In 2001, Pulvermüller and colleagues applied these principles to language treatment for individuals with chronic aphasia. In CILT, compensatory non-verbal communication modalities are constrained and participants are required to make verbal requests and responses. The preliminary study and subsequent follow up studies all showed significant improvement in the amount and quality of communication on language outcome measures including standardized aphasia batteries, communication activity logs, and narrative discourse samples. This evidence dispels the notion that continued recovery is not possible for individuals with chronic aphasia but the variables contributing to remediation remain ambiguous. Constraining compensatory communication is a radical shift for speech-language pathologists who have been trained to assist in the maximization of functional communication. Before adopting such a paradigm shift, it is prudent to determine the contribution each factor makes to the success of treatment.