The Italian Adaptation of the Treatment of Underlying Forms for Object Relatives in Agrammatic Aphasia: Training Efficacy, Generalization Patterns, and Cross-Linguistic Implications.

Purpose: Treatment of Underlying Forms (TUF) is a training program grounded in linguistic theory and aiming to boost complex sentences production in people with agrammatism. Language treatment studies in aphasia confirmed TUF efficacy and led to the formulation of the Complexity Account of Treatment Efficacy (CATE). According to CATE, which relies on the primitive distinction between A- and A'-structures, training complex sentences induces an improvement on simpler structures, but no generalization occurs between different types of syntactic movement. This experiment provides the first adaptation of TUF in Italian and investigates the cross-linguistic validity of training efficacy and its generalization pattern.

Method: Using a single-subject experimental design, five participants with chronic poststroke agrammatism underwent intensive training for object relatives. Performance on trained and untrained object relatives (A'-structures), object clefts (simpler A'-structures), and passive sentences (A-structures) was measured at multiple time points, that is, pre- and posttreatment, during the training, and at follow-up. A standardized assessment of aphasia was also administered pre- and posttreatment.

Results: The results reported a robust improvement in the production of trained and untrained object relatives in all five participants, a generalization to object clefts in four participants, and, unexpectedly, a generalization to passives in three participants. All participants showed improved comprehension on all these structures. A general linguistic improvement was also found in the standardized testing of aphasia, especially in morphosyntactic abilities.

Conclusions: The findings confirmed the efficacy of the Italian adaptation of TUF for object relatives supporting its use in the clinical practice. To explain the generalization to passives in Italian but not in the English version of TUF, we propose an amendment of CATE that takes the syntactic operation of Internal Merge as a primitive (keeping the A vs. A' distinction as a modulating factor).