Fractional anisotropy correlates with auditory simple reaction time performance

Area of Science:

• Neuroscience
• Neuroimaging
• Human Behavior

Background:

• Modern imaging studies have advanced understanding of behavioral performance using reaction time paradigms.
• Interindividual variations in simple reaction time (SRT) remain under-investigated.
• Auditory simple reaction time (aSRT) is a key measure of neural processing speed.

Purpose of the Study:

• To identify neural correlates of interindividual variation in auditory simple reaction time (aSRT).
• To investigate the relationship between brain structure and auditory reaction time performance.
• To explore the role of white matter integrity in processing speed.

Main Methods:

• Whole-head voxel-based morphometry analysis of fractional anisotropy (FA) was performed on 19 healthy, right-handed subjects.
• A Poffenberger paradigm with auditory stimuli was used to measure aSRT.
• Simple regression analysis examined the correlation between FA and aSRT measures.

Main Results:

• A significant positive correlation was found between FA and individual mean aSRT in the right central cerebellum.
• FA in the precentral portion of the left pyramidal tract correlated with the hand performance index.
• Faster right-handed responses correlated with higher local FA values in right-hand control areas.

Conclusions:

• Local myelination, indicated by FA, is a significant factor influencing reaction time performance.
• The findings identify specific brain areas involved in processing speed for aSRT tasks.
• Right-hand preference may influence both FA and aSRT measures in healthy participants.