"A motor readout of visual perception:Deciphering cuttlefish camouflage at single-chromatophore resolution" Dr. Samuel Reiter

Dear all,

Neural Computation Unit (Doya Unit) would like to invite you to a seminar as follows.

--
Date:  Thursday, December 21
Time: 10:00-
Venue: Meeting Room D015 - L1 Bldg

Speaker: Dr. Samuel Reiter,  Max Planck Institute for Brain Research

Title: A motor readout of visual perception: Deciphering cuttlefish camouflage at single-chromatophore resolution

Abstract: Cuttlefish provide a unique opportunity to study visual perception in an animal whose eyes, brain, and motor control strategy evolved independently of the vertebrate lineage. These animals possess the most advanced camouflage in the animal kingdom, displaying their perception of the visual environment as a two dimensional image on their skin. This is accomplished through direct neural control over the expansion and contraction of hundreds of thousands of pigment-filled cells known as chromatophores. How does the cuttlefish perform the mapping from visual scene to camouflage pattern choice?

As a first step towards answering this question, we sought to describe cuttlefish camouflage quantitatively. We developed a multi-level video-analysis pipeline to track tens of thousands of chromatophores simultaneously at 60 frames per second.  In addition, non-affine image registration using small patches of skin as uniquely identifiable features allowed us to stitch together datasets separated in time by up to weeks. By factorizing the resulting chromatophore area x time matrix, we could infer putative elements of a hierarchical motor control strategy. This starts with motor neurons directly coordinating the activity of small groups of chromatophores and proceeds to larger-scale pattern elements. Further, taking advantage of our ability to track single chromatophores over developmental timescales, we detected and studied the continuous integration of large numbers of newly developed chromatophores into the exiting circuit. We built a very simple model that is able to reproduce many aspects of skin patterning in these animals, and that suggests a common mechanism underlying the diversity of cuttlefish, octopus, and squid skin patterns seen in nature.  Our approach provides the first view of cuttlefish skin dynamics at the spatiotemporal scales of the nervous system.  More generally, it uses the unique features of an atypical model to provide a nearly complete readout of visual perceptual behavior at single-cell resolution in a freely moving animal.

Funded by the Max Planck Society.

We hope to see many of you.
Sincerely,
Emiko Asato
Neural Computation Unit