Symposia

The organising committee are pleased to announce the following symposia as part of the ECVP 2014 program.
This year the Symposia will form the key element of the afternoon sessions.

Monday, 25thAugust - Hall 1

“A celebration of the life and scientific work of Ian Howard”

Organizers: Brian Rogers, Rob Allison & Steve Palmisano.

Summary: Ian Porteus Howard (1927-2013) had a remarkable academic career spanning over 60 years that started with his initial appointment at the University of Durham in 1952. He is probably best known for his outstanding books – Human Spatial Orientation (1966) (with Brian Templeton), through Human Visual Orientation (1982), Binocular Vision and Stereopsis (1995), the 2 volumes of Seeing in Depth (2002) and finally the 3 volumes of Perceiving in Depth (2012). Ian was also a talented experimentalist and the creator and builder of many novel pieces of experimental equipment including his rotating sphere and rotating room. Over the six decades he worked on a wide variety of research topics together with many graduate students, post-docs and researchers from Canada, USA, UK, Japan and Australia.
14:30   Opening remarks
Brian Rogers, Robert Allison, Stephen Palmisano
14:30   Howard in Depth
Brian Rogers
14:45   Howard’s wisdom: From OKN to Troxler Fading
Esther G. González
15:00   Howard in Motion
Stephen Palmisano
15:15   Howard’s inclinations
Nick Wade
15:30   Howard’s slant
Hirohiko Kaneko
15:45   Howard’s Devices
Robert Allison
16:00   Howard’s way
Stuart Anstis
16:15   My Ian
Antonie (Toni) Howard</p>

Monday, 25thAugust - Hall1/B

Advances in studying the perception of surface properties

Organizers: Marianne Maertens& Ana Radonjić

Summary: After more than a century of extensive research, the question of how the visual system extracts information about physical properties of an object’s surface — such as color, lightness or material — from the pattern of light that reaches the eyes remains open. In the last decade, how we approach this question has been strongly influenced by advances in stimulus modeling software, which enables controlled studies of more complex and natural stimuli, and the development of more sophisticated computational models. The goal of the symposium is to present a cross-section of current research on surface perception and to identify the main challenges facing the field going forward. The symposium participants come from diverse theoretical perspectives, employ different methodologies and use stimuli of varying complexity, but share the common focus of reexamining and reevaluating traditional methodological and theoretical frameworks for studying the perception of surface properties. Topics to be discussed include: the role of contrast in lightness perception of natural stimuli (Maertens), Bayesian approaches to lightness constancy and lightness anchoring (Murray), lightness perception under controlled illumination conditions (Umbach), the use of natural tasks to study the perception of surface properties (Radonjić), the role of short-term memory in color perception (Olkkonen) and the effects of surface reflectance on 3D shape estimation in dynamic scenes (Doerschner).
14:30   Opening remarks
Ana Radonjić, Marianne Maertens
14:30   Perception of infield-surround stimuli under controlled illumination conditions
Nora Umbach, Jürgen Heller
14:50   The role of contrast in lightness perception
using natural stimuli
Marianne Maertens
15:10   Lightness constancy via Bayesian anchoring
Richard F. Murray, Minjung Kim
15:30   Studying color constancy using natural tasks
Ana Radonjić, David H. Brainard
15:50   The role of memory in surface color perception
Maria Olkkonen, Toni Saarela, Sarah R. Allred
16:10   Effects of surface reflectance on 3D shape estimation in dynamic scenes
Katja Doerschner, Dicle Dovencioglu, Ohad Ben-Shahar, Maarten Wijntjes

Tuesday, 26thAugust - Hall 1

Putting Vision into Context: a fresh look at contextual modulation

Organizers: Michael Herzog & Fred Kingdom

Summary: It is widely believed that vision proceeds from a low level to a high level of analysis, from processing lines and edges to figures and objects. Much of vision research is devoted to understanding basic processing, such as of contrast, color, motion, etc. Most experiments use single isolated stimuli such as drifting gratings. However, in the real world elements are rarely encountered in isolation. How do elements combine into objects when surrounded by other objects? This is the research area of contextual modulation. At the neural level, stimuli placed outside the classical receptive field can change the spiking profile of a neuron. However although contextual modulation has been a hot topic of research for over a decade, there has never been a symposium at ECVP or VSS on the subject. We propose to bring together neurophysiological (Movhson, Pack), clinical (Werner), behavioral (Gheorghiu, Kingdom, Herzog) and computational (Solomon) approaches, and offer a fresh look on contextual modulation. We will show how surround texture information is processed in a non-linear fashion and how a single element can be strongly influenced by elements at very remote positions in the visual field. All speakers are presently contributing to a special issue on contextual modulation, which will be published in Vision Research and will potentially available at the time of ECVP 2014 (editors: Alessandra Angelucci, Colin Clifford & Fred Kingdom).
14:30   Opening remarks
Frederick A.A. Kingdom
14:30   Surround suppression supports second-order feature encoding by macaque V1 and V2 neurons
J. Anthony Movshon, Luke E. Hallum
14:50   Psychophysical correlates of lateral inhibition
Joshua A. Solomon
15:10   Colour constancy in context: the role of different temporal and spatial scales
Annette Werner
15:30   Contextual modulation improves motion coding in area MT
Liu D. Liu, Christopher C. Pack
15:50   Contextual modulation as de-texturizer
Elena Gheorghiu, Frederick A.A. Kingdom, Nicolai Petkov
16:10   Contextual Interpretation and Contextual Modulation across the entire visual field
Michael H. Herzog

Tuesday, 26thAugust - Hall 1/B

Motion Processing in Typical and Atypical Development: symposium in memory
of John Wattam-Bell

Organizers: Oliver Braddick& Janette Atkinson

Summary: Motion is a key area of early human visual development, and has proved to be a revealing signature of brain function in many neurodevelopmental disorders. The symposium will review the state-of-the-art in studies of infants’ capabilities for local and global motion processing, and present new evidence from EEG, ERPs and fMRI on the development of the underlying cortical networks in infancy and beyond, including those that link motion processing to attention networks. New findings will be presented on the specific anomalies of motion processing found in autistic spectrum disorders, and in children at risk for brain injury following preterm birth. It will include new data on the links between individual children’s mathematical ability, global motion processing, and variation in brain structure.
As well as presenting advances in these areas, the symposium will honour the memory of John Wattam-Bell (University College London), whose sudden death in December 2013 robbed the field of a pioneer of motion studies in infancy. A number of the participants were John’s collaborators and friends in this research.
14:30   Opening remarks
Oliver Braddick, Janette Atkinson
14:30   From local to global motion in development:
John Wattam-Bell’s contributions
Oliver Braddick, Janette Atkinson
14:45   Global motion, mathematics and movement: dorsal stream sensitivity relates to children’s individual differences in cognitive abilities and regional brain development
Janette Atkinson, Oliver Braddick, John Wattam-Bell, NatachaAkshoomoff, Erik Newman, Holly Girard,
Anders Dale, Terry Jernigan
15:00   Development and plasticity of human cortical network for motion analysis
Maria ConcettaMorrone
15:15   Immature ERP topography, MRI and global motion responses in pretermborn infants
Dee B. Birtles, Janette Atkinson, Shirley Anker,
John Wattam-Bell, Mary Rutherford, Frances Cowan,
David Edwards, MichelaGroppo, Oliver Braddick
15:30   Global motion processing as a measure of a nutritional intervention in very low birth weight infants
Elin Blakstad, Claes von Hofsten, John Wattam-Bell,
PärNyström, Dorota Green, Katarina Strand-Brodd,
Kenneth Strømmen, SisselMoltu, TrondNordheim,
Astrid N. Almaas, Morten Grønn, Arild E Rønnestad,
Kristin Brække, Per O. Iversen, Marit B. Veierød,
Ane C. Westerberg, Christian Drevon, Britt Nakstad
15:45   Visual motion processing in Autism Spectrum Disorder: What is the research telling us?
David R. Simmons
16:00   Increased integration of motion information in children with autism
Catherine Manning, Steven C. Dakin, Marc S. Tibber,
Elizabeth Pellicano
16:15   Development of neural mechanisms for spatial attention
Louisa V. Kulke, John Wattam-Bell, Janette Atkinson,
Oliver Braddick

Wednesday, 27thAugust - Hall 1

Amodal completion: Michotte’s legacy and new directions fifty years after
‘Les complémentsamodaux’

Organizers: Rob van Lier&VebjørnEkroll

Summary: Exactly fifty years ago Albert Michotte famously coined the term amodal completion, which refers to the perceived completeness of partly occluded shapes. Whereas modal completion refers to processes within a given modality of perception (e.g. vision), the term amodal completion alludes to processes outside that modality. This stance can be defended with regard to the first-person phenomenology; while the visual nature of modal percepts is obvious, we do not see amodally completed shapes in the literal sense. That is, an observer may have a very definite impression of the occluded parts of a shape, but the phenomenological presence clearly differs from modally completed properties. At the level of brain processes, however, it would be a rather hazardous enterprise to label one type of filling-in as perception and the other as cognition. Nobody knows where in the brain perception stops and cognition starts, and it may even be questioned whether a clear line can be drawn at all (e.g. because of neural cross-wiring and feedback connections). Nevertheless, exactly this ‘grey zone’ makes amodal completion a particularly interesting domain of research. This symposium intends to demonstrate that amodal completion provides a unique opportunity for investigating interactions between stimulus-driven and knowledge-driven processing streams.
14:30   Opening remarks
Rob van Lier, VebjørnEkroll
14:30   Michotte’s work on amodal completion: A brief historical and conceptual introduction
Johan Wagemans
14:47   Amodal completion: A conceptual playground between perception and cognition
Rob van Lier
15:04   Whenamodal completion fails
Walter Gerbino
15:21   Michotte magic: Amodal perception and the art of conjuring
VebjørnEkroll
15:38   Perceptual interactions between two kinds of amodal completion in the perception of occlusion
Barbara Gillam
15:55   Consistency criteria for successful interpolation of
partly-occluded contours
Manish Singh
16:12   Dynamic neural mechanisms suggested by the different kinds of perceptual organization in modal and amodal completion
Naoki Kogo</p>

Wednesday, 27thAugust - Hall 1/B

Measuring visual awareness - approaches, applications, recommendations

Organizers: Guido Hesselmann, & Marcus Rothkirch

Summary: One of the scientific approaches developed to investigate perceptual awareness consists in making an exhaustive inventory of the processes that proceed non-consciously, in order to isolate, by contrast, those that are exclusively restricted to conscious perception. In the visual domain, in particular, a wide range of paradigms have been designed to render a stimulus invisible, sometimes dubbed “psychophysical magic” (e.g., backward masking, crowding, binocular rivalry). It is self-evident, however, that before one can claim “invisibility” of a stimulus, the fundamental question of what behavioral report or physiological signal classifies as a valid measure of visual awareness needs to be answered. Although the controversy on the optimal measure has been a long standing one (Eriksen 1960; Holender 1986), a renewed debate seems timely and important. On the one hand, new measures of visual awareness such as post-decision wagering have been introduced, which might (or might not) turn out to be superior to established measures. On the other hand, new visual paradigms such as continuous flash suppression have been developed, which might (or might not) require more rigorous measures to assess observers’ awareness. Ultimately, given the increasingly large inter-study variability of awareness measures and visual paradigms, guidelines or recommendations should be formulated.
14:30   Opening remarks
Guido Hesselmann, Marcus Rothkirch
14:35   The challenge of measuring visual consciousness
Morten Overgaard
14:55   Putting high-level findings in breaking continuous flash suppression in perspective
Moors Pieter
15:15   Modeling of conscious and unconscious visual emotion perception with a signal detection theory approach
RemigiuszSzczepanowski
15:35   Enforcing double dissociations between measures of priming and awareness
Thomas Schmidt
15:55   Don’t trust your subjects – a case for objectifying subjective experience in rivalry
Wolfgang Einhäuser
16:15   Panel Discussion