DaDoEval @ EVALITA 2020: Same-genre and cross-genre dating of historical documents

In this paper we introduce the DaDoEval shared task at EVALITA 2020, aimed at automatically assigning temporal information to documents written in Italian. The evaluation exercise comprises three levels of temporal granularity, from coarse-grained to year-based, and includes two types of test sets, either having the same genre of the training set, or a different one. More specifically, DaDoEval deals with the corpus of Alcide De Gasperi's documents, providing both public documents and letters as test sets. Two systems participated in the competition, achieving results always above the baseline in all subtasks. As expected, coarse-grained classification into five periods is rather easy to perform automatically, while the year-based one is still an unsolved problem also due to the lack of enough training data for some years. Results showed also that, although De Gasperi's letters in our test set were written in standard Italian and in a style which was not too colloquial, cross-genre classification yields remarkably lower results than the same-genre setting

in search of the neurobiological basis of divergent thinking

Human mind can follow two opposite types of reasoning in everyday life as well as in science: convergent thinking, as the ability to get the unique solution to a problem, or divergent thinking, the ability to elaborate different answer to a question. The latter is usually considered as an essential feature of the "creative mind", together with Insight, an unpredictable and unexpected moment of exceptional thinking commonly reported as the "Eureka!" experience. During such processing, an unconscious reorganization process of previously unrelated problem elements is made and when the solution finally emerges to consciousness, the subject is not able to explain how he/she reached it. Because of its unpredictable and unconscious nature, as well as its connection with creativity and scientific discoveries, the definition and evaluation of insight is now one of the biggest challenges for modern cognitive neuroscience. Neurophysiological evidence begins to arise, making the enhancement of creativity thinking using non-invasive neuromodulation techniques a plausible future scenario

Local and Distributed fMRI Changes Induced by 40 Hz Gamma tACS of the Bilateral Dorsolateral Prefrontal Cortex: A Pilot Study

Over the past few years, the possibility of modulating fast brain oscillatory activity in the gamma (γ) band through transcranial alternating current stimulation (tACS) has been discussed in the context of both cognitive enhancement and therapeutic scenarios. However, the effects of tACS targeting regions outside the motor cortex, as well as its spatial specificity, are still unclear. Here, we present a concurrent tACS-fMRI block design study to characterize the impact of 40 Hz tACS applied over the left and right dorsolateral prefrontal cortex (DLPFC) in healthy subjects. Results suggest an increase in blood oxygenation level-dependent (BOLD) activity in the targeted bilateral DLPFCs, as well as in surrounding brain areas affected by stimulation according to biophysical modeling, i.e., the premotor cortex and anterior cingulate cortex (ACC). However, off-target effects were also observed, primarily involving the visual cortices, with further effects on the supplementary motor areas (SMA), left subgenual cingulate, and right superior temporal gyrus. The specificity of 40 Hz tACS over bilateral DLPFC and the possibility for network-level effects should be considered in future studies, especially in the context of recently promoted gamma-induction therapeutic protocols for neurodegenerative disorders. © 2022 Lucia Mencarelli et al

Optimizing transcranial magnetic stimulation for spaceflight applications

As space agencies aim to reach and build installations on Mars, the crews will face longer exposure to extreme environments that may compromise their health and performance. Transcranial magnetic stimulation (TMS) is a painless non-invasive brain stimulation technique that could support space exploration in multiple ways. However, changes in brain morphology previously observed after long-term space missions may impact the efficacy of this intervention. We investigated how to optimize TMS for spaceflight-associated brain changes. Magnetic resonance imaging T1-weighted scans were collected from 15 Roscosmos cosmonauts and 14 non-flyer participants before, after 6 months on the International Space Station, and at a 7-month follow-up. Using biophysical modeling, we show that TMS generates different modeled responses in specific brain regions after spaceflight in cosmonauts compared to the control group. Differences are related to spaceflight-induced structural brain changes, such as those impacting cerebrospinal fluid volume and distribution. We suggest solutions to individualize TMS to enhance its efficacy and precision for potential applications in long-duration space missions. © 2023, The Author(s)

Reduction of intratumoral brain perfusion by noninvasive transcranial electrical stimulation

Malignant brain neoplasms have a poor prognosis despite aggressive treatments. Animal models and evidence from human bodily tumors reveal that sustained reduction in tumor perfusion via electrical stimulation promotes tumor necrosis, therefore possibly representing a therapeutic option for patients with brain tumors. Here, we demonstrate that transcranial electrical stimulation (tES) allows to safely and noninvasively reduce intratumoral perfusion in humans. Selected patients with glioblastoma or metastasis underwent tES, while perfusion was assessed using magnetic resonance imaging. Multichannel tES was applied according to personalized biophysical modeling, to maximize the induced electrical field over the solid tumor mass. All patients completed the study and tolerated the procedure without adverse effects, with tES selectively reducing the perfusion of the solid tumor. Results potentially open the door to noninvasive therapeutic interventions in brain tumors based on stand-alone tES or its combination with other available therapies