a cognitive attractor is a set of material and immaterial elements which potentially contribute to a given activity, and which are simultaneously present from the point of view of the agent. The force of the attractor resides in the combination of several factors: the visibility of the task, its cost, its value.

[more about it here: http://www.utc.fr/arco/publications/intellectica/affiche_numero.php?num=30 in french though :(]