www.imodel.org
DogTrans.0.0
2007 Feb 7
Summary This is a transient ON-center spiking unit. It
consists of a center-surround difference-of-Gaussian linear receptive
field and a Poisson spike generator. This simple model captures some
of the tuning properties of a typical macaque magnocellular LGN cell.
The response is transient and rapid, the surround response is delayed
relative to that of the center, and the spontaneous firing rate is
between 20 and 30 spikes/s. One important limitation is the lack of
adaptive properties such as retinal contrast gain control.
Results
The results here were obtained using this
response file, which records spikes from an ON-center unit near
the center of the stimulus grid.
Sine Tuning
Dynamic Random Stimuli
Discussion
In response to the random counter-phase stimuli, the STA shape
for this model does not change with contrast. This is inconsistent
with the behavior of typical magnocellular LGN cells, for which the
peak of the positive lobe of the STA, and the zero-crossing, shift to
the left at lower contrast. This demonstrates that the model lacks
contrast gain control, which M-cells have. P-cells, however, do not
show this change in the STA.