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Gabor.0.0

2007 Apr 02
Summary   This is an orientation-tuned spiking unit. It consists of a space-time oriented Gabor filter (shown below with vertical orientation) and a Poisson spike generator. This model captures some of the basic response properties of a sustained-firing macaque V1 simple cell. It is similar to Gabor.0.1, which uses an integrate-and-fire spiking mechanism rather than the Poisson spiking used here.

Gabor.0.0.mod

Data

Results

The results here were obtained using this response file, which records spikes from a unit near the center of the stimulus grid.

Sine Tuning

• Direction - at TF 4 Hz, SF 1.2 cyc/deg
• Spatial frequency - at TF 4 Hz
• Temporal frequency - at SF 1.2 cyc/deg
• Static phase

Spike Timing

• ISI - inter-spike interval for a static grating

Discussion

This is arguably the minimal spiking simple-cell model, consisting only of a linear filter, half-wave rectification, and Poisson spiking. As such, it provides a fundamental point of comparison for more elaborate models and neuronal data.

The ISI probability distribution for this model approximates a decaying exponential function, as expected for Poisson spikes. A major limitation of this model is its lack of adaptation to luminance and contrast.