title: Spatiotemporal reconstruction of auditory steady-state responses to acoustic amplitude modulations: Potential sources beyond the auditory pathway.
abstract: Investigating the neural generators of auditory steady-state responses (ASSRs), i.e., auditory evoked brain responses, with a wide range of screening and diagnostic applications, has been the focus of various studies for many years. Most of these studies employed a priori assumptions regarding the number and location of neural generators. The aim of this study is to reconstruct ASSR sources with minimal assumptions in order to gain in-depth insight into the number and location of brain regions that are activated in response to low- as well as high-frequency acoustically amplitude modulated signals. In order to reconstruct ASSR sources, we applied independent component analysis with subsequent equivalent dipole modeling to single-subject EEG data (young adults, 20-30 years of age). These data were based on white noise stimuli, amplitude modulated at 4, 20, 40, or 80Hz. The independent components that exhibited a significant ASSR were clustered among all participants by means of a probabilistic clustering method based on a Gaussian mixture model. Results suggest that a widely distributed network of sources, located in cortical as well as subcortical regions, is active in response to 4, 20, 40, and 80Hz amplitude modulated noises. Some of these sources are located beyond the central auditory pathway. Comparison of brain sources in response to different modulation frequencies suggested that the identified brain sources in the brainstem, the left and the right auditory cortex show a higher responsiveness to 40Hz than to the other modulation frequencies.
authors.affiliation: Research Group Experimental ORL, Department of Neurosciences, KU Leuven - University of Leuven, Herestraat 49 bus 721, 3000 Leuvetabn, Belgium. Electronic address: ehsan.darestani@kuleuven.be.
authors.forename: Ehsan Darestani
authors.initials: ED
authors.lastname: Farahani
authors.affiliation: Research Group Experimental ORL, Department of Neurosciences, KU Leuven - University of Leuven, Herestraat 49 bus 721, 3000 Leuvetabn, Belgium.
authors.forename: Tine
authors.initials: T
authors.lastname: Goossens
authors.affiliation: Research Group Experimental ORL, Department of Neurosciences, KU Leuven - University of Leuven, Herestraat 49 bus 721, 3000 Leuvetabn, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Wouters
authors.affiliation: Research Group Experimental ORL, Department of Neurosciences, KU Leuven - University of Leuven, Herestraat 49 bus 721, 3000 Leuvetabn, Belgium.
authors.forename: Astrid
authors.initials: A
authors.lastname: van Wieringen
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000465:Algorithms; D001303:Auditory Cortex / Q000000981:diagnostic imaging / Q000502:physiology; D001306:Auditory Pathways / Q000502:physiology*; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000502:physiology; D016000:Cluster Analysis; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D016011:Normal Distribution; D010898:Pitch Perception / Q000502:physiology*; D055815:Young Adult
keywords: Auditory pathway; Auditory steady-state response; EEG; Independent component analysis; Source localization