The most powerful submodalities in changing and determining a person's response are known as critical submodalities. Critical Submodalities are the difference that creates the difference in a state or a behaviour.
According to NLP, among the many conceivable submodalities, there will likely be a few "critical" submodalities that can effectively impact large-scale change, and that these submodalities differ between persons and can be determined by observation and inquiry. NLP states that a shift in these critical submodalities is frequently accompanied by a near-immediate subjective change in the emotion or other felt-sense with which a mental impression manifests itself.
Submodalities are thus considered in NLP as providing a valuable therapeutic insight (or metaphor), into how the human mind internally organises and subjectively 'perceives' events, as well as prospective working approaches.