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Human Brain Mapping Feb 2022Noninvasive brain stimulation (NIBS) allows to actively and noninvasively modulate brain function. Aside from inhibiting specific processes, NIBS may also enhance...
Noninvasive brain stimulation (NIBS) allows to actively and noninvasively modulate brain function. Aside from inhibiting specific processes, NIBS may also enhance cognitive functions, which might be used for the prevention and intervention of learning disabilities such as dyslexia. However, despite the growing interest in modulating learning abilities, a comprehensive, up-to-date review synthesizing NIBS studies with dyslexics is missing. Here, we fill this gap and elucidate the potential of NIBS as treatment option in dyslexia. The findings of the 15 included studies suggest that repeated sessions of reading training combined with different NIBS protocols may induce long-lasting improvements of reading performance in child and adult dyslexics, opening promising avenues for future research. In particular, the "classical" reading areas seem to be most successfully modulated through NIBS, and facilitatory protocols can improve various reading-related subprocesses. Moreover, we emphasize the need to further explore the potential to modulate auditory cortex function as a preintervention and intervention approach for affected children, for example, to avoid the development of auditory and phonological difficulties at the core of dyslexia. Finally, we outline how future studies may increase our understanding of the neurobiological basis of NIBS-induced improvements in dyslexia.
Topics: Dyslexia; Humans; Transcranial Direct Current Stimulation; Transcranial Magnetic Stimulation
PubMed: 34716977
DOI: 10.1002/hbm.25700 -
Frontiers in Psychiatry 2019Seed-based studies on resting-state functional connectivity (rsFC) in schizophrenia have shown disrupted connectivity involving a number of brain networks; however, the...
Seed-based studies on resting-state functional connectivity (rsFC) in schizophrenia have shown disrupted connectivity involving a number of brain networks; however, the results have been controversial. We conducted a meta-analysis based on independent component analysis (ICA) brain templates to evaluate dysconnectivity within resting-state brain networks in patients with schizophrenia. Seventy-six rsFC studies from 70 publications with 2,588 schizophrenia patients and 2,567 healthy controls (HCs) were included in the present meta-analysis. The locations and activation effects of significant intergroup comparisons were extracted and classified based on the ICA templates. Then, multilevel kernel density analysis was used to integrate the results and control bias. Compared with HCs, significant hypoconnectivities were observed between the seed regions and the areas in the auditory network (left insula), core network (right superior temporal cortex), default mode network (right medial prefrontal cortex, and left precuneus and anterior cingulate cortices), self-referential network (right superior temporal cortex), and somatomotor network (right precentral gyrus) in schizophrenia patients. No hyperconnectivity between the seed regions and any other areas within the networks was detected in patients, compared with the connectivity in HCs. Decreased rsFC within the self-referential network and default mode network might play fundamental roles in the malfunction of information processing, while the core network might act as a dysfunctional hub of regulation. Our meta-analysis is consistent with diffuse hypoconnectivities as a dysregulated brain network model of schizophrenia.
PubMed: 31354545
DOI: 10.3389/fpsyt.2019.00482 -
BMC Complementary Medicine and Therapies Jan 2024Several studies have reported the effect of rhythmic auditory stimulation (RAS) on functional ambulation in stroke patients, yet no systematic overview has yet been...
BACKGROUND
Several studies have reported the effect of rhythmic auditory stimulation (RAS) on functional ambulation in stroke patients, yet no systematic overview has yet been published. This study aims to synthesize the available evidence describing changes in stroke patients after RAS intervention for functional ambulation and the use of walking assistive devices, and to find out if the effect of RAS and music-based RAS differs depending on the lesioned area.
METHODS
The PubMed, PEDro, Cochrane Central Register of Controlled Trials, Web of Science, Scopus and CINAHL electronic databases were searched for reports evaluating the effect of RAS on walking in stroke patients, applying the PICOS criteria for the inclusion of studies.
RESULTS
Twenty one articles were included (948 stroke survivors). Most studies were of good methodological quality according to the PEDro scale, but they had a high risk of bias. The most consistent finding was that RAS improves walking and balance parameters in stroke patients in all phases compared to baseline and versus control groups with conventional treatment. Functional ambulation and the use of walking assistive devices were inconsistently reported. Several studies also suggest that RAS may be as good as other complementary therapies (horse-riding and visual cueing).
CONCLUSIONS
Despite the beneficial effects of RAS, the question remains as to whether it is better than other complementary therapies. Given the heterogeneity of the interventions, the interventions in control groups, the varied durations, and the different outcome measures, we suggest that care should be taken in interpreting and generalizing findings.
PROSPERO REGISTRATION
CRD42021277940.
Topics: Humans; Acoustic Stimulation; Outcome Assessment, Health Care; Stroke; Stroke Rehabilitation; Walking
PubMed: 38245704
DOI: 10.1186/s12906-023-04310-3 -
Frontiers in Neuroscience 2019Low Intensity Transcranial Ultrasound Stimulation (TUS) is a new form of non-invasive brain modulation with promising data; however, systematic reviews on the brain...
Low Intensity Transcranial Ultrasound Stimulation (TUS) is a new form of non-invasive brain modulation with promising data; however, systematic reviews on the brain modulatory effects of TUS on both animals and humans have not been well-conducted. We aimed to conduct a systematic review on the studies using the TUS to modulate the brain functions and associated behavioral changes in both animals and humans. A literature search for published studies in the past 10 years was conducted. Two authors independently reviewed the relevant articles. Data were extracted and qualitatively summarized. Quality of studies was assessed by the SYRCLE's risk of bias tool for preclinical studies or the PEDro scale for clinical studies. A total of 24 animal studies (506 animals) and 11 human studies (213 subjects) were included. Findings based on most animal studies demonstrated the excitatory or suppressive modulatory effects of ultrasonic stimulations on motor cortex, somatosensory cortex, thalamus, prefrontal cortex, auditory, and visual areas. Brain modulatory effects also were found among healthy human subjects in seven studies and two clinical studies suggested TUS may result in potential benefits on patients with disorder of consciousness or chronic pain. The safety concerns of TUS seem to be minor based on the human studies. TUS appears to be a viable technique in modulating the brain functions; however, research on TUS is still in its early stages, especially in human studies. Parameters need to be optimized before launching systematic investigations in humans.
PubMed: 31396029
DOI: 10.3389/fnins.2019.00696 -
The Journal of Pain 2020This systematic review analyzed available literature on functional brain alterations in low back pain (LBP) measured with electroencephalography (EEG), as until now...
This systematic review analyzed available literature on functional brain alterations in low back pain (LBP) measured with electroencephalography (EEG), as until now evidence thereof was unclear. Four electronic databases were systematically searched the 10th of March 2018, resulting in 12 included studies. Studies showed a risk of bias of 37.5 to 75% using the Newcastle-Ottawa Scale for case-control studies. Limited evidence reported higher amplitudes of balance-related potentials and early components of somatosensory evoked potentials (SEP) to noxious stimuli, and altered feedback-related negativity and P300 potentials during decision-making in chronic LBP (CLBP). These findings suggest postural strategies requiring a higher cortical attention-demand, increased sensory-discriminative processing of noxious input, and altered decision-making in CLBP. However, further research is warranted as these inferences were based on single studies. Moderate evidence for unaltered amplitude of late-phase SEPs to noxious stimuli and auditory evoked potentials in LBP implies that the affective-emotional processing of stimuli might be unaffected in LBP. Furthermore, moderate evidence indicated disturbed habituation of somatosensory stimuli in LBP. Most studies examined nonspecific or mixed CLBP populations, hence EEG-quantified brain activity in (sub)acute or recurrent LBP still needs to be explored. PERSPECTIVE: This review presents an overview of the current understanding of the functional LBP brain measured with EEG. The limited evidence in current research suggests altered cortical function regarding balance control, somatosensory processing, and decision making in LBP, and highlights opportunities for future EEG-research.
Topics: Cerebral Cortex; Chronic Pain; Decision Making; Electroencephalography; Evoked Potentials; Habituation, Psychophysiologic; Humans; Low Back Pain; Postural Balance
PubMed: 31260806
DOI: 10.1016/j.jpain.2019.06.010 -
Trends in Hearing 2021As musicians have been shown to have a range of superior auditory skills to non-musicians (e.g., pitch discrimination ability), it has been hypothesized by many...
As musicians have been shown to have a range of superior auditory skills to non-musicians (e.g., pitch discrimination ability), it has been hypothesized by many researchers that music training can have a beneficial effect on speech perception in populations with hearing impairment. This hypothesis relies on an assumption that the benefits seen in musicians are due to their training and not due to innate skills that may support successful musicianship. This systematic review examined the evidence from 13 longitudinal training studies that tested the hypothesis that music training has a causal effect on speech perception ability in hearing-impaired listeners. The papers were evaluated for quality of research design and appropriate analysis techniques. Only 4 of the 13 papers used a research design that allowed a causal relation between music training and outcome benefits to be validly tested, and none of those 4 papers with a better quality study design demonstrated a benefit of music training for speech perception. In spite of the lack of valid evidence in support of the hypothesis, 10 of the 13 papers made claims of benefits of music training, showing a propensity for confirmation bias in this area of research. It is recommended that future studies that aim to evaluate the association of speech perception ability and music training use a study design that differentiates the effects of training from those of innate perceptual and cognitive skills in the participants.
Topics: Hearing; Hearing Loss; Humans; Music; Pitch Discrimination; Speech Perception
PubMed: 33634750
DOI: 10.1177/2331216520985678 -
Frontiers in Integrative Neuroscience 2020Theta burst stimulation is increasingly growing in popularity as a non-invasive method of moderating corticospinal networks. Theta burst stimulation uses gamma frequency...
Theta burst stimulation is increasingly growing in popularity as a non-invasive method of moderating corticospinal networks. Theta burst stimulation uses gamma frequency trains applied at the rhythm of theta, thus, mimicking theta-gamma coupling involved in cognitive processes. The dorsolateral prefrontal cortex has been found to play a crucial role in numerous cognitive processes. Here, we include 25 studies for review to determine the cognitive effects of continuous theta burst stimulation over the dorsolateral prefrontal cortex; 20 of these studies are healthy participant and five are patient (pharmacotherapy-resistant depression) studies. Due to the heterogeneous nature of the included studies, only a descriptive approach is used and meta-analytics ruled out. The cognitive effect is measured on various cognitive domains: attention, working memory, planning, language, decision making, executive function, and inhibitory and cognitive control. We conclude that continuous theta burst stimulation over the dorsolateral prefrontal cortex mainly inhibits cognitive performance. However, in some instances, it can lead to improved performance by inhibiting the effect of distractors or other competing irrelevant cognitive processes. To be precise, continuous theta burst stimulation over the right dorsolateral prefrontal cortex impaired attention, inhibitory control, planning, and goal-directed behavior in decision making but also improved decision making by reducing impulsivity. Conversely, continuous theta burst stimulation over the left dorsolateral prefrontal cortex impaired executive function, working, auditory feedback regulation, and cognitive control but accelerated the planning, decision-making process. These findings constitute a useful contribution to the literature on the cognitive effects of continuous theta burst stimulation over the dorsolateral prefrontal cortex.
PubMed: 32848648
DOI: 10.3389/fnint.2020.00035