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EEG coherence changes during finger tapping in acallosal and normal children: a study of inter- and intrahemispheric
M Knyazeva1, T Koeda, C Njiokiktjien
1Research Institute of Developmental Physiology, Russian Academy of Education, Moscow.
Insights
Children with acallosal agenesis show altered brainwave patterns, with reduced frontal and increased temporal electroencephalogram (EEG) coherences. Motor tasks reveal distinct differences in brain activity compared to typically developing children.
Area of Science:
- Neuroscience
- Developmental Neuroscience
- Electroencephalography (EEG)
Background:
- Agenesis of the corpus callosum (ACC) is a congenital condition where the corpus callosum is absent, potentially leading to altered brain development and function.
- Understanding interhemispheric and intrahemispheric brain communication is crucial for diagnosing and managing neurodevelopmental disorders.
Purpose of the Study:
- To investigate differences in electroencephalogram (EEG) interhemispheric coherences (ICoh) and intrahemispheric coherences (HCoh) between children with acallosal agenesis and a normal group.
- To examine how these coherences are affected during resting and motor (tapping) conditions.
Main Methods:
- EEG data were collected from five children with acallosal agenesis (ACCG) and 30 age- and sex-matched normal children (NG).
- Coherence analysis was performed in theta, alpha, and beta frequency bands during resting and tapping tasks.
- Motor task performance (tapping intervals, variability, synchronization) was assessed in both groups.
Main Results:
- ACCG exhibited smaller frontal, central, and parietal ICohs, and larger temporal ICohs across all conditions, most notably in the beta band.
- Sagittal HCohs were larger, while temporal HCohs were smaller in the ACCG, suggesting altered intracortical organization.
- Tapping increased ICoh and HCoh in the NG, but only induced weak left temporal HCoh enhancement in the ACCG, with the beta band being 'silent' in ACCG during motor activity.
Conclusions:
- Children with acallosal agenesis display significant alterations in EEG coherence patterns, indicating atypical brain organization and interhemispheric communication.
- These differences are particularly evident in the beta frequency band and during motor tasks, suggesting deviant cortical function associated with callosal agenesis.
- The findings highlight compensatory mechanisms and functional reorganization in the acallosal brain.
Abstract:
The EEG inter- and intrahemispheric coherences (ICoh and HCoh) in the theta, alpha and beta bands were studied in an acallosal group (ACCG) of five children and a normal group of 30 sex- and age-matched children (NG) during resting and tapping conditions. Being functionally deficient, tapping in the ACCG was characterized by increased intertap intervals and variability (in right-hand tapping) and by variability together with decreased synchronization (in bimanual tapping). In the ACCG, frontal, central and parietal ICohs were shown to be smaller, while temporal ICohs were larger under all conditions (see also Koeda, T., Knyazeva, M., Jonkman, J., Njiokiktjien, C., De Sonneville, L., Vildavsky, V., 1995. The resting EEG in acallosal children: compensatory left hemisphere mechanisms? Electroencephalogr. Clin. Neurophysiol. 95, 397-407). The effect was most pronounced in the EEG beta band. The sagittal HCohs, including fronto-central, fronto-parietal, and centro-parietal HCohs within both hemispheres, were larger in the ACCG, whereas temporal HCoh (fronto-temporal, centro-temporal, parieto-temporal and occipito-temporal) were smaller, suggesting rearrangement of intracortical activity associated with callosal agenesis. Tapping induced an increase in ICoh and HCoh between frontal, central and parietal areas in the NG, and weak enhancement only in the left temporal HCoh in the ACCG. The beta band, the most reactive band in the NG, was 'silent' in the ACCG, suggesting deviant cortical function during motor activity as well.