The contribution of the supplementary motor area to explicit and implicit timing: A high-definition transcranial Random Noise Stimulation (HD-tRNS) study

It is becoming increasingly accepted that timing tasks, and underlying temporal processes, can be partitioned on the basis of whether they require an explicit or implicit temporal judgement. Most neuroimaging studies of timing associated explicit timing tasks with activation of the supplementary motor area (SMA). However, transcranial magnetic stimulation (TMS) studies perturbing SMA functioning across explicit timing tasks have generally reported null effects, thus failing to causally link SMA to explicit timing. The present study probed the involvement of SMA in both explicit and implicit timing tasks within a single experiment and using HighDefinition transcranial Random Noise Stimulation (HD-tRNS), a previously less used technique in studies of the SMA. Participants performed two tasks that comprised the same stimulus presentation but differed in the received task instructions, which might or might not require explicit temporal judgments. Results showed a significant HD-tRNS-induced shift of perceived durations (i.e., overestimation) in the explicit timing task, whereas there was no modulation of implicit timing by HD-tRNS. Overall, these results provide initial noninvasive brain stimulation evidence on the contribution of the SMA to explicit and implicit timing tasks

The Neuroscience of Mathematical Cognition and Learning

The synergistic potential of cognitive neuroscience and education for efficient learning has attracted considerable interest from the general public, teachers, parents, academics and policymakers alike. This review is aimed at providing 1) an accessible and general overview of the research progress made in cognitive neuroscience research in understanding mathematical learning and cognition, and 2) understanding whether there is sufficient evidence to suggest that neuroscience can inform mathematics education at this point. We also highlight outstanding questions with implications for education that remain to be explored in cognitive neuroscience. The field of cognitive neuroscience is growing rapidly. The findings that we are describing in this review should be evaluated critically to guide research communities, governments and funding bodies to optimise resources and address questions that will provide practical directions for short- and long-term impact on the education of future generations

The impact of lifestyle factors on the intensity of adverse effects in single and repeated session protocols of transcranial electrical stimulation : an exploratory pilot study

Transcranial electrical stimulation (tES) has shown promise in the treatment of conditions such as depression and chronic pain with mild-to-moderate adverse effects (AEs). Few previous studies have attempted to identify factors predicting tES-induced AEs. In particular, AEs resulting from repeated sessions of tES remain understudied. We conducted an exploratory retrospective analysis of two independent randomized controlled studies to investigate whether lifestyle factors (i.e. chronic alcohol use, smoking, exercise, and quality and length of sleep) modify the severity and frequency of tES-induced AEs, and evaluated the progression of AEs over repeated sessions. We utilized two double-blinded samples: 1) a male sample (n=82) randomized to receive transcranial direct current stimulation (tDCS) or sham for 5 days, and 2) a mixed-sex sample (n=60) who received both transcranial random noise stimulation (tRNS) and sham in a crossover setting. The severity of AEs was recorded on a scale of 0-100. The data was analysed using negative binomial models. In addition, we performed power calculations and, to guide future research, evaluated the numbers of individuals needed to detect non-significant observations as significant. By day 5, the tDCS group experienced more sensations under the electrodes than the sham group. Alcohol use, smoking, exercise, or quality or duration of sleep did not appear to be associated with the intensity of the AEs. The subsequent power analyses indicated that substantially larger samples would be needed to detect the observed associations as significant. Repetitive sessions do not appear to introduce additional AE burden to individuals receiving either tDCS or tRNS, at least with protocols lasting up to 5 days. Alcohol use, smoking, exercise, or quality or duration of sleep appear to only have an effect of negligible size, if any, on AEs induced by tDCS or tRNS, and studies with sample sizes ranging from roughly 100 individuals to hundreds of thousands of individuals would be required to detect such effects as significant

Beyond the target area: an integrative view of tDCS-induced motor cortex modulation in patients and athletes

Transcranial Direct Current Stimulation (tDCS) is a non-invasive technique used to modulate neural tissue. Neuromodulation apparently improves cognitive functions in several neurologic diseases treatment and sports performance. In this study, we present a comprehensive, integrative review of tDCS for motor rehabilitation and motor learning in healthy individuals, athletes and multiple neurologic and neuropsychiatric conditions. We also report on neuromodulation mechanisms, main applications, current knowledge including areas such as language, embodied cognition, functional and social aspects, and future directions. We present the use and perspectives of new developments in tDCS technology, namely high-definition tDCS (HD-tDCS) which promises to overcome one of the main tDCS limitation (i.e., low focality) and its application for neurological disease, pain relief, and motor learning/rehabilitation. Finally, we provided information regarding the Transcutaneous Spinal Direct Current Stimulation (tsDCS) in clinical applications, Cerebellar tDCS (ctDCS) and its influence on motor learning, and TMS combined with electroencephalography (EEG) as a tool to evaluate tDCS effects on brain function

Beyond the target area: an integrative view of tDCS-induced motor cortex modulation in patients and athletes

Transcranial Direct Current Stimulation (tDCS) is a non-invasive technique used to modulate neural tissue. Neuromodulation apparently improves cognitive functions in several neurologic diseases treatment and sports performance. In this study, we present a comprehensive, integrative review of tDCS for motor rehabilitation and motor learning in healthy individuals, athletes and multiple neurologic and neuropsychiatric conditions. We also report on neuromodulation mechanisms, main applications, current knowledge including areas such as language, embodied cognition, functional and social aspects, and future directions. We present the use and perspectives of new developments in tDCS technology, namely high-definition tDCS (HD-tDCS) which promises to overcome one of the main tDCS limitation (i.e., low focality) and its application for neurological disease, pain relief, and motor learning/rehabilitation. Finally, we provided information regarding the Transcutaneous Spinal Direct Current Stimulation (tsDCS) in clinical applications, Cerebellar tDCS (ctDCS) and its influence on motor learning, and TMS combined with electroencephalography (EEG) as a tool to evaluate tDCS effects on brain function161CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP465686/2014-1Não tem2014/50909-8; 13/10187–0; 14/10134–7The authors thank the Ministry of Education (MEC), FAPESP - São Paulo Research Foundation, Universidade Estadual de Londrina, Universidade Federal do Rio Grande do Norte and Universidade Federal do ABC for its support. Postdoctoral scholarships to DGSM from the Coordination for the Improvement of Higher Education Personnel (CAPES). Source(s) of financial support: This study was partially funded by grants to MB from NIH (NIH-NIMH 1R01MH111896, NIH-NINDS 1R01NS101362, NIH-NCI U54CA137788/U54CA132378, R03 NS054783) and New York State Department of Health (NYS DOH, DOH01-C31291GG), CEPID/BRAINN - The Brazilian Institute of Neuroscience and Neurotechnology (Process: 13/07559–3) to LML, Brazilian National Research Council (CNPq, Grant # 465686/2014-1) and the São Paulo Research Foundation (Grant # 2014/50909-8) to MSC, and Postdoctoral scholarships to AHO from FAPESP - Sao Paulo Research Foundation (Process: 13/10187–0 and 14/10134–7

Revealing Connections in Object and Scene Processing Using Consecutive TMS and fMR-Adaptation

When processing the visual world, our brain must perform many computations that may occur across several regions. It is important to understand communications between regions in order to understand perceptual processes underlying processing of our environment. We sought to determine the connectivity of object and scene processing regions of the cortex, which are not fully established. In order to determine these connections repetitive transcranial magnetic stimulation (rTMS) and functional magnetic resonance-adaptation (fMR-A) were paired together. rTMS was applied to object-selective lateral occipital (LO) and scene-selective transverse occipital sulcus (TOS). Immediately after stimulation, participants underwent fMR-A, and pre- and post-TMS responses were compared. TMS disrupted remote regions revealing connections from LO and TOS to remote object and scene-selective regions in the occipital cortex. In addition, we report important neural correlates regarding the transference of object related information between modalities, from LO to outside the ventral network to parietal and frontal areas

The impact of lifestyle factors on the intensity of adverse effects in single and repeated session protocols of transcranial electrical stimulation: an exploratory pilot study

Transcranial electrical stimulation (tES) has shown promise in the treatment of conditions such as depression and chronic pain with mild-to-moderate adverse effects (AEs). Few previous studies have attempted to identify factors predicting tES-induced AEs. In particular, AEs resulting from repeated sessions of tES remain understudied. We conducted an exploratory retrospective analysis of two independent randomized controlled studies to investigate whether lifestyle factors (i.e. chronic alcohol use, smoking, exercise, and quality and length of sleep) modify the severity and frequency of tES-induced AEs, and evaluated the progression of AEs over repeated sessions. We utilized two double-blinded samples: 1) a male sample (n=82) randomized to receive transcranial direct current stimulation (tDCS) or sham for 5 days, and 2) a mixed-sex sample (n=60) who received both transcranial random noise stimulation (tRNS) and sham in a crossover setting. The severity of AEs was recorded on a scale of 0-100. The data was analysed using negative binomial models. In addition, we performed power calculations and, to guide future research, evaluated the numbers of individuals needed to detect non-significant observations as significant. By day 5, the tDCS group experienced more sensations under the electrodes than the sham group. Alcohol use, smoking, exercise, or quality or duration of sleep did not appear to be associated with the intensity of the AEs. The subsequent power analyses indicated that substantially larger samples would be needed to detect the observed associations as significant. Repetitive sessions do not appear to introduce additional AE burden to individuals receiving either tDCS or tRNS, at least with protocols lasting up to 5 days. Alcohol use, smoking, exercise, or quality or duration of sleep appear to only have an effect of negligible size, if any, on AEs induced by tDCS or tRNS, and studies with sample sizes ranging from roughly 100 individuals to hundreds of thousands of individuals would be required to detect such effects as significant

Neuromodulation of Spatial Associations: Evidence from Choice Reaction Tasks During Transcranial Direct Current Stimulation

Various portions of human behavior and cognition are influenced by covert implicit processes without being necessarily available to intentional planning. Implicit cognitive biases can be measured in behavioral tasks yielding SNARC effects for spatial associations of numerical and non-numerical sequences, or yielding the implicit association test effect for associations between insect-flower and negative-positive categories. By using concurrent neuromodulation with transcranial direct current stimulation (tDCS), subthreshold activity patterns in prefrontal cortical regions can be experimentally manipulated to reduce implicit processing. Thus, the application of tDCS can test neurocognitive hypotheses on a unique neurocognitive origin of implicit cognitive biases in different spatial-numerical and non-numerical domains. However, the effects of tDCS are not only determined by superimposed electric fields, but also by task characteristics. To outline the possibilities of task-specific targeting of tDCS, task characteristics and instructions can be varied systematically when combined with neuromodulation. In the present thesis, implicit cognitive processes are assessed in different paradigms concurrent to left-hemispheric prefrontal tDCS to investigate a verbal processing hypothesis for implicit associations in general. In psychological experiments, simple choice reaction tasks measure implicit SNARC and SNARC-like effects as relative left-hand vs. right-hand latency advantages for responding to smaller number or ordinal sequence targets. However, different combinations of polarity-dependent tDCS with stimuli and task procedures also reveal domain-specific involvements and dissociations. Discounting previous unified theories on the SNARC effect, polarity-specific neuromodulation effects dissociate numbers and weekday or month ordinal sequences. By considering also previous results and patient studies, I present a hybrid and augmented working memory account and elaborate the linguistic markedness correspondence principle as one critical verbal mechanism among competing covert coding mechanisms. Finally, a general stimulation rationale based on verbal working memory is tested in separate experiments extending also to non-spatial implicit association test effects. Regarding cognitive tDCS effects, the present studies show polarity asymmetry and task-induced activity dependence of state-dependent neuromodulation. At large, distinct combinations of the identical tDCS electrode configuration with different tasks influences behavioral outcomes tremendously, which will allow for improved task- and domain-specific targeting