Biology subjects

Butorina, A. V.

Publications and source records attributed to Butorina, A. V..

3 recordsLinked to original sources

bioRxiv2024

Intentionally vs. Spontaneously Prolonged Gaze: A MEG Study of Active Gaze-Based Interaction

Eye fixations are increasingly employed to control computers through gaze-sensitive interfaces, yet the brain mechanisms supporting this non-visual use of gaze remain poorly understood. In this study, we employed 306-channel magnetoencephalography (MEG) to find out what is specific to brain activity when gaze is used voluntarily for control. MEG was recorded while participants played a video game controlled by their eye movements. Each move required object selection by fixating it for at least 500 ms. Gaze dwells were classified as intentional if followed by a confirmation gaze on a designated location and as spontaneous otherwise. We identified both induced oscillatory and sustained phase-locked MEG activity differentiating intentional and spontaneous gaze dwells. Induced power analysis revealed prominent alpha-beta band synchronization (8-30 Hz) localized in the frontal cortex, with location broadly consistent with the frontal eye fields. This synchronization began 500-750 ms before intentional fixation onset and peaked shortly after it, suggesting proactive inhibition of saccadic activity. Sustained evoked responses further distinguished the two conditions, showing gradually rising cortical activation with a maximum at 200 ms post-onset in the inferior temporal cortex during intentional fixations, likely indicative of focused attentional engagement on spatial targets. These findings illuminate the neural dynamics underlying intentional gaze control, shedding light on the roles of proactive inhibitory mechanisms and attentional processes in voluntary behavior. By leveraging a naturalistic gaze-based interaction paradigm, this study offers a novel framework for investigating voluntary control under free behavior conditions and holds potential applications for enhancing hybrid eye-brain-computer interfaces.

neuroscience↗

bioRxiv2019

Rapid cortical plasticity induced by active learning of novel words in human adults

Human speech requires that new words are routinely memorized, yet neurocognitive mechanisms of such acquisition of memory remain highly debatable. Major controversy concerns the question whether cortical plasticity related to word learning occurs in neocortical speech-related areas immediately after learning, or neocortical plasticity emerges only on the second day after a prolonged time required for consolidation after learning. The functional spatiotemporal pattern of cortical activity related to such learning also remains largely unknown. In order to address these questions, we examined magnetoencephalographic responses elicited in the cerebral cortex by passive presentations of eight novel pseudowords before and immediately after an operant conditioning task. This associative procedure forced participants to perform an active search for unique meaning of four pseudowords that referred to movements of left and right hands and feet. The other four pseudowords did not require any movement and thus were not associated with any meaning. Familiarization with novel pseudowords led to a bilateral repetition suppression of cortical responses to them; the effect started before or around the uniqueness point and lasted for more than 500 ms. After learning, response amplitude to pseudowords that acquired meaning was greater compared with response amplitude to pseudowords that were not assigned meaning; the effect was significant within 144-362 ms after the uniqueness point, and it was found only in the left hemisphere. Within this time interval, a learning-related selective response initially emerged in cortical areas surrounding the Sylvian fissure: anterior superior temporal sulcus, ventral premotor cortex, the anterior part of intraparietal sulcus and insula. Later within this interval, activation additionally spread to more anterior higher-tier brain regions, and reached the left temporal pole and the triangular part of the left inferior frontal gyrus extending to its orbital part. Altogether, current findings evidence rapid plastic changes in cortical representations of meaningful auditory word-forms occurring almost immediately after learning. Additionally, our results suggest that familiarization resulting from stimulus repetition and semantic acquisition resulting from an active learning procedure have separable effects on cortical activity.

neuroscience↗

bioRxiv2018

Efforful verb recollection drives beta suppression in mesial frontal regions involved in action initiation.

Whether the motor cortex activation accompanying concrete verbs comprehension is necessary for verbs conceptual processing is still a hotly debated topic in the literature. Answering this question, we examined to what extent the more difficult access to verb semantics requires an additional engagement of cortical motor system in verb generation task. Using power suppression of MEG beta oscillations (15-30 Hz) as an index of sensorimotor activation, we presented to our participants the noun cues which either were strongly associated with a single verb and prompted the fast and effortless verb retrieval, or were weakly associated with multiple verbs and were more difficult to respond to. A whole-brain analysis of beta suppression revealed that the only cortical regions sensitive to the difficulty of semantic access were the higher order motor areas on the medial and lateral surfaces of the frontal lobe. This differential activation of cortical motor system accompanied effortful verb retrieval and preceded the preparation of vocal response for more than 500 milliseconds. Since the mid-frontal frontal brain areas are involved in maintaining abstract representations of actions during their initiating and planning, we argue that our finding supports the view that motor associations contribute to retrieval of verb semantics.

neuroscience↗