Related Experiment Video
Updated: Mar 31, 2026

Assessment and Communication for People with Disorders of Consciousness
Published on: August 1, 2017
EEG-detected olfactory imagery to reveal covert consciousness in minimally conscious state
Francesca Pistoia1, Antonio Carolei1, Daniela Iacoviello2
1a Neurological Institute, Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila , L'Aquila , Italy .
Primary Objective:
To reveal covert abilities in a minimally conscious state (MCS) through an innovative activation paradigm based on olfactory imagery.
Research Design:
Case study.
Methods And Procedures:
A patient in MCS was asked to 'imagine an unpleasant odour' or to 'relax' in response to the appearance on a screen of a downward pointing arrow or a cross, respectively. Electrophysiological responses to stimuli were investigated by means of an 8-channel EEG equipment and analysed using a specific threshold algorithm. The protocol was repeated for 10 sessions separated from each other by 2 weeks. Accuracy, defined as the number of successes with respect to the total number of trials, was used to evaluate the number of times in which the classification strategy was successful.
Main Outcomes And Results:
Analyses of accuracy showed that the patient was able to activate and to relax himself purposefully and that he optimized his performances with the number of sessions, probably as a result of training-related improvements.
Conclusions:
Subtle signs of consciousness may be under-estimated and need to be revealed through specific activation tasks. This paradigm may be useful to detect covert signs of consciousness, especially when patients are precluded from carrying out more complex cognitive tasks.
More Related Videos
Related Concept Videos
Subconsciousness and No Awareness
An illustrative example of subconscious processing is its role in problem-solving. Often, individuals...
Understanding Consciousness
Sleep, a crucial state, is characterized by reduced...
High-Level and Low-Level Awareness
Olfaction
The olfactory receptors are embedded in the cilia of the...
Lucid Dreaming
Studies have shown...
Altered States of Awareness
The ingestion of substances like stimulants or hallucinogens leads to chemical alterations in the brain...

