Neuromodulation by transcranial direct current stimulation: investigation on reading processes

Reading is a human skill, fundamental for everyday life, in which a lot of information is given in written form. To explain this process, several theories were advanced: currently there is common agreement on the simultaneous activation of two ways of reading, the direct or lessical one for words, and the phonological one for non-words or novel words. Neuroimaging studies converge in identifying three basic systems for reading, mostly in the left hemisphere: among these, the temporoparietal cortex (TPc) seems to be involved in grapheme to phoneme conversion (phonological route). The aim of the present work is to investigate, through transcranial direct current stimulation (tDCS), the role of TPc in words and non words reading. We also want to investigate different parameters of stimulation. Results of first study suggest bilateral TPc role in reading, and a facilitatory effect of left cathodal-right anodal stimulation on reading onset times. The second study suggest that reference electrode can lead to different effects depending on its position, and that unilateral montage is not as effective as bilateral one, not involving both TPc. The third study suggest that 10 minutes of tDCS are not enough to achieve a modulation, but confirm the role of TPc. The last study with below average readers, suggest that activation state of the stimulated area and difficulty of the task have to be considered too. This work contributes to the study of neural bases of reading and on the functioning of transcranial direct current stimulation on cognitive functions

The role of primary auditory and visual cortices in temporal processing: A tDCS approach

Aim: Many studies showed that visual stimuli are frequently experienced as shorter than equivalent auditory stimuli. These findings suggest that timing is distributed across many brain areas and that "different clocks" might be involved in temporal processing. The aim of this study is to investigate, with the application of tDCS over V1 and A1, the specific role of primary sensory cortices (either visual or auditory) in temporal processing. Method: Forty-eight University students were included in the study. Twenty-four participants were stimulated over A1 and 24 participants were stimulated over VI. Participants performed time bisection tasks, in the visual and the auditory modalities, involving standard durations lasting 300 ms (short) and 900 ms (long). Results: When tDCS was delivered over A1, no effect of stimulation was observed on perceived duration but we observed higher temporal variability under anodic stimulation compared to sham and higher variability in the visual compared to the auditory modality. When tDCS was delivered over V1, an underestimation of perceived duration and higher variability was observed in the visual compared to the auditory modality. Conclusion: Our results showed more variability of visual temporal processing under tDCS stimulation. These results suggest a modality independent role of A1 in temporal processing and a modality specific role of V1 in the processing of temporal intervals in the visual modality. (C) 2016 Elsevier B.V. All rights reserved

Neuromodulation by transcranial direct current stimulation: investigation on reading processes

Reading is a human skill, fundamental for everyday life, in which a lot of information is given in written form. To explain this process, several theories were advanced: currently there is common agreement on the simultaneous activation of two ways of reading, the direct or lessical one for words, and the phonological one for non-words or novel words. Neuroimaging studies converge in identifying three basic systems for reading, mostly in the left hemisphere: among these, the temporoparietal cortex (TPc) seems to be involved in grapheme to phoneme conversion (phonological route). The aim of the present work is to investigate, through transcranial direct current stimulation (tDCS), the role of TPc in words and non words reading. We also want to investigate different parameters of stimulation. Results of first study suggest bilateral TPc role in reading, and a facilitatory effect of left cathodal-right anodal stimulation on reading onset times. The second study suggest that reference electrode can lead to different effects depending on its position, and that unilateral montage is not as effective as bilateral one, not involving both TPc. The third study suggest that 10 minutes of tDCS are not enough to achieve a modulation, but confirm the role of TPc. The last study with below average readers, suggest that activation state of the stimulated area and difficulty of the task have to be considered too. This work contributes to the study of neural bases of reading and on the functioning of transcranial direct current stimulation on cognitive functions.La lettura è una competenza umana, fondamentale per la vita di tutti i giorni, in cui molte informazioni sono fornite in forma scritta. Nel tentativo di spiegare questo processo, diverse teorie sono state avanzate: attualmente vi è comune accordo sull’attivazione simultanea di due vie di lettura, quella diretta o lessicale, per la lettura di parole, e quella fonologica per le parole nuove o le non parole. Gli studi di neuroimaging convergono nell'identificare tre sistemi di base per la lettura, per lo più nell'emisfero di sinistra: tra queste, la corteccia temporo-parietale (TPC) sembra essere coinvolta nella conversione da grafema a fonema (via fonologica). Lo scopo del presente lavoro è quello di indagare, attraverso la stimolazione transcranica a corrente continua (tDCS), il ruolo di TPc nella lettura di parole e non parole. Contemporaneamente vogliamo indagare il ruolo dei diversi parametri di stimolazione. I risultati del primo studio suggeriscono un ruolo di TPc bilaterale nella lettura, ed evidenziano un effetto facilitatorio di sui tempi di risposta vocale con stimolazione catodica sinistra-anodica destra. Il secondo studio suggerisce che l’elettrodo di riferimento può portare ad effetti diversi a seconda della sua posizione, e che il montaggio unilaterale non è efficace come quello bilaterale, coinvolgendo solo la TPc sinistra. Il terzo studio mostra che 10 minuti di tDCS non sono sufficienti per una modulazione efficace, ma conferma il ruolo di TPc. L'ultimo studio è sui lettori con una prestazione di lettura inferiore alla media, ed evidenzia l’importanza dello stato di attivazione dell’area stimolata e della difficoltà del compito. Questo lavoro contribuisce allo studio delle basi neurali del processo di lettura e del funzionamento della stimolazione transcranica a corrente continua sulle funzioni cognitive

Effects of transcranial direct current stimulation (tDCS) on reading processes: a pilot study

BACKGROUND: tDCS is a noninvasive brain stimulation technique which is gaining interest in clinical field, especially for rehabilitation purposes. The aim of this pilot study was to test the effects of tDCS over the left posterior temporal cortex, on reading processes in good readers and in dyslexics performing a words and nonwords reading task. We hypothesized that anodic stimulation facilitates the reading performance. METHOD: One group of 30 good readers and one group of 15 dyslexics were tested in 3 sessions (sham, anodal, cathodal). tDCS was applied over posterior temporal lobe, with a current of 1,5 mA, lasting for 20 minutes. Subjects task was to read aloud lists of words or nonwords, before and after stimulation. During the stimulation participants read a book. We recorded reading times and accuracy of every single lists (words and nonwords) before and after the stimulation. RESULTS: Regarding reading times, we found a faster performance after tDCS. We couldn’t discriminate between different types of stimulation, maybe because of task simplicity. Similarly we found an improvement in reading accuracy for nonwords after tDCS and a better performance after anodal stimulation. Concerning the dyslexic group, we found a significant improvement in reading times for nonwords after anodal stimulation. Further experiments are necessary to prove the benefits of tDCS for reading processes and more generally for rehabilitation purposes

Effects of transcranial direct current stimulation on reading processes: a pilot study

BACKGROUND: tDCS is a noninvasive brain stimulation technique which is gaining interest in clinical field, especially for rehabilitation purposes. The aim of this pilot study was to test the effects of tDCS over the left posterior temporal cortex, on reading processes in good readers and in dyslexics performing a words and nonwords reading task. We hypothesized that anodic stimulation facilitates the reading performance. METHOD: One group of 30 good readers and one group of 15 dyslexics were tested in 3 sessions (sham, anodal, cathodal). tDCS was applied over posterior temporal lobe, with a current of 1,5 mA, lasting for 20 minutes. Subjects task was to read aloud lists of words or nonwords, before and after stimulation. During the stimulation participants read a book. We recorded reading times and accuracy of every single lists (words and nonwords) before and after the stimulation. RESULTS: Regarding reading times, we found a faster performance after tDCS. We couldn\u2019t discriminate between different types of stimulation, maybe because of task simplicity. Similarly we found an improvement in reading accuracy for nonwords after tDCS and a better performance after anodal stimulation. Concerning the dyslexic group, we found a significant improvement in reading times for nonwords after anodal stimulation. Further experiments are necessary to prove the benefits of tDCS for reading processes and more generally for rehabilitation purposes

Il ruolo della corteccia prefrontale dorso laterale in un compito di apprendimento probabilistico: uno studio pilota con la tDCS

Introduzione: L’apprendimento è un processo attraverso il quale si acquisiscono nuove informazioni come risultato delle esperienze positive o negative delle nostre scelte. Compiti di apprendimento probabilistico, con stimoli associati a determinati esiti con probabilità stabilita, sono ottimi per studiare questa funzione. Molti studi suggeriscono il coinvolgimento della corteccia prefrontale e del sistema dopaminergico nell’apprendimento basato su feedback postivi e negativi. L’obiettivo di questo studio è indagare il ruolo della corteccia prefrontale dorsolaterale (DLPFC) in un compito di apprendimento probabilistico e verificare se la stimolazione transcranica di corrente continua (tDCS) può modificare la sensibilità individuale verso i feedback o la strategia di scelta. Metodo: 10 studenti sono stati sottoposti a tre sessioni di stimolazione (anodica sinistra; anodica destra; sham), mentre veniva eseguito un compito di learning probabilistico diviso in una parte di training e in una di testing. Nella fase di learning tre coppie di stimoli erano associati a differenti probabilità di ricevere feedback positivi o negativi. Nella fase di training gli stessi stimoli erano ripresentati senza feedback. Risultati: Nella fase di training, l’analisi ha evidenziato un effetto principale del tipo di stimolazione e un’interazione tra il tipo di stimolazione e tempo di esecuzione del compito: accuratezza maggiore per la stimolazione anodica sinistra è un’accuratezza è maggiore nel blocco 1 con stimolazione anodica sinistra rispetto alle altre due condizioni. Nella fase di testing non sono state osservate differenze tra apprendimento per feedback positivi e negativi e il tipo di stimolazione. Conclusioni: Questi risultati suggeriscono che i soggetti testati hanno utilizzato nella fase di training una strategia di tipo frequency matching la quale era appresa più rapidamente con l’applicazione di una corrente anodica alla DLPFC di sinistra

Modulatory effects of transcranial direct current stimulation (tDCS) on words and non-words reading task

TITLE: Modulatory effects of transcranial direct current stimulation (tDCS) on words and non-words reading task AUTHOR(S): Margherita Forgioneb, Patrizio Tressoldi b, Daniela Mapelli b, Paulo Sergio Boggio a a Centro de Ci\ueancias Biol\uf3gicas e da Sa\ufade, Universidade Presbiteriana Mackenzie, Sao Paulo b Dipartimento di Psicologia Generale, Universit\ue0 degli Studi di Padova, Italia INTRODUCTION: In recent past tDCS has gained much attention for rehabilitation purposes. Moreover, few studies have been conducted to investigate its efficacy on reading process. The aim of these studies was to investigate the role of left and right posterior temporal cortex in words and non-words reading process, through tDCS. We focused on the online task to see if it can influence the subjects\u2019 performance. We hypothesized that the anodal stimulation would facilitate the task execution compared to sham and cathodal, in terms of reaction times and accuracy. METHOD: Twenty good readers were tested in 3 sessions (sham, anodal, cathodal), with different online task (text reading or music listening). tDCS was applied bilaterally over posterior temporal lobe, with a current of 1,5 mA, lasting for 20 minutes. Participants had to read aloud words or non-words, before and after stimulation. We recorded reaction times and accuracy for words and non-words, before and after stimulation. RESULTS: Regarding reaction times, we found significant effect of cathodal tDCS in short words reading task. Similarly, we also found an improvement in reading accuracy for non-words after tDCS. The online task doesn\u2019t seem to affect the performance. CONCLUSIONS: We found a modulatory effect of cathodal tDCS in words reading task, suggesting a compensatory mechanisms of the right hemisphere. To verify this hypothesis, we are investigating different montages, involving left or right hemisphere. Further studies are necessary to understand the modulation effects of this technique, in addition with other methodologies, such as eye tracker, and with clinical sample, in particular dyslexics

The mediatory effects of transcranial direct current stimulation (tDCS) on reading task

In recent past tDCS has gained much attention for rehabilitation purposes. Moreover, few studies have been conducted to investigate its efficacy on reading process. The aim of this study was to investigate the role of left and right posterior temporal cortex in words and non-words reading tasks, through tDCS. We investigated the effects of tDCS on subjects\ub4 reading performance, in terms of reading times and accuracy, using different online tasks. Twenty good readers were tested in 3 sessions (sham, anodal, cathodal), with different online task (text reading or music listening). tDCS was applied bilaterally over posterior temporal lobe, with a current of 1,5 mA, lasting for 20 minutes. Participants had to read aloud words or non-words, before and after stimulation. We recorded reaction times and accuracy for each stimulus, before and after stimulation. We observed an improvement in terms of reaction times in short-word reading task and of accuracy for non-words after cathodal tDCS. However, the online task doesn\u2019t seem to affect the performance. In conclusion, significant effect of cathodal tDCS in reading task, hints a compensatory mechanisms of the right hemisphere. To test the proposed hypothesis, we planned to investigate the effects of tDCS over different brain sites involving left or right hemisphere, to further understand the mediatory effects of stimulation in reading processes, particularly in dyslexia

Real-Life Clinical Data of Lenvatinib versus Sorafenib for Unresectable Hepatocellular Carcinoma in Italy

Background: Lenvatinib has been approved in Italy since October 2019 as a first-line therapy for advanced hepatocellular carcinoma (HCC) and to date data on effectiveness and safety of lenvatinib are not available in our region. To fill this gap, we performed a multicentric analysis of the real-world treatment outcomes with the propensity score matching in a cohort of Italian patients with unresectable HCC who were treated with either sorafenib or lenvatinib. Aims and Methods: To evaluate the effectiveness of sorafenib and lenvatinib as primary treatment of advanced HCC in clinical practice we performed a multicentric analysis of the treatment outcomes of 288 such patients recruited in 11 centers in Italy. A propensity score was used to mitigate confounding due to referral biases in the assessment of mortality and progression-free survival. Results: Over a follow-up period of 11 months the Cox regression model showed 48% reduction of death risk for patients treated with lenvatinib (95% CI: 0.34-0.81; p = 0.0034), compared with those treated with sorafenib. The median PFS was 9.0 and 4.9 months for lenvatinib and sorafenib arm, respectively. Patients treated with lenvatinib showed a higher percentage of response rate (29.4% vs 2.8%; p < 0.00001) compared with patients treated with sorafenib. Sorafenib was shown to be correlated with more HFSR, diarrhea and fatigue, while lenvatinib with more hypertension and fatigue. Conclusion: Our study highlighted for the first time the efficacy and safety of lenvatinib in an Italian cohort of patients