Development of a Set of fMRI Paradigms to Detect the “Covert Cognition” Phenomenon: Neuropsychological Aspects

Abstract

Background. In recent decades, the phenomenon of “covert cognition” has been described in a small proportion of patients with chronic disorders of consciousness. Specialized paradigms (tasks) are being developed to detect it mostly abroad. These paradigms are carried out under the control of various instrumental methods. The Russian researchers are faced with the task of validating already established paradigms on the Russian-speaking population and of creating new ones. Neuropsychological approach can contribute to solving these problems. Objectives. The study was aimed at developing a set of paradigms to detect the “covert cognition” phenomenon in a Russian-speaking sample of patients using functional magnetic resonance imaging. Methods. The development of paradigm sets was based on the analysis of previous studies and on neuropsychological data. Results. The hierarchical complex proposed by the authors includes twelve paradigms. Nine of them are passive, aimed at perceiving stimuli of different modalities. These are somatosensory (painful stimulus, “writing” a letter on the abdomen), auditory non-speech (alarm clock, two musical fragments without words, child’s laughter) and auditory speech (narratives in native and unfamiliar languages, name within the “cocktail party” effect, audio fragment from the film with obscene language) stimuli. The other three paradigms are active, aimed at encouraging people to follow instructions (imagining spatial navigation, cleaning teeth and singing to themselves). Their theoretical justification is given. Conclusions. The developed set of paradigms covers various aspects of cognitive functioning. The results of its testing on healthy volunteers and patients with chronic disorders of consciousness to detecting the “covert cognition” phenomenon will be presented in subsequent publications.

Keywords

• neuropsychology
• consciousness
• diagnostics
• covert cognition
• impaired consciousness
• fmri paradigms