Magnetoencephalographic Correlates of Perceptual State During Auditory Bistability
Robert David Sanders, Joel S. Winston, Gareth Robert Barnes, Geraint Rees
Scientific Reports January 11, 2018 DOI: 10.1038/s41598-018-19287-0 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study using magnetoencephalography and machine-learning classification Peer reviewed |
|---|---|
| Sample size | 14 |
| Population | Human participants listening to a bistable auditory stream of tones |
| Citations | 13 |
| Key findings | Participants reported the two alternative auditory percepts in similar overall proportions (52% vs 48%). Brain activity allowed classification of the reported percept in 9/14 participants with canonical variate analysis or linear support vector machines and in 14/14 with a non-linear support vector machine; source-space analyses showed discrimination in right and left auditory cortex, while right intraparietal sulcus discrimination appeared only with non-linear SVM and in a minority of participants. |
Abstract
Bistability occurs when two alternative percepts can be derived from the same physical stimulus. To identify the neural correlates of specific subjective experiences we used a bistable auditory stimulus and determined whether the two perceptual states could be distinguished electrophysiologically. Fourteen participants underwent magnetoencephalography while reporting their perceptual experience while listening to a continuous bistable stream of auditory tones. Participants reported bistability with a similar overall proportion of the two alternative percepts (52% vs 48%). At the individual level, sensor space electrophysiological discrimination between the percepts was possible in 9/14 participants with canonical variate analysis (CVA) or linear support vector machine (SVM) analysis over space and time dimensions. Classification was possible in 14/14 subjects with non-linear SVM. Similar effects were noted in an unconstrained source space CVA analysis (classifying 10/14 participants), linear SVM (classifying 9/14 subjects) and non-linear SVM (classifiying 13/14 participants). Source space analysis restricted to a priori ROIs showed discrimination was possible in the right and left auditory cortex with each classification approach but in the right intraparietal sulcus this was only apparent with non-linear SVM and only in a minority of particpants. Magnetoencephalography can be used to objectively classify auditory experiences from individual subjects.