http://geekfriendly.org/blog/07/kottke-on-neurons/?utm_source=rss&utm_medium=rss&utm_campaign=kottke-on-neurons Sat, 22 Oct 2011 22:53:40 +0000 hourly 1 http://wordpress.org/?v=3.2.1 http://geekfriendly.org/blog/07/kottke-on-neurons/comment-page-1/#comment-36393 Jon Horvitz Sat, 19 Dec 2009 16:04:54 +0000 http://geekfriendly.org/blog/07/kottke-on-neurons/#comment-36393 There's another possibility, that's similar to the grandmother cell idea, but that permits more content to be held in the limited number of neurons (about 100 billion) in the human brain. The idea is that instead of 1 neuron representing 1 idea (idea can mean a sensory percept, a word/concept, a desire, etc), a group of neurons (a set of about 1000 neurons is sometimes suggested) represents the idea. At first, you should say that this should REDUCE the number of ideas that can be represented (1000-fold!). But the idea is that you have 'overlapping sets', i.e., idea #1 may occur when a given set of 1000 neurons is active (and reverberating in order to give some persistance to the idea over some time, say a second), and idea #2 is active when another set of 1000 neurons is active, BUT the set of 1000 neurons constituting idea #2 can have many of the same neurons that constitute set #1. So, a given neuron can contribute to many different sets. Imagine that the brain had just 2000 neurons, and each idea arose from a specific set of 1000 neurons. With overlapping sets you could represent a LOT more than 2000 ideas. To read more about this type of model of cognition, go to http://www.columbia.edu/~nvg1/Wickelgren/ It's the site of Wayne Wickelgren, a cognitive neuroscientist who passed away about 5 years ago from Motor Neuron Disease. He was an amazing and brilliant person (graudated summa cum laude from MIT). I knew him when I was teaching at Columbia - he had retired from research but continued to work on theories of cognition and the brain even as his movement ability was lost (he had a special device set up so that he could press a key on a keyboard with minimal motor effort). On his site he put free pdf's describing his ideas about neural sets (he calls them 'webs') and coding for ideas. There’s another possibility, that’s similar to the grandmother cell idea, but that permits more content to be held in the limited number of neurons (about 100 billion) in the human brain. The idea is that instead of 1 neuron representing 1 idea (idea can mean a sensory percept, a word/concept, a desire, etc), a group of neurons (a set of about 1000 neurons is sometimes suggested) represents the idea. At first, you should say that this should REDUCE the number of ideas that can be represented (1000-fold!). But the idea is that you have ‘overlapping sets’, i.e., idea #1 may occur when a given set of 1000 neurons is active (and reverberating in order to give some persistance to the idea over some time, say a second), and idea #2 is active when another set of 1000 neurons is active, BUT the set of 1000 neurons constituting idea #2 can have many of the same neurons that constitute set #1. So, a given neuron can contribute to many different sets. Imagine that the brain had just 2000 neurons, and each idea arose from a specific set of 1000 neurons. With overlapping sets you could represent a LOT more than 2000 ideas. To read more about this type of model of cognition,
go to http://www.columbia.edu/~nvg1/Wickelgren/
It’s the site of Wayne Wickelgren, a cognitive neuroscientist who passed away about 5 years ago from Motor Neuron Disease. He was an amazing and brilliant person (graudated summa cum laude from MIT). I knew him when I was teaching at Columbia – he had retired from research but continued to work on theories of cognition and the brain even as his movement ability was lost (he had a special device set up so that he could press a key on a keyboard with minimal motor effort). On his site he put free pdf’s describing his ideas about neural sets (he calls them ‘webs’) and coding for ideas.

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