Functional Localization of the Human Auditory and Visual Thalamus Using a Thalamic Localizer Functional Magnetic...

Area of Science:

• Neuroimaging
• Human Brain Imaging
• Sensory System Neuroscience

Background:

• Functional magnetic resonance imaging (fMRI) is crucial for studying brain health and disease, particularly the auditory and visual systems.
• The medial geniculate nucleus (MGN) and lateral geniculate nucleus (LGN) are key thalamic nuclei for auditory and visual processing, respectively.
• Localizing fMRI signals within the MGN and LGN is challenging due to poor anatomical definition in standard MRI sequences.

Approach:

• Developed and evaluated a novel auditory and visual sensory thalamic localizer (TL) fMRI task.
• Utilized 3 Tesla multiband fMRI with a clustered-sparse temporal acquisition sequence for efficient data collection (under 16 minutes).
• Generated participant-specific, functionally-defined regions of interest (fROIs) for MGN and LGN.

Key Points:

• The TL fMRI task successfully produced MGN and LGN fROIs in human participants.
• These fROIs were effectively used in resting-state functional connectivity (RSFC) analyses.
• MGN and LGN fROIs demonstrated specificity for auditory and visual cortex signals, respectively, outperforming atlas- and segmentation-based methods.

Conclusions:

• The TL fMRI task offers a rapid and effective method for localizing auditory and visual thalamic nuclei.
• This approach enhances the precision of fMRI studies investigating neural pathways in the human brain.
• The TL fMRI task and associated analysis code are publicly available to the research community.