19 NOV 2015 by ideonexus
A Single Neuron Can Recognize Patterns
Neocortical neurons have thousands of excitatory synapses. It is a mystery how neurons integrate the input from so many synapses and what kind of large-scale network behavior this enables. It has been previously proposed that non-linear properties of dendrites enable neurons to recognize multiple patterns. In this paper we extend this idea by showing that a neuron with several thousand synapses arranged along active dendrites can learn to accurately and robustly recognize hundreds of unique p...21 JUN 2013 by ideonexus
von Neumann Correctly Hypothesizes How Memory Works
The question of the physical embodiment of this memory remains. For this, various authorrs have suggested a variety of solutions. It has beeen proposed to assume that the thresholds—orr, more broadly stated, the stimulation criteria—^f or various nerve cells change with time as functions of the previous history of that cell. Thus frequent use of a nerve cell might lower its threshold, i.e. ease the requirements of its stimulation, and the like. If this were true, the memory would reside i...Neurons that get used more often become easier to use. He's just speculating, but his description is spot on.
26 APR 2012 by ideonexus
Number of Neuron Connection in the Brain
Each nerve cell receives connections from other nerve cells at six sites called synapses. But here is an astonishing fact—there are about one million billion connections in the cortical sheet. If you were to count them, one connection (or synapse) per second, you would finish counting some thirty-two million years after you began. Another way of getting a feeling for the numbers of connections in this extraordinary structure is to consider that a large match-head's worth of your brain conta...The different possible number of connections outnumbers the particles in the Universe (this is questionable).
18 JUL 2011 by ideonexus
How Brains Grow Into Bodies
Brain wiring begins with the outgrowth of axons. Once a newborn neuron has migrated, planting its cell body in a permanent position, it sends out a fine axon shoot with an enlarged tip known as a growth cone. At the end of the growth cone are about a dozen long tentacles that shoot out in all directions and act like radar, picking up all manner of navigational signals. They feel out the best-textured surfaces, sniff around for chemical cues, and even use tiny electrical fields to help the axo...Best description yet of the synaptic "pruning" human brains go through as the brain wires up to the body and best reason yet for why children should have rich, mentally-nourishing environments in which to grow so that their synapses don't get unnecessarily pruned, resulting in smaller brains.