Profile

Bosco S. Tjan

Associate Professor of Psychology

Contact Information
E-mail: btjan@usc.edu
Phone: (213) 821-2953
Office: SGM 1017A

LINKS
Curriculum Vitae
Personal Website
Department of Psychology
Neuroscience Graduate Program
Dana & David Dornsife Cognitive Neuroscience Imaging Center

Education

Ph.D. Computer Science, University of Minnesota, 1/1997

Academic Appointment, Affiliation, and Employment History

Tenure Track Appointments

Associate Professor, University of Southern California, 01/29/2008-
Assistant Professor, University of Southern California, 01/01/2001-01/28/2008

PostDoctoral Appointments

Research Associate, NEC Research Institute, 09/01/1998-01/01/2000
Post-Doctoral Research Fellow, Max-Planck Institute for Biological Cybernetics, Germany, 01/01/1997-08/31/1998

Description of Research

Summary Statement of Research Interests

Professor Tjan studies the human visual system by exploring neural computations that underlie the perception of form, a domain that includes object recognition, scene perception, and reading. He uses a combination of techniques such as computational modeling, psychophysics, and functional Magnetic Resonance Imaging in his research.

On-going research topics (as of 6/2007) include:

Letter identification and form vision in the peripheral visual fields
Image enhancement for people with impaired vision
Indoor navigation aid for the blind and the visually impaired
Perception of visual speech
Uncertainty, invariance, and the order of processing in the human visual cortex
Ocular-motor control during form perception
Signal-in-noise methods for determining higher-order receptive fields
Theory of adaptive representation of objects

Affiliations with Research Centers, Labs, and Other Institutions

Laboratory for Functional and Computational Vision,http://tlab.usc.edu
Dana and David Dornsife Cognitive Neuroscience Imaging Center,http://brainimaging.usc.edu

Publications

Book Chapter

Tjan, B. S. (2002). Object Recognition. In Arbib M. (Ed.), The Handbook of Brain Theory and Neural Networks. (Vol. 788-792). Object Recognition. In Arbib M. (Ed.), The Handbook of Brain Theory and Neural Networks/Cambridge: MIT Press..
Klitz, T. S., Legge, G. E., Tjan, B. S. (2000). Saccade planning in reading with central scotomas: comparison of human and ideal performance. Reading as a perceptual process./Elsevier.
Tjan, B. S. (1996). Ideal observer analysis of object recognition. Doctoral Thesis. Minneapolis,MN: Ideal observer analysis of object recognition./University of Minnesota.
Tjan, B. S., Gardiner, D., Slagle, J. R. (1992). Representing and reasoning with set referents and numerical quantifiers. Conceptual Structures – current research and practice./Ellis Horwood.
Gardiner, D., Tjan, B. S., Slagle, J. R. (1992). Extending Conceptual Structures: Representation Issues and Reasoning Operations. Conceptual Structures – current research and practice./Ellis Horwood.

Journal Article

Chung, S. T., Tjan, B. S. (2009). Spatial-frequency and contrast properties of reading in central and peripheral vision. Journal of Vision. Vol. 9 (9), pp. 16: 1-19.
Nandy, A. S., Tjan, B. S. (2008). Efficient integration across spatial frequencies for letter identification in foveal and peripheral vision. Journal of Vision. Vol. 8 (13), pp. 3: 1-20.
Zhou, J., Tjan, B. S., Zhou, Y., Liu, Z. (2008). Better discrimination for illusory than for occluded perceptual completions. Journal of Vision. Vol. 8 (7), pp. 26: 1-17.
Li, X. X., Lu, Z. L., Tjan, B. S., Dosher, B. A., Chu, W. (2008). BOLD contrast response functions identify mechanisms of covert attention in early visual areas. PNAS. Vol. 105, pp. 4068-4073.
Huang, X., Lu, H., Tjan, B. S., Zhou, Y., Liu, Z. (2007). Motion perceptual learning: When only task-relevant information is learned. J Vis. Vol. 7, pp. 14 1-10.
Nandy, A. S., Tjan, B. S. (2007). The nature of letter crowding as revealed by first- and second-order classification images. Journal of Vision. Vol. 7(2), pp. 5, 1–26.
Chung, S. T., Tjan, B. S. (2007). Shift in spatial scale in identifying crowded letters. Vision Res. Vol. 47, pp. 437-51.
Yue, X., Tjan, B. S., Biederman, I. (2006). What makes faces special?. Vision Res. Vol. 46, pp. 3802-11.
Tjan, B. S., Nandy, A. S. (2006). Classification images with uncertainty. J Vis. Vol. 6, pp. 387-413.
Tjan, B. S., Lestou, V., Kourtzi, Z. (2006). Uncertainty and invariance in the human visual cortex. J Neurophysiol. Vol. 96, pp. 1556-68.
Lu, H., Tjan, B. S., Liu, Z. (2006). Shape recognition alters sensitivity in stereoscopic depth discrimination. J Vis. Vol. 6, pp. 75-86.
Tjan, B. S., Liu, Z. (2005). Symmetry impedes symmetry discrimination. J Vis. Vol. 5, pp. 888-900.
Chung, S. T., Levi, D. M., Tjan, B. S. (2005). Learning letter identification in peripheral vision. Vision Res. Vol. 45, pp. 1399-412.
Christou, C. G., Tjan, B. S., Bulthoff, H. H. (2003). Extrinsic cues aid shape recognition from novel viewpoints. J Vis. Vol. 3, pp. 183-98.
Legge, G. E., Hooven, T. A., Klitz, T. S., Stephen Mansfield, J. S., Tjan, B. S. (2002). Mr. Chips 2002: new insights from an ideal-observer model of reading. Vision Res. Vol. 42, pp. 2219-234.
Chung, S. T., Legge, G. E., Tjan, B. S. (2002). Spatial-frequency characteristics of letter identification in central and peripheral vision. Vision Res. Vol. 42, pp. 2137-152.
Chung, S. T., Levi, D. M., Legge, G. E., Tjan, B. S. (2002). Spatial-frequency properties of letter identification in amblyopia. Vision Res. Vol. 42, pp. 1571-81.
Tjan, B. S. (2001). Adaptive object representation with hierarchically-distributed memory sites. Advances in Neural Information Processing Systems. Vol. 13, pp. 66-72.
Newell, F. N., Ernst, M. O., Tjan, B. S., Bulthoff, H. H. (2001). Viewpoint dependence in visual and haptic object recognition. Psychol Sci. Vol. 12, pp. 37-42.
Tjan, B. S., Ruppertsberg, A. I. (2001). The pew illusion--a real-world example of misperceived slant. Perception. Vol. 30, pp. 125-8.
Tjan, B. S., Legge, G. E. (1998). The viewpoint complexity of an object-recognition task. Vision Res. Vol. 38, pp. 2335-50.
Legge, G. E., Klitz, T. S., Tjan, B. S. (1997). Mr. Chips: an ideal-observer model of reading. Psychol Rev. Vol. 104, pp. 524-53.
Dogru, S., Rajan, V., Rieck, k., Slagle, J. R., Tjan, B. S., Wang, Y. (1996). A graphical data flow language for retrieval, analysis, and visualization. Journal of Visual Languages and Computing. Vol. 7, pp. 247-265..
Tjan, B. S., Braje, W. L., Legge, G. E., Kersten, D. (1995). Human efficiency for recognizing 3-D objects in luminance noise. Vision Res. Vol. 35, pp. 3053-69.
Braje, W. L., Tjan, B. S., Legge, G. E. (1995). Human efficiency for recognizing and detecting low-pass filtered objects. Vision Res. Vol. 35, pp. 2955-66.

Proceedings

Tjan, B. S., Beckmann, P., Roy, R., Giudice, N., Legge, G. E. (2005). Digital Sign System for indoor wayfinding for the visually impaired. Washington, DC, USA. Digital Sign System for indoor wayfinding for the visually impaired./IEEE Computer Society.