Based on a large-scale neural network model of striate cortex (V1), we present a simulation study of extra- and intra-cellular response modulations for drifting and contrast reversal grating stimuli. Specifically, we study the dependence of these modulations on the neural circuitry. We find that the frequently used ratio of the first harmonic to the mean response to classify simple and complex cells is highly insensitive to circuitry. Limited experimental sample size for the distribution of this measure makes it unsuitable for distinguishing whether or not the dichotomy of simple and complex cells originate from distinct LGN axon connectivity and/or local circuitry in V1. We show that a possible useful measure in this respect is the ratio of the intracellular second to first harmonic response for contrast reversal gratings. This measure is highly sensitive to neural circuitry and its distribution can be sampled with sufficient accuracy from a limited amount of experimental data. Further, the distribution of this measure is qualitatively similar to that of the subfield correlation coefficient. It is however more robust and easier to obtain experimentally.