Visual priming of inverted and rotated objects.

[Correction Notice: An erratum for this article was reported in Vol 36(4) of Journal of Experimental Psychology: Learning, Memory, and Cognition (see record 2010-12650-021). In the article, there was an error in the sixth sentence of the abstract. The sentence should read “Experiments 2 and 3 demonstrated that although identification was sensitive to orientation, visual priming was relatively invariant with image inversion (i.e., an image visually primed its inverted counterpart approximately as much as it primed itself).”] Object images are identified more efficiently after prior exposure. Here, the authors investigated shape representations supporting object priming. The dependent measure in all experiments was the minimum exposure duration required to correctly identify an object image in a rapid serial visual presentation stream. Priming was defined as the change in minimum exposure duration for identification as a function of prior exposure to an object. Experiment 1 demonstrated that this dependent measure yielded an estimate of predominantly visual priming (i.e., free of name and concept priming). Experiments 2 and 3 demonstrated that although priming was sensitive to orientation, visual priming was relatively invariant with image inversion (i.e., an image visually primed its inverted counterpart approximately as much as it primed itself). Experiment 4 demonstrated a similar dissociation with images rotated 90° off the upright. In all experiments, the difference in the magnitude of priming for identical or rotated–inverted priming conditions was marginal or nonexistent. These results suggest that visual representations that support priming can be relatively insensitive to picture-plane manipulations, although these manipulations have a substantial effect on object identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual attention and the perception of features and objects.

Feature integration theory (Treisman & Gelade, 1980) suggested that simple features are coded in parallel in a number of specialized feature maps, but that focussed attention is required to ensure the correct integration of features to specify objects. This is done by a serial scan through a master-map of locations, giving access to the features currently occupying the attended location. These are then integrated to form a representation of the object in the selected location. The present paper reviewed new evidence that has accrued since 1980 and elaborated the model to accommodate the recent findings. The proposal is that four different mechanisms may be involved in different conditions: selection of locations, directed by an externally controlled window of attention; selection by features through preattentive grouping; selection of objects; and selection for access to responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual information about time-to-collision between two objects.

Evaluated human observers' sensitivity to visual information specifying a moving object's future time of arrival at a designated position in the field of view in a forced-choice paradigm. A geometrical analysis demonstrated that information specifying a 1st-order temporal relationship (i.e., without taking changes in velocity into account) is available in the combination of the relative rate of dilation of the optical contour of the moving object and the relative rate of constriction of the optical gap separating the moving object from the target position. Observers were sensitive to information contained in the relative rate of constriction of the optical gap if no contour dilation component was present and to the combination of information contained in the relative rates of dilation of the optical contour of the moving object and constriction of the optical gap if both were present albeit with a differential weighting of the 2 components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increase in the formability of powders that are difficult to deform

The flowing capacity and relative poured density (RPD) of different fractions of original gas-sprayed high-speed steel powders and those treated in rolls as well as the strength of compacts prepared from them are studied. It is established that with this treatment powder particles are mainly broken down, and their flowability and RPD decrease. The ultimate RPD for treated powders with which quite strong compacts are obtained under normal cold pressing conditions is about 0.45.Compacts with satisfactory processing characteristics are obtained from powders with a RPD below 0.45. A relative poured density of 0.45 may serve as a production criterion of the suitability of powders that are difficult to deform for normal compaction.     

Mental representation of three-dimensional objects in visual problem solving and recognition.

Ss inspected sets of flat, separated orthographic projections of surfaces of potential 3-dimensional objects. After solving problems based on these orthographic views, Ss discriminated between isometric views of the same objects and drawings of distractor structures. Recognition of the isometrics, which had never been shown during the problem-solving phase of the experiment, was excellent. In addition, recognition of isometrics corresponding to problems that had been solved correctly when presented in orthographic form was significantly superior to recognition of isometrics based on problems solved incorrectly. In Exp 2, conditions were included in which either orthographic or isometric views functioned as problem solving or recognition displays. Only in the case of orthographic problem solving followed by isometric recognition (Exp 1) was the superiority of recognition for correctly solved problems over incorrectly solved problems obtained. The pattern of results suggests that viewers construct mental representations embodying structural information about integrated, 3-dimensional objects when asked to reason about flat, disconnected projections. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Visual attention and objects: Two-object cost with equal convexity.

Ss found perceptual judgments of location involving 2 objects to be harder than equivalent judgments involving a single object. This 2-object cost is in agreement with G. C. Baylis and J. Driver (1993). This occurred even when there was no difference in the degree of convexity of the single- and 2-object displays. Thus, parsing differences due to the degree of convexity of the displays (B. Gibson, 1994) cannot account for the present 2-object cost. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual attention and objects: Evidence for hierarchical coding of location.

In 5 experiments, it was found that judging the relative location of 2 contours was more difficult when they belonged to 2 objects rather than 1. This was observed even when the 1- and 2-object displays were physically identical, with perceptual set determining how many objects they were seen to contain. Such a 2-object cost is consistent with object-based views of attention and with a hierarchical scheme for position coding, whereby object parts are located relative to the position of their parent object. In further experiments, it was shown that in accord with this hierarchical scheme, the relative location of objects could disrupt judgments of the relative location of object parts, but the reverse did not occur. This was found even when the relative position of the parts could be judged more quickly than that of the objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual marking: Prioritizing selection for new objects by top-down attentional inhibition of old objects.

The authors propose a new mechanism for prioritizing the selection of new events: visual marking. In a modified conjunction search task the authors presented one set of distractors before the remaining items, which contained the target if present. Search was as efficient as if only the second items were presented. This held when eye movements were prevented and required a gap of 400 ms between the old and new items. The effect was abolished by luminance changes at old distractor locations when the new items appeared, and it was reduced by the addition of an attention demanding load task. The authors propose that old items can be ignored by spatially parallel, top-down attentional inhibition applied to the locations of static stimuli. The authors discuss the relations between marking and other accounts of visual selection and potential neurophysiological mechanisms. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Visual short-term memory benefit for objects on different 3-D surfaces.

Visual short-term memory (VSTM) plays an important role in visual cognition. Although objects are located on different 3-dimensional (3-D) surfaces in the real world, how VSTM capacity may be influenced by the presence of multiple 3-D surfaces has never been examined. By manipulating binocular disparities of visual displays, the authors found that more colored objects could be held in VSTM when they were placed on 2 rather than on 1 planar 3-D surfaces. This between-surface benefit in VSTM was present only when binding of objects' colors to their 3-D locations was required (i.e., when observers needed to remember which color appeared where). When binding was not required, no between-surface benefit in VSTM was observed. This benefit in VSTM could not be attributed to the number of spatial locations attended within a given surface. It was not due to a general perceptual grouping effect either, because grouping by motion and grouping by different regions of the same surface did not yield the same benefit. This increment in capacity indicates that VSTM benefits from the placement of objects in a 3-D scene. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual representation of eye gaze is coded by a nonopponent multichannel system.

To date, there is no functional account of the visual perception of gaze in humans. Previous work has demonstrated that left gaze and right gaze are represented by separate mechanisms. However, these data are consistent with either a multichannel system comprising separate channels for distinct gaze directions (e.g., left, direct, and right) or an opponent-coding system in which all gaze directions are coded by just 2 pools of cells, one coding left gaze and the other right, with direct gaze represented as a neutral point reflecting equal activation of both left and right pools. In 2 experiments, the authors used adaptation procedures to investigate which of these models provides the optimal account. Both experiments supported multichannel coding. Previous research has shown that facial identity is coded by an opponent-coding system; hence, these results also demonstrate that gaze is coded by a different representational system to facial identity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A case for inhibition: Visual attention suppresses the processing of irrelevant objects.

The present study investigated the ability to inhibit the processing of an irrelevant visual object while processing a relevant one. Participants were presented with 2 overlapping shapes (e.g., circle and square) in different colors. The task was to name the color of the relevant object designated by shape. Congruent or incongruent color words appeared in the relevant object, in the irrelevant object, or in the background. Stroop effects indicated how strong the respective area of the display was processed. The results of 4 experiments showed that words in the relevant object produced larger Stroop effects than words in the background, indicating amplification of relevant objects. In addition, words in the irrelevant object consistently produced smaller Stroop effects than words in the background, indicating inhibition of irrelevant objects. Control experiments replicated these findings with brief display durations (250 ms) and ruled out perceptual factors as a possible explanation. In summary, results support the notion of an inhibitory mechanism of object-based attention, which can be applied in addition to the amplification of relevant objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Not to be and then to be: Visual representation of ignored unfamiliar faces.

[Correction Notice: An erratum for this article was reported in Vol 26(6) of Journal of Experimental Psychology: Human Perception and Performance (see record 2007-17426-001). Beena Khurana was listed as the sole author in the original article. Dr. Khurana has indicated that the following names should have been included as authors: W. Carter Smith and Margaret T. Baker. The correct citation for the article should be Khurana, B., Smith, W. O, & Baker, M. T. (2000). Not to be and then to be: Visual representation of ignored unfamiliar faces. Journal of Experimental Psychology: Human Perception and Performance, 26, 246-263. The author note should include the following information: Experiments 1-4 made up a first-year graduate research project that was funded by a Cornell University Sage Graduate Fellowship to W. Carter Smith.] Negative priming, the increase in response time and/or errors to targets previously encountered as distractors, is explained by inhibitory mechanisms that block the access of distractor representations to response systems. The processing of unfamiliar human faces was investigated using negative priming. Observers viewed a row of faces to decide whether 2 target faces were the same or different. Response latencies were longer when 1 or both targets had appeared as distractors on the immediately preceding trial—evidence that never-before seen faces are represented and require inhibition. Response latencies were shorter when face targets had appeared as distractors, either corrupted with high-frequency noise or contrast inverted-evidence that representations are facilitated. Finally, response latencies remained unaltered when face targets had appeared as upside-down distractors—evidence that not all distractor representations afford response priming. The visual system indeed represents ignored unfamiliar faces, but blocks these representations only if they vie with targets for the control of action. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neural representation of objects in space: a dual coding account

I present evidence on the nature of object coding in the brain and discuss the implications of this coding for models of visual selective attention. Neuropsychological studies of task-based constraints on: (i) visual neglect; and (ii) reading and counting, reveal the existence of parallel forms of spatial representation for objects: within-object representations, where elements are coded as parts of objects, and between-object representations, where elements are coded as independent objects. Aside from these spatial codes for objects, however, the coding of visual space is limited. We are extremely poor at remembering small spatial displacements across eye movements, indicating (at best) impoverished coding of spatial position per se. Also, effects of element separation on spatial extinction can be eliminated by filling the space with an occluding object, indicating that spatial effects on visual selection are moderated by object coding. Overall, there are separate limits on visual processing reflecting: (i) the competition to code parts within objects; (ii) the small number of independent objects that can be coded in parallel; and (iii) task-based selection of whether within- or between-object codes determine behaviour. Between-object coding may be linked to the dorsal visual system while parallel coding of parts within objects takes place in the ventral system, although there may additionally be some dorsal involvement either when attention must be shifted within objects or when explicit spatial coding of parts is necessary for object identification.     

Uses of common objects as indicators of cultural orientations.

"A technique for the study of children's concepts of the uses of common objects… has been illustrated with American and Lebanese groups and to a lesser extent with Sudanese Ss. The study has demonstrated that in regard to universally present objects… children of different cultures differ in their ideas as early as five years of age. It has also demonstrated that the test responses enable one to formulate hypotheses concerning the interests, values, and activities which are being developed in different groups of children." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual marking and change blindness: Moving occluders and transient masks neutralize shape changes to ignored objects.

Visual search efficiency improves by presenting (previewing) one set of distractors before the target and remaining distractor items (D. G. Watson & G. W. Humphreys, 1997). Previous work has shown that this preview benefit is abolished if the old items change their shape when the new items are added (e.g., D. G. Watson & G. W. Humphreys, 2002). Here we present 5 experiments that examined whether such object changes are still effective in recapturing attention if the changes occur while the previewed objects are occluded or masked. Overall, the findings suggest that masking transients are effective in preventing both object changes and the presentation of new objects from capturing attention in time-based visual search conditions. The findings are discussed in relation to theories of change blindness, new object capture, and the ecological properties of time-based visual selection. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Illusory figures, illusory objects, and real objects.

Suggests that illusory contours are often described as occurring in special situations and, as a result, are taken to be unecological. In contrast, it can be shown that inducing conditions include displays in which there are (a) mixtures of internal and external support, (b) apparently flat and pictorially bulky elements, and (c) geometrically simple and complex organic shapes. The displays themselves may be either flat drawings or free-standing constructions. The resulting illusory figure may appear to join with (rather than occlude) the inducing elements. As a result of this diversity, it is reasonable to expect that illusory contours arise when, because of low contrast and inadequate lighting, physically real gradients become subliminal. In these cases, the contours, although perceived via illusory-contour processes, would be veridical: Some so-called "illusory" contours, if examined under better conditions, will be found to be real. This seeming paradox is no more than the defining condition of a perceptual system that may overcome inadequacies in stimulation. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual attention and objects: One versus two or convex versus concave?

According to object-based theories of visual attention, attention can be divided within a single object more efficiently than between separate objects (J. Duncan, 1984). Recently, G. C. Baylis and J. Driver (1993) provided a theoretical framework for interpreting this single-object advantage within the domain of spatial organization. Using their hierarchical coding of location hypothesis, they showed that the latency to compare the location of 2 vertices was significantly faster for vertices that were seen as parts of a single (convex) object than for vertices that were seen as parts of separate (concave) objects. This article reports the replication of this finding, as well as new evidence that shows that latency is affected by the convexity of the contour, and not by the number of objects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)