GaryGaulin
Posts: 5385
Joined: Oct. 2012
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From:
http://www.antievolution.org/cgi-bin....y244077
| Quote (Timothy McDougald @ May 01 2015,10:07) | | I wonder what the implications of this is for near death experiences. :O |
Very very paradigm changing implications.
Thanks for the link that helped word my latest writing project:
| Quote |
In this Intelligence Design Lab a place cell self-navigation network provides an "internal world model" for intuitively navigating around obstacles, through tunnels and makes it possible to learn how to slow down ahead of time for a well controlled preplanned landing at a place attracting it, an attractor. In at least humans this network is expected to cause the conscious feeling of being inside (or in the case of Near Death Experiences outside) of one's own body.
HOW IT WORKS
Navigational vectors for two point proprioception (sense of how our bodies are positioned) of a body center and center of mouth are provided by the direction of action potential flow across an inhibitory connected network of room-preferring and arena-preferring place cells. Places to not navigate towards have no place cell discharge. The most attracting places (such as food pellet locations) have the greatest discharge. This signal gradient propagates from highest to lowest activity, around obstacles and places to avoid blocking signal propagation hence navigation through them by becoming completely inactive.
Digital RAM arrays (memory matrices) represent a population of place cells. The room-preferring (but not arena-preferring) place cells are addressed by the room angle by converting the Radian amount to a whole number (such as 0-7 or 0-15) then adding to the serialization by multiplying by power of two for appropriate bit position. The RAM data stored at each memory address contains activity levels (associated bit is 0 or 1) for 6 sectors hexagonally at each place mapped by the place cell memory/network. To these 6 bits are added 1 data bit that is set for behavior to make that place attract and 1 data bit that is set for behavior to make that place repel, avoid. This makes 8 bits of data per RAM address, one data byte per each hexagonally located place on the place cell map. When a food pellet is known to be inside a shock zone the place is set to both attract and avoid, which cancels place cell discharge in the six sectors at that location. The attractor location will resume signaling after the avoid bit is reset to 0, turned off.
Grid cells are expected to be part of the system that provides the rotation (such as to cue card on wall) and translation (distance traveled over time, dead-reckoning deduced position) signals for locating itself on the place cell network map. For computer modeling purposes rotation and translation are here provided by the already program calculated X,Y and rotation of everything in the environment including itself. The computer model then assumes that the in-silico critter has a computer accurate reading of exactly where it is located at any timestep in its lifetime. This is the starting benchmark for models of the grid cell related system where there is the least amount of biological detail but greatest amount of calculation precision. It is not necessary to be computer precise, "close enough" still makes a useful navigation system. It is here best to start with upstream rotation and translation signals free of errors that would otherwise show up in testing of the place cell memory system alone.
See:
Brain scan reveals out-of-body illusion
http://www.sciencedaily.com/release....107.htm
Dynamic Grouping of Hippocampal Neural Activity During Cognitive Control of Two Spatial Frames.
Eduard Kelemen and André A.Fenton (2010)
PLoS Biol 8(6): e1000403. doi:10.1371/journal.pbio.1000403
http://www.plosbiology.org/article....1000403
Arena video:
http://www.plosbiology.org/article....03.s014
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The theory of intelligent design holds that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection.
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