Synthesizing the Origins of Language and Meaning Using Coevolution, Self-organization and Level Formation. Evolution of Communi- Cation in Artiicial Organisms

Negotiation Protocol The model of negotiation used is similar to the model of Alternative OOerss17]. Commitment If an agreement is reached, then the agents honor it. The commitment is not long term; that is, the agent cannot commit itself to any future encounters. Identity The agents can accurately identify each other. We further assume that there are time steps, during which each agent puts forth its ooer. Therefore, time is divided into a set T = 0,1,2,...... There are N >= 2 agents, randomly designated 1,2,...,N. In each time step t, if the negotiation has not terminated earlier, the agent whose turn it is to make an ooer at that time step will put forth its suggestion. The possible responses available to the agent during negotiation are fYes,No,Optg. That is, the agent can either accept the ooer, reject the ooer, or opt out of the negotiation process. If an ooer is accepted by all the agents, then negotiation ends, and the agreement is implemented. If any agent opts out, then the negotiation ends; this may happen if one of the agents determines that a proposed solution is not worth the cost of implementing it. If none of the agents opts out but at least one agent has rejected the ooer, the negotiation proceeds to time step t+1, the next agent makes its ooer, and the same process continues. The utilities the agents will take into account are the costs of implementing the agreement, a time discount factor, as well as a positive reward equal to the expected value of messages that can be transmitted if the agents agree on a solution. At any time step during negotiation the agent whose turn it is will put forth its ooer. Simultaneously, all agents will compute their utilities at this stage of negotiation. For negotiations over the lexicon, the utilities are combinations of the following factors: The cost of implementation, is a measure of eeort to implement the proposed common label in the agent's KB. We assume that a greater relative change to the KB carries a greater implementation cost. A time discount. We assume that this is a constant discount factor applied at each time step of the negotiation. This factor quantiies the fact that the agents would like to reach the agreement earlier rather then sooner, and is dictated by the urgency of the tasks at hand to each of the …