Supplemental Material for Scale (In)Variance in a Unified Diffusion Model of Decision Making and Timing
Psychological Review · 2015
Scale Invariance Supplementary MaterialsFigure S1.Comparison of Skellam probability mass functions (blue dots connected by linearly interpolated lines) and corresponding normal probability density approximations (red curves).Here the narrowest Skellam pmf describes the net spike count distribution at time t equal to one expected inter-spike time (1/ 𝜆 1 ) of process 1 in the opponent Poisson process.In order of increasing dispersion, the blue pmfs describe the count at integer multiples of this duration.A: The two spike rates in each opponent Poisson process are equal.B: The first spike rate is twice the second.C: The second spike rate is 0.01 times the first spike rate, making the process approximately purely Poisson.Here the Poisson approximation is shown in green.