Alexander C. Huk

Neurobiology & Center for Perceptual Systems
The University of Texas at Austin

Dr. Alexander C. Huk has been chosen as the 2011 winner of the Elsevier/VSS Young Investigator Award. Dr. Huk is an Associate Professor of Neurobiology in the Center for Perceptual Systems at the University of Texas at Austin. Dr. Huk impressed the committee with the broad range of techniques he has brought to bear on fundamental questions of visual processing and decision making. Studying both human and non-human primates with psychophysical, electrophysiological and fMRI approaches, Dr. Huk has made significant, influential and ground-breaking contributions to our understanding of the neural mechanisms involved in motion processing and the use of sensory information as a basis for perceptual decisions. His contributions are outstanding in their breadth as well as their impact on the field and represent the uniqueness of the VSS community to integrate behavioral and neural approaches to vision science.

Elsevier/Vision Research Article

Some new perspectives in the primate motion pathway

Sunday, May 8, 7:00 pm, Royal Palm Ballroom

The dorsal (“where”) stream of visual processing in primates stands as one of the most fruitful domains for bridging neural activity with perception and behavior. In early stages of cortical processing, neurophysiology and psychophysics have elucidated the transformations from dynamic patterns of light falling upon the retinae, to simple 1D motion signals in primary visual cortex, and then to the disambiguated 2D motions of complex patterns and objects in the middle temporal area (MT). In later stages, the motion signals coming from MT have been shown to be accumulated over time in parietal areas such as LIP, and this decision-related activity has been quantitatively linked to behavioral outputs (i.e., the speed and accuracy of perceptual decisions). In this talk, I’ll revisit this pathway and suggest new functions in both the visual and decision stages. In the first part, I’ll describe new results revealing how 3D motion is computed in the classic V1-MT circuit. In the second part, I’ll address whether LIP responses are really a “neural correlate” of perceptual decision-making, or instead reflect a more general type of sensorimotor integration. These lines of work suggest that by building on the already well-studied primate dorsal stream, both psychophysics and physiology can investigate richer perceptual functions and entertain more complex underlying mechanisms.

Geoffrey F. Woodman

Department of Psychology and Vanderbilt Vision Research Center
Vanderbilt University

Dr. Geoffrey F. Woodman is the 2012 winner of the Elsevier/VSS Young Investigator Award.  Dr. Woodman is  Assistant Professor in the Department of Psychology and Vanderbilt Vision Research Center at  Vanderbilt University, in Nashville, Tennessee. Geoff’s important contributions to vision science range from fundamental insights into human visual cognition to the development of novel electrophysiological techniques. His uniquely integrated approach to comparative electrophysiology has demonstrated homologies between man and monkey in the ERP components underlying attention and early visual processes, enabling new understanding of their neural bases. Geoff has also made key breakthroughs in the understanding of visual working memory, placing it at the center of the interaction between high-level cognition and perception.  In the ten years since gaining his PhD, Geoff has been exceptionally productive, moving forward the core disciplines of visual perception, attention and memory,  through his many insightful and high-impact papers. His breadth, technical versatility and innovation, particularly in linking human and non-human-primate studies, represent true excellence in vision sciences research.

Elsevier/Vision Research Article

Attention, memory, and visual cognition viewed through the lens of electrophysiology

Sunday, May 13, 7:00 pm, Royal Palm Ballroom

How do we find our children on a crowded playground, our keys in the kitchen, or hazards in the roadway? This talk will begin by discussing how measurements of electrical potentials from the brain offer a lens through which to observe the processing of such complex scenes unfold.  For example, I will discuss our work showing that when humans search for targets in cluttered scenes, we can directly measure the target representations maintained in visual working memory and what information is selected by attention.  Moreover, when the searched-for target is the same across a handful of trials we can watch these attentional templates in working memory handed off to long-term memory. Next, I will discuss our recent work demonstrating that redundant target representations in working and long-term memory appear to underlie our ability to exert enhanced cognitive control over visual cognition.  Finally, I will discuss our work focused on understanding the nature of these electrophysiological tools.  In studies with nonhuman primates we have the ability to record event-related potentials from outside the brain, like we do with humans, but also activity inside the brain revealing the neural network generating these critical indices of attention, memory, and a host of other cognitive processes.

Roland W. Fleming

Kurt Koffka Junior Professor Of Experimental Psychology,
University Of Giessen

Roland W. Fleming is the 2013 winner of the VSS Young Investigator Award. Roland is the Kurt Koffka Junior Professor of Experimental Psychology at University of Giessen in Giessen, Germany.  His work combines deep insight about perceptual processes with rigorous experimentation and computational analysis, and he communicates his findings with exemplary clarity. Roland is well-known for his transformative work connecting the perception of object material properties with image statistics.  Equally important is his work on shape estimation from ‘orientation fields’, which has been widely appreciated for highlighting raw information in the image that is diagnostic of 3D shape. Roland has also applied insights from perception to the advancement of computer graphics. He takes an interdisciplinary approach that combines neural modelling, psychophysical experiments, and advanced image synthesis and analysis methods. In addition to his formidable array of intellectual contributions, Roland has been a tireless contributor to the academic community, serving on editorial boards, organizing symposia and short courses, and training first rate students and postdocs.

Elsevier/Vision Research Article

Shape, Material Perception and Internal Models

Monday, May 13, 1:00 pm, Royal Palm Ballroom

When we look at objects, we don’t just recognize them, we also mentally ‘size them up’, making many visual inferences about their physical and functional properties.  Without touching an object, we can usually judge how rough or smooth it is, whether it is physically stable or likely to topple over, or where it might break if we applied force to it.  High-level inferences like these are computationally extremely challenging, and yet we perform them effortlessly all the time.  In this talk, I will present research on how we perceive and represent the properties of materials and objects.  I’ll discuss gloss perception and the inference of fluid viscosity from shape cues.  Using these examples I’ll argue that the visual system doesn’t actually estimate physical parameters of materials and objects.  Instead, I suggest, the brain is remarkably adept at building ‘statistical generative models’ that capture the natural degrees of variation in appearance between samples.  For example, when determining perceived glossiness, the brain doesn’t estimate parameters of a physical reflection model.  Instead, it uses a constellation of low- and mid-level image measurements to characterize the extent to which the surface manifests specular reflections.  Likewise, when determining apparent viscosity, the brain uses many general-purpose shape and motion measurements to characterize the behaviour of a material and relate it to other samples it has seen before. I’ll argue that these ‘statistical generative models’ are both more expressive and easier to compute than physical parameters, and therefore represent a powerful middle way between a ‘bag of tricks’ and ‘inverse optics’.  In turn, this leads to some intriguing future directions about how ‘generative’ representations of shape could be used for inferring not only material properties but also causal history and class membership from few exemplars.

Duje Tadin

Associate Professor, Department of Brain and Cognitive Sciences, Center for Visual Science, Department of Ophthalmology, University Of Rochester, NY, USA

Duje Tadin is the 2014 winner of the Elsevier/VSS Young Investigator Award. Trained at Vanderbilt, Duje Tadin was awarded the PhD. in Psychology in 2004 under the supervision of Joe Lappin. After 3 years of post-doctoral work in Randolph Blake’s lab, he took up a position at the University of Rochester, where he is currently an associate professor. Duje’s broad research goal is to elucidate neural mechanisms that lead to human visual experience. He seeks converging experimental evidence from a range of methods, including human psychophysics, computational modeling, transcranial magnetic stimulation (TMS), neuroimaging, research on special populations, collaborations on primate neurophysiology, and adaptive optics to control retinal images. Duje is probably best known for his elegant and illuminating research on spatial mechanisms of visual motion perception – work that has had a lasting impact on the field. He developed a new method to quantify motion perception using brief, ecologically relevant time scales, and then used it to discover a functionally important phenomenon of spatial suppression: larger motion patterns are paradoxically more difficult to see. Duje’s results revealed joint influences of spatial integration and segmentation mechanisms, showing that the balance between these two competing mechanisms is not fixed but varies with visibility, with spatial summation giving way to spatial suppression as visibility increases. He has also made significant contributions to several high-profile papers dealing with binocular rivalry, rapid visual adaptation, multi-sensory interactions, and visual function in individuals with low-vision and children with autism.

Elsevier/Vision Research Article

Suppressive neural mechanisms: from perception
to intelligence

Monday, May 19, 12:30 pm, Talk Room 2

Perception operates on an immense amount of incoming information that greatly exceeds brain’s processing capacity. Because of this fundamental limitation, our perceptual efficiency is constrained by the ability to suppress irrelevant information. Here, I will present a series of studies
investigating suppressive mechanisms in visual motion processing, namely perceptual suppression of large, background-like motions. We find that these suppressive mechanisms are adaptive, operating only when the sensory input is sufficiently strong to guarantee visibility. Utilizing a range of methods, we link these behavioral results with inhibitory center-surround receptive fields, such as those in cortical area MT.

What are functional roles of spatial suppression? Spatial suppression is weaker in old age and schizophrenia—as evident by paradoxically better-than-normal performance in some conditions. Moreover, these subjects also exhibit deficits in figure-ground segregation, suggesting a functional
connection. In recent studies, we report direct experimental evidence for a functional link between spatial suppression and figure-ground segregation.

Finally, I will argue that the ability to suppress information is a fundamental neural process that applies not only to perception but also to cognition in general. Supporting this argument, we find that individual differences in spatial suppression of motion signals strongly predict individual variations in WAIS IQ scores (r = 0.71).

John Serences

Associate Professor, Department of Psychology, University of California, San Diego

Trained at Johns Hopkins University, John Serences was awarded the PhD in Psychological and Brain Sciences in 2005 under the supervision of Steven Yantis. After one year of post-doctoral training at the Salk with Geoffrey Boynton, he took up a faculty position at University of California, Irvine in 2007 before moving to University of California, San Diego in 2008, where he was promoted to Associate Professor in 2011.

Dr. Serences is an internationally recognized leader in the field of visual attention and a pioneer of cutting edge quantitative and neuroimaging techniques. He has adopted an interdisciplinary approach that combines psychophysics, cognitive behavioral modeling, functional MRI, and EEG to make significant contributions in the fields of visual attention, working memory, perceptual decision making, and perceptual learning. Dr. Serences has developed cutting edge data analyses that open up new possibilities for the types of questions that can be addressed with human neuroimaging tools.

Dr. Serences is not only prolific, but he exhibits an unwavering commitment to mentorship – resulting in a team of highly motivated and proficient students – and fosters long-lasting collaborations across universities and disciplines. With his development and application of cutting-edge quantitative methods in human neuroimaging, Dr. Serences is changing the face of vision research.

Elsevier/Vision Research Article

Selective attention and visual information processing

Monday, May 18, 12:30 pm, Talk Room 2

Selective information processing – or selective attention – is supported by changes in neural gain, changes in neural variability, and changes in the shape of tuning functions. Traditionally, these effects have been examined in isolation and researchers have tried to infer how each type of modulation impacts the information content of sensory codes. However, examining each modulatory effect in isolation can obscure our understanding of how attention dynamically shapes the quality of perceptual representations. Fortunately, new techniques can more precisely characterize large-scale neural activity patterns, and I will discuss how several such approaches can reveal insights about the joint impact of attentional modulations on information processing in visual cortex.