Biology subjects

Kajsova, M.

Publications and source records attributed to Kajsova, M..

2 recordsLinked to original sources

bioRxiv2024

Neural dynamics of visual streams interactions during memory-guided actions investigated by intracranial EEG

The dorsal and ventral visual streams play distinct roles in visual processing for action: the dorsal stream is assumed to support real-time actions, while the ventral stream facilitates memory-guided actions. As the recent evidence suggests a more integrated function of these streams, we investigated the neural dynamics and functional connectivity between them during memory-guided actions using intracranial EEG. We tracked neural activity in the inferior parietal lobule in the dorsal stream, and ventral temporal cortex in the ventral stream as well as hippocampus during a delayed action task. We found increased alpha power in both streams during the delay, indicating their role in maintaining visual information. We also observed an increase in theta band synchronization between the inferior parietal lobule and ventral temporal cortex, and between the inferior parietal lobule and hippocampus during the delay. Our study provides unique electrophysiological evidence for close interactions between dorsal and ventral streams, supporting an integrated processing model.

neuroscience↗

bioRxiv2024

Antagonistic behavior of brain networks mediated by low-frequency oscillations: electrophysiological dynamics during internal-external attention switching

Antagonistic activity of brain networks likely plays a fundamental role in how the brain optimizes its performance by efficient allocation of computational resources. A prominent example involves externally/internally oriented attention tasks, implicating two anticorrelated, intrinsic brain networks: the default mode network (DMN) and the dorsal attention network (DAN). To elucidate electrophysiological underpinnings and causal interplay during attention switching, we recorded intracranial EEG (iEEG) from 25 epilepsy patients with electrode contacts localized in the DMN and DAN. We show antagonistic network dynamics of activation-related changes in high-frequency (> 50 Hz) and low-frequency (< 30 Hz) power. The temporal profile of information flow between the networks estimated by effective connectivity suggests that the activated network inhibits the other one, gating its activity by increasing the amplitude of the low-frequency oscillations. Insights about inter-network communication may have profound implications for various brain disorders in which these dynamics are compromised.

neuroscience↗