Alan Stocker

Assistant Professor

Education:

Ph.D. Institute of Neuroinformatics, ETH Zurich, Switzerland

Department:

Psychology

Address:

3401 Walnut St., Room 313C

Phone:

215-573-9341

Email:

astocker@sas.upenn.edu

Personal Page

Lab Page

Research Themes:

Cognitive Neuroscience

Sensation and Perception

Specific Research Areas:

Models of visual perception; linking theory to psychophysical and physiological data

Research Synopsis:

My research interest is to understand the role of context in neural information processing, with an emphasis on visual perception. Illusions are often the result of particularly strong contextual effects and are typically strongest when the sensory evidence is most ambiguous in terms of its interpretation (as in the example of the half-full/half-empty glass).
My approach is inherently interdisciplinary by combining theory and experiment. Theory provides the necessary guidance to develop models that are both constrained by fundamental principles, and able to predict perceptual behavior. The theory of evolution (survival of the fittest) proposes that biological systems optimize their perceptual behavior with respect to their environmental conditions. This leads to a description of perception as optimal statistical inference, which can be formulated rigidly within the mathematical framework of Bayesian statistics.
My research goals are to derive computational models that quantitatively account for perceptual behaviors under contextual influences, to test these models with carefully targeted psychophysical and (through collaboration) physiological experiments, and to apply them in artificial perceptual systems.

Representative Courses:

Psyc 111 Perception

Appointments:

Psychology Graduate Group

Publications:

(click here for the full list)

Alan A Stocker and Eero P Simoncelli (2009), Visual motion aftereffects arise from a cascade of two isomorphic adaptation mechanisms, Journal of Vision, vol. 9, no. 9, p. 1-14.

Alan A Stocker and Eero P Simoncelli (2008), A Bayesian Model of Conditioned Perception, NIPS Advances in Neural Information Processing Systems 20, Vancouver Canada, May, MIT Press, p. 1409-1416

Alan A Stocker and Eero P Simoncelli (2006), Noise characteristics and prior expectations in human visual speed perception, Nature Neuroscience, vol.9, no.4, April, p. 578-585

Alan A Stocker (2006), Analog Integrated 2D Optical Flow Sensor, Analog Integrated Circuits and Signal Processing, vol. 46, no. 2, January, p. 121-138

Alan A Stocker and Eero P Simoncelli (2006), Sensory Adaptation within a Bayesian Framework for Perception, NIPS Advances in Neural Information Processing Systems 18, Vancouver Canada, May, MIT Press, p. 1291-1298

Alan A Stocker (2004), Analog VLSI focal-plane array with dynamic connections for the estimation of piecewise-smooth optical flow, IEEE Transactions on Circuits and Systems-1; vol. 51, no. 5, May, p. 963-973

Alan A Stocker and Rodney J Douglas (2004), Analog Integrated 2-D Optical Flow Sensor with Programmable Pixels, ISCAS2004, Vancouver Canada, May, vol. 3, p. 9-12