Brain dynamics and connectivity networks under natural auditory stimulation.

Area of Science:

• Neuroimaging
• Cognitive Neuroscience
• Brain Connectivity Analysis

Background:

• Analyzing functional magnetic resonance imaging (fMRI) data during natural sensory stimulation presents significant challenges.
• Identifying brain connectivity networks requires robust analytical approaches that account for inter-subject variability.

Purpose of the Study:

• To develop and validate a two-stage analysis framework for identifying brain connectivity networks under natural sensory stimulation.
• To assess the concordance between inter-subject and intra-subject correlation analyses in fMRI data.
• To investigate brain network responses to auditory stimulation and visual conditions.

Main Methods:

• A two-stage approach was implemented: Stage 1 statistically assessed concordance between inter-subject and intra-subject correlation analyses, classifying brain areas as concordant or discordant.
• Stage 2 identified connectivity networks using time courses from supra-threshold voxels based on Stage 1 classifications.
• fMRI data were collected from 40 young adults undergoing auditory stimulation (human voices, animal vocalizations) with eyes-open and eyes-closed conditions.

Main Results:

• The two-stage analysis revealed engagement of stress modulation (affective) and language networks in limbic and cortical structures during auditory stimulation, with notable inter-subject variability.
• The visuomotor control network was sensitive to the eyes-open condition, showing minimal variation across subjects.
• High concordance between analyses was found in the primary auditory cortex, which responded strongly to sound pitch variations.

Conclusions:

• The proposed method effectively distinguishes concordant and discordant brain areas, facilitating the identification of connectivity networks during natural sensory stimulation.
• This approach enhances the understanding of how the brain processes sensory information and adapts to different conditions.
• Findings highlight the distinct network responses to auditory stimuli and visual conditions, underscoring the utility of the developed analytical framework.