Faculty


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, Director, http://tlab.usc.edu
    • Center for Vision Science and Technology, member, http://cvst.usc.edu/
    • Dana and David Dornsife Cognitive Neuroscience Imaging Center, co-Director, http://brainimaging.usc.edu

    Publications


    Book
    • Gold, J. M., Abbey, C., Tjan, B. S., Kersten, D. (2009). Special Issue: Ideal observers and efficiency: commemorating 50 years of Tanner and Birdsall. (Vol. 26, (of the Optical Society of America, Ed.). Journal of the Optical Society of America. A, Optics, Image Science, and Vision.

    Book Chapter
    • Tjan, B. S. (2002). Object Recognition. In Arbib M. (Ed.), The Handbook of Brain Theory and Neural Networks. (Vol. 788-792). 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
    • Tjan, B. S., Chao, E., Bernstein, L. E. (2014). A visual or tactile signal makes auditory speech detection more efficient by reducing uncertainty. The European journal of neuroscience. Vol. 39 (8), pp. 1323-31. PubMed Web Address
    • Kwon, M., Nandy, A. S., Tjan, B. S. (2013). Rapid and persistent adaptability of human oculomotor control in response to simulated central vision loss. Current biology : CB. Vol. 23 (17), pp. 1663-9. PubMed Web Address
    • Millin, R., Arman, A. C., Chung, S. T., Tjan, B. S. (2013). Visual Crowding in V1. Cerebral cortex (New York, N.Y. : 1991). PubMed Web Address
    • Wallace, J. M., Chiu, M. K., Nandy, A. S., Tjan, B. S. (2013). Crowding during restricted and free viewing. Vision research. Vol. 84, pp. 50-9. PubMed Web Address
    • Legge, G. E., Beckmann, P. J., Tjan, B. S., Havey, G., Kramer, K., Rolkosky, D., Gage, R., Chen, M., Puchakayala, S., Rangarajan, A. (2013). Indoor navigation by people with visual impairment using a digital sign system. PloS one. Vol. 8 (10), pp. e76783. PubMed Web Address
    • Thompson, B., Tjan, B. S., Liu, Z. (2013). Perceptual learning of motion direction discrimination with suppressed and unsuppressed MT in humans: an fMRI study. PloS one. Vol. 8 (1), pp. e53458. PubMed Web Address
    • Kwon, M., Ramachandra, C., Satgunam, P., Mel, B. W., Peli, E., Tjan, B. S. (2012). Contour enhancement benefits older adults with simulated central field loss. Optometry and vision science : official publication of the American Academy of Optometry. Vol. 89 (9), pp. 1374-84. PubMed Web Address
    • Gold, J. M., Mundy, P. J., Tjan, B. S. (2012). The perception of a face is no more than the sum of its parts. Psychological Science. Vol. 23 (4), pp. 427–434.
    • Nandy, A. S., Tjan, B. S. (2012). Saccade-confounded image statistics explain visual crowding. Nature Neuroscience. Vol. 15 (3), pp. 463–469.
    • Wallace, J. M., Tjan, B. S. (2011). Object crowding. Journal of Vision. Vol. 11 (6), pp. 19: 1–17.
    • Sun, G. J., Chung, S. T., Tjan, B. S. (2010). Ideal observer analysis of crowding and the reduction of crowding through learning. Journal of Vision. Vol. 10 (5), pp. doi:10.1167/10.5.16.
    • Lu, Z., Li, X., Tjan, B. S., Dosher, B. A., Chu, W. (2010). Attention Extracts Signal in External Noise: A BOLD fMRI Study. Journal of Cognitive Neuroscience. Vol. [Epub ahead of print], pp. 10.1162/jocn.2010.21511.
    • Legge, G. E., Tjan, B. S., Chung, S. T., Bigelow, C. (2010). Do image descriptions underlie word recognition in reading. British Journal of Psychology. Vol. 101 (1), pp. 33-39.
    • Gold, J. M., Abbey, C., Tjan, B. S., Kersten, D. (2010). Ideal observers and efficiency: commemorating 50 years of Tanner and Birdsall: introduction. Journal of the Optical Society of America. A, Optics, image science, and vision. Vol. 26 (11), pp. IO1-2. PubMed Web Address
    • 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.
    • Li, X., Lu, Z. L., Tjan, B. S., Dosher, B. A., Chu, W. (2008). Blood oxygenation level-dependent contrast response functions identify mechanisms of covert attention in early visual areas. Proceedings of the National Academy of Sciences of the United States of America. Vol. 105 (16), pp. 6202-7. PubMed Web Address
    • 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. IEEE Computer Society.


    Service to the University

    Administrative Appointments
    • Co-Director, Dana and David Dornsife Neuroscience Imaging Center, 08/01/2011-  
    • Head, Brain and Cognitive Science Area, Department of Psychology, 08/16/2010-  




  • Department of Psychology
  • University of Southern California
  • SGM 501
  • 3620 South McClintock Ave.
  • Los Angeles, CA 90089-1061