DOCSLIB.ORG

Saccadic Eye Movements and Perceptual Judgments Reveal a Shared Visual Representation That Is Increasingly Accurate Over Time ⇑ Wieske Van Zoest A, , Amelia R

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Saccadic Eye Movements and Perceptual Judgments Reveal a Shared Visual Representation That Is Increasingly Accurate Over Time ⇑ Wieske Van Zoest A, , Amelia R View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Vision Research 51 (2011) 111–119 Contents lists available at ScienceDirect Vision Research journal homepage: www.elsevier.com/locate/visres Saccadic eye movements and perceptual judgments reveal a shared visual representation that is increasingly accurate over time ⇑ Wieske van Zoest a, , Amelia R. Hunt b a Cognitive Psychology, Vrije Universiteit Amsterdam, van der Boechorststraat 1, 1081 BT, Amsterdam, The Netherlands b School of Psychology, University of Aberdeen, Aberdeen AB24 2UB, UK article info abstract Article history: Although there is evidence to suggest visual illusions affect perceptual judgments more than actions, Received 7 July 2010 many studies have failed to detect task-dependant dissociations. In two experiments we attempt to Received in revised form 22 September 2010 resolve the contradiction by exploring the time-course of visual illusion effects on both saccadic eye movements and perceptual judgments, using the Judd illusion. The results showed that, regardless of whether a saccadic response or a perceptual judgement was made, the illusory bias was larger when Keywords: responses were based on less information, that is, when saccadic latencies were short, or display duration Perception and action was brief. The time-course of the effect was similar for both the saccadic responses and perceptual judge- Visual illusions ments, suggesting that both modes may be driven by a shared visual representation. Changes in the Saccadic eye movements Time-course of processing strength of the illusion over time also highlight the importance of controlling for the latency of different response systems when evaluating possible dissociations between them. Ó 2010 Elsevier Ltd. All rights reserved. 1. Introduction driving behavior, it may be that behavior is controlled by one com- mon visual representation that changes as a function of time Processes involved in recognition and identification of objects (Hunt, van Zoest, & Kingstone, 2010; van Zoest, Hunt, & Kingstone, rely on different parts of visual cortex than processes that assist 2010). When response decisions occur at different moments in localization and grasping of objects. This is uncontroversial. What time, they may be based on different time points in this emerging is controversial is the idea is that these different processes are dri- representation of objects, their identities, their task relevance, and ven by independent pathways and separate visual representations their spatial relationships. The present study aims to investigate (e.g., Goodale & Milner, 1992; Milner & Goodale, 1993, 1995, 2008). processing dynamics in a visual illusion, as measured by saccadic Neurophysiological and neuropsychological evidence supports the eye movements and perceptual judgments. idea that visually-guided actions can be dissociated from conscious report (e.g., Goodale & Milner, 1992). While this finding suggests that separate representations drive perception and action, several 1.1. Representations for perception and action studies have questioned the existence of a clear separation (Bruno & Franz, 2009; de Grave, Smeets, & Brenner, 2006; Franz, Support for separate processing streams for perception and ac- Fahle, Bulthoff, & Gegenfurtner, 2001; Franz, Gegenfurtner, tion is found in the primate visual system (e.g., Ungerleider & Bulthoff, & Fahle, 2000; Glover, 2002; Knox & Bruno, 2007; Vishton Mishkin, 1982). Under this model, the ventral stream runs from et al., 2007). Here we will focus on evidence that visual represen- occipital to temporal cortex and is responsible for the perception tation changes as a function of time, such that when in time visual and identification of objects. The dorsal stream runs from occipital information is used significantly influences human behavior (e.g., to parietal cortex and is responsible for motor control and actions Donk & van Zoest, 2009; Hunt, von Mühlenen, & Kingstone, towards objects. Further evidence in favor of the dual-route 2007; van Zoest, Donk, & Theeuwes, 2004). Little is known about hypothesis – the idea that these are indeed separate and indepen- how perception and action are affected by processing dynamics dent processing streams – was found in studies of neuropsycholog- in visual representations. Instead of two separate representations ical patients (Goodale & Milner, 1992; Goodale, Milner, Jakobson, & Carey, 1991; Milner & Goodale, 1995). Patients with damage to the ventral stream have difficulties identifying and recognizing ob- jects, yet these patients are unimpaired in their motor abilities to- ⇑ Corresponding author. Address: Department of Cognitive Psychology, Vrije Universiteit Amsterdam, van der Boechorststraat 1, 1081 BT, Amsterdam, The wards the same objects. In contrast, patients with damage to the Netherlands. Fax: +31 20 598 8971. dorsal stream show no difficulties in object-identification, but E-mail address: [email protected] (W. van Zoest). show impaired abilities in grasping and reaching. These two 0042-6989/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.visres.2010.10.013 112 W. van Zoest, A.R. Hunt / Vision Research 51 (2011) 111–119 classes of patients together constitute a double dissociation be- 2003). Unlike reaching and grasping, eye movements can be tween the recognition of common objects and the ability to use elicited much earlier in time and providing a unique window in information about the size, shape and orientation of an object to early visual processing. Indeed, the eye movement system would control the hand and fingers during a grasping movement. These seem to provide conditions most likely to confirm the dual-route results suggest that distinct visual representations underlie per- hypothesis, given that the retinotectal visual pathway enables ception and action. eye movements to be executed in the absence of any cortical visual Supporting evidence for the dual-route hypothesis has also processing (Schiller, 1977). Nevertheless, similar to results with come from research showing that visual illusions affect perception manual movement responses described above, results from studies more than action (Aglioti, DeSouza, & Goodale, 1995; Bridgeman, on oculomotor behavior are inconsistent. Some have found that Lewis, Heit, & Nagle, 1979; Westwood & Goodale, 2003). For exam- oculomotor programming is resistant to visual illusions (Wong & ple, Aglioti et al. (1995) used a variation of the Titchener illusion to Mack, 1981) while others have found it is not (Bernardis, Knox, & investigate the effect of the illusion on perception and action. Bruno, 2005; de Grave, Franz et al., 2006; de Grave, Smeets et al., When participants were presented with two disks of equal size, 2006; Knox & Bruno, 2007; McCarley et al., 2003). they perceived a disk surrounded by smaller circles as larger than One way to explain the inconsistent effects of illusions on ocu- a disk surrounded by larger circles. However, when participants lomotor behavior was put forward by McCarley et al. (2003). They were asked to pick up one of the disks, grip size was similar for suggested that differences in saccadic control might account for the two disks. Aglioti et al. concluded that processing in the ventral differences in effect size of the illusion on saccadic performance stream was susceptible to the visual illusion while processing in (see also, DiGirolamo et al., 2008). Specifically, stimulus-driven the dorsal stream was not, or much less. Because contextual infor- reflexive eye movements may be differently influenced by a visual mation plays an important role in perceptual processes, they are illusion than goal-driven voluntary controlled eye movements. susceptible to context-based visual illusions. In contrast, the visu- McCarley et al. (2003) asked participants to saccade to the end- omotor system encodes information with respect to the appropri- point of a Müller-Lyer illusion stimulus. Saccades were controlled ate egocentric reference frame for a given action and does not either reflexively, by a transient go-signal that was presented at require a high-level perceptual representation that contains con- the endpoint of the stimuli, or voluntarily, by a spoken go-signal. textual information about the object. As a result, it was argued, vis- The results showed that the effect of the illusion was larger for vol- uomotor processing in the dorsal stream is better able to resist untary than for reflexive movements. In this study, voluntary sac- visual illusions. These findings not only support the idea that per- cades showed effects of the illusion similar in magnitude to those ception and action are served by distinct spatial representations, evident in perceptual judgments. The results are explained by the but also imply that the action representations exist outside of con- idea that reflexive and voluntary saccades are controlled by differ- scious visual experience. ent representations. Reflexive saccades rely on automatic collicular However, as briefly noted before, some have questioned the programs that are based on low-level retinotopic representations. idea of strong separate representations in the dual-route model These low-level representations are not susceptible to context (Clark, 2009; Franz & Gegenfurtner, 2008; Franz et al., 2000, and hence are not influenced by the illusion. Voluntary saccades, 2001; Glover, 2002; Glover & Dixon, 2001; Smeets & Brenner, it was argued, occur
Load more

Recommended publications
  • 234 CHAPTER 6: GENERAL DISCUSSION Introduction the Broad Themes of This Thesis Have Ranged from Crossmodal Plasticity to Automat
    234 CHAPTER 6: GENERAL DISCUSSION Introduction The broad themes of this thesis have ranged from crossmodal plasticity to automaticity (behavioral and neural), and rehabilitation of the blind population. Crossmodal plasticity is critical to the learning of any sensory substitution encoding, as sensory substitution inherently bridges across two modalities: the sense that receives the information, and that which interprets it. The automaticity of sensory substitution was studied both behaviorally (Chapter 3) and with neural imaging (Chapter 4). Automaticity of SS is critical to improving blind rehabilitation with sensory substitution, and the studies in this thesis will aid in the development of better training techniques and device encodings. Finally, blind rehabilitation has recurred as a theme throughout all of the thesis chapters, and is an important end application of this research. Discussion Crossmodal Plasticity Crossmodal plasticity is the foundation of all sensory substitution learning. Through crossmodal interactions and then plastic changes of those interactions, sensory substitution stimuli are interpreted visually, and action is generated. The type of plasticity, whether strengthening or weakening of existing neural connections or the generation of new neural connections, likely depends on the task, duration of training, and visual deprivation of the participant (i.e., blind or sighted). 235 The experiments in this thesis all rely on plastic changes across the senses to generate improved performance at sensory substitution tasks. The results of these plastic changes are measured behaviorally in Chapters 2 and 3, and with neural imaging (fMRI) in Chapters 4 and 5. In Chapter 2, the constancy processing of SS stimuli (after training) is likely mediated by visual neural regions that are activated by crossmodal plastic changes.
    [Show full text]
  • The Ponzo Illusion with Auditory Substitution of Vision in Sighted and Early-Blind Subjects
    Perception, 2005, volume 34, pages 857 ^ 867 DOI:10.1068/p5219 The Ponzo illusion with auditory substitution of vision in sighted and early-blind subjects L Renier, C Laloyauxô, O Collignon, D Tranduy, A Vanlierde, R Bruyer½, A G De Volder# Neural Rehabilitation Engineering Laboratory, Universite¨ Catholique de Louvain, 54 Avenue Hippocrate, Brussels B-1200, Belgium; ô Cognitive Science Research Unit, Universite¨ Libre de Bruxelles, 50 Avenue F D Roosevelt, Brussels B-1050, Belgium; ½ Cognitive Neurosciences Unit, Universite¨ Catholique de Louvain, 10 Place du Cardinal Mercier, Louvain-la-Neuve B-1348, Belgium; e-mail: [email protected] Received 12 February 2004, in revised form 22 November 2004; published online 6 July 2005 Abstract. We tested the effects of using a prosthesis for substitution of vision with audition (PSVA) on sensitivity to the Ponzo illusion. The effects of visual experience on the susceptibility to this illusion were also assessed. In one experiment, both early-blind and blindfolded sighted volunteers used the PSVA to explore several variants of the Ponzo illusion as well as control stimuli. No effects of the illusion were observed. The results indicate that subjects focused their attention on the two central horizontal bars of the stimuli, without processing the contextual cues that convey perspective in the Ponzo figure. In a second experiment, we required subjects to use the PSVA to consider the two converging oblique lines of the stimuli before comparing the length of the two horizontal bars. Here we were able to observe susceptibility to the Ponzo illusion in the sighted group, but to a lesser extent than in a sighted non-PSVA control group.
    [Show full text]
  • Optical Illusion - Wikipedia, the Free Encyclopedia
    Optical illusion - Wikipedia, the free encyclopedia Try Beta Log in / create account article discussion edit this page history [Hide] Wikipedia is there when you need it — now it needs you. $0.6M USD $7.5M USD Donate Now navigation Optical illusion Main page From Wikipedia, the free encyclopedia Contents Featured content This article is about visual perception. See Optical Illusion (album) for Current events information about the Time Requiem album. Random article An optical illusion (also called a visual illusion) is characterized by search visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a percept that does not tally with a physical measurement of the stimulus source. There are three main types: literal optical illusions that create images that are interaction different from the objects that make them, physiological ones that are the An optical illusion. The square A About Wikipedia effects on the eyes and brain of excessive stimulation of a specific type is exactly the same shade of grey Community portal (brightness, tilt, color, movement), and cognitive illusions where the eye as square B. See Same color Recent changes and brain make unconscious inferences. illusion Contact Wikipedia Donate to Wikipedia Contents [hide] Help 1 Physiological illusions toolbox 2 Cognitive illusions 3 Explanation of cognitive illusions What links here 3.1 Perceptual organization Related changes 3.2 Depth and motion perception Upload file Special pages 3.3 Color and brightness
    [Show full text]
  • 2019 Abstracts Sessions Overiew
    Vision Sciences Society 19th Annual Meeting, May 17-22, 2019 TradeWinds Island Resorts, St. Pete Beach, Florida Abstracts Contents Sessions Overview . 2 Monday Morning Talks . .169 Abstract Numbering System . .3 Monday Morning Posters . .176 Member-Initiated Symposia . 4 Tuesday Morning Talks . 209 Saturday Morning Talks . 12 Tuesday Morning Posters . .216 Saturday Morning Posters . 19 Tuesday Afternoon Talks . 249 Saturday Afternoon Talks . 51 Tuesday Afternoon Posters . 257 Saturday Afternoon Posters . 58 Wednesday Morning Talks. 289 Sunday Morning Talks . 89 Wednesday Morning Posters . 296 Sunday Morning Posters. 96 Topic Index . 322 Sunday Afternoon Talks . .128 Author Index . 325 Sunday Afternoon Posters . .136 Sessions Overview Sessions Overview........................ 2 Sunday Morning Talks.................... .89 Shape, Motion, Color and Depth: Integration .................... 89 Member-Initiated Symposia . .4 Visual Memory: Neural mechanisms . 90 S1 Reading as a Visual Act: Recognition of Visual Letter Symbols Faces: Dynamics, convolutional neural networks .................92 in the Mind and Brain . .4 Perceptual Organization........................................ 93 S2 Rhythms of the Brain, Rhythms of Perception ..................5 S3 What Can Be Inferred About Neural Population Codes from Sunday Morning Posters ................. .96 Psychophysical and Neuroimaging Data? ......................6 Perceptual Organization and Scene S4 Visual Search: From Youth to Old Age, from the Lab to Perception: Art, aesthetics, image preference................
    [Show full text]
  • Geometrical Illusions
    Oxford Reference The Oxford Companion to Consciousness Edited by Tim Bayne, Axel Cleeremans, and Patrick Wilken Publisher: Oxford University Press Print Publication Date: 2009 Print ISBN-13: 9780198569510 Published online: 2010 Current Online Version: 2010 eISBN: 9780191727924 illusions Illusions confuse and bias the machinery in the brain that constructs our representations of the world, because they reveal a discrepancy between what we perceive and what is objectively out there in the world. But both illusions and accurate perceptions are governed by the same lawful perceptual processes. Despite the deceptive simplicity of illusions, there are no fully agreed theories about their causes. Illusions include geometrical illusions, in which angles, lengths, or shapes are misperceived; illusions of lightness, in which the context distorts the perceived lightness of objects; and illusions of representation, including puzzle pictures, ambiguous pictures, and impossible figures. 1. Geometrical illusions 2. Illusions of lightness 3. Illusions of representation 1. Geometrical illusions Figure I1 shows some illusory distortions in perceived angles, named after their discoverers; the Zollner, Hering and Poggendorff illusions, and Fraser's LIFE figure. Length illusions include the Müller–Lyer, the vertical–horizontal, and the Ponzo illusion. Shape illusions include Roger Shepard's tables and Kitaoka's bulge illusion. In the Zollner illusion, the long oblique lines are parallel, but they appear to be tilted away from the small fins that cross them. In the Hering illusion the verticals are parallel but appear to be bowed outward, again in a direction away from the inducing lines. In the Poggendorff illusion, the right‐hand oblique line looks as though it would pass above the left‐hand oblique if extended, although both are really exactly aligned.
    [Show full text]
  • Research Article Looking Into Task-Specific Activation Using a Prosthesis Substituting Vision with Audition
    International Scholarly Research Network ISRN Rehabilitation Volume 2012, Article ID 490950, 15 pages doi:10.5402/2012/490950 Research Article Looking into Task-Specific Activation Using a Prosthesis Substituting Vision with Audition Paula Plaza,1 Isabel Cuevas,1 Cecile´ Grandin,2 Anne G. De Volder,1 and Laurent Renier1 1 Neural Rehabilitation Group, Institute of Neuroscience, Universit´eCatholiquedeLouvain,AvenueHippocrate54, UCL B1.54.09, 1200 Brussels, Belgium 2 Functional Magnetic Resonance Imaging Section, Department of Radiology, Universit´e Catholique de Louvain, Cliniques Universitaires Saint-Luc, Avenue Hippocrate 10, 1200 Brussels, Belgium Correspondence should be addressed to Anne G. De Volder, [email protected] Received 26 August 2011; Accepted 25 October 2011 Academic Editors: G. Kerkhoff and C. I. Renner Copyright © 2012 Paula Plaza et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. A visual-to-auditory sensory substitution device initially developed for the blind is known to allow visual-like perception through sequential exploratory strategies. Here we used functional magnetic resonance imaging (fMRI) to test whether processing the location versus the orientation of simple (elementary) “visual” stimuli encoded into sounds using the device modulates the brain activity within the dorsal visual stream in the absence of sequential exploration of these stimuli. Location and orientation detection with the device induced a similar recruitment of frontoparietal brain areas in blindfolded sighted subjects as the corresponding tasks using the same stimuli in the same subjects in vision. We observed a similar preference of the right superior parietal lobule for spatial localization over orientation processing in both sensory modalities.
    [Show full text]
  • Susceptibility to Ebbinghaus and Müller-Lyer
    Manning et al. Molecular Autism (2017) 8:16 DOI 10.1186/s13229-017-0127-y RESEARCH Open Access Susceptibility to Ebbinghaus and Müller- Lyer illusions in autistic children: a comparison of three different methods Catherine Manning1* , Michael J. Morgan2,3, Craig T. W. Allen4 and Elizabeth Pellicano4,5 Abstract Background: Studies reporting altered susceptibility to visual illusions in autistic individuals compared to that typically developing individuals have been taken to reflect differences in perception (e.g. reduced global processing), but could instead reflect differences in higher-level decision-making strategies. Methods: We measured susceptibility to two contextual illusions (Ebbinghaus, Müller-Lyer) in autistic children aged 6–14 years and typically developing children matched in age and non-verbal ability using three methods. In experiment 1, we used a new two-alternative-forced-choice method with a roving pedestal designed to minimise cognitive biases. Here, children judged which of two comparison stimuli was most similar in size to a reference stimulus. In experiments 2 and 3, we used methods previously used with autistic populations. In experiment 2, children judged whether stimuli were the ‘same’ or ‘different’, and in experiment 3, we used a method-of- adjustment task. Results: Across all tasks, autistic children were equally susceptible to the Ebbinghaus illusion as typically developing children. Autistic children showed a heightened susceptibility to the Müller-Lyer illusion, but only in the method-of- adjustment task. This result may reflect differences in decisional criteria. Conclusions: Our results are inconsistent with theories proposing reduced contextual integration in autism and suggest that previous reports of altered susceptibility to illusions may arise from differences in decision-making, rather than differences in perception per se.
    [Show full text]
  • Visual Illusions: an Interesting Tool to Investigate Developmental Dyslexia and Autism Spectrum Disorder
    fnhum-10-00175 April 21, 2016 Time: 15:22 # 1 CORE Metadata, citation and similar papers at core.ac.uk Provided by Frontiers - Publisher Connector REVIEW published: 25 April 2016 doi: 10.3389/fnhum.2016.00175 Visual Illusions: An Interesting Tool to Investigate Developmental Dyslexia and Autism Spectrum Disorder Simone Gori1,2*, Massimo Molteni2 and Andrea Facoetti2,3 1 Department of Human and Social Sciences, University of Bergamo, Bergamo, Italy, 2 Child Psychopathology Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Italy, 3 Developmental and Cognitive Neuroscience Lab, Department of General Psychology, University of Padova, Padua, Italy A visual illusion refers to a percept that is different in some aspect from the physical stimulus. Illusions are a powerful non-invasive tool for understanding the neurobiology of vision, telling us, indirectly, how the brain processes visual stimuli. There are some neurodevelopmental disorders characterized by visual deficits. Surprisingly, just a few studies investigated illusory perception in clinical populations. Our aim is to review the literature supporting a possible role for visual illusions in helping us understand the visual deficits in developmental dyslexia and autism spectrum disorder. Future studies could develop new tools – based on visual illusions – to identify an early risk for neurodevelopmental disorders. Keywords: illusory effect, perception, attention, autistic traits, reading disorder VISUAL ILLUSION AS A TOOL TO INVESTIGATE BRAIN Edited by: PROCESSING Baingio Pinna, University of Sassari, Italy A visual illusion refers to a percept that is different from what would be typically predicted based Reviewed by: on the physical stimulus. Illusory perception is often experienced as a real percept.
    [Show full text]
  • A Review of Abnormalities in the Perception of Visual Illusions in Schizophrenia
    Psychon Bull Rev (2017) 24:734–751 DOI 10.3758/s13423-016-1168-5 THEORETICAL REVIEW A review of abnormalities in the perception of visual illusions in schizophrenia Daniel J. King1 & Joanne Hodgekins2 & Philippe A. Chouinard3 & Virginie-Anne Chouinard4,5 & Irene Sperandio6 Published online: 11 October 2016 # The Author(s) 2016. This article is published with open access at Springerlink.com Abstract Specific abnormalities of vision in schizophre- Keywords Schizophrenia . Visual illusions . Low-level nia have been observed to affect high-level and some vision . High-level vision low-level integration mechanisms, suggesting that people with schizophrenia may experience anomalies across dif- ferent stages in the visual system affecting either early or Introduction late processing or both. Here, we review the research into visual illusion perception in schizophrenia and the Visual illusions are a key methodology in vision research to issues which previous research has faced. One general help us understand and make inferences about the mecha- finding that emerged from the literature is that those with nisms for creating subjective experiences of the visual world. schizophrenia are mostly immune to the effects of high- They place constraints on the processing of a stimulus and level illusory displays, but this effect is not consistent allow for the reliable manipulation and quantification of the across all low-level illusions. The present review sug- visual mechanisms the illusion engages (Silverstein & Keane, gests that this resistance is due to the weakening of 2011b). Examining visual illusions in individuals with schizo- top–down perceptual mechanisms and may be relevant phrenia may provide further insight into how these individuals to the understanding of symptoms of visual distortion perceive the world and how their visual perception differs rather than hallucinations as previously thought.
    [Show full text]
  • Perceived Depth Modulates Perceptual Resolution
    1 Perceived depth modulates perceptual resolution Tasfia Ahsana,b, Kathryn Boltona, Laurie M. Wilcoxa,b, Erez Freuda,b a Department of Psychology, York University, Toronto, Ontario M3J 1P3, Canada b Centre for Vision Research, York University, Toronto, Ontario M3J 1P3, Canada Acknowledgements – This study was supported by the Vision Science to Applications (VISTA) program funded by the Canada First Research Excellence Fund (CFREF, 2016–2023) and by the Discovery grant from the Natural Sciences and Engineering Research Council (NSERC). We thank Johnathan Tong for his guidance in data analysis and Krista Chiasson for her help in data collection. The authors declare no conflicts of interest. Correspondence concerning this article should be addressed to Erez Freud ([email protected]) 2 Abstract Humans constantly use depth information to support perceptual decisions about object size and location in space, as well as planning and executing actions. It was recently reported that perceived depth modulates perceptual performance even when depth information is not relevant to the task, with faster shape discrimination for objects perceived as being close to the observer. However, it is yet to be determined if the observed “close advantage” reflects differences in psychophysical sensitivity or response bias. Moreover, it is unclear whether this advantage is generalizable to other viewing situations and tasks. To address these outstanding issues, we evaluated whether visual resolution is modulated by perceived depth defined by 2D pictorial cues. In a series of experiments, we used the method of constant stimuli to measure the precision of perceptual judgements for stimuli positioned at close, far, and flat perceived distances.
    [Show full text]
  • Illusory Distance Modulates Perceived Size of Afterimage Despite the Disappearance of Depth Cues
    RESEARCH ARTICLE Illusory Distance Modulates Perceived Size of Afterimage despite the Disappearance of Depth Cues Jiehui Qian1*, Shengxi Liu1, Quan Lei2 1 Department of Psychology, Sun Yat-Sen University, Guangzhou, Guangdong, China, 2 Department of Psychology, University of Minnesota Twin-Cities, Minneapolis, MN, United States of America * [email protected] a11111 Abstract It is known that the perceived size of an afterimage is modulated by the perceived distance between the observer and the depth plane on which the afterimage is projected (Emmert’s law). Illusions like Ponzo demonstrate that illusory distance induced by depth cues can also affect the perceived size of an object. In this study, we report that the illusory distance not OPEN ACCESS only modulates the perceived size of object’s afterimage during the presence of the depth Citation: Qian J, Liu S, Lei Q (2016) Illusory Distance cues, but the modulation persists after the disappearance of the depth cues. We used an Modulates Perceived Size of Afterimage despite the adapted version of the classic Ponzo illusion. Illusory depth perception was induced by lin- Disappearance of Depth Cues. PLoS ONE 11(7): ear perspective cues with two tilted lines converging at the upper boundary of the display. e0159228. doi:10.1371/journal.pone.0159228 Two horizontal bars were placed between the two lines, resulting in a percept of the upper Editor: Philip Allen, University of Akron, UNITED bar to be farther away than the lower bar. Observers were instructed to make judgment STATES about the relative size of the afterimage of the lower and the upper bars after adaptation.
    [Show full text]
  • The Use of Illusory Visual Information in Perception and Action
    I Medische E;t:JliDtheek !2oo.)" E.U.R. ~~ ~ The Use of Illusory Visual Information in Perception and Action Het gebruik van illusoire visuele informatie in perceptie en actie Proefschrift ter verkrijging van de graad van doctor aan de Erasmus Universiteit Rotterdam op gezag van de rector magnificus Prof.dr. S.W.J. Lamberts en volgens besluit van het College voor Promoties. De openbare verdediging zal plaatsvinden op donderdag 19 mei 2005 om 13.30 uur door Denise Desiree J osefina de Grave geboren te Winterswijk Promotiecommissie Promotor: Prof.dr. J.G.G. Borst Overige leden: Dr. M.A. Frens Prof.dr. C.J. Erkelens Prof.dr. C.I. de Zeeuw Copromotoren: Dr. E. Brenner Dr. J.B.J. Smeets Dit proefschrift werd mede mogelijk gemaakt door financiele steun van de Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), gebied Maatschappij- en Gedragswetenschappen (MaGW), dossiemummer 490-22-lSOb. Contents Contents Chapter 1 5 General Introduction Chapter 2 17 Are the original and the induced Roelofs effect caused by the same shift in straight ahead? Chapter3 31 Effects ofthe Ebbinghaus figure on grasping are not only due to misjudged size Chapter4 45 The coding of pointing movements ChapterS 61 The coding of saccades Chapter 6 75 Summary and conclusions Hoofdstuk6 87 Samenvatting en conclusies References 95 Dankwoord 107 Curriculum Vitae 109 Publications Ill Chapter 1 General introduction Chapter 1 Humans constantly interact with objects in the environment (e.g. grasp a pencil for writing or pick up a cup of tea) without making many mistakes in these performed actions. To guide these actions, visual information is used.
    [Show full text]