Atypical interhemispheric communication in left-handed individuals

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Human Neurophysiology

Background:

• Interhemispheric transfer time (IHTT) measures communication speed between brain hemispheres.
• Previous research indicated directional asymmetry in IHTT for right-handed individuals.
• Understanding hemispheric communication is crucial for brain function studies.

Purpose of the Study:

• To investigate interhemispheric transfer time (IHTT) in both right-handed and left-handed males.
• To determine if directional asymmetry in IHTT exists in left-handed males.
• To explore the relationship between handedness, hemispheric asymmetry, and brain communication.

Main Methods:

• Utilized evoked electroencephalogram potentials (EEG) in response to lateralized visual stimuli.
• Calculated interhemispheric transfer time (IHTT) by measuring signal latencies between hemispheres.
• Compared IHTT across different visual field presentations and between right-handed and left-handed participants.

Main Results:

• Confirmed significant directional asymmetry in IHTT for right-handed males (right-to-left faster than left-to-right).
• Demonstrated the absence of this directional IHTT asymmetry in left-handed males.
• Observed that differences in hemispheric cytoarchitecture may underlie these findings.

Conclusions:

• Directional hemispheric asymmetry in IHTT is characteristic of right-handed males.
• Left-handed males exhibit a lack of directional IHTT asymmetry, suggesting less pronounced hemispheric specialization.
• Cytoarchitectural differences between hemispheres likely account for asymmetric IHTT, with these differences being less pronounced in left-handers.