Objective: The aim of this study was to determine the EEG changes induced by emotional non-verbal sounds using nonlinear signals' features and also to examine the subjective emotional response in patients with different neurological and psychiatric disorders.
Methods: 141 subjects participated in our study: patients after moderate TBI, patients in acute coma, patients after stroke, patients with schizophrenia and controls. 7 types of emotionally charged stimuli were presented. Non-comatose participants were asked to assess the levels of experienced emotions. We analyzed fractal dimension, signal's envelope parameters and Hjorth mobility and complexity.
Results: The Hjorth parameters were negatively correlated with irritation. The fractal dimension was positively correlated with arousal and empathy levels. The only presentation of laughter to post-stroke patients induced the reaction similar to the control group.
Conclusions: The results showed that the investigated nonlinear features of resting state EEG are quite group-specific and also specific to the emotional state.
Significance: The investigated features could serve to diagnose emotional impairments.
Keywords: EEG; EEG envelope; Hjorth; coma; fractal dimension; schizophrenia; stroke; traumatic brain injury.
© 2018 the Author(s), licensee AIMS Press.