Neural Representations of Trajectories

Harry Erwin harry.erwin at
Sat Jul 21 15:36:29 EST 2001

Matt Jones <jonesmat at> wrote:

> harry.erwin at (Harry Erwin) wrote in message
news:<1ewuuak.1ynor76163al0wN%harry.erwin at>...
> > I'm seeing evidence that trajectories of moving objects are represented
> > 4-dimensionally in the brain. Has anyone thought about the topology of
> > neural representations?
> Spatial movement requires four orthogonal dimensions, so is there any
> way that the brain could represent a trajectory unambiguously with
> -less- than 4 dimensions?

Yes. However, I'm seeing evidence that bats localize in 3D and maintain
a track history over time.

> I know of at least one body of sound localization work in which the
> representation is topologically spherical (i.e., 2 dimensional,
> because distance information and intensity cannot be unambiguously
> separated in many cases):

Actually it usually can.


I've been in touch with them. My work is based on behavioral data.

> Which 4 dimensions are you seeing?

a tube built around position measurements in general cartesian

> Cheers,
> Matt

Dr. Harry Erwin, harry at,

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