3.6 Modeling interactions between processes and agents

3.6.1 The Competetive Lottka-Volterra Equations

The coupled predator-prey dynamics in the previous assignment are not a very realistic model of an actual ecological system. Both equations are exponential growth functions, but Rabbits for example, also have to eat! One way to increase realism is to consider coupled logistic growth by introducing a carrying capacity.

• Follow the link to this Wiki page and try to model the system!

This is what interaction dynamics refers to, modeling mutual dependiencies using the if ... then conditional rules isn’t really about interaction, or coupling between processes.

3.6.2 Predator-Prey (and other) dynamics as Agent Based Models

Agent-Based models are an expansion of the idea of “connected growers” that includes a spatial location of the things that is subject to change over time.

Have a look at some of the NETlogo demo’s:

• Rabbits Weeds Grass
• Wolf Sheep Grass

3.6.3 The dynamic field model

Probably the most impressive modelling example in developmental psychology is the Dynamic Field Model for infant perservative reaching, also known as the A-not-B error:

• Thelen, E., Schöner, G., Scheier, C., & Smith, L. (2001). The dynamics of embodiment: A field theory of infant perseverative reaching. Behavioral and Brain Sciences, 24(1), 1-34. doi:10.1017/S0140525X01003910

The model makes some very interesting predictions that have been confirmed and it has been generalized to other phenomena and scientific disciplines as well

• Smith, L. B., & Thelen, E. (2003). Development as a dynamic system. Trends in cognitive sciences, 7(8), 343-348.

• Schöner, G., & Thelen, E. (2006). Using dynamic field theory to rethink infant habituation. Psychological review, 113(2), 273.

• TWOMEY, K. E., & HORST, J. S. (2014). TESTING A DYNAMIC NEURAL FIELD MODEL OF CHILDREN’S CATEGORY LABELLING. In Computational Models of Cognitive Processes: Proceedings of the 13th Neural Computation and Psychology Workshop (pp. 83-94).

You can learn about it on the Dynamic Field Theory website centered around the book:

• Schöner, G., & Spencer, J. (2015). Dynamic thinking: A primer on dynamic field theory. Oxford University Press.