Cortical activation patterns during voluntary blinks and voluntary saccades

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Previous fMRI studies identified frontal eye fields (FEF) and supplementary eye fields (SEF) involved in voluntary saccades.
• Parietal cortex activation during saccades was not previously studied.
• Cortical areas for voluntary blinking using fMRI remained largely unexplored.

Purpose of the Study:

• To investigate brain activation in frontal, parietal, and occipital areas during voluntary blinks and saccades using fMRI.
• To compare the neural correlates of voluntary blinking and saccades.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was performed on 12 healthy volunteers using a 1.5-T scanner.
• Anatomical and functional imaging data were acquired.
• Voxel-by-voxel cross-correlation analysis was employed for data interpretation.

Main Results:

• Voluntary blinks activated the FEF, SEF, posterior parietal cortex (parietal eye field [PEF]), and visual cortex.
• Both voluntary blinks and saccades engaged similar cerebral structures.
• Blinking resulted in fewer activated voxels in the visual cortex and FEF but greater activation extent in the SEF and PEF compared to saccades.

Conclusions:

• Voluntary blinks and saccades share overlapping activation patterns in the brain.
• Quantitative differences in activation suggest the middle frontal gyrus and posterior parietal cortex are particularly important for voluntary blinking.
• The study highlights the significance of considering quantitative distributional properties in parallel cortical activities for both saccades and blinks.