Sensory modality defines the relation between EEG Lempel–Ziv diversity and meaningfulness of a stimulus
Scientific Reports March 1, 2023 DOI: 10.1038/s41598-023-30639-3 via Springer Nature
Summary
Greater meaningfulness of visual stimuli is linked to higher Lempel–Ziv diversity of EEG signals, but the opposite effect occurs for auditory stimuli. Visual perception generally produces higher EEG diversity than auditory perception. Compared to resting state, meaningful visual stimuli increase EEG diversity while meaningful auditory stimuli decrease it. These findings show that brain signal diversity depends on the sensory modality being stimulated, so it cannot serve as a generic measure of the variability of conscious experience.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Citations | 9 |
| Key finding | The signal diversity of continuous brain signals depends on the stimulated sensory modality, therefore it is not a generic index of the variability of conscious experience. |
Abstract
Diversity of brain activity is a robust neural correlate of global states of consciousness. It has been proposed that diversity measures specifically reflect the temporal variability of conscious experience. Previous studies supported this hypothesis by showing that perception of meaningful visual stimuli causes richer, more-variable experiences than perception of meaningless stimuli, and this is reflected in greater brain signal diversity. To investigate whether this relation is consistent across sensory modalities, to participants we presented three versions of naturalistic visual and auditory stimuli (videos and audiobooks) that varied in the amount of meaning (original, scrambled, and noise), while recording electroencephalographic signals. We report three main findings. First, greater meaningfulness of visual stimuli was related to higher Lempel–Ziv diversity of EEG signals, but the opposite effect was found in the auditory modality. Second, visual perception was related to generally higher EEG diversity than auditory perception. Third, perception of meaningful visual stimuli and auditory stimuli respectively resulted in higher and lower EEG diversity in comparison to the resting state. In conclusion, the signal diversity of continuous brain signals depends on the stimulated sensory modality, therefore it is not a generic index of the variability of conscious experience.