March 29, 1994 - March 29, 2027

  • Date:13TuesdayNovember 2018

    Perception and retinal integration of rod and cone signals in primate

    More information
    Time
    12:30
    Location
    Gerhard M.J. Schmidt Lecture Hall
    Lecturer
    Dr. William Grimes
    NINDS/NIH
    Organizer
    Department of Brain Sciences
    Contact
    DetailsShow full text description of Host: Dr. Michal Rivlin michal.rivlin@weizmann.ac.il tel: ...»
    Host: Dr. Michal Rivlin michal.rivlin@weizmann.ac.il tel: 2792

    For assistance with accessibility issues, please contact naomi.moses@weizmann.ac.il

    AbstractShow full text abstract about Over the course of a natural day-night cycle, mean luminance...»
    Over the course of a natural day-night cycle, mean luminance levels can span ten log units or more. Mammalian retinas effectively encode visual information over this vast range, in part by utilizing exquisitely sensitive rod photoreceptors in dim conditions and multiple color-variant cone photoreceptors in bright conditions. These visual signals, regardless of origin, must pass through a common set of retinal ganglion cells, thereby creating opportunities for signal interactions. Human perceptual experiments conducted under intermediate lighting conditions reveal constructive and destructive interactions between flickering rod and cone stimuli that are thought to originate in the retina. In support of this hypothesis, we find rod-cone flicker interference in On and Off retinal ganglion cells that project! to magnocellular visual pathways in primates. The dependence of this interference on the frequency and phase of the temporal modulation is similar to that observed in perceptual measurements. Recordings from within the retinal circuitry indicate that rod-cone signal interference reflects a linear combination of kinetically-distinct rod and cone signals upstream of the ganglion cell synaptic inputs. Ultimately, using our empirically-derived data as a foundation, we construct a mathematical model that recapitulates known rod-cone interactions and predicts retinal output in response to a broad range of time-varying rod and cone stimuli.
    Lecture