Figure 1.

Stimuli and Examples of Results

(A and B) Balanced stimulus. (C and D) Biased stimulus. Stimulus examples (B and D) are 20 s samples from the full stimulus sequence (typically ∼10 min). Stimulus histograms (A and C) are computed from the full stimuli. (E) Linear-Nonlinear-Poisson (LNP) model used to describe responses to balanced stimuli. (F) Examples of tuning curves obtained for 15 neurons in LGN. Position is expressed relative to the position that will be used as adaptor in the biased condition. (G) Same, for 15 neurons in V1. Open and closed circles denote ON and OFF center cells. (H) LNP model for responses to biased stimuli. (I) The tuning curve of an LGN neuron (thick curve in F) measured in response to balanced stimuli (blue) and biased stimuli (red). The gain, or responsiveness, at each position was normalized to the peak value measured in the balanced condition. Curves are best-fitting Gaussians. Error bars indicate two SDs in the estimate. (J) Same, for a V1 neuron. See also Figure S1.