Laboratories
Gardner Research Unit
Justin L. GARDNER
Unit Leader
Justin L. GARDNER (Ph.D.)
mail

Research Areas

Vision is a fabrication of our minds. Sensory information from our eyes is often ambiguous or limited, yet vision is remarkably robust and surprisingly able to correctly interpret impoverished sensory signals. What cortical computations make this possible? In the framework of Bayesian statistical decision theory; how does the cortex combine sensory evidence from the eyes with priors or expectations to form percepts? Priors may be short term and signaled by the task at hand - a particular spatial location may be more likely to contain information that is needed. Or priors may be long-term and developed over extended exposure to the natural statistics of the visual world - objects may tend to move slowly rather than quickly. While much is known about the encoding of sensory evidence, comparatively little is known about priors. Where do priors interact with sensory signals and how do they modify and augment perception? We use psychophysics to make precise
behavioral measurements of how priors bias sensory decisions while concurrently measuring cortical activity with functional magnetic resonance imaging. Using knowledge of the visual system and decision theoretical models of how behavior is linked to cortical activity, we seek to understand the cortical computations that construct human vision.

Research Subject

  1. Linking human perception and cortical activity with fMRI
  2. Prior information and visual perception
  3. Functional organization of cortical vasculature

Related links

  1. RIKEN Brain Science Institute Website_Laboratories PageNew Window
  2. Individual Website Laboratory PageNew Window

Press release

December 8, 2011
How our brains keep us focused

List of Selected Publications

  1. Pestilli, F., Carrasco, M., Heeger, D.J., and *Gardner, J. L.:
    " Attentional enhancement via selection and pooling of early sensory responses in human visual cortex."
    Neuron 72: 832-846 (2011)
  2. Liu, T., Hospadaruk, L., Zhu, D., and *Gardner, J. L.:
    " Feature-specific attentional priority signals in human cortex."
    Journal of Neuroscience 31: 4484-95 (2011)
  3. *Gardner, J.L., Merriam, E.P., Movshon, J.A., and Heeger, D.J.:
    " Maps of visual space in human occipital cortex are retinotopic, not spatiotopic."
    Journal of Neuroscience 28:3988-3999 (2008)
  4. *Gardner, J.L., Sun, P., Waggoner, R.A., Ueno, K., Tanaka, K., and Cheng, K.:
    " Contrast adaptation and representation in human early visual cortex."
    Neuron 47:607-620 (2005)
  5. *Gardner, J.L., Tokiyama, S., and Lisberger, S.G.:
    " A population decoding framework for motion aftereffects on smooth pursuit eye movements."
    Journal of Neuroscience 24:9035-9048 (2004)
  6. *Gardner, J. L. and Lisberger, S. G.:
    " Serial linkage of target selection for orienting and tracking eye movements."
    Nature Neuroscience 5:892-899 (2002)

Members

Principal Investigator

Justin Lawrence GARDNER
Unit Leader

Members

Kenji HARUHANA
Technical Staff II
Toshiko IKARI
Assistant
Franco PESTILLI
Visiting Scientist