Can Salient Stimuli Enhance Responses in Disorders of Consciousness? A Systematic Review
Purpose of Review
Diagnostic classification of patients with disorders of consciousness (DoC) is based on clinician’s observation of volitional behaviours. However, patients’ caregivers often report higher levels of responsiveness with respect to those observed during the clinical assessment. Thus, increasing efforts have been aimed at comprehending the effects of self-referential and emotional stimuli on patients’ responsiveness. Here we systematically reviewed the original experimental studies that compared behavioural and electrophysiological responses with salient vs. neutral material in patients in vegetative state/unresponsive wakefulness syndrome or in minimally conscious state.
Most of the reviewed studies showed that salient stimuli (i.e. patient’s own or familiar faces, patient’s own name, and familiar voices) seem to elicit a higher amount of behavioural or electrophysiological responses with respect to neutral pictures or sounds. Importantly, a quite high percentage of patients seem to respond to salient stimuli only.
The present review could foster use of personally salient stimuli in assessing DoC. However, the low overall quality of evidence and some limitations in the general reviewing process might induce caution in transferring these suggestions into clinical practice.
KeywordsDisorders of consciousness Vegetative state Minimally conscious state Clinical evaluation Saliency-self-related stimuli
This work was supported by grant from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 778234—DoCMA project.
Compliance with Ethical Standards
Conflict of Interest
Alfonso Magliacano, Francesco De Bellis, Alejandro Galvao-Carmona, Anna Estraneo, and Luigi Trojano each declare no potential conflicts of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
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