April 2019 UWIN seminar speakers

The April 2019 UWIN seminar series continues with a pair of short talks by Eberhard Fetz and Ramkumar Sabesan. The seminar is on Wednesday, April 10, 2019 at 3:30 in Husky Union Building (HUB) 337. Refreshments will be served prior to the talks.

  • “Computational models of cortical plasticity induced with brain-computer interfaces”
    Eberhard Fetz, Professor, Department of Physiology & Biophysics, University of Washington
  • “Probing spatial and color vision at the resolution of single cone photoreceptors”
    Ramkumar Sabesan , Research Assistant Professor, Department of Ophthalmology, University of Washington
  • Abstracts:

    “Computational models of cortical plasticity induced with brain-computer interfaces” (Eberhard Fetz)

    Changes in cortical connectivity have been induced in awake behaving monkeys with head-fixed bidirectional brain-computer interfaces. This talk will discuss results from three experimental protocols that have been modeled: spike-triggered and cycle-triggered stimulation and paired-pulse stimulation. Conditioning results were simulated for the first with an analytical statistical model and for all three with an integrate-and-fire spiking network model.

    “Probing spatial and color vision at the resolution of single cone photoreceptors” (Ramkumar Sabesan)

    The visual system reconstructs fine spatial detail and rich color experience from a paucity of wavelength and intensity signals originating in the cone mosaic. We use a combination of adaptive optics and high speed eye-tracking to allow light stimuli of multiple wavelengths to be targeted on individual cones. Consequently, visual perception upon controlled activation of a single or a group of cones can be addressed in a living human yielding psychophysical measures ultimately limited by the cone mosaic and downstream retinal and cortical circuitry. I will describe results from a recent set of experiments aimed at outlining the spatial characteristics of color appearance and conclude by framing these results in relation to contemporary models of neural circuitry mediating color and spatial vision.