Open Access

# Erratum to: A moderate role for cognitive models in agent-based modeling of cultural change

DOI: 10.1186/2194-3206-2-1

Accepted: 3 December 2013

Published: 6 January 2014

The original article was published in Complex Adaptive Systems Modeling 2013 1:16

## Correction

After publication of (Abrams 2013), I discovered errors in two formulas in the settle-nets paragraphs of the POPCO main loop section in Methods (page 13 in the PDF file). I correct these errors here. In the definition of the weighted sum n i of input activations a j from nodes j to node i across links with weights w ij , the direction of the inequality was reversed. The definition of n i should read:
${n}_{i}=\sum _{j}{w}_{\mathit{\text{ij}}}max\left(0,{a}_{j}\right)\phantom{\rule{2.77626pt}{0ex}}\phantom{\rule{2.77626pt}{0ex}}\phantom{\rule{2.77626pt}{0ex}}\text{for}\phantom{\rule{2.77626pt}{0ex}}{w}_{\mathit{\text{ij}}}<0\phantom{\rule{0.3em}{0ex}}.$
There were also errors in the definition of s i , the weighted sum of a node’s current activation a i and its summed inputs p i and n i across positively and negatively weighted links, respectively. The definition of s i should read as follows:
${s}_{i}=\left(1-.1\right)\phantom{\rule{0.3em}{0ex}}{a}_{i}+\left(.99-{a}_{i}\right)\phantom{\rule{0.3em}{0ex}}{p}_{i}+\left({a}_{i}-\left(-.99\right)\right)\phantom{\rule{0.3em}{0ex}}{n}_{i}$

I regret these errors and hope that they do not cause confusion. Full source code for the version of POPCO used in Abrams (2013) can be found at https://github.com/mars0i/popco.

## Authors’ Affiliations

(1)
Department of Philosophy, University of Alabama at Birmingham

## References

1. Abrams M: A moderate role for cognitive models in agent-based modeling of cultural change. Complex Adaptive Syst Model 2013, 1(16):1–33.