Dependency representing Markov properties of nonstationary spike trains recorded from the cat's optic tract fibers

The order and the values of Markov properties of nonstationary stochastic processes are inferred by the use of them-th order Markov value and simplified dependency, respectively: andHereK=0.5log₂e, and is the correlation coefficient determinant obtained from the ensemble averages of sample records. When an observed value is greater than or equal to the critical value,, the null hypothesis of the (m-1)th order,, is rejected at the level of significance . Here₁²() is the chi-square value with one degree of freedom at andN is sample size. With these statistics it was shown that the order and the values of Markov properties of spike trains of optic tractX- andY-fibers became higher and larger, respectively, after the light spot presentation; and that the values due to negative correlation came to increase and returned to the maintained level earlier inY-fibers than inX-fibers, while the maximum values forX-fibers continued to the light off. It is discussed that Markov properties of spike trains of optic tract fibers in the visual pathway seem to constitute a significant component of the neural information code.