from the related object rather than inhibition from the unrelated object. In addition, naming of the target object was much slower in both experiments when there was not a peripheral preview of the target object on fixation n. However, because the effect of the foveal priming object was greater when the target was not present than when it was present, priming did not appear to make extraction of the extrafoveal information more efficient. In Experiment 3, fixation times were recorded while subjects looked at four objects in order to identify them. Fixation time on an object was shorter when a related object was fixated immediately before it, even though the four objects did not form a scene. The size of the facilitation was roughly comparable to that in several analogous experiments where scenes were used. The results suggest that the effects of a predictive scene context on object identification may be explainable in terms of an object-to-object or "intralevel" priming mechanism.     

Repetition priming and the haptic recognition of familiar and unfamiliar objects

In four experiments, we examined the haptic recognition of 3-D objects. In Experiment 1, blindfolded participants named everyday objects presented haptically in two blocks. There was significant priming of naming, but no cost of an object changing orientation between blocks. However, typical orientations of objects were recognized more quickly than nonstandard orientations. In Experiment 2, participants accurately performed an unannounced test of memory for orientation. The lack of orientation-specific priming in Experiment 1, therefore, was not because participants could not remember the orientation at which they had first felt an object. In Experiment 3, we examined haptic naming of objects that were primed either haptically or visually. Haptic priming was greater than visual priming, although significant cross-modal priming was also observed. In Experiment 4, we tested recognition memory for familiar and unfamiliar objects using an old-new recognition task. Objects were recognized best when they were presented in the same orientation in both blocks, suggesting that haptic object recognition is orientation sensitive. Photographs of the unfamiliar objects may be downloaded from www.psychonomic.org/archive.     

Perceived causality and perceived force: Same or different?

Visually perceived interactions between objects, such as animated versions of billiard ball collisions, give rise to causal impressions, impressions that one object produces some effect in another, and force impressions, impressions that one object exerts a certain amount of force on another. In four experiments, evidence for strong divergence between these two impressions is reported. Manipulations of relative direction of motion and point of contact between the objects had different effects on the causal and force impressions (Experiment 1); delay between one object contacting another and the latter starting to move had a stronger effect on the causal impression than on the force impression (Experiment 2); a context of other moving objects significantly weakened the causal impression but not the force impression (Experiment 3); and there was an inverse relation between an impression of one object penetrating another and the amount of force the former was perceived as exerting on the latter (Experiment 4). These findings are explained in terms of differential effects of instructions on attention, and also in terms of differences in meaning between force and causality.     

What’s in an object file? Evidence from priming studies

Six experiments were conducted to investigate the nature of the contents of object files, temporary representations that store information about objects. Experiment 1 used a lexical priming paradigm with a lexical decision task, in which the prime and target could appear in either the same or different locations. The results indicated a greater priming effect when the prime and target appeared in the same location than when they appeared in different locations (object- or location-specific priming). Experiment 2 replicated these findings for objects that changed position during the display. Experiment 3 demonstrated that these findings reflected the inclusion of abstract identity information, rather than physical form, in object files. Three additional experiments tested for the presence of three types of semantic information (related concepts, semantic features, and category membership) in object files. No object-specific priming effects were found. Taken together, these experiments suggest that an object file includes identity information, but not semantic information. Implications of the results for object file theory are discussed.     

Spatiotemporal integration and contour interpolation revealed by a dot localization task with serial presentation paradigm

The visual system seems to integrate information that is presented over time in a spatially fragmented fashion, with the result that observers are able to report the whole shape of objects. This research considers relations in space and time that allow the integrated percepts of complete objects. Specifically, temporal characteristics for spatiotemporal integration of illusory contour and spatial characteristics of interpolated contour are examined. A serial presentation paradigm and a dot localization task were used in two experiments; observers localized a probe dot relative to a perceived contour of an illusory object. Each of four inducing figures was briefly presented in a serial order to observers and the total time of the series was manipulated. In Experiment 1 short time ranges varied up to 180 ms, whereas longer times were examined in Experiment 2. Overall, the results demonstrate that a short time allows spatiotemporal integration, and that the perceived location of contour consistently shifts with time range. These experiments suggest that the mechanism of spatiotemporal integration operates on spatial integration as a limiting case.     

Selective attention during scene perception: Evidence from negative priming

In two experiments, we examined the role of semantic scene content in guiding attention during scene viewing. In each experiment, performance on a lexical decision task was measured following the brief presentation of a scene. The lexical decision stimulus named an object that was either present or not present in the scene. The results of Experiment 1 revealed no priming from inconsistent objects (whose identities conflicted with the scene in which they appeared), but negative priming from consistent objects. The results of Experiment 2 indicated that negative priming from consistent objects occurs only when inconsistent objects are present in the scenes. Together, the results suggest that observers are likely to attend to inconsistent objects, and that representations of consistent objects are suppressed in the presence of an inconsistent object. Furthermore, the data suggest that inconsistent objects draw attention because they are relatively difficult to identify in an inappropriate context.