Matt Jones <jonesmat at physiology.wisc.edu> wrote:
>harry.erwin at sunderland.ac.uk (Harry Erwin) wrote in message
news:<1ewuuak.1ynor76163al0wN%harry.erwin at sunderland.ac.uk>...
> > 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.
>>http://wavelet.psych.wisc.edu/jenison.html
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
coordinates.
>>> Cheers,
>> Matt
--
Dr. Harry Erwin, harry at dherwin.org, http://world.std.com/~herwin
