Viewpoint dependence in visual and haptic object recognition

On the whole, people recognize objects best when they see the objects from a familiar view and worse when they see the objects from views that were previously occluded from sight. Unexpectedly, we found haptic object recognition to be viewpoint-specific as well, even though hand movements were unrestricted. This viewpoint dependence was due to the hands preferring the back "view" of the objects. Furthermore, when the sensory modalities (visual vs. haptic) differed between learning an object and recognizing it, recognition performance was best when the objects were rotated back-to-front between learning and recognition. Our data indicate that the visual system recognizes the front view of objects best, whereas the hand recognizes objects best from the back.     

Experience,action and representations: Critical realism and the enactive theory of vision

This paper defends a dynamic model of the way in which perception is integrated with action, a model I refer to as ‘the navigational account’. According to this account, employing vision and other forms of distance perception, a creature acquires information about its surroundings via the senses, information that enables it to select and navigate routes through its environment, so as to attain objects that satisfy its needs. This form of perceptually guided activity should be distinguished from other kinds of semi-automatic responses to visual stimuli that do not necessarily involve conscious experiences. It essentially involves inner states, which involve both the awareness of phenomenal qualities, and also a representational component. The navigational account is compared here with the enactive approach to perception, which opposes the view that perceptual experiences are inner states. This paper argues that a full account of perception raises a number of different questions. One central explanatory project concerns questions about the kinds of processes that currently enable a creature to identify and respond appropriately to distant objects: the answer, it is argued, lies in acknowledging the role of conscious inner representations in guiding navigational behaviour through complex environments. The fact that perception and action are interdependent does not conflict with the claim that inner representational states comprise an essential stage in visual processing.

Action priming by briefly presented objects

Three experiments investigated how visual objects prime the actions they afford. The principal concern was whether such visuomotor priming depends upon a concurrent visual input--as would be expected if it is mediated by on-line dorsal system processes. Experiment 1 showed there to be essentially identical advantages for making afforded over non-afforded responses when these were made to objects still in view and following brief (30 or 50 ms) object exposures that were backward masked. Experiment 2 showed that affordance effects were also unaffected by stimulus degradation. Finally, Experiment 3 showed there to be statistically equal effects from images of objects and their names. The results suggest that an active object representation is sufficient to generate affordance compatibility effects based on associated actions, whether or not the object is concurrently visible.     

Visual space perception and action: Introductory remarks

Vision evolved from the vital necessity to act in a dynamic environment. Following this view it is clear that perceptual processes and action planning are much more interlocked than is evident at first sight. This is especially evident in visual space perception; actions are performed in space and are guided and controlled by objects in spatial positions. Here we shortly introduce the three research camps dealing with the relationship between space perception and action: the ecological camp, the two‐visual‐systems camp, and the constructivist camp. We show that these camps emphasize and open different theoretical and empirical perspectives, but that they can be seen to complement each other. We end with an overview of the papers in this special issue.     

The perceptual root of object-based storage: an interactive model of perception and visual working memory

Mainstream theories of visual perception assume that visual working memory (VWM) is critical for integrating online perceptual information and constructing coherent visual experiences in changing environments. Given the dynamic interaction between online perception and VWM, we propose that how visual information is processed during visual perception can directly determine how the information is going to be selected, consolidated, and maintained in VWM. We demonstrate the validity of this hypothesis by investigating what kinds of perceptual information can be stored as integrated objects in VWM. Three criteria for object-based storage are introduced: (a) automatic selection of task-irrelevant features, (b) synchronous consolidation of multiple features, and (c) stable maintenance of feature conjunctions. The results show that the outputs of parallel perception meet all three criteria, as opposed to the outputs of serial attentive processing, which fail all three criteria. These results indicate that (a) perception and VWM are not two sequential processes, but are dynamically intertwined; (b) there are dissociated mechanisms in VWM for storing information identified at different stages of perception; and (c) the integrated object representations in VWM originate from the "preattentive" or "proto" objects created by parallel perception. These results suggest how visual perception, attention, and VWM can be explained by a unified framework.     

Causal capture: contextual effects on the perception of collision events

In addition to perceiving the colors, shapes, and motions of objects, observers can perceive higher–level properties of visual events. One such property is causation, as when an observer sees one object cause another object to move by colliding with it. We report a striking new type of contextual effect on the perception of such collision events. Consider an object (A) that moves toward a stationary object (B) until they are adjacent, at which point A stops and B starts moving along the same path. Such "launches" are perceived in terms beyond these kinematics: As noted in Michotte's classic studies, observers perceive A as being the cause of B's motion. When A and B fully overlap before B's motion, however, observers often see this test event as a completely noncausal "pass": One object remains stationary while another passes over it. When a distinct launch event occurs nearby, however, the test event is "captured": It too is now irresistibly seen as causal. For this causal capture to occur, the context event need be present for only 50 ms surrounding the "impact," but capture is destroyed by only 200 ms of temporal asynchrony between the two events. We report a study of such cases, and others, that help define the rules that the visual system uses to construct percepts of seemingly high–level properties like causation.     

“Is It Me,or Isn't It?”—Transplanted Organs and Their Donors as Transitional Objects

There are indications in psychosomatic transplant literature that the "transitional space" (in the D.W. Winnicott's sense) plays an important part in the psychic integration of an transplanted organ or its donor. The present case study is based on a semi-standard textbook interview carried out in the course of a qualitative research program with 20 male and female patients following a lung transplant. Two transcribed passages in the text, which relate to the transplanted organ and its donor, were interpreted from the point of view of Winnicott's "transitional phenomenon" model. The case study made it clear that, even years after a lung transplant, the patient experiences the organ and donor as transitional objects. The donor, as perceived by the patient, is a living, omnipotent person who is really present and to whom the recipient attributes ideal (personality) qualities. The transplanted lung, however, insofar as a psychosomatic integration of the organ has only partially succeeded, remains in the possession of both the donor and the recipient. The donor, as a typical transitional object, performs a creative function in helping the patient to cope with everyday life. The employment of the donor or the transplanted organ as "transitional object" may be seen, above all, as a positive assimilation strategy. On the other hand, transitional phenomena may also draw attention to desintegrative processes in surmounting an organ transplant. These clinical questions are discussed at the end of the paper.     

Three-quarter views are subjectively good because object orientation is uncertain

Because the objects that surround us are three-dimensional, their appearance and our visual perception of them change depending on an object’s orientation relative to a viewpoint. One of the most remarkable effects of object orientation is that viewers prefer three-quarter views over others, such as front and back, but the exact source of this preference has not been firmly established. We show that object orientation perception of the threequarter view is relatively imprecise and that this impreciseness is related to preference for this view. Human vision is largely insensitive to variations among different three-quarter views (e.g., 45° vs. 50°); therefore, the three-quarter view is perceived as if it corresponds to a wide range of orientations. In other words, it functions as the typical representation of the object.     

Making features similar: comparison processes affect perception

In this paper, the constructive nature of comparison processes (both similarity- and differenceoriented judgments) is examined through their effects on visual perception. Previous research has shown that comparison processes enhance the tendency to interpret ambiguous objects in the light of the unambiguous objects with which they are compared (Medin, Goldstone, & Gentner, 1993). In the present paper, it is argued that comparison processes affect not only the interpretation of objects, but also their perception. In addition, it is argued that the perceptual effects of similarity-oriented comparison processes differ from those of difference-oriented comparison processes. Accordingly, it is demonstrated that when estimation of an object’s size is preceded by similarity-oriented comparisons, the Ebbinghaus illusion practically disappears, whereas prior difference-oriented comparisons tend to enhance the illusion.     

手近效应：研究内容、影响因素与神经机制

把手放在刺激旁边,会对知觉、记忆、语义和执行控制等认知加工产生影响,这类现象被称为手近效应。手近效应反映了身体与环境的互动对认知的塑造作用,为具身认知提供了新证据。本文从手近效应的内容,影响因素,及其认知、神经机制等方面对相关研究进行梳理。并从手近效应的神经机制,应用研究,以及动作意图和人际社会因素的调节作用等方面探讨当前手近效应还未解决的问题。     

When less is more: Line drawings lead to greater boundary extension than do colour photographs

Is boundary extension (false memory beyond the edges of the view) determined solely by the schematic structure of the view or does the quality of the pictorial information impact this error? To examine this, colour photographs or line-drawings of 12 multi-object scenes (Experiment 1: N=64) and 16 single-object scenes (Experiment 2: N=64) were presented for 14 s each. At test, the same pictures were each rated as being the “same”, “closer-up”, or “farther away” (five-point scale). Although the layout, the scope of the view, the distance of the main objects to the edges, the background space and the gist of the scenes were held constant, line drawings yielded greater boundary extension than did their photographic counterparts for multi-object (Experiment 1) and single-object (Experiment 2) scenes. Results are discussed in the context of the multisource model and its implications for the study of scene perception and memory.     

When a Dog Has a Pen for a Tail: the Time Course of Creative Object Processing

Creative objects differ from ordinary objects in that they are created by human beings to contain novel, creative information. Previous research has demonstrated that ordinary object processing involves both a perceptual process for analyzing different features of the visual input and a higher-order process for evaluating the relevance of this visual information. However, it is unclear how and when these processes are influenced by the creative information of the object. This study utilized event-related potentials (ERPs) to investigate the time course of creative object processing. Behavioral results revealed that participants spent more time processing creative objects than they did ordinary objects. Analysis of scalp ERPs further revealed that creative objects elicited a more negative ERP deflection between 190 and 340 ms (N190–340) with an anterior scalp distribution. Additionally, creative objects elicited more positive ERP deflection than did ordinary objects between 400 and 700 ms (P400–700) with a right centro–parietal scalp distribution and between 700 and 1000 ms (late positive component) with a right anterior–central scalp distribution. Such results suggest that the processing of creative objects is composed of two distinct stages. The early perceptual stage involves the detection of visual differences exhibited by the creative objects, while the late stage involves the right-lateralized processes of understanding and encoding the creative information.     

Grasp cueing shows obligatory attention to action goals

To understand the grounding of cognitive mechanisms in perception and action, we used a simple detection task to determine how long it takes to predict an action goal from the perception of grasp postures and whether this prediction is under strategic control. Healthy observers detected visual probes over small or large objects after seeing either a precision grip or a power grip posture. Although the posture was uninformative it induced attention shifts to the grasp-congruent object within 350 ms. When the posture predicted target appearance over the grasp-incongruent object, observers' initial strategic allocation of attention was overruled by the congruency between grasp and object. These results might help to characterize the human mirror neuron system and reveal how joint attention tunes early perceptual processes toward action prediction.     

Cognition as the Cooperative Appropriation of Affordances

Michaels (2000) expressed concerns about the implications of the notion of 2 visual systems (Milner &; Goodale, 1995) for ecological psychology. This leads her to suggest a decoupling of perception and action, by which action is separate from perception. It is suggested that although Michaels noted, on the one hand, that Milner and Goodale's approach to perception is a constructivist one, she mistakenly adopts their view that separates vision for perception from vision for action. An alternative position is presented, based on a recent article (Norman, in press), in which the parallels between the 2 visual systems, dorsal and ventral, and the 2 theoretical approaches, ecological and constructivist, are elucidated. According to this dual-process approach to perception, both systems are perceptual systems. The ecological-dorsal system is the system that picks up information about the ambient environment allowing the organism to negotiate it. It is suggested that this type of perception always processes the relevant information for action and that there is no need to sever the perception-action coupling. Ecological psychology and the 2 visual systems are quite compatible, and there is no need for concern.     

Influence of object size on baseline identification, priming, and explicit memory

We investigated the influence of size on identification, priming, and explicit memory for color photos of common objects. Participants studied objects displayed in small, medium, and large sizes and memory was assessed with both implicit identification and explicit recognition tests. Overall, large objects were easier to identify than small objects and study-to-test changes in object size impeded performance on explicit but not implicit memory tests. In contrast to previous findings with line-drawings of objects but consistent with predictions from the distance-as-filtering hypothesis, we found that study-test size manipulations had large effects on old/new recognition memory test for objects displayed in large size at test but not for objects displayed small or medium at test. Our findings add to the growing body of literature showing that the findings obtained using line-drawings of objects do not necessarily generalize to color photos of common objects. We discuss implications of our findings for theories of object perception, memory, and eyewitness identification accuracy for objects.     

ERP evidence for temporal independence of set size and object updating in object substitution masking

To keep track of dynamically changing objects in one’s environment, it is necessary to individuate them from other objects, both temporally and spatially. Spatially, objects can be selected from nearby distractors using selective attention. Temporally, object updating processes incorporate new information into existing representations over time. Both of these processes have been implicated in a type of visual masking called object-substitution masking (OSM). Previous studies have found that the number of distractors (impacting selective attention) interacts with the strength of OSM. However, it has been suggested that this interaction is an artifact of ceiling performance at low set sizes, rather than necessitating a failure of attention during masking. Using event-related potentials (ERPs), we examined whether set size and masking interact as measured by markers of selective attention (N2pc) and visual working memory consolidation/maintenance (SPCN). Set size was found to affect the N2pc (200–350 ms) and late SPCN (500–650 ms), reflecting increased demands on selective attention and unnecessary storage respectively. An early window of the SPCN (350–500 ms) was affected by masking, suggesting that OSM influences object consolidation processes in this window, independent of the number of distractors. Overall, it was found that selective attention and visual awareness are dissociable neural processes in OSM, and that they are independently affected by set size and masking manipulations. Moreover, we found that the early SPCN may reflect disruptions to object consolidation, potentially revealing a neural mechanism supporting an object individuation-through-updating account of OSM.     

Discrimination of contour-deleted images in baboons (<Emphasis Type="Italic">Papio papio</Emphasis>) and chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)

Humans readily group component elements into a coherent perceptual whole and perceive the global form of visual patterns in priority over local features, which stands in contrast to at least some data from the animal literature, suggesting possible species differences in perceptual processes. In this study, chimpanzees and baboons were required to match intact and partially contour-deleted line-drawings in a computerized task in order to further explore the ability of nonhuman primates to group component elements into a coherent perceptual whole and to determine to what extent they use the global form or the local features. Experiment 1 showed that the baboons and chimpanzees matched intact continuous line-drawings (intact-intact) more easily than partially contour-deleted line-drawings (deleted-deleted). Both species could also match partially deleted line-drawings with their intact version (deleted-intact), but at a lower performance level. Experiment 2 further showed that subjects from the two species could match partially deleted coherent line-drawings (deleted-deleted) more easily than their scrambled incoherent versions (scrambled-scrambled). They could however match the coherent deleted forms with their scrambled version (deleted-scrambled). It is suggested that solutions of these tasks rely on the processing of both global and local cues, with no clear-cut species difference in that ability. Overall, the results show that contour completion of line-drawings was not easy. Implications on the processing of human-made two-dimensional representations such as line-drawings are discussed.     

Denial of visual perception.

An adult with the diagnosis of cortical blindness, complaining of a complete visual loss of 2 years in duration, was found to have a small preserved visual field and remarkably preserved visual abilities. Although denying visual perception, he correctly named objects, colors, and famous faces, recognized facial emotions, and read various types of single words with greater than 50% accuracy when presented in the upper right visual field. Upon confrontation regarding his apparent visual abilities, the patient continued to deny visual perceptual awareness, typically stating "I feel it." CT indicated bioccipital lesions sparing the left inferior occipital area but involving the left parietal lobe. The denial of visual perception evidenced by this patient may be explained by a disconnection of parietal lobe attentional systems from visual perception. The clinical presentation is described as representing "inverse Anton's syndrome."     

Visual motion disambiguation by a subliminal sound

There is growing interest in the effect of sound on visual motion perception. One model involves the illusion created when two identical objects moving towards each other on a two-dimensional visual display can be seen to either bounce off or stream through each other. Previous studies show that the large bias normally seen toward the streaming percept can be modulated by the presentation of an auditory event at the moment of coincidence. However, no reports to date provide sufficient evidence to indicate whether the sound bounce-inducing effect is due to a perceptual binding process or merely to an explicit inference resulting from the transient auditory stimulus resembling a physical collision of two objects. In the present study, we used a novel experimental design in which a subliminal sound was presented either 150 ms before, at, or 150 ms after the moment of coincidence of two disks moving towards each other. The results showed that there was an increased perception of bouncing (rather than streaming) when the subliminal sound was presented at or 150 ms after the moment of coincidence compared to when no sound was presented. These findings provide the first empirical demonstration that activation of the human auditory system without reaching consciousness affects the perception of an ambiguous visual motion display.