Champions of Illusion

by Susana Martinez-Conde

  “either because [the planets’] light is refracted”: Galileo Galilei, Dialogue Concerning the Two Chief World Systems, trans. Stillman Drake (Berkeley and Los Angeles: University of California Press, 1953).

  This illusion by Bettella: Sergio Roncato, “Brightness/Darkness Induction and the Genesis of a Contour,” Frontiers in Human Neuroscience 8 (Oct. 20, 2014): 841, doi:10.3389/fnhum.2014.00841.

  5. AMBIGUOUS ILLUSIONS

  the experimental psychologist Edwin Boring: Edwin Boring, “A New Ambiguous Figure,” The American Journal of Psychology 42, no. 3 (1930): 444–45.

  the vision scientist Gerald H. Fisher: Gerald H. Fisher, “Mother, Father, and Daughter: A Three-Aspect Ambiguous Figure,” The American Journal of Psychology 81, no. 2 (June 1968), pp. 274–77.

  The Ghostly Gaze Illusion: Rob Jenkins, “The Lighter Side of Gaze Perception,” Perception 36, no. 8 (2007): 1266–68, doi:10.1068/p5745; Rob Jenkins, John D. Beaver, and Andrew J. Calder, “I Thought You Were Looking at Me: Direction-Specific Aftereffects in Gaze Perception,” Psychological Science 17, no. 6 (June 1, 2006): 506–13, doi:10.1111/j.1467-9280.2006.01736.x; Rob Jenkins and Christie Kerr, “Identifiable Images of Bystanders Extracted from Corneal Reflections,” ed. Matthew Longo, PLOS ONE 8, no. 12 (Dec. 26, 2013): e83325, doi:10.1371/journal.pone.0083325.

  6. PERSPECTIVE AND DEPTH ILLUSIONS

  the Leaning Tower Illusion: Frederick A. A. Kingdom, Ai Yoonessi, and Elena Gheorghiu, “The Leaning Tower Illusion: A New Illusion of Perspective,” Perception 36, no. 3 (2007): 475–77; Frederick A. A. Kingdom, Ali Yoonessi, and Elena Gheorghiu, “Leaning Tower Illusion,” Scholarpedia 2, no. 12 (2007); F.A.A. Kingdom, A. Yoonessi, and E. Gheorghiu, “Leaning Tower Illusion,” in The Oxford Compendium of Visual Illusions, ed. Arthur G. Shapiro and Dejan Todorovi´c (Oxford, U.K.: Oxford University Press: 2017).

  two different images can look identical: Kimberley D. Orsten-Hooge, Mary C. Portillo, and James R. Pomerantz, “False Pop Out,” Journal of Experimental Psychology: Human Perception and Performance 41, no. 6 (2015): 1623–33, doi:10.1037/xhp0000077.

  Skye’s illusion: Mathematics Awareness Month 2014 Poster, Penrose Tile Martin Gardner Rubin’s Vase, www.mathaware.org/mam/2014/poster/; Martin Gardner Rubin’s Vase Illusion: www.huffingtonpost.com/colm-mulcahy/martin-gardner_b_4125273.html; James Randi Rubin’s Vase Illusion: http://turnermagic.com/2011/05/foreground-background-and-perspective/.

  Geiger and Ishikawa’s illusion: Davi Geiger, Hsingkuo Pao, and Nava Rubin, “Salient and Multiple Illusory Surfaces,” Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 1998, pp. 118–24, cat. no. 98CB36231, doi:10.1109/cvpr.1998.698597; Hiroshi Ishikawa and Davi Geiger, “Illusory Volumes in Human Stereo Perception,” Vision Research 46, nos. 1–2 (2006): 171–78, doi:10.1016/j.visres.2005.06.028; Gaetano Kanizsa, Organization in Vision: Essays on Gestalt Perception (New York: Praeger, 1979).

  7. MOTION ILLUSIONS

  our own research has shown: Xoana G. Troncoso, Michael B. McCamy, Ali Najafian Jazi, Jie Cui, Jorge Otero-Millan, Stephen L. Macknik, Francisco M. Costela, and Susana Martinez-Conde, “V1 Neurons Respond Differently to Object Motion Versus Motion from Eye Movements,” Nature Communications 6 (2015): article 8114.

  the Spinning Disks Illusion: Johannes M. Zanker, “85: Motion Illusions in Static Patterns,” in The Oxford Compendium of Visual Illusions, ed. Arthur G. Shapiro and Dejan Todorovi´c (Oxford, U.K.: Oxford University Press, 2017).

  Our previous research had shown: S. Martinez-Conde, S. L. Macknik, X. G. Troncoso, and T. A. Dyer, “Microsaccades Counteract Visual Fading During Fixation,” Neuron 49, no. 2 (2006): 297–305.

  The results, published in 2008: X. G. Troncoso, S. L. Macknik, J. Otero-Millan, and S. Martinez-Conde, “Microsaccades Drive Illusory Motion in the Enigma Illusion,” Proceedings of the National Academy of Sciences of the United States of America 105, no. 41 (2008): 16033-38.

  The neuroscientist Bevil Conway: “Neural Basis for a Powerful Static Motion Illusion,” The Journal of Neuroscience 25, no. 23 (2005): 5651–6.

  The Blurry Heart Illusion: Kohske Takahashi, Shun’ya Yamada, Fuminori Ono, and Katsumi Watanabe, “Loss of Color by Afterimage Masking,” i-Perception 4, no. 3 (2013): 144–46, doi:10.1068/i0584sas; Kohske Takahashi, Haruaki Fukuda, Katsumi Watanabe, and Kazuhiro Ueda, “Scintillating Lustre Induced by Radial Fins,” i-Perception 3, no. 2 (2012): 101–103, doi:10.1068/i0488sas; Kohske Takahashi, Ryosuke Niimi, and Katsumi Watanabe, “Illusory Motion Induced by Blurred Red-Blue Edges,” Perception 39, no. 12 (2010): 1678–80, doi:10.1068/p6811.

  magnificent example of how we perceive: Hiroshi Ashida, Ichiro Kuriki, Ikuya Murakami, Rumi Hisakata, and Akiyoshi Kitaoka, “Direction-Specific FMRI Adaptation Reveals the Visual Cortical Network Underlying the ‘Rotating Snakes’ Illusion,” NeuroImage 61, no. 4 (2012): 1143–52, doi:10.1016/j.neuroimage.2012.03.033; Akiyoshi Kitaoka, “Color-Dependent Motion Illusions in Stationary Images and Their Phenomenal Dimorphism,” Perception 43, no. 9 (2014): 914–25, doi:10.1068/p7706; A. Kitaoka and S. Anstis, “Second-Order Footsteps Illusions,” i-Perception 6, no. 6 (Dec. 24, 2015): 1–4, doi:10.1177/2041669515622085.

  in collaboration with Jorge Otero-Millan: Jorge Otero-Millan, Stephen L. Macknik, and Susana Martinez-Conde, “Microsaccades and Blinks Trigger Illusory Rotation in the ‘Rotating Snakes’ Illusion,” Journal of Neuroscience 32, no. 17 (April 25, 2012): 6043–51, doi:10.1523/jneurosci.5823-11.2012.

  Alex Fraser and Kimerly J. Wilcox discovered: Alex Fraser and Kimerly J. Wilcox, “Perception of Illusory Movement,” Nature 281 (October 18, 1979): 565–66.

  In a 2009 study, Jutta Billino: J. Billino, K. Hamburger, and K. R. Gegenfurtner, “Age Effects on the Perception of Motion Illusions,” Perception 38, no. 4 (2009): 508–21.

  8. IMPOSSIBLE ILLUSIONS

  in 1958 published his observations: L. S. Penrose and R. Penrose, “Impossible Objects: A Special Type of Visual Illusion,” British Journal of Psychology 49, no. 1 (1958): 31–33.

  his magnetlike illusion: Kokichi Sugihara, “Classification of Impossible Objects,” Perception 11, no. 1 (Jan. 1982): 65–74; Kokichi Sugihara, “Design of Solids for Antigravity Motion Illusion,” Computational Geometry: Theory and Applications 47, no. 6 (2014): 675–82; Kokichi Sugihara, “Ambiguous Cylinders: A New Class of Impossible Objects,” Computer Aided Drafting, Design and Manufacturing 25, no. 3 (2015): 19–25.

  our brain interprets the bright streaks: Dejan Todorovi´c, “How Shape from Contours Affects Shape from Shading,” Vision Research 103 (Oct. 2014): 1–10, doi:10.1016/j.visres.2014.07.014; Phillip J. Marlow, Dejan Todorovi´c, and Barton L. Anderson, “Coupled Computations of Three-Dimensional Shape and Material,” Current Biology 25, no. 6 (March 2015): R221–22, doi:10.1016/j.cub.2015.01.062.

  9. MULTISENSORY AND NONVISUAL ILLUSIONS

  The mirage box: Roger Newport and Helen R. Gilpin, “Multisensory Disintegration and the Disappearing Hand Trick,” Current Biology 21, no. 19 (Oct. 2011): R804–805, doi:10.1016/j.cub.2011.08.044; Valeria Bellan, Helen R. Gilpin, Tasha R. Stanton, Roger Newport, Alberto Gallace, and G. Lorimer Moseley, “Untangling Visual and Proprioceptive Contributions to Hand Localisation over Time,” Experimental Brain Research 233, no. 6 (June 2015): 1689–1701, doi:10.1007/s00221-015-4242-8.

  This tactile illusion: M. Nakatani, R. D. Howe, and S. Tachi, “The Fishbone Tactile Illusion,” in Proceedings of EuroHaptics, 2006, pp. 69–73; M. Nakatani, R. D. Howe, and S. Tachi, “Surface Texture Can Bias Tactile Form Perception,” Experimental Brain Research 208, no. 1 (2011): 151–56, doi:10.1007/s00221-010-2464-3, PMID: 20981539.

  10. ATTENTION ILLUSIONS

  we discovered some of the initial circuits: Y. Chen, S. Martinez-Conde, S. L. Macknik, Y. Bereshpolova, H. A. Swadlow, and J. M. Alonso, “Task Difficulty Modulates the Activity of Specific Neuronal Populations in Primary Visual Cortex,” Nature Neuroscience 11, no. 8 (2008): 974–82.

  create a variation: Dani
el J. Simons, “Monkeying Around with the Gorillas in Our Midst: Familiarity with an Inattentional-Blindness Task Does Not Improve the Detection of Unexpected Events,” i-Perception 1, no. 1 (2010): 3–6, doi:10.1068/i0386.

  three semitransparent overlapping circles: P. U. Tse, “Voluntary Attention Modulates the Brightness of Overlapping Transparent Surfaces,” Vision Research 45, no. 9 (2005): 1095–98, doi:10.1016/j.visres.2004.11.001.

  Tse showed that attention: Eric A. Reavis, Peter J. Kohler, Gideon P. Caplovitz, Thalia P. Wheatley, and Peter U. Tse, “Effects of Attention on Visual Experience During Monocular Rivalry,” Vision Research 83 (2013): 76–81, doi:10.1016/j.visres.2013.03.002.

  CONTRIBUTOR BIOGRAPHIES

  Arash Afraz was born in Tehran in 1974. He received his M.D. from Tehran University of Medical Sciences and his Ph.D. from Harvard University. He is currently a scientist at MIT, studying visual object recognition in the brain. Arash is also a photographer; he believes in no solid boundaries between art and science. In his current work, Arash combines scientific knowledge of visual processing in the brain with aerial photography techniques to blur the line between art and science and create new visual experiences.

  Barton Anderson is a professor at the University of Sydney in Australia, where he studies various problems in vision, including perceptual organization, segmentation, grouping, and surface attributes such as color, material composition, and shape.

  Stuart Anstis was born in England and studied at the University of Winchester and at Cambridge University, where he was Richard Gregory’s first graduate student. He is a professor of psychology at UC San Diego, a Humboldt Fellow, a Koffka medalist, and a visiting fellow at the University of Oxford’s Pembroke College. He has been a visiting scientist at the Smith-Kettlewell Eye Research Institute in San Francisco, the San Francisco Exploratorium, and IPRI in Japan. Working with international collaborators, he has published some 170 articles on visual perception.

  Yuval Barkan received a B.Sc. degree in physics, a B.Sc. in electrical engineering, and an M.Sc. in biomedical engineering from Tel Aviv University, where he is currently a Ph.D. candidate. His research interests have focused on understanding the mechanisms behind visual illusions and developing computational models and algorithms that leverage this knowledge to engineering and biomedical needs.

  Sandro Bettella has been a laboratory technician in the Department of General Psychology at the University of Padua since 1973. He has conducted research in attention, vision, visual and auditory perception, memory, psycholinguistics, neurophysiology, neural networks, virtual reality, and face recognition in newborns. He has discovered several illusions while processing visual stimuli for experimental purposes.

  Christopher Blair obtained his master’s and Ph.D. in psychology at the University of Nevada, Reno, while working in the Caplovitz Vision Lab, where he studied topics ranging from size, form, and motion perception to synesthesia. He is currently a postdoctoral fellow at McGill University, in Dr. Jelena Ristic’s Laboratory for Attention and Social Cognition, where he investigates the neural correlates of directed attention.

  Gianluca Campana is an associate professor of general psychology at the University of Padua. He received his Ph.D. from the University of Padua and was subsequently awarded a postdoctoral Marie Curie Fellowship at the University of Oxford. His work has covered various aspects of vision science and neuroscience, including perceptual priming, perceptual learning, and visual motion processing, which he has investigated with psychophysics and noninvasive brain-stimulation techniques. He has published more than forty articles in international peer-reviewed journals.

  Gideon Caplovitz is a cognitive neuroscientist who researches the principles and neural mechanisms that underlie how we visually experience the world. He received his Ph.D. in cognitive neuroscience from Dartmouth College and did postdoctoral training at Princeton University. In addition, he has a master’s degree in mathematics from the Courant Institute of Mathematical Sciences at NYU, and has completed internships at the Naval Undersea Warfare Center, AT&T Bell Laboratories, and Lucent Technologies. He has received funding for his research from the National Science Foundation and the National Institutes of Health and is currently an associate professor of psychology at the University of Nevada, Reno.

  Clara Casco was born in Martignacco, in Udine, Italy, and is currently a professor of visual psychophysics and brain development and aging at the University of Padua. Her research interests include motion perception, texture segmentation, perceptual learning and brain plasticity, and low-vision rehabilitation.

  Peter Delahunt received a B.S. in psychology from Lancaster University, U.K., in 1996. He earned his M.A. (1998) and Ph.D. (2001) in psychology from UC Santa Barbara, under the supervision of Dr. David Brainard. He was then a postdoctoral fellow with Dr. John Werner at the UC Davis Medical Center, where he studied the effects of aging on visual perception. Dr. Delahunt currently works at Posit Science, where he helps develop and evaluate visual training exercises designed to improve brain function across the life span.

  Luciano Gamberini is a professor of work and organizational psychology at the University of Padua in Italy, where he is also the director of the Human Inspired Technology Research Centre, the vice director of the Ph.D. School in Brain, Mind and Computer Science, and the cofounder of the Human Technology Lab (HTLab). His research interests include human-computer interaction, information visualization, ergonomics, work psychology, and applied cognitive science.

  Davi Geiger is a professor at the Courant Institute of Mathematical Sciences and at the Neural Science Center at NYU. He received his Ph.D. in physics from MIT and is a recipient of the National Science Foundation CAREER Award.

  Elena Gheorghiu is a lecturer in psychology at the University of Stirling, U.K. She obtained her Ph.D. in physics from the University of Utrecht, The Netherlands, and worked as a postdoctoral research fellow at McGill University, Canada, and the University of Leuven, Belgium. Her studies of human vision focus on elucidating the relationship between the low-level stages of vision that detect simple features and the intermediate-to-higher stages of vision that connect these features to form surfaces and shapes. Her research interests include shape processing, curvature, contour and texture perception, stereopsis, color, motion, and symmetry processing.

  Helen Gilpin was a psychology undergraduate at the University of Nottingham when, in 2011, she was the first to use the Disappearing Hand Trick experimentally, discovering that it temporarily changes the brain’s mental representation of the body. She conducted more experiments with the illusion for a brief spell with the Body in Mind research group in Adelaide, Australia, and is currently training to be a clinical psychologist.

  During his degree course in psychology, Pietro Guardini began working in the Virtual Reality Lab of the general psychology department at the University of Padua as a research assistant and developer. His research projects focused mainly on the usability of virtual environments. The unique opportunity to handle VR hardware, as well as software for the construction of 3-D environments, allowed him to study visual illusions in exotic new contexts. That is how the Illusory Contoured Tilting Pyramid was born. Thanks to his interest in human-computer interaction and his passion for video games, he entered the video game industry in 2008 with the task of introducing user research activities to Milestone, the major video game studio in Italy. In 2016, he decided to work independently and extended his services and analyses to other developers.

  Kai Hamburger received his diploma in psychology from the University of Frankfurt in 2004. From 2005 to 2007, he was a Ph.D. student at the University of Giessen under Professor Karl R. Gegenfurtner. Currently, he is an assistant professor at the University of Giessen. His main research topics are spatial cognition (human way-finding) and consciousness.

  Joe Hardy is a technologist and an inventor. He received his Ph.D. in cognitive psychology from UC Berkeley and performed postdoctoral research at the UC Davis Medical Center. He also has a mast
er’s in business administration from the Haas School of Business at UC Berkeley.

  Eri Ishii was a student at the School of Human Sciences, Osaka University, advised by Kazunori Morikawa.

  Hiroshi Ishikawa received his B.S. and M.S. degrees in mathematics from Kyoto University and his Ph.D. degree in computer science from NYU. In 2010, after working at Nagoya City University, he became a full professor at the Department of Computer Science and Engineering, Waseda University, Tokyo. He received the PRESTO and CREST Grants from the Japan Science and Technology Agency. He has also received the NYU Courant Institute’s Harold Grad Memorial Prize, the IEEE Computer Society Japan Chapter Young Author Award, and the MIRU Nagao Award. He is on the editorial board of the IEEE TPAMI and IJCV.

  Rob Jenkins obtained a degree in cognitive science at the University of Westminster, followed by a Ph.D. in the psychology department of University College London. His research interests include face perception and social interaction. He has published on these topics in Science, Current Biology, Psychological Science, and other journals. In 2007 he was awarded the British Science Association’s Joseph Lister Prize for science communication, and in 2012 the Royal Society of Edinburgh’s Sir Thomas Makdougall Brisbane Early Career Prize for physical sciences. Rob Jenkins is a member of the RSE Young Academy of Scotland. In 2012, he was elected to the Global Young Academy.

  Ryota Kanai is the founder and CEO of the Tokyo-based start-up Araya Brain Imaging, which aims to understand consciousness and then to apply concepts of conscious computing to artificial intelligence. He is also an affiliated reader (associate professor) at the Sackler Centre for Consciousness Science at the University of Sussex. He obtained his Ph.D. in psychophysical studies of visual awareness from Utrecht University in The Netherlands in 2005 and continued his research into visual awareness at the California Institute of Technology and at University College London.