Lateralization Aspects of Theta Oscillation in Hippocampus During Semantic Processing

Although the hippocampus is typically not considered a brain region involved in language processing, there is growing evidence to suggest that it may play a role in this process. Based on data indicating that the power of theta oscillations in the hippocampus increases with the arrival of a more coherent semantic context, we have chosen to investigate the laterality of this phenomenon by using the classic paradigm of presenting participants with semantically correct and incorrect sentences and analyzing their stereo EEG recordings while they complete a language task. Our findings indicate that the right hippocampus exhibits a stronger power of theta oscillations during processing of semantically incorrect sentences compared to semantically correct ones, whereas the left hippocampus shows the opposite pattern. This effect may be due to the increased cognitive load associated with processing semantically incorrect information, which leads to compensation in the right hippocampal region.