The case grammar experiment investigates how a population of autonomous artificial agents can self-organize a grammatical language that features similar properties as those found in case-languages such as Latin, German and Turkish. The case grammar experiment is the most advanced experiment in artificial language evolution to date: it is the first multi-agent experiment ever that features multifunctional, polysemous grammatical categories as opposed to other experiments in the field in which the agents always converge on one-to-one mappings.
In the experiment, the agents have to describe dynamic real-world scenes to each other (click here to see an example movie). Starting with a lexicon but without grammar, the agents gradually start to introduce case markers in order to reduce the cognitive load they need for interpreting sentences. For example, an utterance such as boy girl pushed is ambiguous as to whom did what to whom, so the hearer has to witness the scene to find the correct meaning. Adding more grammar could thus avoid this effort by directing the hearer to the correct interpretation. For example, in the utterance boy-bo girl-ka push, the grammatical markers can be used for indicating that the girl was being pushed and that the boy was the pusher.
Through analogical reasoning over event structures, agents can then generalize these markers to become more abstract. In the experiments, we typically see the emergence of agent-like and patient-like case markers, as in the following sentences:
- jack-fuitap walk-to jill-ginah
Lit.: jack-sem-role-6 walk-to jill-sem-role-26
‘Jack walks to Jill.’
- touch jill-fuitap house-payis
Lit.: touch jill-sem-role-6 house-sem-role-29
‘Jill touches the house.’
- house-woechen move-inside boy-fuitap
Lit.: house-sem-role-10 move-inside boy-sem-role-6
‘The boy moves inside the house.’
Team: Luc Steels, Remi van Trijp
