Autonomic responsivity and semantic associative competences in disturb of consciousness

Linguistic associative functions in Disorders of Consciousness patient (DOC) were studied in the present research by using autonomic measures (Skin Conductance Response, SCR; Heart Rate, HR). We intended to verify the preservation of semantic linguistic processes in Vegetative State (VS) and Minimal Consciousness State (MCS) by considering arousal modulation. Twenty-four patients and twenty controls were submitted to an auditory semantic task (congruous or incongruous word sequences). A similar increased SCR/HR was found for both DOC and control group in response to incongruous condition. This modulation was interpreted as a marker of the increased cognitive difficulty in processing and restoring incongruent information. However, MCS and VS groups quantitatively (but not qualitatively) differed in term of degree of increased arousal, since higher SCR and HR increasing was observed for MCS than VS. These results were interpreted as a marker that the semantic processing was partially preserved in both VS and MCS patients.