Decomposing the control and development of skin patterning in cuttlefish

Few animals provide as objective a readout of their perceptual state as camouflaging cephalopods. Their skin display system includes an extensive array of pigment cells (chromatophores), each activated by radial muscles controlled by motoneurons. If one could track the individual expansion states of the chromatophores, one would obtain a quantitative description—and potentially even, a neural description by proxy— of the perceptual state of the animal in real time. We developed computational and analytical methods to achieve this in behaving animals, quantifying the state of tens of thousands of chromatophores at sixty frames per second, single-cell resolution, and over weeks. We could infer a statistical hierarchy of motor control, reveal an underlying low-dimensional structure to pattern dynamics, and uncover rules governing skin pattern development. This approach provides an objective description of complex perceptual behaviour, and powerful means to uncover organizational principles underlying neural systems function, dynamics, and morphogenesis.