1. A method, comprising: representing, in a memory of a mobile communications device having a physically constrained user interface, a plurality of contact tasks via a hierarchical multi-level decision tree structure comprised of a root node, a plurality of internal nodes and a plurality of leaf nodes in a hierarchical arrangement of parent nodes and child nodes under the root node, where each contact task comprises a contact command to be executed upon selection of a leaf node corresponding to the contact task, where the root node is designated as a contact list for a plurality of contacts, where each leaf node corresponds to contact information for one of the contacts; receiving, by the mobile communications device, information derived from detected mental states of a user, where the received information is configured to enable traversal of the hierarchical multi-level decision tree structure from the root node to a particular leaf node by providing a selected child node for any parent node encountered that has a plurality of child nodes, where the particular leaf node corresponds to a particular contact for whom a particular contact task is to be performed; navigating, by the mobile communications device and using the received information, through levels of the hierarchical multi-level decision tree structure to reach the particular leaf node; and executing, by the mobile communications device, a particular contact command corresponding to the particular leaf node in order to accomplish the particular contact task.