Recursion all the way: in Language, Action and Semantic
                       Association

                                    Katerina Pastra 1
                     1 Cognitive Systems Research Institute, Greece




    Abstract. Recursion has been considered to be a unique characteristic of human
    language. However, increasing evidence in Neuroscience points to the fact that
    a fundamental syntactic mechanism is shared between language and action,
    both of which have a hieararchical and compositional organisation; Broca's area
    has been suggested as the neural locus of this mechanism. In this talk, we will
    present the first formal specification of action with biological bases, the Mini-
    malist Grammar of Action. The grammar allows the development of generative
    computational models for action in the motor and visuomotor space. Through
    the grammar, we present examples of recursion in the action space and how a
    generative action perception/execution system may account for the phe-
    nomenon. Furthemore, we go a step further, arguing that recursion is not a phe-
    nomenon that arises in the language or action space only; it is a phenomenon
    that lies in any 'syntactic' activity, in any space that comprises 'merging' of ele-
    ments into more and more complex units. We present recursion in the Semantic
    Association space (Semantic Memory), through the PRAXICON, the first ever
    recursive and referential semantic network. We will demonstrate the importance
    of the network in generalisation and reasoning for a number of applications and
    discuss the interdisciplinary implications of our argument on recursion.