Cognitive enhancement by means of TMS and video game training: synergistic effects

L'estimulació magnètica transcranial (TMS) ens permet modular els nivells d'excitabilitat cortical amb una resolució espacial molt alta, amb un impacte sobre les funcions cognitives que poden donar lloc a millora cognitiva. No obstant això, aquests canvis sovint són transitoris, per la qual cosa hi ha la necessitat de desenvolupar protocols optimitzats que puguin potenciar i estendre la durada dels efectes. L'efectivitat de la TMS per a aconseguir canvis cognitius es potencia quan s'usa juntament amb un entrenament cognitiu que emfatitza la funció cognitiva que es té com a objectiu. Els videojocs posseeixen totes les característiques apropiades per a ser utilitzats amb aquest propòsit. S'espera que l'ús conjunt de la TMS i l'entrenament amb videojocs produeixi efectes sinèrgics en el rendiment cognitiu, amb millora de les funcions cognitives relacionades amb el lloc d'estimulació i els contextos exposats durant el videojoc. Aquesta tesi proporciona una anàlisi en profunditat sobre la temàtica de la millora cognitiva per mitjà de TMS, els correlats neuronals dels videojocs i la millora cognitiva com a resultat de l'entrenament de videojocs a través d'exhaustives revisions bibliogràfiques. Per a l'etapa experimental, s'ha emprat una TMS theta-burst intermitent (iTBS) sobre la DLPFC dreta, esperant induir efectes comparables a la potenciació a llarg termini. Deu sessions d'estimulació van ser administrades durant dues setmanes. Es van formar quatre grups experimentals combinant l'administració d'estimulació iTBS activa i simulada, i l'alta i baixa experiència prèvia en videojocs. El rendiment cognitiu es va avaluar per mitjà d'una bateria neuropsicològica exhaustiva en tres punts temporals. Els efectes de l'estimulació cerebral no invasiva sobre la millora cognitiva juntament amb l'entrenament de videojocs van ser menys notoris i consistents del que s'esperava. No obstant això, l'experiència prèvia en videojocs era determinant tant per al rendiment inicial com per a la taxa d'adquisició d'habilitats en una sèrie de dominis cognitius.La estimulación magnética transcraneal (TMS) nos permite modular los niveles de excitabilidad cortical con una resolución espacial muy alta, y con un impacto sobre las funciones cognitivas que pueden resultar en mejora cognitiva. Sin embargo, estos cambios a menudo son transitorios, y existe la necesidad de desarrollar protocolos optimizados que puedan potenciar y extender la duración de estos efectos. La efectividad de la TMS para lograr cambios cognitivos se potencia cuando se usa junto con un entrenamiento cognitivo que enfatiza la función cognitiva pretendida. Los videojuegos poseen todas las características apropiadas para ser utilizados con este propósito. Se espera que el uso conjunto de la TMS y el entrenamiento con videojuegos produzca efectos sinérgicos en el rendimiento cognitivo, con mejora de las funciones cognitivas relacionadas con el lugar de estimulación y los contextos expuestos durante el videojuego. Esta tesis proporciona un análisis en profundidad sobre la temática de la mejora cognitiva a través de TMS, los correlatos neuronales de los videojuegos y la mejora cognitiva como resultado del entrenamiento de videojuegos a través de exhaustivas revisiones bibliográficas. Para la etapa experimental, se ha empleado una TMS theta-burst intermitente (iTBS) sobre la DLPFC derecha, esperando inducir efectos comparables a la potenciación a largo plazo. Diez sesiones de estimulación fueron administradas durante dos semanas. Se formaron cuatro grupos experimentales combinando la administración de estimulación iTBS activa y simulada, y la alta y baja experiencia previa en videojuegos. El rendimiento cognitivo se evaluó mediante una batería neuropsicológica exhaustiva en tres puntos temporales. Los efectos de la estimulación cerebral no invasiva sobre la mejora cognitiva junto con el entrenamiento de videojuegos fueron menos notorios y consistentes de lo esperado. Sin embargo, la experiencia previa en videojuegos era determinante tanto para el rendimiento inicial como para la tasa de adquisición de habilidades en una serie de dominios cognitivos.Transcranial magnetic stimulation (TMS) allows us to modulate cortical excitability levels with an exceptionally high spatial resolution, thereby achieving an impact on cognitive functions that may result in cognitive improvement. However, such changes are often transitory, meaning there is a need to develop optimized protocols that are capable of prolonging the duration of the effects. The effectiveness of TMS in achieving cognitive changes is potentiated when used in conjunction with cognitive training that stimulates the targeted cognitive function. Video games possess all the appropriate features for this purpose. The joint use of TMS and video game training is expected to create synergistic effects on cognitive performance, thereby enhancing the cognitive functions related to the stimulation site and the contexts exposed during video game play. Through exhaustive literature reviews, this thesis provides an in-depth analysis on cognitive enhancement through TMS, the neural correlates of video games, and cognitive enhancement as a result of video game training. For the experimental stage, intermittent theta-burst transcranial magnetic stimulation (iTBS) over the right dorsolateral prefrontal cortex was employed in hopes of inducing effects comparable to long-term potentiation. This was carried out during ten stimulation sessions performed over a two-week period. The variables (i.e. administration of active and sham iTBS together with high and low previous video game experience) were paired to create four experimental groups. Cognitive performance was assessed through a comprehensive neuropsychological battery at three different points in time. The effects of the non-invasive brain stimulation on cognitive enhancement in conjunction with the video game training were less evident and consistent than expected. However, previous video game experience was found to be determinant for both the baseline performance and the skill acquisition rate in a series of cognitive domains

Cognitive enhancement by means of TMS and video game training: synergistic effects

L'estimulació magnètica transcranial (TMS) ens permet modular els nivells d'excitabilitat cortical amb una resolució espacial molt alta, amb un impacte sobre les funcions cognitives que poden donar lloc a millora cognitiva. No obstant això, aquests canvis sovint són transitoris, per la qual cosa hi ha la necessitat de desenvolupar protocols optimitzats que puguin potenciar i estendre la durada dels efectes. L'efectivitat de la TMS per a aconseguir canvis cognitius es potencia quan s'usa juntament amb un entrenament cognitiu que emfatitza la funció cognitiva que es té com a objectiu. Els videojocs posseeixen totes les característiques apropiades per a ser utilitzats amb aquest propòsit. S'espera que l'ús conjunt de la TMS i l'entrenament amb videojocs produeixi efectes sinèrgics en el rendiment cognitiu, amb millora de les funcions cognitives relacionades amb el lloc d'estimulació i els contextos exposats durant el videojoc. Aquesta tesi proporciona una anàlisi en profunditat sobre la temàtica de la millora cognitiva per mitjà de TMS, els correlats neuronals dels videojocs i la millora cognitiva com a resultat de l'entrenament de videojocs a través d'exhaustives revisions bibliogràfiques. Per a l'etapa experimental, s'ha emprat una TMS theta-burst intermitent (iTBS) sobre la DLPFC dreta, esperant induir efectes comparables a la potenciació a llarg termini. Deu sessions d'estimulació van ser administrades durant dues setmanes. Es van formar quatre grups experimentals combinant l'administració d'estimulació iTBS activa i simulada, i l'alta i baixa experiència prèvia en videojocs. El rendiment cognitiu es va avaluar per mitjà d'una bateria neuropsicològica exhaustiva en tres punts temporals. Els efectes de l'estimulació cerebral no invasiva sobre la millora cognitiva juntament amb l'entrenament de videojocs van ser menys notoris i consistents del que s'esperava. No obstant això, l'experiència prèvia en videojocs era determinant tant per al rendiment inicial com per a la taxa d'adquisició d'habilitats en una sèrie de dominis cognitius.La estimulación magnética transcraneal (TMS) nos permite modular los niveles de excitabilidad cortical con una resolución espacial muy alta, y con un impacto sobre las funciones cognitivas que pueden resultar en mejora cognitiva. Sin embargo, estos cambios a menudo son transitorios, y existe la necesidad de desarrollar protocolos optimizados que puedan potenciar y extender la duración de estos efectos. La efectividad de la TMS para lograr cambios cognitivos se potencia cuando se usa junto con un entrenamiento cognitivo que enfatiza la función cognitiva pretendida. Los videojuegos poseen todas las características apropiadas para ser utilizados con este propósito. Se espera que el uso conjunto de la TMS y el entrenamiento con videojuegos produzca efectos sinérgicos en el rendimiento cognitivo, con mejora de las funciones cognitivas relacionadas con el lugar de estimulación y los contextos expuestos durante el videojuego. Esta tesis proporciona un análisis en profundidad sobre la temática de la mejora cognitiva a través de TMS, los correlatos neuronales de los videojuegos y la mejora cognitiva como resultado del entrenamiento de videojuegos a través de exhaustivas revisiones bibliográficas. Para la etapa experimental, se ha empleado una TMS theta-burst intermitente (iTBS) sobre la DLPFC derecha, esperando inducir efectos comparables a la potenciación a largo plazo. Diez sesiones de estimulación fueron administradas durante dos semanas. Se formaron cuatro grupos experimentales combinando la administración de estimulación iTBS activa y simulada, y la alta y baja experiencia previa en videojuegos. El rendimiento cognitivo se evaluó mediante una batería neuropsicológica exhaustiva en tres puntos temporales. Los efectos de la estimulación cerebral no invasiva sobre la mejora cognitiva junto con el entrenamiento de videojuegos fueron menos notorios y consistentes de lo esperado. Sin embargo, la experiencia previa en videojuegos era determinante tanto para el rendimiento inicial como para la tasa de adquisición de habilidades en una serie de dominios cognitivos.Transcranial magnetic stimulation (TMS) allows us to modulate cortical excitability levels with an exceptionally high spatial resolution, thereby achieving an impact on cognitive functions that may result in cognitive improvement. However, such changes are often transitory, meaning there is a need to develop optimized protocols that are capable of prolonging the duration of the effects. The effectiveness of TMS in achieving cognitive changes is potentiated when used in conjunction with cognitive training that stimulates the targeted cognitive function. Video games possess all the appropriate features for this purpose. The joint use of TMS and video game training is expected to create synergistic effects on cognitive performance, thereby enhancing the cognitive functions related to the stimulation site and the contexts exposed during video game play. Through exhaustive literature reviews, this thesis provides an in-depth analysis on cognitive enhancement through TMS, the neural correlates of video games, and cognitive enhancement as a result of video game training. For the experimental stage, intermittent theta-burst transcranial magnetic stimulation (iTBS) over the right dorsolateral prefrontal cortex was employed in hopes of inducing effects comparable to long-term potentiation. This was carried out during ten stimulation sessions performed over a two-week period. The variables (i.e. administration of active and sham iTBS together with high and low previous video game experience) were paired to create four experimental groups. Cognitive performance was assessed through a comprehensive neuropsychological battery at three different points in time. The effects of the non-invasive brain stimulation on cognitive enhancement in conjunction with the video game training were less evident and consistent than expected. However, previous video game experience was found to be determinant for both the baseline performance and the skill acquisition rate in a series of cognitive domains

Cognitive enhancement by means of TMS and video game training: synergistic effects

L'estimulació magnètica transcranial (TMS) ens permet modular els nivells d'excitabilitat cortical amb una resolució espacial molt alta, amb un impacte sobre les funcions cognitives que poden donar lloc a millora cognitiva. No obstant això, aquests canvis sovint són transitoris, per la qual cosa hi ha la necessitat de desenvolupar protocols optimitzats que puguin potenciar i estendre la durada dels efectes. L'efectivitat de la TMS per a aconseguir canvis cognitius es potencia quan s'usa juntament amb un entrenament cognitiu que emfatitza la funció cognitiva que es té com a objectiu. Els videojocs posseeixen totes les característiques apropiades per a ser utilitzats amb aquest propòsit. S'espera que l'ús conjunt de la TMS i l'entrenament amb videojocs produeixi efectes sinèrgics en el rendiment cognitiu, amb millora de les funcions cognitives relacionades amb el lloc d'estimulació i els contextos exposats durant el videojoc. Aquesta tesi proporciona una anàlisi en profunditat sobre la temàtica de la millora cognitiva per mitjà de TMS, els correlats neuronals dels videojocs i la millora cognitiva com a resultat de l'entrenament de videojocs a través d'exhaustives revisions bibliogràfiques. Per a l'etapa experimental, s'ha emprat una TMS theta-burst intermitent (iTBS) sobre la DLPFC dreta, esperant induir efectes comparables a la potenciació a llarg termini. Deu sessions d'estimulació van ser administrades durant dues setmanes. Es van formar quatre grups experimentals combinant l'administració d'estimulació iTBS activa i simulada, i l'alta i baixa experiència prèvia en videojocs. El rendiment cognitiu es va avaluar per mitjà d'una bateria neuropsicològica exhaustiva en tres punts temporals. Els efectes de l'estimulació cerebral no invasiva sobre la millora cognitiva juntament amb l'entrenament de videojocs van ser menys notoris i consistents del que s'esperava. No obstant això, l'experiència prèvia en videojocs era determinant tant per al rendiment inicial com per a la taxa d'adquisició d'habilitats en una sèrie de dominis cognitius.La estimulación magnética transcraneal (TMS) nos permite modular los niveles de excitabilidad cortical con una resolución espacial muy alta, y con un impacto sobre las funciones cognitivas que pueden resultar en mejora cognitiva. Sin embargo, estos cambios a menudo son transitorios, y existe la necesidad de desarrollar protocolos optimizados que puedan potenciar y extender la duración de estos efectos. La efectividad de la TMS para lograr cambios cognitivos se potencia cuando se usa junto con un entrenamiento cognitivo que enfatiza la función cognitiva pretendida. Los videojuegos poseen todas las características apropiadas para ser utilizados con este propósito. Se espera que el uso conjunto de la TMS y el entrenamiento con videojuegos produzca efectos sinérgicos en el rendimiento cognitivo, con mejora de las funciones cognitivas relacionadas con el lugar de estimulación y los contextos expuestos durante el videojuego. Esta tesis proporciona un análisis en profundidad sobre la temática de la mejora cognitiva a través de TMS, los correlatos neuronales de los videojuegos y la mejora cognitiva como resultado del entrenamiento de videojuegos a través de exhaustivas revisiones bibliográficas. Para la etapa experimental, se ha empleado una TMS theta-burst intermitente (iTBS) sobre la DLPFC derecha, esperando inducir efectos comparables a la potenciación a largo plazo. Diez sesiones de estimulación fueron administradas durante dos semanas. Se formaron cuatro grupos experimentales combinando la administración de estimulación iTBS activa y simulada, y la alta y baja experiencia previa en videojuegos. El rendimiento cognitivo se evaluó mediante una batería neuropsicológica exhaustiva en tres puntos temporales. Los efectos de la estimulación cerebral no invasiva sobre la mejora cognitiva junto con el entrenamiento de videojuegos fueron menos notorios y consistentes de lo esperado. Sin embargo, la experiencia previa en videojuegos era determinante tanto para el rendimiento inicial como para la tasa de adquisición de habilidades en una serie de dominios cognitivos.Transcranial magnetic stimulation (TMS) allows us to modulate cortical excitability levels with an exceptionally high spatial resolution, thereby achieving an impact on cognitive functions that may result in cognitive improvement. However, such changes are often transitory, meaning there is a need to develop optimized protocols that are capable of prolonging the duration of the effects. The effectiveness of TMS in achieving cognitive changes is potentiated when used in conjunction with cognitive training that stimulates the targeted cognitive function. Video games possess all the appropriate features for this purpose. The joint use of TMS and video game training is expected to create synergistic effects on cognitive performance, thereby enhancing the cognitive functions related to the stimulation site and the contexts exposed during video game play. Through exhaustive literature reviews, this thesis provides an in-depth analysis on cognitive enhancement through TMS, the neural correlates of video games, and cognitive enhancement as a result of video game training. For the experimental stage, intermittent theta-burst transcranial magnetic stimulation (iTBS) over the right dorsolateral prefrontal cortex was employed in hopes of inducing effects comparable to long-term potentiation. This was carried out during ten stimulation sessions performed over a two-week period. The variables (i.e. administration of active and sham iTBS together with high and low previous video game experience) were paired to create four experimental groups. Cognitive performance was assessed through a comprehensive neuropsychological battery at three different points in time. The effects of the non-invasive brain stimulation on cognitive enhancement in conjunction with the video game training were less evident and consistent than expected. However, previous video game experience was found to be determinant for both the baseline performance and the skill acquisition rate in a series of cognitive domains

Neural basis of video gaming: A systematic review

Background: Video gaming is an increasingly popular activity in contemporary society, especially among young people, and video games are increasing in popularity not only as a research tool but also as a field of study. Many studies have focused on the neural and behavioral effects of video games, providing a great deal of video game derived brain correlates in recent decades. There is a great amount of information, obtained through a myriad of methods, providing neural correlates of video games. Objectives: We aim to understand the relationship between the use of video games and their neural correlates, taking into account the whole variety of cognitive factors that they encompass. Methods: A systematic review was conducted using standardized search operators that included the presence of video games and neuro-imaging techniques or references to structural or functional brain changes. Separate categories were made for studies featuring Internet Gaming Disorder and studies focused on the violent content of video games. Results: A total of 116 articles were considered for the final selection. One hundred provided functional data and 22 measured structural brain changes. One-third of the studies covered video game addiction, and 14%focused on video game related violence. Conclusions: Despite the innate heterogeneity of the field of study, it has been possible to establish a series of links between the neural and cognitive aspects, particularly regarding attention, cognitive control, visuospatial skills, cognitive workload, and reward processing. However, many aspects could be improved. The lack of standardization in the different aspects of video game related research, such as the participants¿ characteristics, the features of each video game genre and the diverse study goals could contribute to discrepancies in many related studies. ©2017 Palaus, Marron, Viejo-Sobera and Redolar-Ripoll

Neural basis of video gaming: A systematic review

Background: Video gaming is an increasingly popular activity in contemporary society, especially among young people, and video games are increasing in popularity not only as a research tool but also as a field of study. Many studies have focused on the neural and behavioral effects of video games, providing a great deal of video game derived brain correlates in recent decades. There is a great amount of information, obtained through a myriad of methods, providing neural correlates of video games. Objectives: We aim to understand the relationship between the use of video games and their neural correlates, taking into account the whole variety of cognitive factors that they encompass. Methods: A systematic review was conducted using standardized search operators that included the presence of video games and neuro-imaging techniques or references to structural or functional brain changes. Separate categories were made for studies featuring Internet Gaming Disorder and studies focused on the violent content of video games. Results: A total of 116 articles were considered for the final selection. One hundred provided functional data and 22 measured structural brain changes. One-third of the studies covered video game addiction, and 14%focused on video game related violence. Conclusions: Despite the innate heterogeneity of the field of study, it has been possible to establish a series of links between the neural and cognitive aspects, particularly regarding attention, cognitive control, visuospatial skills, cognitive workload, and reward processing. However, many aspects could be improved. The lack of standardization in the different aspects of video game related research, such as the participants¿ characteristics, the features of each video game genre and the diverse study goals could contribute to discrepancies in many related studies. ©2017 Palaus, Marron, Viejo-Sobera and Redolar-Ripoll

Neural basis of video gaming: a systematic review.

Video gaming is an increasingly popular activity in contemporary society, especially among young people, and video games are increasing in popularity not only as a research tool but also as a field of study. Many studies have focused on the neural and behavioral effects of video games, providing a great deal of video game derived brain correlates in recent decades. There is a great amount of information, obtained through a myriad of methods, providing neural correlates of video games.We aim to understand the relationship between the use of video games and their neural correlates, taking into account the whole variety of cognitive factors that they encompass. A systematic review was conducted using standardized search operators that included the presence of video games and neuro-imaging techniques or references to structural or functional brain changes. Separate categories were made for studies featuring Internet Gaming Disorder and studies focused on the violent content of video games. A total of 116 articles were considered for the final selection. One hundred provided functional data and 22 measured structural brain changes. One-third of the studies covered video game addiction, and 14% focused on video game related violence.Despite the innate heterogeneity of the field of study, it has been possible to establish a series of links between the neural and cognitive aspects, particularly regarding attention, cognitive control, visuospatial skills, cognitive workload, and reward processing. However, many aspects could be improved. The lack of standardization in the different aspects of video game related research, such as the participants' characteristics, the features of each video game genre and the diverse study goals could contribute to discrepancies in many related studies

Impact of Prefrontal Theta Burst Stimulation on Clinical Neuropsychological Tasks

International audienceTheta burst stimulation (TBS) protocols hold high promise in neuropsychological rehabilitation. Nevertheless, their ability to either decrease (continuous, cTBS) or increase (intermittent, iTBS) cortical excitability in areas other than the primary motor cortex, and their consistency modulating human behaviors with clinically relevant tasks remain to be fully established. The behavioral effects of TBS over the dorsolateral prefrontal cortex (dlPFC) are particularly interesting given its involvement in working memory (WM) and executive functions (EF), often impaired following frontal brain damage. We aimed to explore the ability of cTBS and iTBS to modulate WM and EF in healthy individuals, assessed with clinical neuropsychological tests (Digits Backward, 3-back task, Stroop Test, and Tower of Hanoi). To this end, 36 participants were assessed using the four tests 1 week prior to stimulation and immediately following a single session of either cTBS, iTBS, or sham TBS, delivered to the left dlPFC. No significant differences were found across stimulation conditions in any of the clinical tasks. Nonetheless, in some of them, active stimulation induced significant pre/post performance modulations, which were not found for the sham condition. More specifically, sham stimulation yielded improvements in the 3-back task and the Color, Color-Word, and Interference Score of the Stroop Test, an effect likely caused by task practice. Both, iTBS and cTBS, produced improvements in Digits Backward and impairments in 3-back task accuracy. Moreover, iTBS increased Interference Score in the Stroop Test in spite of the improved word reading and impaired color naming, whereas cTBS decreased the time required to complete the Tower of Hanoi. Differing from TBS outcomes reported for cortico-spinal measures on the primary motor cortex, our analyses did not reveal any of the expected performance differences across stimulation protocols. However, if one considers independently pre/post differences for each individual outcome measure and task, either one or both of the active protocols appeared to modulate WM and EF. We critically discuss the value, potential explanations, and some plausible interpretations for this set of subtle impacts of left dlPFC TBS in humans

Impact of prefrontal theta burst stimulation on clinical neuropsychological tasks [dataset]

This dataset corresponds to the results published in: Viejo-Sobera, R., Redolar-Ripoll, D., Boixadós, M., Palaus, M., Valero-Cabré, A., & Marron, E. M. (2017). Impact of prefrontal theta burst stimulation on clinical neuropsychological tasks. Frontiers in neuroscience, 11, 462. https://doi.org/10.3389/fnins.2017.00462 The data was collected in 2014-2015 at the Cognitive NeuroLab (cognitiveneurolab.org, Universitat Oberta de Catalunya, UOC) as part of a project founded by the Spanish Ministerio de Economía y Competitividad (grant number: PSI2012-36610; PI Diego Redolar Ripoll). For more information contact the corresponding author Raquel Viejo-Sobera ([email protected])

Impact of Prefrontal Theta Burst Stimulation on Clinical Neuropsychological Tasks

Theta burst stimulation (TBS) protocols hold high promise in neuropsychological rehabilitation. Nevertheless, their ability to either decrease (continuous, cTBS) or increase (intermittent, iTBS) cortical excitability in areas other than the primary motor cortex, and their consistency modulating human behaviors with clinically relevant tasks remain to be fully established. The behavioral effects of TBS over the dorsolateral prefrontal cortex (dlPFC) are particularly interesting given its involvement in working memory (WM) and executive functions (EF), often impaired following frontal brain damage. We aimed to explore the ability of cTBS and iTBS to modulate WM and EF in healthy individuals, assessed with clinical neuropsychological tests (Digits Backward, 3-back task, Stroop Test, and Tower of Hanoi). To this end, 36 participants were assessed using the four tests 1 week prior to stimulation and immediately following a single session of either cTBS, iTBS, or sham TBS, delivered to the left dlPFC. No significant differences were found across stimulation conditions in any of the clinical tasks. Nonetheless, in some of them, active stimulation induced significant pre/post performance modulations, which were not found for the sham condition. More specifically, sham stimulation yielded improvements in the 3-back task and the Color, Color-Word, and Interference Score of the Stroop Test, an effect likely caused by task practice. Both, iTBS and cTBS, produced improvements in Digits Backward and impairments in 3-back task accuracy. Moreover, iTBS increased Interference Score in the Stroop Test in spite of the improved word reading and impaired color naming, whereas cTBS decreased the time required to complete the Tower of Hanoi. Differing from TBS outcomes reported for cortico-spinal measures on the primary motor cortex, our analyses did not reveal any of the expected performance differences across stimulation protocols. However, if one considers independently pre/post differences for each individual outcome measure and task, either one or both of the active protocols appeared to modulate WM and EF. We critically discuss the value, potential explanations, and some plausible interpretations for this set of subtle impacts of left dlPFC TBS in humans