Abstract
Neural oscillations are ubiquitous measurements of cognitive processes and dynamic routing and gating of information. The fundamental and so far unresolved problem for neuroscience remains to understand how oscillatory activity in the brain codes information for human cognition. In a biologically relevant cognitive task, we instructed six human observers to categorize facial expressions of emotion while we measured the observers' EEG. We combined state-of-the-art stimulus control with statistical information theory analysis to quantify how the three parameters of oscillations (i.e., power, phase, and frequency) code the visual information relevant for behavior in a cognitive task. We make three points: First, we demonstrate that phase codes considerably more information (2.4 times) relating to the cognitive task than power. Second, we show that the conjunction of power and phase coding reflects detailed visual features relevant for behavioral response—that is, features of facial expressions predicted by behavior. Third, we demonstrate, in analogy to communication technology, that oscillatory frequencies in the brain multiplex the coding of visual features, increasing coding capacity. Together, our findings about the fundamental coding properties of neural oscillations will redirect the research agenda in neuroscience by establishing the differential role of frequency, phase, and amplitude in coding behaviorally relevant information in the brain.
Highlights
Invasive and noninvasive studies in humans under physiological and pathological conditions converged on the suggestion that the amplitude and phase of neural oscillations implement cognitive processes such as sensory representations, attentional selection, and dynamical routing/gating of information [1,2,3,4]
To recognize visual information rapidly, the brain must continuously code complex, high-dimensional information impinging on the retina, not all of which is relevant, because a low-dimensional code can be sufficient for both recognition and behavior
The oscillatory networks of the brain dynamically reduce the high-dimensional information into a low dimensional code, but it remains unclear which aspects of these oscillations produce the low dimensional code
Summary
Invasive and noninvasive studies in humans under physiological and pathological conditions converged on the suggestion that the amplitude and phase of neural oscillations implement cognitive processes such as sensory representations, attentional selection, and dynamical routing/gating of information [1,2,3,4]. By presenting on each trial a random sample of face information—smoothly sampled from the image using Gaussian apertures at different spatial frequency bands. The Gaussian apertures randomly sampled face parts simultaneously across the two dimensions of the image and the third dimension of spatial frequency bands (Figure S1 illustrates the sampling process for one illustrative trial; [20,21]). We recorded the observers’ categorization and EEG responses to these samples (see Materials and Methods, Procedure)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
