Dr Chris Lewis | Cortical feedback and repetition enhance sensory coding in primary visual cortex

Gastvortrag

  • Datum: 26.09.2016
  • Uhrzeit: 14:30 - 15:30
  • Vortragende(r): Dr Chris Lewis
  • Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt am Main, Germany
  • Ort: Max-Planck-Institut für Kognitions- und Neurowissenschaften
  • Raum: Wilhelm Wundt Raum (A400)
  • Gastgeber: Max-Planck-Forschungsgruppe "Neuroanatomie & Konnektivität"
Identical sensory stimulation results in highly dynamic response patterns in primary sensory cortex, despite the physical constancy of external factors. This response modulation is thought to be partly attributable to activity intrinsic to the brain itself, such as behavioral state and previous experience. Two prominent factors contributing to intrinsic brain activity are feedback signals from higher order areas and the history of coactivation amoung sensory cells. I will discuss a series of experiments that investigate the effects of cortical feedback and stimulus repetition on sensory coding in the primary visual cortex. We find that both feedback activity and sensory experience increase the amount of sensory information retrievable from population responses without changing the average activity of single cells or the mean activity across the population. Specifically, the information is encoded in the distributed pattern of activity across the population, as predicted by population coding and Hebbian plasticity. These findings suggest that early sensory cortices provide a highly flexible representation of external variables which reflects both the current state of higher order brain areas, as well as the history of previous stimulation. Time permitting, I will also discuss recent progress in our attempts to increase the spatial coverage of in vivo electrophysiology, while simultaneously acquiring signals at multiple spatial scales: from single neurons to whole brain areas.
Zur Redakteursansicht