Previous Issue

Table of Contents

Brain Sci., Volume 9, Issue 5 (May 2019)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-22
Export citation of selected articles as:
Open AccessArticle
Joint Modulation of Facial Expression Processing by Contextual Congruency and Task Demands
Brain Sci. 2019, 9(5), 116; https://doi.org/10.3390/brainsci9050116 (registering DOI)
Received: 15 April 2019 / Revised: 10 May 2019 / Accepted: 15 May 2019 / Published: 17 May 2019
Viewed by 177 | PDF Full-text (2355 KB)
Abstract
Faces showing expressions of happiness or anger were presented together with sentences that described happiness-inducing or anger-inducing situations. Two main variables were manipulated: (i) congruency between contexts and expressions (congruent/incongruent) and (ii) the task assigned to the participant, discriminating the emotion shown by [...] Read more.
Faces showing expressions of happiness or anger were presented together with sentences that described happiness-inducing or anger-inducing situations. Two main variables were manipulated: (i) congruency between contexts and expressions (congruent/incongruent) and (ii) the task assigned to the participant, discriminating the emotion shown by the target face (emotion task) or judging whether the expression shown by the face was congruent or not with the context (congruency task). Behavioral and electrophysiological results (event-related potentials (ERP)) showed that processing facial expressions was jointly influenced by congruency and task demands. ERP results revealed task effects at frontal sites, with larger positive amplitudes between 250–450 ms in the congruency task, reflecting the higher cognitive effort required by this task. Effects of congruency appeared at latencies and locations corresponding to the early posterior negativity (EPN) and late positive potential (LPP) components that have previously been found to be sensitive to emotion and affective congruency. The magnitude and spatial distribution of the congruency effects varied depending on the task and the target expression. These results are discussed in terms of the modulatory role of context on facial expression processing and the different mechanisms underlying the processing of expressions of positive and negative emotions. Full article
(This article belongs to the Special Issue Perceptual and Affective Mechanisms in Facial Expression Recognition)
Open AccessArticle
Epilepsy Detection by Using Scalogram Based Convolutional Neural Network from EEG Signals
Brain Sci. 2019, 9(5), 115; https://doi.org/10.3390/brainsci9050115 (registering DOI)
Received: 27 March 2019 / Revised: 15 May 2019 / Accepted: 17 May 2019 / Published: 17 May 2019
Viewed by 183 | PDF Full-text (834 KB) | XML Full-text
Abstract
The studies implemented with Electroencephalogram (EEG) signals are progressing very rapidly and brain computer interfaces (BCI) and disease determinations are carried out at certain success rates thanks to new methods developed in this field. The effective use of these signals, especially in disease [...] Read more.
The studies implemented with Electroencephalogram (EEG) signals are progressing very rapidly and brain computer interfaces (BCI) and disease determinations are carried out at certain success rates thanks to new methods developed in this field. The effective use of these signals, especially in disease detection, is very important in terms of both time and cost. Currently, in general, EEG studies are used in addition to conventional methods as well as deep learning networks that have recently achieved great success. The most important reason for this is that in conventional methods, increasing classification accuracy is based on too many human efforts as EEG is being processed, obtaining the features is the most important step. This stage is based on both the time-consuming and the investigation of many feature methods. Therefore, there is a need for methods that do not require human effort in this area and can learn the features themselves. Based on that, two-dimensional (2D) frequency-time scalograms were obtained in this study by applying Continuous Wavelet Transform to EEG records containing five different classes. Convolutional Neural Network structure was used to learn the properties of these scalogram images and the classification performance of the structure was compared with the studies in the literature. In order to compare the performance of the proposed method, the data set of the University of Bonn was used. The data set consists of five EEG records containing healthy and epilepsy disease which are labeled as A, B, C, D, and E. In the study, A-E and B-E data sets were classified as 99.50%, A-D and B-D data sets were classified as 100% in binary classifications, A-D-E data sets were 99.00% in triple classification, A-C-D-E data sets were 90.50%, B-C-D-E data sets were 91.50% in quaternary classification, and A-B-C-D-E data sets were in the fifth class classification with an accuracy of 93.60%. Full article
(This article belongs to the Special Issue Advances in EEG/ MEG Source Imaging)
Open AccessArticle
Evaluation of Postnatal Sedation in Full-Term Infants
Brain Sci. 2019, 9(5), 114; https://doi.org/10.3390/brainsci9050114
Received: 10 April 2019 / Revised: 6 May 2019 / Accepted: 16 May 2019 / Published: 17 May 2019
Viewed by 127 | PDF Full-text (1107 KB) | HTML Full-text | XML Full-text
Abstract
Prolonged sedation in infants leads to a high incidence of physical dependence. We inquired: (1) “How long does it take to develop physical dependence to sedation in previously naïve full-term infants without known history of neurologic impairment?” and (2) “What is the relationship [...] Read more.
Prolonged sedation in infants leads to a high incidence of physical dependence. We inquired: (1) “How long does it take to develop physical dependence to sedation in previously naïve full-term infants without known history of neurologic impairment?” and (2) “What is the relationship between length of sedation to length of weaning and hospital stay?”. The retrospective study included full-term patients over a period of one year that were <1 year of age and received opioids and benzodiazepines >72 hours. Quantification of fentanyl, morphine, and midazolam were compared among three time periods: <5 days, 5–30 days, and >30 days using t-test or one-way analysis of variance. Identified full-term infants were categorized into surgical (14/44) or medical (10/44) groups, while those with neurological involvement (20/44) were excluded. Physical dependence in full-term infants occurred following sedation ≥5 days. Infants with surgical disease received escalating doses of morphine and midazolam when administered >30 days. A positive association between length of sedation and weaning period was found for both respiratory (p < 0.01) and surgical disease (p = 0.012) groups, while length of sedation is related to hospital stay for the respiratory (p < 0.01) but not the surgical disease group (p = 0.1). Future pharmacological directions should lead to standardized sedation protocols and evaluate patient neurocognitive outcomes. Full article
(This article belongs to the Special Issue Mechanisms Underlying Alleviation of Pain)
Figures

Figure 1

Open AccessReview
Loss of Prefrontal Cortical Higher Cognition with Uncontrollable Stress: Molecular Mechanisms, Changes with Age, and Relevance to Treatment
Brain Sci. 2019, 9(5), 113; https://doi.org/10.3390/brainsci9050113
Received: 17 April 2019 / Revised: 13 May 2019 / Accepted: 13 May 2019 / Published: 17 May 2019
Viewed by 118 | PDF Full-text (2441 KB) | HTML Full-text | XML Full-text
Abstract
The newly evolved prefrontal cortex (PFC) generates goals for “top-down” control of behavior, thought, and emotion. However, these circuits are especially vulnerable to uncontrollable stress, with powerful, intracellular mechanisms that rapidly take the PFC “off-line.” High levels of norepinephrine and dopamine released during [...] Read more.
The newly evolved prefrontal cortex (PFC) generates goals for “top-down” control of behavior, thought, and emotion. However, these circuits are especially vulnerable to uncontrollable stress, with powerful, intracellular mechanisms that rapidly take the PFC “off-line.” High levels of norepinephrine and dopamine released during stress engage α1-AR and D1R, which activate feedforward calcium-cAMP signaling pathways that open nearby potassium channels to weaken connectivity and reduce PFC cell firing. Sustained weakening with chronic stress leads to atrophy of dendrites and spines. Understanding these signaling events helps to explain the increased susceptibility of the PFC to stress pathology during adolescence, when dopamine expression is increased in the PFC, and with advanced age, when the molecular “brakes” on stress signaling are diminished by loss of phosphodiesterases. These mechanisms have also led to pharmacological treatments for stress-related disorders, including guanfacine treatment of childhood trauma, and prazosin treatment of veterans and civilians with post-traumatic stress disorder. Full article
Figures

Graphical abstract

Open AccessPerspective
The Endocannabinoid System as a Potential Mechanism through which Exercise Influences Episodic Memory Function
Brain Sci. 2019, 9(5), 112; https://doi.org/10.3390/brainsci9050112
Received: 4 May 2019 / Revised: 13 May 2019 / Accepted: 14 May 2019 / Published: 16 May 2019
Viewed by 219 | PDF Full-text (452 KB) | HTML Full-text | XML Full-text
Abstract
Emerging research demonstrates that exercise, including both acute and chronic exercise, may influence episodic memory function. To date, mechanistic explanations of this effect are often attributed to alterations in long-term potentiation, neurotrophic production, angiogenesis, and neurogenesis. Herein, we discuss a complementary mechanistic model, [...] Read more.
Emerging research demonstrates that exercise, including both acute and chronic exercise, may influence episodic memory function. To date, mechanistic explanations of this effect are often attributed to alterations in long-term potentiation, neurotrophic production, angiogenesis, and neurogenesis. Herein, we discuss a complementary mechanistic model, suggesting that the endocannabinoid system may, in part, influence the effects of exercise on memory function. We discuss the role of the endocannabinoid system on memory function as well as the effects of exercise on endocannabinoid alterations. This is an exciting line of inquiry that should help delineate new insights into the mechanistic role of exercise on memory function. Full article
(This article belongs to the Special Issue Cannabis: Neuropsychiatry and Its Effects on Brain and Behavior)
Figures

Figure 1

Open AccessArticle
Pro-Inflammatory Activation of A New Immortalized Human Microglia Cell Line
Brain Sci. 2019, 9(5), 111; https://doi.org/10.3390/brainsci9050111
Received: 1 April 2019 / Revised: 6 May 2019 / Accepted: 13 May 2019 / Published: 15 May 2019
Viewed by 200 | PDF Full-text (1864 KB)
Abstract
: The characterization of human microglia has been hampered by poor availability of human cell sources. However, microglia is involved in the physiopathology of multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, HIV dementia, retinal degenerative diseases, cancer, and many other conditions. Therefore, there is [...] Read more.
: The characterization of human microglia has been hampered by poor availability of human cell sources. However, microglia is involved in the physiopathology of multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, HIV dementia, retinal degenerative diseases, cancer, and many other conditions. Therefore, there is an important need to have experimental paradigms of human microglia characterized and usable to study the role of microglia in the different pathologies in which it is involved. In the present work, we carried out an extensive characterization of Immortalized Human Microglia—SV40 cell line (IMhu), marketed by Applied Biological Material. The functional response of IMhu to a large variety of stimuli was studied. In particular, we investigated morphology, mortality, and changes in the production of different cytokines and chemokines, both under basal conditions and after stimulation. Moreover, western blotting analysis was conducted on phospho-mTOR (Ser 2448) and downstream parameters, p-P70S6K and 4EBP1, in order to understand if IMhu can be used for evaluations of mTOR pathway. In conclusion, IMhu cells proved to be a useful experimental model to investigate the physiopathology of inflammatory disease that involved microglia cells, including pathological conditions that involved the mTOR pathway. Full article
(This article belongs to the Section Neuroglia)
Open AccessArticle
The Neural Correlates of Conflict Detection and Resolution During Multiword Lexical Selection: Evidence from Bilinguals and Monolinguals
Brain Sci. 2019, 9(5), 110; https://doi.org/10.3390/brainsci9050110
Received: 29 March 2019 / Revised: 5 May 2019 / Accepted: 13 May 2019 / Published: 14 May 2019
Viewed by 254 | PDF Full-text (4299 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Previous studies have identified the Event Related Potential (ERP) components of conflict detection and resolution mechanisms in tasks requiring lexical selection at the individual word level. We investigated the brain potentials associated with these mechanisms in a lexical selection task based on multiword [...] Read more.
Previous studies have identified the Event Related Potential (ERP) components of conflict detection and resolution mechanisms in tasks requiring lexical selection at the individual word level. We investigated the brain potentials associated with these mechanisms in a lexical selection task based on multiword units made up of verb–noun combinations (e.g., eat breakfast, skip school). Native and non-native English speakers were asked to select a familiarized target verb–noun sequence (eat breakfast) between two choices. Trials were low-conflict, with only one plausible candidate (e.g., eat – shoot – breakfast) or high-conflict, with two plausible verbs (e.g., eat – skip – breakfast). Following the presentation of the noun, native English speakers showed a biphasic process of selection, with a conflict-detection centro-parietal negativity between 500 and 600 ms (Ninc), followed by a right frontal effect (RFE) between 600 and 800 ms preceding responses. Late Spanish–English bilinguals showed a similar but more sustained and more widespread effect. Additionally, brain activity was only significantly correlated with performance in native speakers. Results suggest largely similar basic mechanisms, but also that different resources and strategies are engaged by non-native speakers when resolving conflict in the weaker language, with a greater focus on individual words than on multiword units. Full article
(This article belongs to the Special Issue Cognitive Neuroscience of Cross-Language Interaction in Bilinguals)
Figures

Figure 1

Open AccessArticle
A Laboratory Word Memory Test Analogue Differentiates Intentional Feigning from True Responding Using the P300 Event-Related Potential
Brain Sci. 2019, 9(5), 109; https://doi.org/10.3390/brainsci9050109
Received: 9 April 2019 / Revised: 7 May 2019 / Accepted: 7 May 2019 / Published: 14 May 2019
Viewed by 236 | PDF Full-text (1308 KB) | HTML Full-text | XML Full-text
Abstract
Symptom exaggeration and feigned cognitive impairment occur commonly in forensic and medicolegal evaluations. As a result, methods to detect feigned cognitive impairment are an indispensable component of neuropsychological assessments. This study reports the results of two neurophysiological experiments using a forced-choice recognition task [...] Read more.
Symptom exaggeration and feigned cognitive impairment occur commonly in forensic and medicolegal evaluations. As a result, methods to detect feigned cognitive impairment are an indispensable component of neuropsychological assessments. This study reports the results of two neurophysiological experiments using a forced-choice recognition task built from the stimuli of the Word Memory Test and Medical Symptom Validity Test as well as a new linguistically informed stimulus set. Participant volunteers were instructed either to do their best or to feign cognitive impairment consistent with a mild traumatic brain injury while their brain activity was monitored using event-related potentials (ERP). Experiment 1 varied instructions across individuals, whereas Experiment 2 varied instructions within individuals. The target brain component was a positive deflection indicating stimulus recognition that occurs approximately 300 ms after exposure to a stimulus (i.e., the P300). Multimodal comparison (P300 amplitude to behavioral accuracy) allowed the detection of feigned cognitive impairment. Results indicate that, for correct responses, P300s were equivalent for the simulated malingering and good effort conditions. However, for incorrect responses, feigned impairment produced reliable but significantly reduced P300 amplitudes. Although the P300 is an automatic index of recognition—even when knowledge is hidden—its amplitude appears capable of modulation by feigning strategies. Implications of this finding are discussed for research and clinical applications. Full article
(This article belongs to the collection Collection on Cognitive Neuroscience)
Figures

Figure 1

Open AccessArticle
Effects of GLP-1 Receptor Activation on a Pentylenetetrazole—Kindling Rat Model
Brain Sci. 2019, 9(5), 108; https://doi.org/10.3390/brainsci9050108
Received: 16 March 2019 / Revised: 26 April 2019 / Accepted: 6 May 2019 / Published: 14 May 2019
Viewed by 205 | PDF Full-text (3984 KB) | XML Full-text
Abstract
Objectives: To study the possible anti-seizure and neuroprotective effect of glucagon like peptide 1 (GLP1) analogue (liraglutide) in a pentylenetetrazole (PTZ) induced kindled rat model and its underlying mechanisms. Methods: Thirty Sprague Dawley rats were allocated into 3 equal groups; i) [...] Read more.
Objectives: To study the possible anti-seizure and neuroprotective effect of glucagon like peptide 1 (GLP1) analogue (liraglutide) in a pentylenetetrazole (PTZ) induced kindled rat model and its underlying mechanisms. Methods: Thirty Sprague Dawley rats were allocated into 3 equal groups; i) Normal group: normal rats received normal saline, ii) PTZ (kindling) group: received PTZ (50 mg/Kg intraperitoneally (i.p.)) every other day for 2 weeks and iii) PTZ + GLP1 group: same as the PTZ group but rats received liraglutide (75 µg/kg i.p. daily) for 2 weeks before PTZ injection. Seizure severity score, seizure latency and duration were assessed. Also, the expression of caspase-3 (apoptotic marker) and β-catenin (Wnt pathway) by western blotting, markers of oxidative stress (GSH, CAT and MDA) by biochemical assay and the expression of LC3 (marker of autophagy) and heat shock protein 70 (Hsp70) by immunostaining were assessed in hippocampal regions of brain tissues. Results: PTZ caused a significant increase in Racine score and seizure duration with a significant decrease in seizure latency. These effects were associated with a significant increase in MDA, β-catenin, caspase-3, Hsp70 and LC3 in brain tissues (p < 0.05). Meanwhile, liraglutide treatment caused significant attenuation in PTZ-induced seizures, which were associated with significant improvement in markers of oxidative stress, reduction in LC3, caspase-3 and β-catenin and marked increase in Hsp70 in hippocampal regions (p < 0.05). Conclusion: Activation of GLP1R might have anticonvulsant and neuroprotective effects against PTZ-induced epilepsy. These effects could be due to suppression of oxidative stress, apoptosis and autophagy and upregulation of Hsp70. Full article
(This article belongs to the collection Collection on Clinical Neuroscience)
Open AccessReview
I Am Conscious, Therefore, I Am: Imagery, Affect, Action, and a General Theory of Behavior
Brain Sci. 2019, 9(5), 107; https://doi.org/10.3390/brainsci9050107
Received: 16 April 2019 / Revised: 3 May 2019 / Accepted: 8 May 2019 / Published: 10 May 2019
Viewed by 344 | PDF Full-text (2207 KB)
Abstract
Organisms are adapted to each other and the environment because there is an inbuilt striving toward security, stability, and equilibrium. A General Theory of Behavior connects imagery, affect, and action with the central executive system we call consciousness, a direct emergent property of [...] Read more.
Organisms are adapted to each other and the environment because there is an inbuilt striving toward security, stability, and equilibrium. A General Theory of Behavior connects imagery, affect, and action with the central executive system we call consciousness, a direct emergent property of cerebral activity. The General Theory is founded on the assumption that the primary motivation of all of consciousness and intentional behavior is psychological homeostasis. Psychological homeostasis is as important to the organization of mind and behavior as physiological homeostasis is to the organization of bodily systems. Consciousness processes quasi-perceptual images independently of the input to the retina and sensorium. Consciousness is the “I am” control center for integration and regulation of (my) thoughts, (my) feelings, and (my) actions with (my) conscious mental imagery as foundation stones. The fundamental, universal conscious desire for psychological homeostasis benefits from the degree of vividness of inner imagery. Imagery vividness, a combination of clarity and liveliness, is beneficial to imagining, remembering, thinking, predicting, planning, and acting. Assessment of vividness using introspective report is validated by objective means such as functional magnetic resonance imaging (fMRI). A significant body of work shows that vividness of visual imagery is determined by the similarity of neural responses in imagery to those occurring in perception of actual objects and performance of activities. I am conscious; therefore, I am. Full article
Figures

Graphical abstract

Open AccessArticle
Can Evaluative Conditioning Change Well-Established Attitudes Towards Popular Brands? Your Brain Says Yes Even Though Your Mouth Says No
Brain Sci. 2019, 9(5), 106; https://doi.org/10.3390/brainsci9050106
Received: 1 March 2019 / Revised: 29 April 2019 / Accepted: 6 May 2019 / Published: 10 May 2019
Viewed by 311 | PDF Full-text (4009 KB) | HTML Full-text | XML Full-text
Abstract
In the present study, using both implicit and explicit measures, we addressed the issue of whether strongly developed relationships towards brands could be modified through the use of evaluative conditioning. Using an online survey, individual participant brand lists were created, and formed the [...] Read more.
In the present study, using both implicit and explicit measures, we addressed the issue of whether strongly developed relationships towards brands could be modified through the use of evaluative conditioning. Using an online survey, individual participant brand lists were created, and formed the basis of this experiment. Participants were then exposed to conditioning during a longitudinal study. Throughout the experiment, a combination of explicit and implicit measures was used to assess changes in attitude. Specifically, participants were asked to rate the brand names on a Likert-type scale. Simultaneously, changes in the brains electrical activity in response to the brands were recorded via electroencephalography (EEG). Upon completion of this task, participants underwent two Implicit Association Tests (IAT; one for liked brands and one for disliked brands). There were two main findings of this study. Firstly, no significant changes in attitude were observed via the use of explicit measures, and those that were found relating to the IAT were regarded as questionable. Secondly, EEG presented consistent results which showed that conditioning elicited changes in cortical activity towards both liked and disliked brands, which suggest it may be a useful tool in measuring the impact of evaluative conditioning that is not reflected in verbal responses. Full article
(This article belongs to the collection Collection on Cognitive Neuroscience)
Figures

Figure 1

Open AccessFeature PaperCase Report
Benign Giant Cell Lesion of C1 Lateral Mass: A Case Report and Literature Review
Brain Sci. 2019, 9(5), 105; https://doi.org/10.3390/brainsci9050105
Received: 24 March 2019 / Revised: 6 May 2019 / Accepted: 7 May 2019 / Published: 8 May 2019
Viewed by 301 | PDF Full-text (1206 KB) | HTML Full-text | XML Full-text
Abstract
Primary osseous tumors of the spinal column account for approximately 1% of the total number of spinal tumors found in the pediatric patient population. The authors present a case of a C1 benign giant cell lesion that was incidentally found in a 15-year-old [...] Read more.
Primary osseous tumors of the spinal column account for approximately 1% of the total number of spinal tumors found in the pediatric patient population. The authors present a case of a C1 benign giant cell lesion that was incidentally found in a 15-year-old patient. A transoral biopsy was performed followed by treatment with denosumab, with definitive management in the form of transoral tumor resection with subsequent occiput-cervical three posterior instrumented fusion. The patient tolerated all of the procedures well, as there were no post-operative complications, discharged home neurologically intact and was eager to return to school when assessed during a follow-up visit in clinic. Osteolytic lesions affecting the cervical spine are rare in the pediatric population. It is of utmost importance to have sufficient background knowledge in order to formulate a differential diagnosis, as well as an understanding of principles underlying surgical techniques required to prevent occipital-cervical instability in this patient population. The information presented will guide surgical decision-making by identifying the patient population that would benefit from neurosurgical interventions to stabilize the atlantoaxial junction, in the context of rare osteolytic conditions affecting the cervical spine. Full article
(This article belongs to the Special Issue Surgery for Spine Disease and Intractable Pain)
Figures

Figure 1

Open AccessPerspective
What Role Does the Prefrontal Cortex Play in the Processing of Negative and Positive Stimuli in Adolescent Depression?
Brain Sci. 2019, 9(5), 104; https://doi.org/10.3390/brainsci9050104
Received: 27 March 2019 / Revised: 30 April 2019 / Accepted: 3 May 2019 / Published: 7 May 2019
Viewed by 296 | PDF Full-text (327 KB)
Abstract
This perspective describes the contribution of the prefrontal cortex to the symptoms of depression in adolescents and specifically the processing of positive and negative information. We also discuss how the prefrontal cortex (PFC) activity and connectivity during tasks and at rest might be [...] Read more.
This perspective describes the contribution of the prefrontal cortex to the symptoms of depression in adolescents and specifically the processing of positive and negative information. We also discuss how the prefrontal cortex (PFC) activity and connectivity during tasks and at rest might be a biomarker for risk for depression onset in adolescents. We include some of our recent work examining not only the anticipation and consummation of positive and negative stimuli, but also effort to gain positive and avoid negative stimuli in adolescents with depression. We find, using region of interest analyses, that the PFC is blunted in those with depression compared to controls across the different phases but in a larger sample the PFC is blunted in the anticipatory phase of the study only. Taken together, in adolescents with depression there is evidence for dysfunctional PFC activity across different studies and tasks. However, the data are limited with small sample sizes and inconsistent findings. Larger longitudinal studies with more detailed assessments of symptoms across the spectrum are needed to further evaluate the role of the PFC in adolescent depression. Full article
Open AccessArticle
Stimulation of the Angular Gyrus Improves the Level of Consciousness
Brain Sci. 2019, 9(5), 103; https://doi.org/10.3390/brainsci9050103
Received: 19 March 2019 / Revised: 2 May 2019 / Accepted: 5 May 2019 / Published: 6 May 2019
Viewed by 329 | PDF Full-text (1614 KB) | HTML Full-text | XML Full-text
Abstract
Background: Navigated repetitive transcranial magnetic stimulation (rTMS) is a promising tool for neuromodulation. In previous studies it has been shown that the activity of the default mode network (DMN) areas, particularly of its key region—the angular gyrus—is positively correlated with the level of [...] Read more.
Background: Navigated repetitive transcranial magnetic stimulation (rTMS) is a promising tool for neuromodulation. In previous studies it has been shown that the activity of the default mode network (DMN) areas, particularly of its key region—the angular gyrus—is positively correlated with the level of consciousness. Our study aimed to explore the effect of rTMS of the angular gyrus as a new approach for disorders of consciousness (DOC) treatment; Methods: A 10-session 2-week high-frequency rTMS protocol was delivered over the left angular gyrus in 38 DOC patients with repeated neurobehavioral assessments obtained at baseline and in 2 days after the stimulation course was complete; Results: 20 Hz-rTMS over left angular gyrus improved the coma recovery scale revised (CRS-R) total score in minimally conscious state (MCS) patients. We observed no effects in vegetative state (VS) patients; and Conclusions: The left angular gyrus is likely to be effective target for rTMS in patients with present signs of consciousness. Full article
(This article belongs to the Special Issue Advances in Disorders of Consciousness)
Figures

Figure 1

Open AccessArticle
Superior Effects of Modified Chen-Style Tai Chi versus 24-Style Tai Chi on Cognitive Function, Fitness, and Balance Performance in Adults over 55
Brain Sci. 2019, 9(5), 102; https://doi.org/10.3390/brainsci9050102
Received: 11 April 2019 / Revised: 2 May 2019 / Accepted: 3 May 2019 / Published: 4 May 2019
Viewed by 485 | PDF Full-text (2237 KB) | HTML Full-text | XML Full-text
Abstract
Background: Cognitive decline and balance impairment are prevalent in the aging population. Previous studies investigated the beneficial effects of 24-style Tai Chi (TC-24) on either cognitive function or balance performance of older adults. It still remains largely unknown whether modified Chen-style TC (MTC) [...] Read more.
Background: Cognitive decline and balance impairment are prevalent in the aging population. Previous studies investigated the beneficial effects of 24-style Tai Chi (TC-24) on either cognitive function or balance performance of older adults. It still remains largely unknown whether modified Chen-style TC (MTC) that includes 18 complex movements is more beneficial for these age-related health outcomes, as compared to TC-24. Objective: We investigated if MTC would show greater effects than TC-24 on global cognitive function and balance-related outcomes among older adults. Methods: We conducted a randomized trial where 80 eligible adults aged over 55 were allocated into two different styles of Tai Chi (TC) arms (sixty-minute session × three times per week, 12 weeks). Outcome assessments were performed at three time periods (baseline, Week 6, and Week 12) and included the Chinese Version of the Montreal Cognitive Assessment (MoCA) for overall cognitive function, One-leg Standing Test (LST) for static balance, Timed Up and Go Test (TUGT) for dynamic balance, chair Stand Test (CST) for leg power, and the six-meter Walk Test (6MWT) for aerobic exercise capacity. Results: Compared to TC-24 arm, MTC arm demonstrated significantly greater improvements in MoCA, LST, TUGT, CST, and 6MWT (all p < 0.05). Conclusions: Both forms of TC were effective in enhancing global cognitive function, balance, and fitness. Furthermore, MTC was more effective than TC-24 in enhancing these health-related parameters in an aging population. Full article
(This article belongs to the Special Issue Exercising against Age-Effects on the Brain)
Figures

Figure 1

Open AccessArticle
Preserved Cerebral Oxygen Metabolism in Astrocytic Dysfunction: A Combination Study of 15O-Gas PET with 14C-Acetate Autoradiography
Brain Sci. 2019, 9(5), 101; https://doi.org/10.3390/brainsci9050101
Received: 20 March 2019 / Revised: 24 April 2019 / Accepted: 29 April 2019 / Published: 3 May 2019
Viewed by 338 | PDF Full-text (1055 KB)
Abstract
Fluorocitrate (FC) is a specific metabolic inhibitor of the tricarboxylic acid (TCA) cycle in astrocytes. The purpose of this study was to evaluate whether inhibition of the astrocyte TCA cycle by FC would affect the oxygen metabolism in the rat brain. At 4 [...] Read more.
Fluorocitrate (FC) is a specific metabolic inhibitor of the tricarboxylic acid (TCA) cycle in astrocytes. The purpose of this study was to evaluate whether inhibition of the astrocyte TCA cycle by FC would affect the oxygen metabolism in the rat brain. At 4 h after the intracranial FC injection, the rats (n = 9) were investigated by 15O-labeled gas PET to measure the cerebral blood flow (CBF), the cerebral metabolic rate of oxygen (CMRO2), oxygen extraction fraction (OEF), and cerebral blood volume (CBV). After the 15O-gas PET, the rats were given an intravenous injection of 14C-acetate for autoradiography. 15O-gas PET showed no significant differences in any of the measured parameters between the ipsilateral and contralateral striatum (high dose group: CBF (54.4 ± 8.8 and 55.3 ± 11.6 mL/100mL/min), CMRO2 (7.0 ± 0.9 and 7.1 ± 1.2 mL/100mL/min), OEF (72.0 ± 8.9 and 70.8 ± 8.2%), and CBV (4.1 ± 0.8 and 4.2 ± 0.9 mL/100mL), respectively). In contrast, the 14C-acetate autoradiography revealed a significant inhibition of the astrocyte metabolism in the ipsilateral striatum. The regional cerebral oxygen consumption as well as the hemodynamic parameters were maintained even in the face of inhibition of the astrocyte TCA cycle metabolism in the rat brain. Full article
Open AccessReview
Cognitive Fatigue in Multiple Sclerosis: An Objective Approach to Diagnosis and Treatment by Transcranial Electrical Stimulation
Brain Sci. 2019, 9(5), 100; https://doi.org/10.3390/brainsci9050100
Received: 22 March 2019 / Revised: 29 April 2019 / Accepted: 30 April 2019 / Published: 2 May 2019
Viewed by 464 | PDF Full-text (671 KB) | HTML Full-text | XML Full-text
Abstract
Cognitive fatigue is one of the most frequent symptoms in multiple sclerosis (MS), associated with significant impairment in daily functioning and quality of life. Despite its clinical significance, progress in understanding and treating fatigue is still limited. This limitation is already caused by [...] Read more.
Cognitive fatigue is one of the most frequent symptoms in multiple sclerosis (MS), associated with significant impairment in daily functioning and quality of life. Despite its clinical significance, progress in understanding and treating fatigue is still limited. This limitation is already caused by an inconsistent and heterogeneous terminology and assessment of fatigue. In this review, we integrate previous literature on fatigue and propose a unified schema aiming to clarify the fatigue taxonomy. With special focus on cognitive fatigue, we survey the significance of objective behavioral and electrophysiological fatigue parameters and discuss the controversial literature on the relationship between subjective and objective fatigue assessment. As MS-related cognitive fatigue drastically affects quality of life, the development of efficient therapeutic approaches for overcoming cognitive fatigue is of high clinical relevance. In this regard, the reliable and valid assessment of the individual fatigue level by objective parameters is essential for systematic treatment evaluation and optimization. Transcranial electrical stimulation (tES) may offer a unique opportunity to manipulate maladaptive neural activity underlying MS fatigue. Therefore, we discuss evidence for the therapeutic potential of tES on cognitive fatigue in people with MS. Full article
(This article belongs to the Special Issue Fatigue in Multiple Sclerosis: Current Concepts and Future Challenges)
Figures

Figure 1

Open AccessArticle
Magnitude of Reduction and Speed of Remission of Suicidality for Low Amplitude Seizure Therapy (LAP-ST) Compared to Standard Right Unilateral Electroconvulsive Therapy: A Pilot Double-Blinded Randomized Clinical Trial
Brain Sci. 2019, 9(5), 99; https://doi.org/10.3390/brainsci9050099
Received: 6 March 2019 / Revised: 14 April 2019 / Accepted: 25 April 2019 / Published: 29 April 2019
Viewed by 450 | PDF Full-text (779 KB) | HTML Full-text | XML Full-text
Abstract
Background: Although treatment guidelines support use of electroconvulsive therapy (ECT) for acute suicidality, it is associated with cognitive side effects. The effect of Low Amplitude Seizure Therapy (LAP-ST) on suicidality is unknown. Our prior precision LAP-ST (pLAP-ST) performing titrating in the current [...] Read more.
Background: Although treatment guidelines support use of electroconvulsive therapy (ECT) for acute suicidality, it is associated with cognitive side effects. The effect of Low Amplitude Seizure Therapy (LAP-ST) on suicidality is unknown. Our prior precision LAP-ST (pLAP-ST) performing titrating in the current domain has provided initial proof of concept data in humans of its advantage in terms of reduction of cognitive side effects. The aims of this report are to: 1) compare LAP-ST (at 500mA) versus standard Right Unilateral (RUL) ECT (at 900 mA) in terms of magnitude of remission of suicidality in a randomized allocation and 2) compare the speed of remission of suicidality between LAP-ST versus RUL ECT. Methods: Patients were randomized to either LAP-ST or RUL ECT. The scores pertaining to the suicidal ideation (SI) item on the Montgomery-Åsberg Depression Rating Scale (MADRS) were analyzed using descriptive analysis and no confirmatory statistical analysis was performed due to a priori sample size limitations for this pilot study. SI item remission was defined as 2 or below on this item. Results: Eleven patients with major depressive episode (MDE) of mainly unipolar or bipolar disorders signed consent. Of these, 7 were eligible and were randomized and included in the analysis; all were actively suicidal at baseline (suicide item above 2), except 1 patient who had suicide item at 2 in the RUL ECT group. Suicidality remitted on average by session 3 and remission occurred for all patients by session 4. The SI mean score improvement from baseline to endpoint for LAP-ST was 5.1 and for RUL ECT was 3.0. Conclusions: LAP-ST has larger effect size and speed of remission of suicidality compared to standard RUL ECT. Future studies are warranted for replicating these findings. (ClinicalTrials.gov ID: NCT02583490). Full article
Figures

Figure 1

Open AccessArticle
Anodal Transcranial Direct Current Stimulation over the Vertex Enhances Leg Motor Cortex Excitability Bilaterally
Brain Sci. 2019, 9(5), 98; https://doi.org/10.3390/brainsci9050098
Received: 4 March 2019 / Revised: 19 April 2019 / Accepted: 26 April 2019 / Published: 29 April 2019
Viewed by 468 | PDF Full-text (882 KB) | HTML Full-text | XML Full-text
Abstract
In many studies, anodal transcranial Direct Current Stimulation (tDCS) is applied near the vertex to simultaneously facilitate leg motor cortex (M1) of both hemispheres and enhance recovery of gait and balance in neurological disorders. However, its effect on the excitability of leg M1 [...] Read more.
In many studies, anodal transcranial Direct Current Stimulation (tDCS) is applied near the vertex to simultaneously facilitate leg motor cortex (M1) of both hemispheres and enhance recovery of gait and balance in neurological disorders. However, its effect on the excitability of leg M1 in either hemisphere is not well known. In this double-blind sham-controlled study, corticospinal excitability changes induced in leg M1 of both hemispheres by anodal (2 mA for 20 minutes) or sham tDCS (for 20 min) over the vertex were evaluated. Peak amplitudes of Transcranial Magnetic Stimulation (TMS) induced motor evoked potentials (MEPs) were measured over the contralateral Tibialis Anterior (TA) muscle before and up to 40 min after tDCS in 11 normal participants. Analysis of data from all participants found significant overall increase in the excitability of leg M1 after tDCS. However, in individual subjects there was variability in observed effects. In 4 participants, 20 min of tDCS increased mean MEPs of TAs on both sides; in 4 participants there was increased mean MEP only on one side and in 3 subjects there was no change. It’s not known if the benefits of tDCS in improving gait and balance are dependent on excitability changes induced in one or both leg M1; such information may be useful to predict treatment outcomes. Full article
(This article belongs to the collection Collection on Clinical Neuroscience)
Figures

Figure 1

Open AccessPerspective
Cognitive Decline Secondary to Therapeutic Brain Radiation—Similarities and Differences to Traumatic Brain Injury
Brain Sci. 2019, 9(5), 97; https://doi.org/10.3390/brainsci9050097
Received: 13 March 2019 / Revised: 18 April 2019 / Accepted: 25 April 2019 / Published: 27 April 2019
Viewed by 485 | PDF Full-text (239 KB) | HTML Full-text | XML Full-text
Abstract
Traumatic brain injury (TBI) resulting from forceful impacts on the torso and head has been of major interest because of the prevalence of such injuries in military personnel, contact sports and the elderly. Cognitive and behavioral changes associated with TBI are also seen [...] Read more.
Traumatic brain injury (TBI) resulting from forceful impacts on the torso and head has been of major interest because of the prevalence of such injuries in military personnel, contact sports and the elderly. Cognitive and behavioral changes associated with TBI are also seen following whole brain radiation treatment for cancer and chemotherapy for disseminated tumors. The biological mechanisms involved in the initiation of TBI from impact, radiation, and chemotherapy to loss of cognitive function have several shared characteristics including increases in blood brain barrier permeability, blood vessel density, increases in inflammatory and autoimmune responses, alterations in NMDA and glutamate receptor levels and release of proteins normally sequestered in the brain into the blood and spinal fluid. The development of therapeutic agents that mitigate the loss of cognition and development of behavioral disorders in patients experiencing radiation-induced injury may provide benefit to those with TBI when similar processes are involved on a cellular or molecular level. Increased collaborative efforts between the radiation oncology and the neurology and psychiatry communities may be of major benefit for the management of brain injury from varied environmental insults. Full article
Open AccessReview
Molecular Biomarkers in Fragile X Syndrome
Brain Sci. 2019, 9(5), 96; https://doi.org/10.3390/brainsci9050096
Received: 7 March 2019 / Revised: 22 April 2019 / Accepted: 24 April 2019 / Published: 27 April 2019
Viewed by 719 | PDF Full-text (1116 KB) | HTML Full-text | XML Full-text
Abstract
Fragile X syndrome (FXS) is the most common inherited form of intellectual disability (ID) and a known monogenic cause of autism spectrum disorder (ASD). It is a trinucleotide repeat disorder, in which more than 200 CGG repeats in the 5’ untranslated region (UTR) [...] Read more.
Fragile X syndrome (FXS) is the most common inherited form of intellectual disability (ID) and a known monogenic cause of autism spectrum disorder (ASD). It is a trinucleotide repeat disorder, in which more than 200 CGG repeats in the 5’ untranslated region (UTR) of the fragile X mental retardation 1 (FMR1) gene causes methylation of the promoter with consequent silencing of the gene, ultimately leading to the loss of the encoded fragile X mental retardation 1 protein, FMRP. FMRP is an RNA binding protein that plays a primary role as a repressor of translation of various mRNAs, many of which are involved in the maintenance and development of neuronal synaptic function and plasticity. In addition to intellectual disability, patients with FXS face several behavioral challenges, including anxiety, hyperactivity, seizures, repetitive behavior, and problems with executive and language performance. Currently, there is no cure or approved medication for the treatment of the underlying causes of FXS, but in the past few years, our knowledge about the proteins and pathways that are dysregulated by the loss of FMRP has increased, leading to clinical trials and to the path of developing molecular biomarkers for identifying potential targets for therapies. In this paper, we review candidate molecular biomarkers that have been identified in preclinical studies in the FXS mouse animal model and are now under validation for human applications or have already made their way to clinical trials. Full article
(This article belongs to the Special Issue Towards Mechanism-based Treatments for Fragile X Syndrome)
Figures

Graphical abstract

Open AccessArticle
Cognitive Control Facilitates Attentional Disengagement during Second Language Comprehension
Brain Sci. 2019, 9(5), 95; https://doi.org/10.3390/brainsci9050095
Received: 1 April 2019 / Revised: 23 April 2019 / Accepted: 25 April 2019 / Published: 27 April 2019
Cited by 1 | Viewed by 600 | PDF Full-text (1586 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Bilinguals learn to resolve conflict between their two languages and that skill has been hypothesized to create long-term adaptive changes in cognitive functioning. Yet, little is known about how bilinguals recruit cognitive control to enable efficient use of one of their languages, especially [...] Read more.
Bilinguals learn to resolve conflict between their two languages and that skill has been hypothesized to create long-term adaptive changes in cognitive functioning. Yet, little is known about how bilinguals recruit cognitive control to enable efficient use of one of their languages, especially in the less skilled and more effortful second language (L2). Here we examined how real-time cognitive control engagement influences L2 sentence comprehension (i.e., conflict adaptation). We tested a group of English monolinguals and a group of L2 English speakers using a recently-developed cross-task adaptation paradigm. Stroop sequences were pseudo-randomly interleaved with a visual-world paradigm in which participants were asked to carry out spoken instructions that were either syntactically ambiguous or unambiguous. Consistent with previous research, eye-movement results showed that Stroop-related conflict improved the ability to engage correct-goal interpretations, and disengage incorrect-goal interpretations, during ambiguous instructions. Such cognitive-to-language modulations were similar in both groups, but only in the engagement piece. In the disengagement portion, the modulation emerged earlier in bilinguals than in monolinguals, suggesting group differences in attentional disengagement following cognitive control recruitment. Additionally, incorrect-goal eye-movements were modulated by individual differences in working memory, although differently for each group, suggesting an involvement of both language-specific and domain-general resources. Full article
(This article belongs to the Special Issue Cognitive Neuroscience of Cross-Language Interaction in Bilinguals)
Figures

Figure 1

Brain Sci. EISSN 2076-3425 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top