Fig. 2.
Analysis of spatial frequency tuning dynamics. A: variance (V) of the response to different spatial frequencies over different delay times (τ) for a representative neuron. The solid line indicates the mean variance over the first 20 ms. The dashed line indicates the criterion level of response significance. Where the variance crosses the criterion line defines τonset and τfinal. B: maximum [Mx(τ), black line] and minimum [Mn(τ), gray line] response level times as a function of τ. τmax is the time delay where the response reached maximal levels. The dashed line corresponds to half the maximal response levels. τdev and τdecay, respectively, are defined to the delay times where the maximal response levels crossed this level during development and decay of the response. C: response for different spatial frequencies at τmax. Circles show the measured response levels for 15 different spatial frequencies relative to baseline response [R(f,τmax) = 0]. Responses below 0 correspond with response suppression. The thick line is the smoothed response level, used to estimate fpk, the spatial frequency that produced the highest response level. flow and fhigh mark the low and high spatial frequency cutoffs, respectively, and are used to calculate the quality (Q)-factor.