Receptive field sizes and neuronal encoding bandwidth are constrained by axonal conduction delays
Fig 6
Information content of homogeneous and heterogeneous populations of P-units.
A: Mutual information estimated from the stimulus response coherence (Eq 8) carried by populations of increasing size. Blue lines show information content of homogeneous populations created by combining randomly chosen trials of the same neuron. Since not all recordings have the same number of stimulus repetitions, the maximum possible population size varies between recorded neurons. Thick blue line is the average across all homogeneous populations. Red dots show the average information estimated from heterogeneous populations (see Methods for details). Error bars indicate the standard deviation, thin red lines depict the best and worst performance observed in the sample of heterogeneous populations. Tests on statistically significant differences in mutual information in homogeneous and heterogeneous population were performed using a Mann Whitney U-Test with Bonferroni correction for the highlighted population sizes, one asterisk: α < 5% two stars indicate α < 1%. B: Comparison of the mutual information carried by homogeneous (x-axis) and heterogeneous (y-axis) populations that are similarly driven by the stimulus (response modulation of heterogeneous population response within a ±20% range of the respective homogeneous response) for three different population sizes. Large symbols depict the center of gravity of the respective distributions. Dashed line is the identity line. Abbreviations: m.i., mutual information; het., heterogeneous; hom., homogeneous.