Informativeness of Auditory Stimuli Does Not Affect EEG Signal Diversity.
Frontiers in psychology January 1, 2018 Michał Bola, Paweł Orłowski, Karolina Baranowska et al. 11 citations
Brain signal diversity is a marker of consciousness, being lower in unconscious states and higher during psychedelic states. This study tested whether increasing the information rate of speech would increase signal diversity, reflecting richer experience. Nineteen participants listened to an audiobook at five speeds (65–135% of original) and to backward (unintelligible) speech, plus a resting-state condition. EEG Lempel-Ziv diversity was measured. The main hypothesis was not supported: Bayes Factor showed evidence for no effect of speech speed on diversity. Resting-state diversity was greater than during any speech condition. Diversity also gradually declined over the experiment, possibly due to decreasing vigilance, suggesting that unconstrained rest allows more varied experiences like mind wandering.