Internal (inner) speech

Sokolov et al. studied the activity of the tongue and lip muscles in planning speech and found that alterations in this muscular activity correlated with difficulties with internal speech or planning of speech.

from Luria The Working Brain. Luria described the transition from general plan to narration requiring the recoding of a plan into speech, with a role played by internal speech, which has a "predicative" nature. This linear scheme of a sentence" is obliterated in patients with lesions in the inferior postfrontal zones of the left hemisphere. Patients cannot express the scheme, but may be able to do so if given cards indicating the pertinent parts of the sentence and asked to arrange them in order (Leontiev).

Vygotsky (Luria's mentor and the not originator of the concept of inner speech) was a silent stage of sentence formation between a preverbal intent to communicate and a fully formed message. It has a simplified syntax as in a message to oneself. It allows a transition from inner concepts to formal syntax. Developmentally, a child received names for symbols externally, helping to develop its mental functions. Acquisition of language then become internal to the individual in late childhood, and becomes the means by which theindividual regulates his/her own behavior. Pavlov ostensibly admitted that certain cerebral processes were not conditioned and excluded from his analysis of reflexes.

Luria also wrote (1970) that one must condense a heard message into inner speech in order to deal with its syntax. That may explain impaired comprehension of syntax in agrammatics.