Cortical response variation with different sound pressure levels: a combined event-related potentials and FMRI study

• Published in: PloS one 2014-10, Vol.9 (10), p.e109216-e109216
• Main Authors: Neuner, Irene, Kawohl, Wolfram, Arrubla, Jorge, Warbrick, Tracy, Hitz, Konrad, Wyss, Christine, Boers, Frank, Shah, N Jon
• Format: Article
• Language: English
• Subjects: Acoustic Stimulation; Adult; Analysis of Variance; Auditory evoked potentials; Auditory Perception; Auditory stimuli; Biology and Life Sciences; Brain; Brain mapping; Brain Mapping - methods; Brain research; Cortex (auditory); Cortex (cingulate); Cortex (frontal); Cortex (temporal); Cross-modal; Data analysis; Data processing; EEG; Electroencephalography; Event-related potentials; Evoked Potentials, Auditory; Female; Functional magnetic resonance imaging; Human health sciences; Humans; Limbic System - physiology; Localization; Magnetic resonance; Magnetic Resonance Imaging; Male; Medicine; Medicine and Health Sciences; Neuroimaging; Neurophysiology; Neurosciences; NMR; Nuclear magnetic resonance; Pressure; Psychiatry; Psychotherapy; Radiologie, médecine & imagerie nucléaire; Radiology, nuclear medicine & imaging; Sciences de la santé humaine; Sensorimotor integration; Sensory integration; Sensory stimulation; Sound pressure; Studies; Temporal resolution; Variance analysis; Visual cortex
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0109216

Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) provides high spatial and temporal resolution. In this study we combined EEG and fMRI to investigate the structures involved in the processing of different sound pressure levels (SPLs). EEG data were recorded simultaneously with fMRI from 16 healthy volunteers using MR compatible devices at 3 T. Tones with different SPLs were delivered to the volunteers and the N1/P2 amplitudes were included as covariates in the fMRI data analysis in order to compare the structures activated with high and low SPLs. Analysis of variance (ANOVA) and ROI analysis were also performed. Additionally, source localisation analysis was performed on the EEG data. The integration of averaged ERP parameters into the fMRI analysis showed an extended map of areas exhibiting covariation with the BOLD signal related to the auditory stimuli. The ANOVA and ROI analyses also revealed additional brain areas other than the primary auditory cortex (PAC) which were active with the auditory stimulation at different SPLs. The source localisation analyses showed additional sources apart from the PAC which were active with the high SPLs. The PAC and the insula play an important role in the processing of different SPLs. In the fMRI analysis, additional activation was found in the anterior cingulate cortex, opercular and orbito-frontal cortices with high SPLs. A strong response of the visual cortex was also found with the high SPLs, suggesting the presence of cross-modal effects.