Visual coding with a population of direction-selective neurons.
The brain decodes the visual scene from the action potentials of ∼20 retinal ganglion cell types. Among the retinal ganglion cells, direction-selective ganglion cells (DSGCs) encode motion direction. Several studies have focused on the encoding or decoding of motion direction by recording multiunit activity, mainly in the visual cortex. In this study, we simultaneously recorded from all four types of ON-OFF DSGCs of the rabbit retina using a microelectronics-based high-density microelectrode array (HDMEA) and decoded their concerted activity using probabilistic and linear decoders. Furthermore, we investigated how the modification of stimulus parameters (velocity, size, angle of moving object) and the use of different tuning curve fits influenced decoding precision. Finally, we simulated ON-OFF DSGC activity, based on real data, in order to understand how tuning curve widths and the angular distribution of the cells' preferred directions influence decoding performance. We found that probabilistic decoding strategies outperformed, on average, linear methods and that decoding precision was robust to changes in stimulus parameters such as velocity. The removal of noise correlations among cells, by random shuffling trials, caused a drop in decoding precision. Moreover, we found that tuning curves are broad in order to minimize large errors at the expense of a higher average error, and that the retinal direction-selective system would not substantially benefit, on average, from having more than four types of ON-OFF DSGCs or from a perfect alignment of the cells' preferred directions.
Bio Engineering Laboratory, ETH Zurich, Basel, Switzerland; michele.fiscella@bsse.ethz.ch.
Michele
M
Fiscella
Bio Engineering Laboratory, ETH Zurich, Basel, Switzerland;
Felix
http://orcid.org/0000-0001-5550-1222
F
Franke
Neuro-Electronics Research Flanders IMEC, Leuven, Belgium;
Karl
K
Farrow
Bio Engineering Laboratory, ETH Zurich, Basel, Switzerland;
Jan
J
Müller
Neural Circuits Laboratory, Friedrich Miescher Institute, Basel, Switzerland;
Botond
B
Roska
Department of Physics, Ecole Normale Supérieure, Paris, France; and Laboratoire de Physique Statistique, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, Université Denis Diderot, Paris, France.
Rava Azeredo
RA
da Silveira
Bio Engineering Laboratory, ETH Zurich, Basel, Switzerland;
Andreas
A
Hierlemann
D000200:Action Potentials; D000818:Animals; D003198:Computer Simulation; D005260:Female; D016014:Linear Models; D008839:Microelectrodes; D008959:Models, Neurological; D010775:Photic Stimulation; D011336:Probability; D011817:Rabbits; D012165:Retinal Ganglion Cells / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted; D046509:Tissue Culture Techniques; D014785:Vision, Ocular / Q000502:physiology*
coding; direction-selective system; microelectrode array; retina; retinal ganglion cells