Hazal ARTUVAN KORKMAZ, Canan KALAYCIOĞLU
Turkish Journal of Neurology - 2026;32(1):50-61
Objectives: The main objective of our study was to investigate the role of the interhemispheric callosal network, specifically focusing on the interhemispheric transfer times of different frequency bands during word reading. Patients and methods: This experimental study involved healthy volunteers. Interhemispheric transfer time was calculated as the latency difference of event-related potentials between the contralateral and ipsilateral hemispheres. Interhemispheric transfer times for alpha, theta, and beta frequency bands were separately calculated in electroencephalogram recordings during word reading. We then analyzed differences in interhemispheric transfer times between fast and slow adult readers, with a particular focus on the directionality of interhemispheric transmission. Results: Our findings revealed a specific slowness in right to left transmission within the alpha band for slow readers. Conclusion: Slower interhemispheric transfer time during word decoding and lexicon access in slow readers may be attributed to a neuronal synchronization problem caused by alpha oscillations in smaller-diameter axonal callosal channels. Considering the existing research on alpha oscillation and attention networks, we propose that this result may indicate a difference in attention processes between the two groups. The study sheds light on the importance of callosal network dynamics, specifically alpha oscillations in reading, offering insights into the underlying neural mechanisms and potential attention-related differences between fast and slow readers.
