Significant Difference In Amplitude Research Articles

Effect of otitis media with effusion on vestibular function in children: a pilot study

Objective:To investigate the effect of otitis media with effusion（OME） on vestibular function in children. Method:A total of 57 patients diagnosed with OME were collected and treated with grommet insertion and returned to our hospital 2 weeks later. Sixty children were also included as control group. Bone conducted vestibular evoked myogenic potentials（VEMP） and video head impulse（vHIT） were performed with OME patients both preoperatively and postoperatively. Control group received the same examination. The N1 latency, P1 latency, N1-P1 amplitude, N1-P1 latency were recorded with 60 dB nHL bone conducted stimulus, also bone conducted VEMP threshold. Single factor analysis of variance and paired t-test were used for statistical analysis. Result:In OME group, threshold value of oVEMP was higher and amplitude of N1-P1 in OME group was lower after grommet insertion. In cVEMP, amplitude of N1-P1 in the normal group and OME preoperative group was larger than that in postoperative group. In oVEMP, there was no significant difference in N1-P1 amplitude between control group and OME preoperative group, N1 latency, P1 latercy and N1-P1 latency showed no significant difference as well. In cVEMP, there was no significant difference in N1-P1 amplitude between control group and OME group. There were no significant differences in threshold, N1 latency, P1 latency and N1-P1 latency. In vHIT, there was no significant difference between OME group, postoperative group and control group. After grommet insertion, instantaneous gain of the horizontal semicircular canal at 60 ms was lower than that before surgery. Conclusion:Vestibular test results of children with OME are different from those of normal children, and the corresponding changes also occur after grommet insertion, which deserves further clinical attention.

Characterization of Respiration-Induced Motion in Prone Versus Supine Patient Positioning for Thoracic Radiation Therapy

PurposeVariations in the breathing characteristics, both on short term (intrafraction) and long term (interfraction) time scales, may adversely affect the radiation therapy process at all stages when treating lung tumors. Prone position has been shown to improve consistency (ie, reduced intrafraction variability) and reproducibility (ie, reduced interfraction variability) of the respiratory pattern with respect to breathing amplitude and period as a result of natural abdominal compression, with no active involvement required from the patient. The next natural step in investigating breathing-induced changes is to evaluate motion amplitude changes between prone and supine targets or organs at risk, which is the purpose of the present study. Methods and MaterialsPatients with lung cancer received repeat helical 4-dimensional computed tomography scans, one prone and one supine, during the same radiation therapy simulation session. In the maximum-inhale and maximum-exhale phases, all thoracic structures were delineated by an expert radiation oncologist. Geometric centroid trajectories of delineated structures were compared between patient orientations. Motion amplitude was measured as the magnitude of difference in structure centroid position between inhale and exhale. ResultsAmplitude of organ motion was larger when the patient was in the prone position compared with supine for all structures except the lower left lobe and left lung as a whole. Across all 12 patients, significant differences in mean motion amplitude between orientations were identified for the right lung (3.0 mm, P = .01), T2 (0.5 mm, P = .01) and T12 (2.1 mm, P < .001) vertebrae, the middle third of the esophagus (4.0 mm, P = .03), and the lung tumor (1.7 mm, P = .02). ConclusionsRespiration-induced thoracic organ motion was quantified in the prone position and compared with that of the supine position for 12 patients with thoracic lesions. The prone position induced larger organ motion compared with supine, particularly for the lung tumor, likely requiring increases in planning margins compared with supine.

Effect of puerarin on action potential and sodium channel activation in human hypertrophic cardiomyocytes.

Objective: To study the effect of puerarin on electrophysiology using a hypertrophic cardiomyocyte (HC) model.Materials and methods: Human urine epithelial cells were used to generate the HC model (hiPSC-CM). Cardiomyocyte hypertrophy was induced by applying 10 nM endothelin-1 (ET-1). Effects of puerarin pre-treatment (PPr) and post-treatment (PPo) on action potential, sodium current (INa) activation and inactivation, and recovery following INa inactivation were tested using patch clamp electrophysiology.Results: Depolarization to repolarization 50% time (APD50) and repolarization 30% time (APD30) were significantly prolonged in the PPo and PPr groups compared with the controls. However, there were no significant differences in the action potential depolarization amplitude (APA) or the maximum depolarization velocity (Vmax) in phase 0. The PPr group had a slightly shortened APD90, and an extended APD50 and APD30, but did not exhibit any significant changes in stage A of APA and Vmax. The PPo group did not exhibit any significant changes in INa, while 12 h of PPr improved INa. However, puerarin did not significantly affect the activation, inactivation, or recovery of the sodium channel.Conclusions: Cardiomyocyte hypertrophy significantly decreased the Vmax of the action potential and the peak density of INa. PPr inhibited the decrease in Vmax and increased the peak density of INa. Thus, puerarin could be used to stabilize the electrophysiological properties of hypertrophic cardiomyocytes and reduce arrhythmias.

A preliminary study on the safety of berberine solution in rabbit eyes with topical application

Objective: To study the safety of topical berberine solution in rabbit eyes and its effect on corneal epithelial repair in rabbit eyes. Methods: Experimental Study. Ninety-two Japanese rabbits were randomly divided into two groups by random number table method: the general group (32 rabbits, 64 eyes) and the corneal injury group (60 rabbits, 60 eyes).The general groups were further divided into 4 groups by random number table method, and each group has 8 rabbits (16 eyes). According to the administration of deionized water or 0.5, 1.0, 1.5 mg/ml berberine solution, they were divided into the general control group and the general A, B, and C group. Dosing with both eyes, each eye was given a single dose, and then it was given multiple times for 4 weeks after observation for 72h. After the corneal epithelium injury model made in the right eye of rabbits in the corneal injury groups, they were divided into a corneal injury control group and a corneal injury group A, B, and C according to the administration of deionized water or 0.5, 1.0, 1.5 mg/ml berberine solution. there were 5 rabbits (15 eyes) in each group, and the solutions were given continuously for 1 week. The rabbits in the general group were observed their behavioral changes, ocular surface and iris were scored by Draize eye irritation test scoring system. IOP was measured at different time points. Electroretinogram (ERG) was used to detect b-wave amplitude. In the corneal injury group, corneal epithelial defect repairment was observed at 1, 2, 3, 4, 5, 6, and 7 days after the corneal defect. Corneal histopathology observation after discontinuation of all rabbits. The pH value of rabbit tears was described by the paired t test, and the score of Draize eye irritation test were described by the rank-sum test. The analysis of variance and SNK-q were used for IOP, electroretinogram b-wave amplitude, corneal epithelial injury area and repair time. Results: No abnormal behavior was observed in the general group rabbits after single and multiple administration. There was no significant difference in the Draize eye irritation score among the general control group and the general group A, B, C at 1, 2, and 4 weeks of multiple administrations. Among them, the Draize eye irritation score of the general group C was 7 (0, 12), 6 (0, 10), 6 (0, 16) points (χ(2)=1.640, 0.265, 1.963, 1.381; P>0.05).There were no significant difference in IOP at different times among the general control group and the general group A, B, C at different times (F=0.065, 0.292, 0.015, 0.041; P>0.05). Before multiple administrations and after administration at 2, 4 weeks, the b-wave amplitudes of the general control group were (127.75±17.12), (129.18±15.83), (128.81±13.58) μV, and the general group A were (130.68).±18.75), (131.38±16.96), (130.62±12.18) μV,and the general group B were (128.00±16.74), (128.44±16.64), (129.06±16.16) μV, and the general group C were (131.81±19.37), (132.13±18.36), (129.94±12.60) μV. There was no statistically significant difference in b-wave amplitude in the groups at different times before and after administration (F=0.037, 0.011, 0.017, 0.702; P>0.05). There was no significant difference in the results of corneal histopathology among the general control group and the general group A, B, C. The area of corneal epithelial defect in each corneal injury group was statistically significant at different time (F=5.316, 25.864, 127.613; P<0.05). The corneal injury control group compared with the corneal injury group A, B, C, the corneal epithelial defect area in the corneal injury group C was significantly larger than the other three groups, with statistical differences (q=5.153, 10.313, 6.976; P<0.05). The repair time of corneal epithelial in control group and the group A,B,C of corneal injury were (83.0±1.85), (82.9±2.07), (83.7±2.09) and (101.6±2.20) h. The corneal epithelium defect repair time in group C was longer and the difference was statistically significant (F=301.437, P=0.000). Comparing the corneal injury control group and corneal injury group A and B, there was no statistical difference in the repair time of corneal epithelial defect (F=0.813, P=0.450). After repair, there was no significant difference in the pathological results of the corneal tissue between the corneal injury groups. Conclusions: Berberine solution in rabbit eyes with topical application was safety, and has no obvious toxic effect on the ocular surface and ERG of normal rabbits. 1.5 mg/ml berberine solution delayed the repair of experimental corneal epithelial defect, but had no effect on the integrity of corneal tissue after repair. (Chin J Ophthalmol, 2020, 56: 131-137).

Mirror movement-like muscle hypertonia stroke model based on ipsilateral weight load.

In stroke patients, muscle tone on the unaffected side is often increased during voluntary tasks. This is known as a mirror movement and might be an impediment to function recovery, but its neural background is still unclear. In this study, we investigated the effect of unilateral muscle hypertonia on ipsilateral cortical activity and contralateral motor function. Fourteen right-handed healthy young subjects lifted a weight of 10% body weight with the right upper limb to increase muscle tone (weight task), while no weight lifting was set as the control 'nonweight' task. We recorded the motor-evoked potential (MEP), resting motor threshold and H-reflex from the left flexor carpi radialis muscle during both tasks. To estimate the functional effect of the weight task, subjects performed the 'Purdue pegboard test', consisting of examination for 30 seconds (peg-30) and assembly for 60 seconds (peg assembly). Left-hand grip strength was also measured. When subjects performed the weight task, the MEP amplitude increased significantly and the MT decreased significantly. There was no significant difference of H-reflex amplitude between the two tasks. No significant difference of the peg-30 score was observed between weight and nonweight tasks, but the peg assembly score was significantly lower during the weight task. Grip strength showed a significant increase during the weight task. These results indicate that the present weight load model may have the potential to advance our understanding of the mechanisms underlying mirror movements after stroke.

Sex differences in vocalization are reflected by event-related potential components in the music frog.

Sex differences in vocalization have been commonly found in vocal animals. It remains unclear, however, how animals perceive and discriminate these differences. The amplitudes and latencies of event-related potentials (ERP) components can reflect the auditory processing efficiency and time course. We investigated the neural mechanisms of auditory processing in the Emei music frog (Nidirana daunchina) using an Oddball paradigm with ERP. We recorded and analyzed eletroencephalogram (EEG) signals from the forebrain and midbrain when the subjects listened to white noise (WN) and conspecific sex-specific vocalizations. We found that (1) both amplitudes and latencies of some ERP components evoked by conspecific calls were significantly higher than those by WN, suggesting the music frogs can discriminate conspecific vocalizations from background noise; (2) both amplitudes and latencies of most ERP components evoked by female calls were significantly higher or longer than those by male calls, implying that the ERP components can reflect sex differences in vocalization; and (3) there were significant differences in ERP amplitudes between male and female subjects, suggesting a sexual dimorphism in auditory perception. Together, the present results indicate that the music frog could discriminate conspecific calls from noise, male's calls from female's ones, and sexual dimorphism of auditory perception existed in this species.

Neural responses of in-group “favoritism” and out-group “discrimination” toward moral behaviors

People hate being deceived. However, what would it be if lies come from in-group members compared with that from out-group members? In the current Electroencephalography (EEG) study, we recruited thirty-six participants to play a modified estimator and advisor game to investigate the mental and neural processes to lies and truth conveyed by in-group and out-group members. At the behavioral level, lies are less morally acceptable, arose less positive emotion, and made participants distribute less money to the advisor in a dictator game. Meanwhile, participants liked the in-group university more than the out-group university and they thought they were more similar to in-group members than to out-group members. However, there were no significant interactions of group type (i.e., in-group and out-group) and message type (i.e., lies and truth) in the aforementioned behavioral assessments. At the neural level, significant interaction effects were found in the parietal N1 and P3 amplitude. More importantly, no significant N1 and P3 amplitude differences between in-group lies and truth were found, while outgroup lies elicited larger P3 amplitude than outgroup truth and out-group truth elicited larger N1 amplitude than outgroup lies. What's more, P3 amplitude differences between lies vs. truth positively correlated with fairness scores only in the in-group condition but not in the out-group condition. Current study showed that the P3 component was sensitive in capturing subtle differences when participants were processing different types of lies and truth that could not be captured by behavioral measurements. Besides, the fairness trait modulated the in-group bias related P3 patterns. The current study provides insight into the neurobiological mechanism underlying the mental process of in-group and out-group lies and truth, and suggests individuals' tendency of general in-group favoritism and out-group discrimination toward moral behaviors.

Long-Term Performance of Right Ventricular Implantable Cardioverter-Defibrillator Leads in Arrhythmogenic Right Ventricular Cardiomyopathy and Hypertrophic Cardiomyopathy.

Patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and hypertrophic cardiomyopathy (HCM) implanted with implantable cardioverter-defibrillators (ICDs) may show a large decrease in R-wave amplitude during long-term follow-up. However, it is unclear whether this decrease is higher in these patients than in those without structural heart disease. This study investigated ICD-lead intracardiac parameters over a long duration in patients with ARVC and HCM and compared these parameters with those of a control group. We included 50 patients (mean age, 55.2 ± 17.2 years; 26% female) with ICD leads in the right ventricular apex, and compared 7 ARVC and 14 HCM patients with 29 control patients without structural heart disease. ICD-lead parameters, including R-wave amplitude, pacing threshold, and impedance during follow-up, were compared. The difference in these parameters between the time of implantation and year 5 were also compared. There were no significant differences in R-wave amplitude at implantation among the 3 groups. The change in R-wave amplitude between the time of implantation and year 5 was significantly greater in the ARVC group (-3.3 ± 5.4 mV, P = 0.012) in comparison to the control group (1.3 ± 2.8 mV); the HCM group showed no significant difference (-0.4 ± 2.3 mV, P = 0.06). Thus, in the ARVC group, R-wave amplitude at year 5 was significantly lower than that in the control group (5.7 ± 4.8 mV versus 12.5 ± 4.5 mV, P = 0.001). In ARVC patients with ICDs, ventricular sensing is likely to deteriorate during long-term follow-up; however, in HCM patients, sensing may not deteriorate.

Mapping vowel sounds onto phonemic categories in two regional varieties of French: An ERP study

Abstract This study examines ERP correlates of the different processes associating two phones to one vs. two phonemic categories in two regional varieties of French. Two groups of French listeners are compared, respectively exploiting two regional varieties, with a contrast between the mid-low /ϵ/ and the mid-high /e/ for Northern French (NF) but not for Southern French (SF). It is expected that the competition between the two close categories /e/ vs. /ϵ/ in NF could induce an ERP modulation in the processing of/ϵ/compared to a phoneme/a/with no close competitor, serving as control. In contrast, there should be no difference in ERP response in /ϵ/ vs. /a/ in SF, where there is no competition between the close neighbors /e/ and /ϵ/. The participants of the two groups listened to words containing either /ϵ/ or /a/ in a go/no-go semantic categorization task in which the critical /ϵ/ and /a/ words did not require an overt behavioral response. We found a significant difference in the N400 amplitude between the two conditions in the NF but not in the SF variety. The fact that the ERP modulations appear on the N400 component suggests that lexical access is influenced by the regional variety of the speakers.

The diagnostic value of tremor analysis for defining the Parkinson's disease subtype

Objective: To find more objective evidence and support for clinical classification of Parkinson's disease by means of tremor analysis in patients with early confirmed Parkinson's disease. Methods: A cross-sectional study was conducted to collect 65 patients with early Parkinson's disease treated in the Third Hospital of Peking University from January 2015 to December 2016. Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn-Yahr scale (H-Y scale), Mini-mental state examination (MMSE), Hamilton depression scale (HAMD) were recorded in all patients. According to the ratio of UPDRS rigidity score to tremor score, the patients were divided into tremor dominant (TD), postural instability/gait difficulty (PIGD) and mixed types. All patients were examined by tremor analysis and the results were analyzed and compared. Results: Among the 65 patients, the mean age of onset was (63±10) years, the course of disease was (14±8) months. Twenty-one patients were classified to TD group, 28 patients were classified to PIGD type, and 16 patients with mixed type. There was no significant difference in frequency and amplitude of tremor between the three groups (P>0.05), but the proportion of alternating contraction and harmonic resonance of active and antagonistic muscles in TD group was significantly higher (P<0.05). Twenty patients (71.4%) in TD group showed typical Parkinson's disease manifestations in tremor analysis. Only four patients (14.3%) in PIGD group showed the typical manifestations. More patients in PIGD group showed no clear main peak of tremor at rest. Some patients showed 6-8 Hz/sec peak frequency in posture position and simultaneous contraction of the active and antagonist muscles. These two manifestations occured simultaneously in mixed type patients, including 10 cases (62.5%) with typical Parkinson's disease manifestations. Conclusion: As an objective electrophysiological method to evaluate tremor type, tremor analysis can be used as an important assistant method for clinical classification of Parkinson's disease. It can provide information of the pathway of pathological loss in different types and give important hints in prognosis and treatment.

Short-term effects of two deep dry needling techniques on pressure pain thresholds and electromyographic amplitude of the lumbosacral multifidus in patients with low back pain - a randomized clinical trial

ABSTRACT Objectives: The purpose of this study was to compare the effects of deep dry needling (DN) with and without needle manipulation on pressure pain thresholds (PPTs) and electromyographic (EMG) amplitude of the lumbosacral multifidus (LM) in adults with low back pain (LBP). Methods: Participants were randomized into two treatment groups: with needle manipulation (n = 21) and without needle manipulation (n = 21). All participants received a single session of the assigned DN intervention. PPTs and EMG amplitude of the LM muscle were collected three times: before DN, immediately after DN, and one week after DN. Results: The needle manipulation group had a significantly greater increase in PPT immediately after the intervention and at the one-week follow-up as compared to the no needle manipulation group. The increase of PPT in the needle manipulation group was significant immediately after the intervention, and the increase remained significant at the one-week follow-up. However, there was no significant difference in EMG amplitude of the LM muscle between groups across the three time points. Discussion: Deep DN with needle manipulation appeared to reduce mechanical pressure sensitivity more than DN without manipulation for patients with LBP. Although a single session of DN could reduce pressure pain sensitivity, it may not be sufficient to improve LM muscle function. Level of Evidence: 1b. Trial registration numbers: NCT03970486.

Loss of circadian gene Bmal1 in the collecting duct lowers blood pressure in male, but not female, mice.

Kidney function follows a 24-h rhythm subject to regulation by circadian genes including the transcription factor Bmal1. A high-salt diet induces a phase shift in Bmal1 expression in the renal inner medulla that is dependent on endothelin type B (ETB) receptors. Furthermore, ETB receptor-mediated natriuresis is sex dependent. Therefore, experiments tested the hypothesis that collecting duct Bmal1 regulates blood pressure in a sex-dependent manner. We generated a mouse model that lacks Bmal1 expression in the collecting duct, where ETB receptor abundance is highest. Male, but not female, collecting duct Bmal1 knockout (CDBmal1KO) mice had significantly lower 24-h mean arterial pressure (MAP) than flox controls (105 ± 2 vs. 112 ± 3 mmHg for male mice and 106 ± 1 vs. 108 ± 1 mmHg for female mice, by telemetry). After 6 days on a high-salt (4% NaCl) diet, MAP remained significantly lower in male CDBmal1KO mice than in male flox control mice (107 ± 2 vs. 113 ± 1 mmHg), with no significant differences between genotypes in female mice (108 ± 2 vs. 109 ± 1 mmHg). ETB receptor blockade for another 6 days increased MAP similarly in both male and female CDBmal1KO and flox control mice. However, MAP remained lower in male CDBmal1KO mice than in male flox control mice (124 ± 2 vs. 130 ± 2 mmHg). No significant differences were observed between female CDBmal1KO and flox mice during ETB blockade (130 ± 2 vs. 127 ± 2 mmHg). There were no significant genotype differences in amplitude or phase of MAP in either sex. These data suggest that collecting duct Bmal1 has no role in circadian MAP but plays an important role in overall blood pressure in male, but not female, mice.

Effect of resistance training to muscle failure vs non-failure on strength, hypertrophy and muscle architecture in trained individuals.

The aim of this study was to compare the effects of resistance training to muscle failure (RT-F) and non-failure (RT-NF) on muscle mass, strength and activation of trained individuals. We also compared the effects of these protocols on muscle architecture parameters. A within-subjects design was used in which 14 participants had one leg randomly assigned to RT-F and the other to RT-NF. Each leg was trained 2 days per week for 10 weeks. Vastus lateralis (VL) muscle cross-sectional area (CSA), pennation angle (PA), fascicle length (FL) and 1-repetition maximum (1-RM) were assessed at baseline (Pre) and after 20 sessions (Post). The electromyographic signal (EMG) was assessed after the training period. RT-F and RT-NF protocols showed significant and similar increases in CSA (RT-F: 13.5% and RT-NF: 18.1%; P < 0.0001), PA (RT-F: 13.7% and RT-NF: 14.4%; P < 0.0001) and FL (RT-F: 11.8% and RT-NF: 8.6%; P < 0.0001). All protocols showed significant and similar increases in leg press (RT-F: 22.3% and RT-NF: 26.7%; P < 0.0001) and leg extension (RT-F: 33.3%, P < 0.0001 and RT-NF: 33.7%; P < 0.0001) 1-RM loads. No significant differences in EMG amplitude were detected between protocols (P > 0.05). In conclusion, RT-F and RT-NF are similarly effective in promoting increases in muscle mass, PA, FL, strength and activation.

Electroacoustic and electrophysiological auditory assessment in aphasic individuals

ABSTRACT Purpose: to verify the functioning of the outer hair cells and the medial efferent olivocochlear system, and the integrity of the auditory pathways in the brainstem up to the auditory cortex, in aphasic individuals. Methods: the sample comprised 20 individuals - 10 without aphasia and 10 with it, aged from 21 to 58 years. The procedures used were the research of the otoacoustic emissions by a transient stimulus with and without noise, and the cognitive potential (tone-burst and speech stimuli). The findings were analyzed based on descriptive statistics. Results: the suppression effect was more present in individuals without aphasia when compared with the aphasic ones. In the cognitive potential, the mean latency values of P3 was within normality standards, with a higher latency in the individuals presented with aphasia for the tone-burst stimulus in both ears. A statistically significant difference of the P3-N2 amplitude was observed for the tone-burst stimulus, comparing the ears in both groups, and for speech stimulus only to the left ear in both groups. Conclusions: aphasic individuals did not present significant differences regarding suppression of the otoacoustic emissions. As for the cognitive potential, the aphasic individuals presented higher latency values when compared to those with no aphasia.

An Event-related Potential Study of Second Language Semantic and Syntactic Processing: Evidence From the Declarative/Procedural Model.

Introduction:This study examined the effect of proficiency level on the second Language (L2) syntactic and semantic processing by addressing the role of procedural and declarative memory systems in light of the Declarative/Procedural (DP) model. The primary purpose was to determine to what extent proficiency accounts for native-like language processing in L2 in adult bilinguals who learned English (L2) after the age of 15 under explicit instruction.Methods:Using a mixed-method design and an oddball violation paradigm, we examined the functional neural correlates of syntactic and semantic processing in two groups of Persian-English bilinguals (L1=Persian, L2=English; N=10 high-proficient, N=10 pre-intermediate levels; Gender= Female; mean age=25.50 years, SD = 5.09 years, age range = 19–35 years of age) across 6 different conditions. They included a visual stimulus task of 240 English sentences with three different experimental conditions (violated regular past forms or phrase structure rules or final-word semantic violation) and three control conditions (sets of correct sentences for each experimental condition). Both groups started learning English late (age of onset=15+) and under an explicit learning context. To evaluate the effect of L2 proficiency, Event-related potentials (ERPs) to target words in each condition were elicited across the N400 time window (300–500 ms) and the P600 time window (500–700 ms).Results:Results showed different cortical responses in the two groups. Upon processing the violated forms, high-proficient subjects showed more native-like patterns of scalp activity in both lexical-semantic and syntactic processing. In contrast, less proficient learners have shown delayed onsets and or peaks of components, reduced amplitudes, or absent components in some regions. For instance, the difference in N400 amplitude for the incorrect regular past conditions was observed only in the pre-intermediate (PI) subjects in the O1 channel. This finding is compatible with the DP Model in that at lower levels of L2 proficiency, the participants show N400s or N400-like posterior negativities instead of Anterior Negativities (ANs). This finding shows the initial reliance on the declarative memory system for syntactic processing at lower levels of L2.Conclusion:Our findings suggest that attained proficiency was a more determinant factor in the L1-like cortical representation of L2 than the age of acquisition and or the type of instruction/context. Several brain areas, similar to those observed for L1, were activated during L2 syntactic processing in high-proficient subjects addressing their reliance on the procedural memory system for syntactic processing to gain more proficiency. For instance, our results showed a significant difference in N400 amplitude for the incorrect regular past conditions in O1 for the PI subjects, which shows the initial reliance on the declarative memory system for syntactic processing at lower levels of L2.

Long Latency Reflexes in Patients with Postural Instability and Ataxia

Objectives: Distal electrical stimulation of an upper extremity mixed nerve can generate a reflex response from the trapezius muscle. This reflex response may have a central neural pathway and can be affected by postural changes. Materials and Methods: In this study, long latency reflexes (LLRs) from both distal and trapezius muscle were evaluated in patients with Parkinson's disease (PD) with and without postural dysfunction and in patients with cerebellar ataxias. Thirty-three patients with PD, 10 patients with degenerative cerebellar ataxia and 22 healthy volunteers were included in the study. LLRs were recorded from ipsilateral thenar and trapezius muscles. Latencies and amplitudes of LLRs obtained from thenar (thenar LLR) and trapezius (trapezius LLR) muscles were analyzed. Results: In patients with PD, thenar LLRs showed significant shortening in the onset latencies and significant increase in the amplitudes in comparison with healthy controls. Trapezius LLRs did not show any significant difference in latencies or amplitudes; however, these responses showed a significant absence in one or two components in patients with Parkinson's disease with postural dysfunction. Additionally, this reflex was not recorded in patients with cerebellar ataxia. Conclusion: Trapezius LLRs can give some information regarding the physiology of neural circuits responsible for postural arrangement. Cerebellar connections may have a major role in the generation of trapezius LLRs.

Effects of Action Observation Training with 1 Hz Low Frequency Repeated Transcranial Magnetic Stimulation on Cerebral Cortex Activity and Hand Function in Patients with Ideomotor Apraxia after Stroke

The aim of this study was to investigate the effects of action observation training with low frequency repeated transcranial magnetic stimulation (rTMS) on cerebral cortex activity and hand function in patients with ideomotor apraxia after Stroke. Fourteen patients were randomly divided into two groups which in action observation training (AOT) with 1 Hz low-frequency rTMS and AOT without rTMS. Motor evoked potential (MEP) amplitude and latency were examined by TMS for cerebral cortex activity and hand function was evaluated by manual function test (MFT). As a result, there was a significant difference in MEP amplitude in group, but only AOT with rTMS group was a significant difference in MEP latency and MFT. In addition, there was a significant difference of MEP amplitude, latency and MFT between groups. These results suggest that application of AOT and rTMS can have a positive effect on the recovery of hand function in ideomotor apraxia after patients.

The Effects of Motor Imagery Combined with Neuromuscular Electrical Stimulation on Using Transcranial Magnetic Stimulation in Stroke Patients

The purpose of this study was to investigate the effect of motor imagery combined with neuromuscular electrical stimulation (MI-NMES) on cerebral cortex excitability in stroke patients. We examined the effect of MINMES on cerebral cortex excitability using transcranial magnetic stimulation (TMS) of motor evoked potential (MEP) amplitude and latency, quantitative electroencephalography (QEEG) of δα ratio (DAR) and power ratio index (PRI) assessments. This study was to evaluate 30 stroke patients who were satisfied the selection criteria of the study. Experiments were divided into MI-NMES group, motor imagery (MI) group. This study showed that there was a significant difference for all evaluations within the MI-NMES group, with significant differences in MEP amplitude and latency, QEEG DAR, and PRI index values in the comparison that those of the MI group. MI-NMES is suggested to be an effective approach for cerebral cortex excitability in stroke patients.

Effect of 1 Hz Low Frequency Repetitive Transcranial Magnetic Stimulation on Cerebral Activity and Recovery on Upper Limb Motor Function in Chronic Stroke Patients

The purpose of this study was to evaluate the effect of 1 Hz low frequency repetitive transcranial magnetic stimulation (rTMS) on cerebral cortex activity and recovery of hand function in chronic stroke patients. It was evaluated by motor evoked potentials (MEPs) amplitude, latency, and MFT. In Results, rTMS group and neurorehabilitation training (NRT) group showed differences in MEPs amplitude, latency, and MFT before and after intervention (p 0.05). and rTMS group showed significant differences in MEPs amplitude and MEPs latency compared to NRT group (p 0.05), but both groups did not show significant differences (p 0.05). These results suggest that rTMS and NRT in chronic stroke patients have positive changes in cerebral cortex activity, but 1 Hz rTMS is more effective in cerebral cortex activity than in NRT. However, for recovery of hand function in chronic stroke patients, motor learning considering neurophysiology and biomechanics as well as cerebral cortex activity is required.

Core Muscle Activation in Three Lower Extremity Exercises With Different Stability Requirements.

Saeterbakken, AH, Stien, N, Pedersen, H, and Andersen, V. Core muscle activation in three lower extremity exercises with different stability requirements. J Strength Cond Res 36(2): 304-309, 2022-The aim of the study was to compare core muscle surface electromyography (sEMG) during 3-repetition maximum (3RM) and the sEMG amplitude in the turnover from the descending to ascending phase in leg press, free-weight squats, and squats using the Smith machine. Nineteen women with 4.5 (±2.0) years of resistance training were recruited. After one familiarization session, the subjects performed 3RM in randomized order measuring electromyographic activity in the rectus abdominis, external oblique, and erector spinae. The exercises with the lowest stability requirements (leg press) demonstrated 17-59% and 17-42% lower core muscle sEMG amplitude than free weights and the Smith machine, respectively. No statistically significant differences were observed between the Smith machine and free weights. No statistically significant differences in turnover sEMG amplitude in the rectus abdominis between the exercises was observed, but lower sEMG amplitude was observed in external oblique and erector spinae in leg press compared with the other exercises. The 3RM loads in leg press were 54 and 47% greater than squats using the Smith machine and free weights, with 5% greater loads with the Smith machine than with free weights. In conclusion, lower mean and turnover core muscle sEMG amplitude were observed with the leg press but greater 3RM loads compared with squats with the Smith machine and free weights. The authors recommend that resistance-trained individuals use squats to include the core muscles in the kinetic chain, but there is no evidence that greater stability requirements (free weights instead of the Smith machine) will result in greater core muscle sEMG amplitude.