{"id":1825,"date":"2019-04-14T16:17:20","date_gmt":"2019-04-14T06:17:20","guid":{"rendered":"https:\/\/www.cognav.net\/?p=1825"},"modified":"2019-04-14T16:17:20","modified_gmt":"2019-04-14T06:17:20","slug":"how-to-implement-long-range-navigation-by-path-integration-and-decoding-of-grid-cells-in-a-neural-network","status":"publish","type":"post","link":"https:\/\/braininspirednavigation.com\/?p=1825","title":{"rendered":"How to implement long-range navigation by path integration and decoding of grid cells in a neural network?"},"content":{"rendered":"<p style=\"text-align: justify;\">Edvardsen, Vegard. &#8220;<a href=\"https:\/\/ieeexplore.ieee.org\/abstract\/document\/7966406\"><strong>Long-range navigation by path integration and decoding of grid cells in a neural network<\/strong><\/a>.&#8221; In 2017 International Joint Conference on Neural Networks (IJCNN), pp. 4348-4355. IEEE, 2017.<\/p>\n<p style=\"text-align: justify;\">The following content is extracted from Edvardsen 2017.<\/p>\n<p style=\"text-align: justify;\">Neural modelers in the domain of robot navigation, e.g. within the fields of neurorobotics and neuromorphic engineering, can benefit from a wealth of inspiration from neuroscientific research in the hippocampal formation\u2014cell types such as place cells and grid cells provide a window into the inner workings of high-level cognitive processing, and have spawned many interesting computational models.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: red;\"><strong>Grid cells are thought to participate in path integration and to implement a general coordinate system, both of which are useful features in a neural navigation model.<\/strong> <strong>Continuous attractor networks are a computational model that can embody both aspects of grid cells<\/strong><\/span>, and in previous work they showed that a neural network can successfully decode the outputs of such networks in order to implement vector navigation. That work assumes that the grid cell system represents long distances by employing a geometric progression in its spatial scaling of successive submodules, in such a way that &#8220;nested&#8221; grid cell decoding can be performed. <span style=\"color: red;\"><strong>For long-range navigation this requires that the continuous attractor networks can implement sufficiently long geometric progressions of grid scales, but this turns out to trigger the issue of &#8220;pinning&#8221;<\/strong><\/span>.<\/p>\n<p style=\"text-align: justify;\">In this paper Edvardsen <span style=\"color: red;\"><strong>demonstrates conditions under which pinning occurs as well as its consequences for the grid cell-based navigation model<\/strong><\/span>. They <span style=\"color: red;\"><strong>propose and assess several<\/strong> <strong>candidate solutions to the problem<\/strong><\/span>, in particular based on differential adjustment of neurons&#8217; update rates in the model. They finally demonstrate that the system is able to perform long-range navigation using our chosen solution.<\/p>\n<p style=\"text-align: center;\"><img decoding=\"async\" src=\"https:\/\/www.braininspirednavigation.com\/wp-content\/uploads\/2019\/04\/041419_0538_Howtoimplem1.png\" alt=\"\" \/><\/p>\n<p style=\"text-align: justify;\">Fig. 6 Self-motion velocity is used to update multiple CAN-based grid modules of increasing grid scales that follow a geometric progression. Larger grid scales are achieved by attenuating the input to the grid module, so that the module&#8217;s produced grid pattern appears stretched across space. The collective activity of all grid modules represents a set of &#8220;coordinates&#8221; in the navigation model. Larger-scaled grid modules are given priority in the decoding process, in accordance with the view that smaller-scaled grid modules are &#8220;nested&#8221;within the larger ones.<\/p>\n<p style=\"text-align: center;\">Fig from Edvardsen 2017.<\/p>\n<p>&nbsp;<\/p>\n<p>For further info, please read the paper Edvardsen 2017.<\/p>\n<p>Edvardsen, Vegard. &#8220;<a href=\"https:\/\/ieeexplore.ieee.org\/abstract\/document\/7966406\"><strong>Long-range navigation by path integration and decoding of grid cells in a neural network<\/strong><\/a>.&#8221; In 2017 International Joint Conference on Neural Networks (IJCNN), pp. 4348-4355. IEEE, 2017.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Edvardsen, Vegard. &#8220;Long-range navigation by path integration and decoding of grid cells in a neural network.&#8221; In 2017 International Joint Conference on Neural Networks (IJCNN), pp. 4348-4355. IEEE, 2017. The following content is extracted from Edvardsen 2017. Neural modelers in the domain of robot navigation, e.g. within the fields of neurorobotics and neuromorphic engineering, can [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[96,346,419],"tags":[251,103,459,292],"_links":{"self":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts\/1825"}],"collection":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1825"}],"version-history":[{"count":2,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts\/1825\/revisions"}],"predecessor-version":[{"id":1839,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=\/wp\/v2\/posts\/1825\/revisions\/1839"}],"wp:attachment":[{"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1825"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1825"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/braininspirednavigation.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1825"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}