

Navigational Cell Systems Located in Human Brains - whyenot
http://www.nytimes.com/2013/08/06/science/navigational-cell-systems-located-in-human-brains.html

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simonster
I was just reading this paper
([http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.34...](http://www.nature.com/neuro/journal/vaop/ncurrent/full/nn.3466.html)),
and I noticed that they say only 5% of cells in the parahippocampal gyrus show
grid-like activity p < 0.05, but in Fig. 2 and the supplemental information
they still plot the grid responses from the parahippocampal gyrus, which are
presumably noise, lumped together with the responses from the entorhinal
cortex, cingulate, and hippocampus, at least some of which are presumably
real. This doesn't invalidate the rest of the paper, which suggests there are
really grid cells in the latter three regions, but it's frustrating. But I
probably care more whether there are grid cells in the parahippocampal gyrus
than most people.

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tod222
What the NYT article omits is that a triangular grid [1] encoded by the grid
cells is used to track movement, according to Wikipedia's entry for Grid cell.
[2]

Further questions: How many grid cells are there? What is the largest area
that can be fully represented? How are grid cells reused as the subject
travels?

[1]
[https://twitter.com/th222/status/364156774309314560](https://twitter.com/th222/status/364156774309314560)

[2]
[http://en.wikipedia.org/wiki/Grid_cell](http://en.wikipedia.org/wiki/Grid_cell)

