Object detection and basic-level categorization: Sometimes you know it is there before you know what it is

A tight temporal coupling between object detection (is an object there?) and object categorization (what kind of object is it?) has recently been reported (Grill-Spector &; Kanwisher, 2005), suggesting that image segmentation into different objects and categorization of those objects at the basic level may be the very same mechanism. In the present work, we decoupled the time course of detection and categorization through two task manipulations. First, inverted objects were categorized significantly less accurately than upright objects across a range of image presentation durations, but no significant effect on object detection was observed. Second, systematically degrading stimuli affected categorization significantly more than object detection. The time course of object detection and object categorization can be selectively manipulated. They are not intrinsically linked. As soon as you know an object is there, you do not necessarily know what it is.     

Object specificity and personal relevance in long-term visual remembering

The personal relevance of an object is multi-faceted, each facet being capable of contributing to the effects on object memory attributed to personal relevance. An object's status as an individual object (object specificity), rather than just a category of object, is one such facet and its impact on the long-term visual remembering of everyday objects is assessed in two experiments. Images and drawings were produced under generic (e.g., “Please draw a bed”) and personal exemplar (e.g., “Please draw your bed”) instructions, and participants indicated the degree to which the image on which their drawing was based was of a specific object or a generic object. Object specificity induced a sense of time and place for a remembered object, the most recent encounter with the object being most salient. Other aspects of personal relevance collectively facilitated the retrieval of an object's category-irrelevant features (thereby increasing the vividness of the object image), the other objects with which it was seen, and a more general episodic sense of place. Against a broader theoretical perspective, it is proposed that visual episodic memory and visual knowledge are primary sources of information for specific personally relevant objects and generic objects, respectively.     

Adaptation in motion perception: Alteration of motion evoked by ocular pursuit

A new perceptual adaptation, an alteration in the perceived direction of motion given by ocular pursuit, is reported. When an object starts to move on a straight path, its displacement is initially given by a shift of its image on the retinas of the stationary eyes; then, after about 200 msec, the eyes start to track the moving object. The perception of motion that results from ocular pursuit was altered by causing ocular pursuit of a moving object to be preceded regularly by a displacement of the object’s image whose direction differed from the direction of the pursuit movement. This was arranged by changing the direction of the given motion at approximately the moment when image displacement changed into tracking. Prolonged exposure to such conditions resulted in a change of the tracked motion’s apparent direction, which became somewhat more like the direction of the preceding motion phase that was given by image displacement.     

Distinct mechanisms for the representation of moving and static objects

The visual system has been suggested to integrate different views of an object in motion. We investigated differences in the way moving and static objects are represented by testing for priming effects to previously seen ("known") and novel object views. We showed priming effects for moving objects across image changes (e.g., mirror reversals, changes in size, and changes in polarity) but not over temporal delays. The opposite pattern of results was observed for objects presented statically; that is, static objects were primed over temporal delays but not across image changes. These results suggest that representations for moving objects are: (1) updated continuously across image changes, whereas static object representations generalize only across similar images, and (2) more short-lived than static object representations. These results suggest two distinct representational mechanisms: a static object mechanism rather spatially refined and permanent, possibly suited for visual recognition, and a motion-based object mechanism more temporary and less spatially refined, possibly suited for visual guidance of motor actions.     

Accuracy of body size estimation: Role of biopsychosocial variables

This study evaluated factors related to the perceptual disturbances of body image. Using a digital body image computer program, 191 participants (107 women, 82 men) adjusted an image of their body to the perceived actual size at five body regions; chest, waist, hips, thighs and calves. A neutral object (a vase) was also adjusted to partial out the level of perceptual distortion present with a neutral object. Men and women overestimated the size of the neutral object and their body image. Among women, overestimation was primarily predicted by high levels of depression, and media and peer influences to be thinner and increase muscles. Among men, overestimation was predicted by high BMI, media influences to lose weight and increase muscles, and peer influences to increase muscles. These findings suggest that perceptual accuracy of body image is primarily predicted by biopsychosocial influences.     

Priming contour-deleted images: evidence for intermediate representations in visual object recognition

The speed and accuracy of perceptual recognition of a briefly presented picture of an object is facilitated by its prior presentation. Picture priming tasks were used to assess whether the facilitation is a function of the repetition of: (a) the object's image features (viz., vertices and edges), (b) the object model (e.g., that it is a grand piano), or (c) a representation intermediate between (a) and (b) consisting of convex or singly concave components of the object, roughly corresponding to the object's parts. Subjects viewed pictures with half their contour removed by deleting either (a) every other image feature from each part, or (b) half the components. On a second (primed) block of trials, subjects saw: (a) the identical image that they viewed on the first block, (b) the complement which had the missing contours, or (c) a same name-different exemplar of the object class (e.g., a grand piano when an upright piano had been shown on the first block). With deletion of features, speed and accuracy of naming identical and complementary images were equivalent, indicating that none of the priming could be attributed to the features actually present in the image. Performance with both types of image enjoyed an advantage over that with the different exemplars, establishing that the priming was visual rather than verbal or conceptual. With deletion of the components, performance with identical images was much better than that with their complements. The latter were equivalent to the different exemplars, indicating that all the visual priming of an image of an object is through the activation of a representation of its components in specified relations. In terms of a recent neural net implementation of object recognition (Hummel & Biederman, in press), the results suggest that the locus of object priming may be at changes in the weight matrix for a geon assembly layer, where units have self-organized to represent combinations of convex or singly concave components (or geons) and their attributes (e.g., aspect ratio, orientation, and relations with other geons such as TOP-OF). The results of these experiments provide evidence for the psychological reality of intermediate representations in real-time visual object recognition.     

Dissociating the effects of angular disparity and image similarity in mental rotation and object recognition

Performance is often impaired linearly with increasing angular disparity between two objects in tasks that measure mental rotation or object recognition. But increased angular disparity is often accompanied by changes in the similarity between views of an object, confounding the impact of the two factors in these tasks. We examined separately the effects of angular disparity and image similarity on handedness (to test mental rotation) and identity (to test object recognition) judgments with 3-D novel objects. When similarity was approximately equated, an effect of angular disparity was only found for handedness but not identity judgments. With a fixed angular disparity, performance was better for similar than dissimilar image pairs in both tasks, with a larger effect for identity than handedness judgments. Our results suggest that mental rotation involves mental transformation procedures that depend on angular disparity, but that object recognition is predominately dependent on the similarity of image features.     

Looking at object-substitution masking in depth and motion: toward a two-object theory of object substitution

When attention is divided, a briefly presented target surrounded by four small dots is difficult to identify when the dots persist beyond target offset, but not when these dots terminate with the target. This object-substitution masking effect likely reflects processes at both the image level and the object level. At the image level, visual contours of the mask make feature extraction difficult. Recent data (Lleras & Moore, 2003) suggest that, at the object level, an object file is created for the target-plus-mask, and this single-object token later morphs into a single-object token containing the mask alone. In the present experiments, we used stimuli presented in 3-D space and apparent motion; the results indicate that object-substitution masking also arises when the mask and the target are represented in two separate object tokens and the mask token interferes with the target token.     

The relationship of spiritual maturity to level of object relations development and God image

Several theoretical studies have suggested that spiritual maturity parallels psychological maturity from an object relations perspective in that both involve a relationality that is characterized by mature dependence (Shackelford, 1978; Pingleton, 1984). In addition, previous research has suggested that there is a positive relationship between level of object relations development and God image (Rizzuto, 1979; McDargh, 1983, 1986; Birky & Ball, 1988; Brokaw, 1991). In light of this, the present study theoretically and empirically explored the notion that both level of object relations development and God image are positively correlated with spiritual maturity. The results suggest initial support for the present hypotheses. Theoretical as well as clinical implications of the results are discussed.This paper was presented at the 1994 American Psychological Association Annual Meeting, Los Angeles, CA.     

Relationship between frames of reference and mirror-image reversals

The mirror puzzle related to the perception of mirror images as left-right reversed can be more fully understood by considering an extended problem that includes also the perception of mirror images that are not left-right reversed. The purpose of the present study is to clarify the physical aspect of this extended problem logically and parsimoniously. Separate use of the intrinsic frame of reference that belongs to the object and one that belongs to its mirror image always leads to the perception of left-right reversal when the object has left-right asymmetry; on the other hand, the perception of left-right nonreversal is always due to the application of a common frame of reference to the object and its mirror image.     

Determinants of naming latencies, object comprehension times, and new norms for the Russian standardized set of the colorized version of the Snodgrass and Vanderwart pictures

We report object-naming and object recognition times collected from Russian native speakers for the colorized version of the Snodgrass and Vanderwart (Journal of Experimental Psychology: Human Learning and Memory 6:174–215, 1980) pictures (Rossion & Pourtois, Perception 33:217–236, 2004). New norms for image variability, body–object interaction [BOI], and subjective frequency collected in Russian, as well as new name agreement scores for the colorized pictures in French, are also reported. In both object-naming and object comprehension times, the name agreement, image agreement, and age-of-acquisition variables made significant independent contributions. Objective word frequency was reliable in object-naming latencies only. The variables of image variability, BOI, and subjective frequency were not significant in either object naming or object comprehension. Finally, imageability was reliable in both tasks. The new norms and object-naming and object recognition times are provided as supplemental materials.     

A new theory to explain geometrical illusions produced by crossing lines

Due to the diffraction of light and other optical distortions of the eye, the image of an object is not exactly the same as the object. When two objects are close enough, their two images overlap so as to form one image, located at a position somewhere between the two original images. This fact is used to explain illusions produced by the crossing of lines, including Poggendorffs, Zollner’s, Hering’s, Wundt’s, the Müller-Lyer and other illusions of this class.     

Measuring the speed of newborn object recognition in controlled visual worlds

How long does it take for a newborn to recognize an object? Adults can recognize objects rapidly, but measuring object recognition speed in newborns has not previously been possible. Here we introduce an automated controlled‐rearing method for measuring the speed of newborn object recognition in controlled visual worlds. We raised newborn chicks (Gallus gallus) in strictly controlled environments that contained no objects other than a single virtual object, and then measured the speed at which the chicks could recognize that object from familiar and novel viewpoints. The chicks were able to recognize the object rapidly, at presentation rates of 125 ms per image. Further, recognition speed was equally fast whether the object was presented from familiar viewpoints or novel viewpoints (30° and 60° azimuth rotations). Thus, newborn chicks can recognize objects across novel viewpoints within a fraction of a second. These results demonstrate that newborns are capable of both rapid and invariant object recognition at the onset of vision.     

Mapping the contours of faith in the land of separation: spiritual geographies for children

According to Jean Piaget, children begin to develop a concept of an object, such as that it has sides that are not visible from the child's perspective or that it is likely to be where one saw it last, in early infancy. By the close of the prelinguistic phase at about 2 years old, the child has developed a mature object concept, one that comprehends the object as a continuing entity even when it is not visible. Many children's picture books demonstrate Piaget's concept of object permanence through narrative and image. This paper offers a close reading of three classics, Goodnight moon, Harold and the purple crayon and Where the wild things are, in an explanation of how children are able to develop faith in an invisible, omnipresent deity.     

PERCEIVED CONTINUITY OF OCCLUDED VISUAL OBJECTS

Abstract— The human visual system does not rigidly preserve the properties of the retinal image as neural signals are transmitted to higher areas of the brain Instead, it generates a representation that captures stable surface properties despite a retinal image that is often fragmented in space and time because of occlusion caused by object and observer motion The recovery of this coherent representation depends at least in part on input from an abstract representation of three-dimensional (3-D) surface layout In the two experiments reported, a stereoscopic apparent motion display was used to investigate the perceived continuity of a briefly interrupted visual object When a surface appeared in front of the object's location during the interruption, the object was more likely to be perceived as persisting through the interruption (behind an occluder) than when the surface appeared behind the object's location under otherwise identical stimulus conditions The results reveal the influence of 3-D surface-based representations even in very simple visual tasks.     

Achieving visual object constancy across plane rotation and depth rotation.

Visual object constancy is the ability to recognise an object from its image despite variation in the image when the object is viewed from different angles. I describe research which probes the human visual system's ability to achieve object constancy across plane rotation and depth rotation. I focus on the ecologically important case of recognising familiar objects, although the recognition of novel objects is also discussed. Cognitive neuropsychological studies of patients with specific deficits in achieving object constancy are reviewed, in addition to studies which test neurally intact subjects. In certain cases, the recognition of invariant features allows objects to be recognised irrespective of the view depicted, particularly if small, distinctive sets of objects are presented repeatedly. In contrast, in most situations, recognition is sensitive to both the view in-plane and in-depth from which an object is depicted. This result suggests that multiple, view-specific, stored representations of familiar objects are accessed in everyday, entry-level visual recognition, or that transformations such as mental rotation or interpolation are used to transform between retinal images of objects and view-specific, stored representations.     

Classification objects, ideal observers & generative models

A successful vision system must solve the problem of deriving geometrical information about three-dimensional objects from two-dimensional photometric input. The human visual system solves this problem with remarkable efficiency, and one challenge in vision research is to understand how neural representations of objects are formed and what visual information is used to form these representations. Ideal observer analysis has demonstrated the advantages of studying vision from the perspective of explicit generative models and a specified visual task, which divides the causes of image variations into the separate categories of signal and noise. Classification image techniques estimate the visual information used in a task from the properties of “noise” images that interact most strongly with the task. Both ideal observer analysis and classification image techniques rely on the assumption of a generative model. We show here how the ability of the classification image approach to understand how an observer uses visual information can be improved by matching the type and dimensionality of the model to that of the neural representation or internal template being studied. Because image variation in real world object tasks can arise from both geometrical shape and photometric (illumination or material) changes, a realistic image generation process should model geometry as well as intensity. A simple example is used to demonstrate what we refer to as a “classification object” approach to studying three-dimensional object representations.     

The Development of Representations of Pretend Object Substitutions

Many theories of how pretense is mentally represented have been posited, but none have been effectually empirically tested to date. This research is the first to explore how children and adults mentally process simple pretend actions, specifically pretend object substitutions, and whether this representation changes with age. Preschoolers, older children, and undergraduates heard or read about a variety of pretend object substitutions, and their reaction time to name an image related to the object's real identity, pretend identity, or an unrelated image was measured. To test what is unique to pretense, these reaction times were compared to those from participants who responded to the same images after reading about nonpretend versions of the same actions. Results suggest that preschoolers inhibit reality when representing a pretend action, older children activate an object's real and pretend identities equally, and adults activate the object's real identity more than the pretend one. Implications for current theories of pretense representation are discussed.     

CHILDREN'S PERCEPTIONS OF CHANGES IN SIZE OF TELEVISED IMAGES

Using a Piagétan perspective, this study investigated the ways in which elementary school children perceive changes in the size of a televised image (in this case, a candy bar). The findings suggest that younger children perceive changes in image size from a medium shot to a close-up as changes in the object itself. Children's responses to changes in the televised image parallel their responses to traditional conservation tasks, but conservation of televised images occurs at a later age. In addition, children appear to use different cognitive skills to interpret how a zoom or a cut transforms the size of a televised image. When a zoom is used, children more readily perceive the object as “growing larger.”