Calculate first node probability densities of the correlated accumulator model
n1PDF_cnorm(x, A, b, t0, mean_v, sd_v, st0, corr_v, n, h, debug = FALSE)
response time vector
start point variability
threshold
nondecision time
mean drift rate vector
standard deviation of the drift rates
nondecision time variability
correlation among accumulators
number of simulations
kernel bandwidth
debugging?