1
|
Nakada H, Murakami I. Local motion signals silence the perceptual solution of global apparent motion. J Vis 2023; 23:12. [PMID: 37378990 DOI: 10.1167/jov.23.6.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023] Open
Abstract
Stimuli for apparent motion can have ambiguity in frame-to-frame correspondences among visual elements. This occurs when visual inputs cause a correspondence problem that allows multiple alternatives of perceptual solutions. Herein we examined the influence of local visual motions on a perceptual solution under such a multistable situation. We repeatedly alternated two frames of stimuli in a circular configuration in which discrete elements in two different colors alternated in space and switched their colors frame by frame. These stimuli were compatible with three perceptual solutions: globally consistent clockwise and counterclockwise rotations and color flickers at the same locations without such global apparent motion. We added a sinusoidal grating continuously drifting within each element to examine whether the perceptual solution for the global apparent motion was affected by the local continuous motions. We found that the local motions suppressed global apparent motion and promoted another perceptual solution that the local elements were only flickering between the two colors and drifting within static windows. It was concluded that local continuous motions as counterevidence against global apparent motion contributed to individuating visual objects and integrating visual features for maintaining object identity at the same location.
Collapse
Affiliation(s)
- Hoko Nakada
- Department of Psychology, The University of Tokyo, Tokyo, Japan
| | - Ikuya Murakami
- Department of Psychology, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
2
|
Jiang H. Effects of Transient and Nontransient Changes of Surface Feature on Object Correspondence. Perception 2020; 49:452-467. [DOI: 10.1177/0301006620913238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Object correspondence is a fundamental problem in perception. Classic theories hold that the computation of correspondence is solely based on spatiotemporal information. Recent research showed that surface features also play an important role. However, the surface features of objects in many studies did not change throughout a trial. This study investigated the effect of feature change on object correspondence using the object-reviewing paradigm. Two moving objects underwent transient feature changes on color dimension (Experiment 1A) or a combination of three dimensions (Experiment 2A). Moreover, the objects moved behind four occluders to make the feature change nontransient (Experiments 1B and 2B). Object-specific preview benefits were reduced or eliminated when feature changes were transient, but the benefits were not affected when feature changes were nontransient. The effects of transient versus nontransient changes of surface feature in object correspondence are discussed.
Collapse
Affiliation(s)
- Hao Jiang
- Institute of Aviation Human Factors and Ergonomics, Civil Aviation Flight University of China, Sichuan, China
| |
Collapse
|
3
|
Abstract
The visual system needs to solve the correspondence problem (i.e., which elements belong together across space and time) to allow stable representations of objects. It has been shown that spatiotemporal and feature information can influence this correspondence process, but it is unclear how these factors interact with each other, especially when they are more or less prominent due to changes in contrast magnitude. We investigated this question using a variation of the Ternus display, an ambiguous apparent motion display, in which three elements can either be perceived as moving together (group motion) or as one element jumping across the others (element motion). In the first experiment, we biased the percept by presenting some of the elements with the same feature (isoluminant color or luminance), such that they were either compatible with group motion or with element motion (simple feature biases). To change the strength of the feature bias, we manipulated the contrast magnitude of the feature. In three more experiments we introduced competitive displays, in which some of the elements showed a color/luminance based element bias of varying contrast magnitude, while other elements showed a luminance/color based group bias of varying contrast magnitude (competing feature bias). We found that for a simple feature bias the contrast magnitude did not affect the strength of the bias. For competing feature biases, however, the contrast magnitude did influence correspondence, as the bias strength increased with contrast. The implications of our results for current motion and feature-based theories of correspondence are discussed.
Collapse
|
4
|
Mitsven SG, Cantrell LM, Luck SJ, Oakes LM. Visual short-term memory guides infants' visual attention. Cognition 2018; 177:189-197. [PMID: 29704857 PMCID: PMC5975244 DOI: 10.1016/j.cognition.2018.04.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 04/08/2018] [Accepted: 04/19/2018] [Indexed: 10/17/2022]
Abstract
Adults' visual attention is guided by the contents of visual short-term memory (VSTM). Here we asked whether 10-month-old infants' (N = 41) visual attention is also guided by the information stored in VSTM. In two experiments, we modified the one-shot change detection task (Oakes, Baumgartner, Barrett, Messenger, & Luck, 2013) to create a simplified cued visual search task to ask how information stored in VSTM influences where infants look. A single sample item (e.g., a colored circle) was presented at fixation for 500 ms, followed by a brief (300 ms) retention interval and then a test array consisting of two items, one on each side of fixation. One item in the test array matched the sample stimulus and the other did not. Infants were more likely to look at the non-matching item than at the matching item, demonstrating that the information stored rapidly in VSTM guided subsequent looking behavior.
Collapse
Affiliation(s)
- Samantha G Mitsven
- Center for Mind and Brain, University of California, Davis, United States
| | - Lisa M Cantrell
- Center for Mind and Brain, University of California, Davis, United States
| | - Steven J Luck
- Center for Mind and Brain, University of California, Davis, United States; Department of Psychology, University of California, Davis, United States
| | - Lisa M Oakes
- Center for Mind and Brain, University of California, Davis, United States; Department of Psychology, University of California, Davis, United States.
| |
Collapse
|
5
|
Allen R, McGeorge P, Pearson DG, Milne A. Multiple-Target Tracking: A Role for Working Memory? Q J Exp Psychol (Hove) 2018; 59:1101-16. [PMID: 16885145 DOI: 10.1080/02724980543000097] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In order to identify the cognitive processes associated with target tracking, a dual-task experiment was carried out in which participants undertook a dynamic multiple-object tracking task first alone and then again, concurrently with one of several secondary tasks, in order to investigate the cognitive processes involved. The research suggests that after designated targets within the visual field have attracted preattentive indexes that point to their locations in space, conscious processes, vulnerable to secondary visual and spatial task interference, form deliberate strategies beneficial to the tracking task, before tracking commences. Target tracking itself is realized by central executive processes, which are sensitive to any other cognitive demands. The findings are discussed in the context of integrating dynamic spatial cognition within a working memory framework.
Collapse
Affiliation(s)
- Roy Allen
- School of Psychology, University of Aberdeen, Aberdeen, UK.
| | | | | | | |
Collapse
|
6
|
Abstract
Object tokens are episodic visual representations that mediate the ability to track visual events as they move about and change over time. Multiple tokens also allow the viewer to individuate multiple instances of a single type of object. In the present study, we established a functional link for object tokens in two seemingly disparate visual phenomena: apparent motion and repetition blindness (RB). In RB, repeated items are more difficult to perceive than unrepeated items. Using displays in which two sets of alphanumeric characters streamed in opposite directions across a computer screen in apparent motion, we found increased RB for targets appearing within a single apparent motion stream, relative to targets in different apparent motion streams. The results are inconsistent with refractory period or memory retrieval accounts of RB and support the role of object tokens in both apparent motion and RB.
Collapse
|
7
|
Abstract
To maintain stable object representations as our eyes or the objects themselves move, the visual system must determine how newly sampled information relates to existing object representations. To solve this correspondence problem, the visual system uses not only spatiotemporal information (e.g., the spatial and temporal proximity between elements), but also feature information (e.g., the similarity in size or luminance between elements). Here we asked whether motion correspondence relies solely on image-based feature information, or whether it is influenced by scene-based information (e.g., the perceived sizes of surfaces or the perceived illumination conditions). We manipulated scene-based information separately from image-based information in the Ternus display, an ambiguous apparent-motion display, and found that scene-based information influences how motion correspondence is resolved, indicating that theories of motion correspondence that are based on "scene-blind" mechanisms are insufficient.
Collapse
|
8
|
|
9
|
Hein E, Moore CM. Spatio-temporal priority revisited: the role of feature identity and similarity for object correspondence in apparent motion. J Exp Psychol Hum Percept Perform 2012; 38:975-88. [PMID: 22564159 DOI: 10.1037/a0028197] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We live in a dynamic environment in which objects change location over time. To maintain stable object representations the visual system must determine how newly sampled information relates to existing object representations, the correspondence problem. Spatiotemporal information is clearly an important factor that the visual system takes into account when solving the correspondence problem, but is feature information irrelevant as some theories suggest? The Ternus display provides a context in which to investigate solutions to the correspondence problem. Two sets of three horizontally aligned disks, shifted by one position, were presented in alternation. Depending on how correspondence is resolved, these displays are perceived either as one disk "jumping" from one end of the row to the other (element motion) or as a set of three disks shifting back and forth together (group motion). We manipulated a feature (e.g., color) of the disks such that, if features were taken into account by the correspondence process, it would bias the resolution of correspondence toward one version or the other. Features determined correspondence, whether they were luminance-defined or not. Moreover, correspondence could be established on the basis of similarity, when features were not identical between alternations. Finally, the stronger the feature information supported a certain correspondence solution the more it dominated spatiotemporal information.
Collapse
Affiliation(s)
- Elisabeth Hein
- Laboratoire Psychologie de la Perception, Université Paris Descartes, Sorbonne Paris Cité, and Centre National de la Recherche Scientifique Unités Mixtes de Recherche 8158, Paris, France.
| | | |
Collapse
|
10
|
Navon D, Kasten R. A demonstration of direct access to colored stimuli following cueing by color. Acta Psychol (Amst) 2011; 138:30-8. [PMID: 21621179 DOI: 10.1016/j.actpsy.2011.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2010] [Revised: 05/01/2011] [Accepted: 05/04/2011] [Indexed: 11/19/2022] Open
Abstract
To test whether cueing by color can affect orienting without first computing the location of the cued color, the impact of reorienting on the validity effect was examined. In Experiment 1 subjects were asked to detect a black dot target presented at random on either of two colored forms. The forms started being presented 750 ms before the onset of a central cue (either an arrow or a colored square). In some proportion of the trials the colors switched locations 150 ms after cue onset, simultaneously with target onset. The color switch was not found to retard responses following a color cue more than following a location cue. Furthermore, it did not reduce the validity effect of the color cue: Though the validity effect of the location cue was quite larger than the validity effect of the color cue, both effects were additive with the presence/absence of a color switch. In Experiment 2, subjects were rather asked to detect a change in shape of one of the colored forms. In this case, color switch was found to affect performance even less following a color cue. The fact that across experiments, color switch did not retard neither responding nor orienting selectively in the color cue condition, indicates that when attention is set to a certain color, reorienting to a new object following color switch does not require re-computing the address of the cued color. That finding is argued to embarrass a strong space-based view of visual attention.
Collapse
|
11
|
Watamaniuk SNJ, Sekuler R, McKee SP. Perceived global flow direction reveals local vector weighting by luminance. Vision Res 2011; 51:1129-36. [PMID: 21396393 DOI: 10.1016/j.visres.2011.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/25/2011] [Accepted: 03/04/2011] [Indexed: 10/18/2022]
Abstract
Global flow occurs when random dots, each selecting their direction of motion randomly each frame from a distribution of directions spanning up to 180°, appear to move as a whole in the mean direction of the components. This percept arises because the visual system integrates the many independent local motion signals over space and time. Through a series of direction discrimination experiments with random-dot cinematograms (RDCs), we show that varying the luminance of dots over a suprathreshold range profoundly affects perceived direction; the brightest dots appear to be weighted more and dimmer dots weighted less when determining perceived global direction. This effect is not observable if all dots in the display have the same luminance but only when the display contains dots with different luminance values. The results are consistent with energy models of motion detectors whose responses are contrast dependent. A Monte Carlo simulation of global direction discrimination employing a 12-mechanism line-element model that weighted the local motion vectors by the normalized squared contrast of the component dots (a proxy for contrast energy) captured well the features of the experimental data.
Collapse
Affiliation(s)
- Scott N J Watamaniuk
- Department of Psychology, 3640 Col. Glenn Hwy, Wright State University, Dayton, OH 45435, USA.
| | | | | |
Collapse
|
12
|
Petersik JT, Rice CM. Spatial correspondence and relation correspondence: grouping factors that influence perception of the Ternus display. Perception 2008; 37:725-39. [PMID: 18605146 DOI: 10.1068/p5900] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
We cite two different perceptual-correspondence principles whose emphasis can help to disambiguate the otherwise ambiguous Ternus display in apparent movement (a display that can alternately be seen in one of two possible configurations). One of these principles is spatial correspondence, which emphasizes the maintenance of similar stimulus elements in given locations over time. The other principle is relation correspondence, which emphasizes the maintenance of the inter-organization of stimulus elements across frames. Each of four experiments reported here made use of a different stimulus feature (eg element color or element texture) to emphasize these different correspondence principles in Ternus displays. As predicted, an emphasis upon spatial correspondence resulted in an increase in reports of element movement compared to a featureless control condition. Emphasis on relation correspondence resulted in an increase in reports of group movement. Extensions and limitations of the use of these principles to explain apparent movement are discussed.
Collapse
|
13
|
Abstract
When dissimilar monocular images are presented separately to each of a person's eyes, these images compete for visual dominance, with dominance of one image or the other alternating over time. While this phenomenon, called binocular rivalry, transpires, local image features distributed over space and between the eyes can become visually dominant at the same time; the resulting global figure implicates interocular grouping. Previous studies have suggested that color tends to influence the incidence of global dominance; in this study, we assess whether illusory color can also influence interocular grouping. To test this, we exploited the McCollough effect, an orientation-contingent color aftereffect induced by prolonged adaptation to different colors paired with different orientations. Results show that during binocular rivalry, illusory colors induced by the McCollough adaptation enhance strong interocular grouping relative to preadaptation testing, to an extent comparable in strength with the enhancement induced by real colors. Thus, illusory colors that are present only in an observer's mind are sufficiently potent to influence low-level visual processes such as binocular rivalry.
Collapse
Affiliation(s)
- Chai-Youn Kim
- Department of Psychology, Vanderbilt University, Nashville, Tennessee 37203, USA.
| | | |
Collapse
|
14
|
Tse PU, Caplovitz GP. Contour discontinuities subserve two types of form analysis that underlie motion processing. PROGRESS IN BRAIN RESEARCH 2007; 154:271-92. [PMID: 17010718 DOI: 10.1016/s0079-6123(06)54015-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Form analysis subserves motion processing in at least two ways: first, in terms of figural segmentation dedicated to solving the problem of figure-to-figure matching over time, and second, in terms of defining trackable features whose unambiguous motion signals can be generalized to ambiguously moving portions of an object. The former is a primarily ventral process involving the lateral occipital complex and also retinotopic areas such as V2 and V4, and the latter is a dorsal process involving V3A. Contour discontinuities, such as corners, deep concavities, maxima of positive curvature, junctions, and terminators, play a central role in both types of form analysis. Transformational apparent motion will be discussed in the context of figural segmentation and matching, and rotational motion in the context of trackable features. In both cases the analysis of form must proceed in parallel with the analysis of motion, in order to constrain the ongoing analysis of motion.
Collapse
Affiliation(s)
- Peter Ulric Tse
- H B 6207, Moore Hall, Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA.
| | | |
Collapse
|
15
|
Sterzer P, Kleinschmidt A. A neural signature of colour and luminance correspondence in bistable apparent motion. Eur J Neurosci 2005; 21:3097-106. [PMID: 15978019 DOI: 10.1111/j.1460-9568.2005.04133.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The 'correspondence problem' refers to the ambiguity of apparent motion (AM) paths if several similar objects are displaced across successive displays. We investigated the effect of intrinsic object properties such as colour and luminance on AM paths, and used functional magnetic resonance imaging to localize neural correlates of correspondence matching in visual cortical regions. Human subjects looked at an AM display where two dots in diagonally opposite corners of an implicit rectangle were flashed in alternation with two dots in the other two corners, yielding spontaneous alternations between horizontal and vertical AM. The dots differed in colour or luminance, or were identical. Neural activity was analysed as a function of whether the perceived AM path matched the dots' colour or luminance, and was also compared to activity during bistable AM displays without correspondence cues. When AM paths matched colour and luminance cues, activity in early visual cortex was the same as during perception of uncued displays, whereas it was suppressed when perceived AM paths violated colour or luminance cues. Colour-sensitive extrastriate cortex (V4 complex) transiently activated whenever AM perception switched from a pattern violating colour correspondence to one consistent with colour. We propose that the neural correlate of correspondence in early visual cortex reflects regulatory mechanisms that flexibly gate early visual feature processing in accord with an overriding perceptual decision. Conversely, activation of feature-selective extrastriate regions depends on the type of cue used for correspondence matching and may reflect the salience of percepts that match in colour and motion.
Collapse
Affiliation(s)
- Philipp Sterzer
- Cognitive Neurology Unit, Department of Neurology, Johann Wolfgang Goethe University, Frankfurt-am-Main, Germany.
| | | |
Collapse
|
16
|
Abstract
The present study explored the effects of luminance, color, and distance on apparent motion direction of some repeated stimuli of alternating colors. Two experiments were performed to specify what affects apparent motion direction when the stroboscopic alternative is between proximity and similarity in color. In Exp. 1 the influence of luminance on apparent motion was systematically studied with seven different background luminance values. Analysis pointed out that apparent motion direction depends on the discriminability among the disks, in relation also to the background values. A formula to predict the apparent motion direction from luminance values was proposed. In Exp. 2 the influence of hue on apparent motion was studied. Stimuli with equiluminant disks on different backgrounds were used. Analysis pointed out that the stroboscopic unification was based mainly on proximity and that discriminability between the disks was rather poor, especially when apparent motion occurred also on an equiluminant background, as already pointed out by Ramachandran and Gregory in 1978. A different influence on apparent motion of the red-blue and red-green disks, as opposed to that of the blue-green ones, was also noted.
Collapse
|
17
|
|
18
|
Cole GG, Heywood C, Kentridge R, Fairholm I, Cowey A. Attentional capture by colour and motion in cerebral achromatopsia. Neuropsychologia 2003; 41:1837-46. [PMID: 14527546 DOI: 10.1016/s0028-3932(03)00184-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cerebral achromatopsia is a rare condition in which damage to the ventromedial occipital area of the cortex results in the loss of colour experience. Nevertheless, cortically colour-blind patients can still use wavelength variation to perceive form and motion. In a series of six experiments we examined whether colour could also direct exogenous attention in an achromatopsic observer. We employed the colour singleton paradigm, the phi motion effect, and the correspondence process to assess attentional modulation. Although colour singletons failed to capture attention, a motion signal, based solely on chromatic information, was able to direct attention in the patient. We then show that the effect is abolished when the chromatic contours of stimuli are masked with simultaneous luminance contrast. We argue that the motion effect is dependent on chromatic contrast mediated via intact colour-opponent mechanisms. The results are taken as further evidence for the processing of wavelength variation in achromatopsia despite the absence of colour experience.
Collapse
Affiliation(s)
- Geoff G Cole
- Department of Psychology, University of Durham, South Road, Durham DH1 3LE, UK.
| | | | | | | | | |
Collapse
|
19
|
Tse PU, Logothetis NK. The duration of 3-d form analysis in transformational apparent motion. PERCEPTION & PSYCHOPHYSICS 2002; 64:244-65. [PMID: 12013379 DOI: 10.3758/bf03195790] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Transformational apparent motion (TAM) occurs when a figure changes discretely from one configuration to another overlapping configuration. Rather than an abrupt shape change, the initial shape is perceived to transform smoothly into the final shape as if animated by a series of intermediate shapes. We find that TAM follows an analysis of form that takes 80-140 msec. Form analysis can function both at and away from equiluminance and can occur over contours defined by uniform regions as well as outlines. Moreover, the forms analyzed can be 3-D, resulting in motion paths that appear to smoothly project out from or into the stimulus plane. The perceived transformation is generally the one that involves the least change in the shape or location of the initial figure in a 3-D sense. We conclude that perception of TAM follows an analysis of 3-D form that takes approximately 100 msec. This stage of form analysis may be common to both TAM and second-order motion.
Collapse
Affiliation(s)
- Peter Ulric Tse
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | | |
Collapse
|
20
|
Li HC, Kingdom FA. Segregation by color/luminance does not necessarily facilitate motion discrimination in the presence of motion distractors. PERCEPTION & PSYCHOPHYSICS 2001; 63:660-75. [PMID: 11436736 DOI: 10.3758/bf03194428] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Under what circumstances is the common motion of a group of elements more easily perceived when the elements differ in color and/or luminance polarity from their surround? Croner and Albright (1997), using a conventional global motion paradigm, first showed that motion coherence thresholds fell when target and distractor elements were made different in color. However, in their paradigm, there was a cue in the static view of the stimulus as to which elements belonged to the target. Arguably, in order to determine whether the visual system automatically groups, or prefilters, the image into different color maps for motion processing, such static form cues should be eliminated. Using various arrangements of the global motion stimulus in which we eliminated all static form cues, we found that global motion thresholds were no better when target and distractors differed in color than when they were identical, except under certain circumstances in which subjects had prior knowledge of the specific target color. We conclude that, in the absence of either static form cues or the possibility of selective attention to the target color, features with similar colors/luminance-polarities are not automatically grouped for global motion analysis.
Collapse
Affiliation(s)
- H C Li
- Department of Industrial Psychology, Kwangwoon University, Nowon-Gu, Wolgae-Dong, 447-1, Seoul, Korea.
| | | |
Collapse
|
21
|
Oyama T, Simizu M, Tozawa J. Effects of similarity on apparent motion and perceptual grouping. Perception 2000; 28:739-48. [PMID: 10664768 DOI: 10.1068/p2799] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Effects of similarity in colour, luminance, size, and shape on apparent motion and perceptual grouping were examined in part 1 in two parallel experiments on the same seven subjects. In both experiments, the effect of similarity was compared with that of proximity in competitive, bistable stimulus situations. A combination of a larger horizontal separation between the homogeneous stimulus elements and a smaller constant vertical separation between heterogeneous stimulus elements produced two kinds of apparent motion (or perceptual grouping) with equal probabilities. Such matched separations between homogeneous stimulus elements were obtained by the double staircase method in various stimulus conditions. In both experiments on apparent motion and perceptual grouping matched separation was found to increase as the difference between the heterogeneous stimulus elements increased. High correlations (0.71 to 0.94) of matched separations were found between apparent motion and perceptual grouping in four stimulus series: colour, luminance, size, and shape. Six of the seven subjects were also tested in part 2. Here, the effects of differences were found to work additively across different perceptual attributes in both phenomena, when multiple differences were combined in heterogeneous elements. The experimental results are discussed from the point of view that apparent motion is an example of perceptual constancy.
Collapse
Affiliation(s)
- T Oyama
- Department of Psychology, Nihon University, Tokyo, Japan.
| | | | | |
Collapse
|
22
|
Abstract
The primate visual system uses form cues-such as hue, contrast polarity, luminance, and texture-to segment complex retinal images into the constituent objects of the visual scene. We investigated whether segmentation of dynamic images on the basis of hue, luminance contrast polarity, or luminance contrast amplitude aids discrimination of motion direction. Human subjects viewed dynamic displays of randomly positioned dots, in which a variable proportion of the dots moved in the same direction at the same speed ("signal" dots) while the remaining dots were randomly displaced ("noise" dots). In agreement with previous reports, we observed a reliable relationship between the strength of the motion signal and subjects' ability to discriminate motion direction, enabling the measurement of thresholds for direction discrimination. When signal dots had a different luminance contrast amplitude than noise dots, direction discrimination performance was directly related to the relative contrast of the signal dots, demonstrating the importance of matching the perceived contrast amplitude of signal and noise tokens when testing the effects of segmentation by other cues. When Michelson luminance contrast was matched, distinguishing signal from noise dots by hue or by luminance contrast polarity strongly improved direction discrimination, lowering thresholds by an average factor of five. These results reveal a strong influence of form cues on motion processing in the human visual system, and suggest that segmentation on the basis of form cues occurs prior to motion processing.
Collapse
Affiliation(s)
- L J Croner
- Vision Center Laboratory, Salk Institute, La Jolla, CA 92037, USA.
| | | |
Collapse
|
23
|
Sekuler AB, Bennett PJ. Spatial phase differences can drive apparent motion. PERCEPTION & PSYCHOPHYSICS 1996; 58:174-90. [PMID: 8838163 DOI: 10.3758/bf03211874] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Can shape differences drive apparent motion? Results from previous research are equivocal. Much of the confusion may be due to the use of relatively complex stimuli: letters or geometric shapes, comprising many spatial frequencies, phases, orientations, and contrasts. We focus on relatively simple stimuli: Gaussian damped f+nf compound sinewave gratings. We examine whether relative phase differences, which are critical for shape perception, can drive apparent motion. We find that some, but not all, phase differences can drive apparent motion. Specifically, stimuli that are easily discriminable and perceptually dissimilar can affect the solution of the correspondence problem. In this case, observers consistently perceive stimuli in one frame moving to the position of perceptually similar stimuli in the next frame. This general result holds over a wide range of spatial frequencies, orientations, and contrasts. Implications for theories of motion processing are discussed.
Collapse
|
24
|
A unified approach to the perception of motion, stereo, and static-flow patterns. ACTA ACUST UNITED AC 1995. [DOI: 10.3758/bf03200441] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
25
|
Abstract
Two experiments were conducted to examine the effect of changes in the sign of element contrast on perceptions of the Ternus apparent motion display. In the first experiment, the contrast polarity of all three elements in the display were alternated from the first frame of view to the second. At short durations, this increased perceptions (relative to a control condition) of simultaneity in the display, decreased perceptions of element motion, and did not significantly affect perceptions of group motion. At long durations, this manipulation did not affect performance. In a second experiment, patterns of element polarity were manipulated to favour perceptions of either element motion or of group motion relative to a control condition in which all elements had identical contrast polarity. At a long duration, this manipulation affected perceptions of the configuration; this manipulation did not affect the appearance of the display at a short duration. Together, these results are inconsistent with the predictions of Grossberg and Rudd's [Psychological Review, 99, 78-121 (1992)] motion oriented contrast filter. However, they are consistent with a model of motion correspondence processing that includes a polarity matching constraint.
Collapse
Affiliation(s)
- M R Dawson
- Department of Psychology, University of Alberta, Edmonton, Canada
| | | | | |
Collapse
|
26
|
Oyama T, Naito K, Naito H. Long-range apparent motion as a result of perceptual organisation. Perception 1994; 23:269-86. [PMID: 7971106 DOI: 10.1068/p230269] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Five kinds of percept have been found to occur when two different stimulus objects are simultaneously presented, exchanging positions with each other in successive exposures. These five percepts can be classified as follows: (i) Appearance-Disappearance (succession), (ii) Lateral Motion, (iii) Depth Motion, (iv) Transmutation (in colour, brightness, and/or shape), and (v) Overlapping (simultaneity). Results of three experiments indicate that relative dominance among these five percepts systematically depends upon differences between the two stimulus objects in colour, luminance, shape, and size. The relative dominance depended upon the stimulus onset asynchrony (SOA) between successive presentations and on the spatial separation between the two objects. Lateral Motion became more dominant as a result of (a) an increase in the number of stimulus attributes differing between the two objects, (b) an increase in the SOA, or (c) a decrease in the distance between the two objects. Colour difference, even without a luminance difference, was one of the determinants for Lateral Motion. Depth Motion frequently occurred when the two objects differed in size and the SOA and the distances between them were relatively great. Transmutation occurred when the objects differed in colour, luminance, or shape. Perceptual modes (ii) to (iv) can be understood as different results of perceptual organisation that always maintains perceptual identity of objects and maintains perceptual constancy of their attributes as much as possible. Long-range apparent motion could be a result of such perceptual organisation.
Collapse
Affiliation(s)
- T Oyama
- Department of Psychology, Nihon University, Tokyo, Japan
| | | | | |
Collapse
|
27
|
Dobkins KR, Albright TD. What happens if it changes color when it moves?: psychophysical experiments on the nature of chromatic input to motion detectors. Vision Res 1993; 33:1019-36. [PMID: 8506643 DOI: 10.1016/0042-6989(93)90238-r] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Several lines of evidence indicate that the processing of motion by the primate visual system continues even when a moving stimulus differs from its surroundings by color alone. To illuminate the mechanisms by which our visual system uses color as a token for motion correspondence, we have developed an "apparent motion" paradigm in which red/green sine-wave gratings undergo reversal of chromatic contrast sign each time they are displaced in a particular direction. Under such conditions, correspondence based upon conservation of chromatic sign conflicts with correspondence based upon chromatically-defined borders. When these heterochromatic stimuli also possess luminance modulation, motion is always perceived in the direction in which the sign of luminance contrast is preserved. At isoluminance, however, two very different chromatic influences on motion detection are revealed. First, when stimuli undergo small spatial displacements, motion is perceived in the direction of the nearest chromatically-defined border even when the sign of chromatic contrast at that border alternates over time. Under these conditions, motion detectors apparently exploit information about image borders defined by color while sacrificing information about the colors that make up those borders. By contrast, when spatial displacement is large, motion is more apt to be perceived in the direction for which sign of chromatic contrast is preserved. In this instance, information about the polarity of chromatic contrast facilitates motion detection. These results suggest that chromatic signals contributing to motion detection are of two distinct types. This conclusion has implications for the degree of crosstalk between magnocellular and parvocellular processing streams in the primate visual system and it reinforces our understanding of how image features affect the way we see things move.
Collapse
|
28
|
Ohtani Y, Takemoto A, Kaihara T, Ejima Y. On the loss of apparent motion between isolated chromatic stimuli near isoluminance. Vision Res 1993; 33:935-8. [PMID: 8506636 DOI: 10.1016/0042-6989(93)90076-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Long range apparent motion (AM) between two isolated stimuli breaks down following prolonged inspection. Time-till-breakdown (TTB) for AM between random-dot squares (red or green) on a red random-dot background was measured as a function of luminance contrast of the stimuli against the background. For the same-color (red squares on the red background) and the different-color (green squares on the red background) conditions, TTB showed clear dependence on the luminance contrast, diminishing with decreasing the contrast. Near isoluminance (luminance contrast of approx. -14 to +14%), AM for the same-color condition disappeared, but AM for the different-color condition was clearly seen and persisted for 7-14 sec. These results show that AM can be produced by color alone. Previous controversial question on the loss of long range AM near isoluminance may be explained by taking into account the contrast dependence of the breakdown effect and the experimental procedures employed.
Collapse
Affiliation(s)
- Y Ohtani
- Department of Liberal Arts and Sciences, Faculty of Engineering, Toyama Prefectural University, Japan
| | | | | | | |
Collapse
|
29
|
Kahneman D, Treisman A, Gibbs BJ. The reviewing of object files: object-specific integration of information. Cogn Psychol 1992; 24:175-219. [PMID: 1582172 DOI: 10.1016/0010-0285(92)90007-o] [Citation(s) in RCA: 1058] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A series of experiments explored a form of object-specific priming. In all experiments a preview field containing two or more letters is followed by a target letter that is to be named. The displays are designed to produce a perceptual interpretation of the target as a new state of an object that previously contained one of the primes. The link is produced in different experiments by a shared location, by a shared relative position in a moving pattern, or by successive appearance in the same moving frame. An object-specific advantage is consistently observed: naming is facilitated by a preview of the target, if (and in some cases only if) the two appearances are linked to the same object. The amount and the object specificity of the preview benefit are not affected by extending the preview duration to 1 s, or by extending the temporal gap between fields to 590 ms. The results are interpreted in terms of a reviewing process, which is triggered by the appearance of the target and retrieves just one of the previewed items. In the absence of an object link, the reviewing item is selected at random. We develop the concept of an object file as a temporary episodic representation, within which successive states of an object are linked and integrated.
Collapse
|
30
|
Abstract
The phenomenon of apparent motion can arise when two spatially separated visual tokens are presented in temporal sequence. If tokens at opposite corners of a hypothetical square are presented simultaneously followed by simultaneous presentation of tokens at the remaining two corners, an apparent motion percept may occur along either the vertical or horizontal axis. The display is perceptually metastable since most observers will perceive motion along only one axis at a time. The metastable display, however, produces anisotropic results, in that with central fixation, vertical motion is seen more frequently than horizontal motion. The ratio of the vertical to horizontal length of the sides of a rectangle needed to achieve equal frequencies of motion judgments along the respective axes falls in the range of 1.18-1.92 for different observers in our experiments. It appears that signal transmission across the vertical midline is a major determinant of the vertical bias, since the anisotropic effects disappear when the fixation point is sufficiently offset along the horizontal meridian so as to cause a fully homonymous representation of all of the metastable tokens. One of the factors may be signal degradation or delay in callosal transmission which could reduce the strength of the motion signal along the horizontal axis. In addition, there appears to be a strip along the vertical midline with a width of 30-50 min arc within which reduced levels of anisotropy are found. The possibility that this strip is a consequence of a zone of naso-temporal overlap in the projection of the retina to the brain along the vertical meridian will be discussed.
Collapse
Affiliation(s)
- A Chaudhuri
- School of Optometry, University of California, Berkeley
| | | |
Collapse
|
31
|
Green M. Visual search, visual streams, and visual architectures. PERCEPTION & PSYCHOPHYSICS 1991; 50:388-403. [PMID: 1758771 DOI: 10.3758/bf03212232] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Most psychological, physiological, and computational models of early vision suggest that retinal information is divided into a parallel set of feature modules. The dominant theories of visual search assume that these modules form a "blackboard" architecture: a set of independent representations that communicate only through a central processor. A review of research shows that blackboard-based theories, such as feature-integration theory, cannot easily explain the existing data. The experimental evidence is more consistent with a "network" architecture, which stresses that: (1) feature modules are directly connected to one another, (2) features and their locations are represented together, (3) feature detection and integration are not distinct processing stages, and (4) no executive control process, such as focal attention, is needed to integrate features. Attention is not a spotlight that synthesizes objects from raw features. Instead, it is better to conceptualize attention as an aperture which masks irrelevant visual information.
Collapse
Affiliation(s)
- M Green
- Computer Studies Programme, Trent University, Peterborough, Ontario, Canada
| |
Collapse
|
32
|
Abstract
Starting with the experiments of Ramachandran and Gregory (Nature, 275, 55-56, 1978), several psychophysical studies in apparent motion (AM) have established that the perception of motion is significantly impaired at equiluminance. Still debated, however, is whether color alone can resolve ambiguities in AM. We report here on several psychophysical experiments, the quantitative results of which indicate that color does play a substantial role in AM. These findings seem to support recently proposed neurophysiological frameworks according to which there exist significant interactions among the neuronal pathways mediating the perception of basic visual attributes such as color, motion, form and depth.
Collapse
Affiliation(s)
- T V Papathomas
- Visual Perception Research Department, AT&T Bell Laboratories, Murray Hill, NJ 07974
| | | | | |
Collapse
|
33
|
Shimojo S, Nakayama K. Amodal representation of occluded surfaces: role of invisible stimuli in apparent motion correspondence. Perception 1990; 19:285-99. [PMID: 2267141 DOI: 10.1068/p190285] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A series of demonstrations were created where the perceived depth of targets was controlled by stereoscopic disparity. A closer object (a cloud) was made to jump back and forth horizontally, partially occluding a farther object (a full moon). The more distant moon appeared stationary even though the unoccluded portion of it, a crescent, changed position. Reversal of the relative depth of the moon and cloud gave a totally different percept: the crescent appeared to flip back and forth in the front depth plane. Thus, the otherwise-robust apparent motion of the moon crescents was completely abolished in the cloud-closer case alone. This motion-blocking effect is attributed to the 'amodal presence' of the occluded surface continuing behind the occluding surface. To measure the effect of this occluded 'invisible' surface quantitatively, a bistable apparent motion display was used (Ramachandran and Anstis 1983a): two small rectangular-shaped targets changed their positions back and forth between two frames, and the disparity of a large centrally positioned rectangle was varied. When the perceived depths supported the possibility of amodal completion behind the large rectangle, increased vertical motion of the targets was found, suggesting that the amodal presence of the targets behind the occluder had effectively changed the center position of the moving targets for purposes of motion correspondence. Amodal contours are literally 'invisible', yet it is hypothesized that they have a neural representation at sufficiently early stages of visual processing to alter the correspondence solving process for apparent motion.
Collapse
Affiliation(s)
- S Shimojo
- Smith-Kettlewell Eye Research Institute, San Francisco, CA 94115
| | | |
Collapse
|
34
|
Abstract
When a single rectangle is replaced by two flanking ones, or vice versa, one sees split or fusion motion. The motion correspondence in these displays is supposed to reflect the affinity between elements. We examined the effects of the element luminance on the affinity. The results indicated that the affinity did not reflect the luminance similarity; it monotonically increased with increasing the luminance of either element of the matching pair. It was also found that the effects of luminance was symmetric in the time axis. These results were obtained for both long-range and short-range apparent motion. Our findings suggest that the affinity directly reflects the response of the simple motion detectors regardless of the displacement size.
Collapse
Affiliation(s)
- S Nishida
- Department of Psychology, Faculty of Letters, Kyoto University, Japan
| | | |
Collapse
|
35
|
Abstract
The perception of the direction of motion in luminance kinematograms breaks down when the displacement exceeds a few element widths (this limit is called Dmax). When kinematograms whose elements differ only, in hue are used, motion can be seen but performance declines at smaller displacements. The short-range process, once thought to be only a luminance correlator, is thus able to use hue. If the size of Dmax indicates how well a feature stimulates the motion sensors, hue might be said to have an especially weak input to motion sensors. In order to find the relative potency of luminance and hue as bases of the short-range matching process, Dmax for these features was compared to those obtained for kinematograms whose elements differed in phase (T-phase or L-phase) or orientation (/or/). The matching process could use all the features tested. Luminance seems to be the preferred basis for motion matching, with hue and phase (a tie) yielding smaller Dmax and orientation the smallest.
Collapse
Affiliation(s)
- W A Simpson
- Department of Psychology, University of Winnipeg, Manitoba, Canada
| |
Collapse
|