Erratum: A single theoretical framework for circular features processing in humans: orientation and direction of motion compared

A commentary on
A single theoretical framework for circular features processing in humans: orientation and direction of motion compared

by Tzvetanov, T. (2012). Front. Comput. Neurosci. 6:28. doi: 10.3389/fncom.2012.00028

In the article A single theoretical framework for circular features processing in humans: orientation and direction of motion compared (Tzvetanov, 2012, Front. Comput. Neurosci. 6:28. doi: 10.3389/fncom.2012.00028) a presentation error occurred concerning the equations defining a and w within the text (subsection 4.4, page 9).

The sentence on page 9, subsection 4.4:

The priors on the three parameters were: l - beta probability distribution with parameters Beta (1.1, 20); μ - normal probability distribution with parameters Norm (a, 10w) with a and w being the mean and standard deviation obtained from each experimental data set {x_i, p_i} (a = ∑ p_ix_i and $w=\sqrt{{\displaystyle \sum p_i}{(x_i-a)}^2})$; σ - gamma probability distribution with parameters Gamma (a_G, b_G) fixed at a_G = 1 + w/b_G and $b_G=(\sqrt{5}-1)w/2$ such that the mode and variance of the Gamma distribution is w.

must be replaced by:

The priors on the three parameters were: l - beta probability distribution with parameters Beta (1.1, 20); μ - normal probability distribution with parameters Norm (a, 10w) with a and w being the mean and standard deviation obtained from each experimental data set {x_i, n_i, y_i} as follows: a = ∑q_i x_i, $w=\sqrt{{\displaystyle \sum p_i}{(x_i-a)}^2}$, and q_i = n_i/∑_in_i; σ - gamma probability distribution with parameters Gamma (a_G, b_G) fixed at a_G = 1 + w/b_G and $b_G=(\sqrt{5}-1)w/2$ such that the mode and variance of the Gamma distribution is w.

Acknowledgments

During this project the author was supported by the Deutsche Forschungsgemeinschaft (grant number TZ 69/1-1).