Probabilistic and self-organising models for complex psychological phenomena

Symposium at the Conference on Complex Systems 2017

  • Time: September 20, 14:30 – 18:30
  • Location: Room 9
  • Organizers: Sacha Epskamp and Lourens Waldorp

Explaining psychological phenomena, such as decision making or depression, is complex. What exactly goes on when making a decision or how do you get into a depression? Recently there has been interest in probabilistic models that are to a certain extent self-organising. For instance, diffusion processes are a popular choice to describe decision making. Such processes can be seen as a ‘mean field’ approach to a self-organising system where the active or inactive state of a unit is determined by local interactions with other units. Such processes are informative of how decisions are taken and attempt to describe the process evolving over time.

A prime example used in psychology for self-organising systems is the Ising model. In the Ising model, borrowed from statistical physics, the probability of a node is determined by the number of active neighbours and the connection strengths to those neighbours. Higher order interactions are ignored in the Ising model. The Ising model appears to give an accurate description of depression and is able to explain phenomena like sudden mood shifts (phase transitions) and resilience to improvement by therapy. Such models are essential in psychology because they provide a better description of what is going on and provide a way to determine how to intervene on patients. Additionally, such models allow for predictions about particular changes to the system (model). For instance, if a connection between units or a unit itself were to be removed, then we can use theory to describe what the consequences will be. This will provide powerful advancements for the field of psychological processes.

In this symposium we will provide several examples of the principle of self-organisation used to describe and predict psychological phenomena related to decision making and psychopathology. The aim of this symposium is to introduce the audience to psychological process modeling and to discuss the state of the art as well as discuss challenges of this emerging field.