N1 Latency Research Articles

Association between vestibular evoked myogenic potentials and different dizziness status in Parkinson's disease: A controlled study.

This study compared ocular and cervical vestibular evoked myogenic potentials (oVEMP and cVEMP) among individuals with Parkinson's disease (PD) without dizziness, with nonspecific dizziness (dizziness without orthostatic hypotension), or with dizziness combined with orthostatic hypotension. We prospectively analyzed 30 of each of the three types of individuals who were admitted to Yongchuan Hospital of Chongqing Medical University (Chongqing, China) between June 2022 and April 2023. The three groups received oVEMP and cVEMP measurements using an electromyography-evoked potential system. For oVEMP, the N10 latency, P16 latency, and amplitude were compared between the three groups and the reference values. For cVEMP, the P13 latency, N23 latency, and amplitude were compared between the three groups and the reference values. Overall characteristics of oVEMP and cVEMP were also assessed using a previously published scoring scale originally developed for individuals with multiple sclerosis between the three groups included. The correlation between VEMP parameters (the latency and amplitude) and VEMP scores were simultaneously analyzed using Pearson's bivariate correlation analysis. When compared with reference values, the oVEMP and cVEMP parameters of all three groups were found to be slightly different from the reference values. When the three groups included were compared with each other, in terms of oVEMP, the average amplitude in the left eye was significantly higher in those with nonspecific dizziness than in the other two groups. In terms of cVEMP, the average N23 latency on both the right and left sides of the neck and average amplitude on the right side of the neck were significantly higher in those with nonspecific dizziness than in the other two groups. Scores for oVEMP and cVEMP were also significantly higher for those with nonspecific dizziness than for the other two groups. There were no significant differences in oVEMP and cVEMP parameters, and scores for oVEMP and cVEMP between patients with dizziness combined with orthostatic hypotension and those without dizziness. In terms of correlation analysis, the N23 latency of left neck (r = 0.509, p < 0.001), the N23 latency of right neck (r = 0.495, p < 0.001), and the amplitude of right neck (r = 0.304, p = 0.004) correlated positively with cVEMP score. Patients with PD without dizziness, with dizziness attributable to orthostatic hypotension, and with nonspecific dizziness may be all associated with vestibular dysfunction. The VEMP scores were highest in patients with nonspecific dizziness, so vestibular function is more severely affected in patients with nonspecific dizziness. The VEMP especially cVEMP may be useful for early diagnosis of nonspecific dizziness in PD.

The effect of bilingualism on obligatory components of auditory late responses in young adults: a cross-sectional study

IntroductionBilingualism significantly contributes to neuroplasticity in the brain, with research indicating enhanced auditory processing in bilingual individuals. Obligatory sensory components of the auditory late responses (ALRs) reflect primary and secondary auditory cortex activity, serving as an electrophysiological measure of auditory processing. This study aims to compare ALRs' obligatory components (P1-N1-P2) in bilingual (Turkish-Persian) and monolingual (Persian) young adults.MethodThis cross-sectional study analyzed ALRs in 28 monolingual and 28 bilingual participants aged 19 to 30 years, using a 70 dB nHL speech stimulus (/da/). ALRs were recorded monaurally with insert earphones. The study then compared the mean latency and amplitude of P1- N1- P2 complex in the right and left ear between two groups.ResultThe study revealed shorter latency for all three ALRs components in bilingual participants compared to monolinguals. This difference was statistically significant (P-value < 0.05) for N1 with right ear stimulation and P2 with right and left ear stimulations. No significant differences were found in the amplitude of P1-N1 and N1-P2 between the groups.ConclusionThe significant reduction in N1 and P2 latency observed in bilingual subjects' ALRs likely results from neural plasticity. This may enhance neural transmission and accelerate speech sound processing in the respective cortical regions. These latency changes could serve as a cortical neural biomarker distinguishing monolinguals from bilinguals, highlighting the impact of bilingualism on auditory processing efficiency.

Machine Learning-Based Diagnosis of Chronic Subjective Tinnitus With Altered Cognitive Function: An Event-Related Potential Study.

Due to the absence of objective diagnostic criteria, tinnitus diagnosis primarily relies on subjective assessments. However, its neuropathological features can be objectively quantified using electroencephalography (EEG). Despite the existing research, the pathophysiology of tinnitus remains unclear. The objective of this study was to gain a deeper comprehension of the neural mechanisms underlying tinnitus through the comparison of cognitive event-related potentials in patients with tinnitus and healthy controls (HCs). Furthermore, we explored the potential of EEG-derived features as biomarkers for tinnitus using machine learning techniques. Forty-eight participants (24 patients with tinnitus and 24 HCs) underwent comprehensive audiological assessments and EEG recordings. We extracted N2 and P3 components of the midline electrodes using an auditory oddball paradigm, to explore the relationship between tinnitus and cognitive function. In addition, the current source density for N2- and P3-related regions of interest was computed. A linear support vector machine classifier was used to distinguish patients with tinnitus from HCs. The P3 peak amplitudes were significantly diminished in patients with tinnitus at the AFz, Fz, Cz, and Pz electrodes, whereas the N2 peak latencies were significantly delayed at Cz electrode. Source analysis revealed notably reduced N2 activities in bilateral fusiform gyrus, bilateral cuneus, bilateral temporal gyrus, and bilateral insula of patients with tinnitus. Correlation analysis revealed significant associations between the Hospital Anxiety and Depression Scale-Depression scores and N2 source activities at left insula, right insula, and left inferior temporal gyrus. The best classification performance showed a validation accuracy of 85.42%, validation sensitivity of 87.50%, and validation specificity of 83.33% in distinguishing between patients with tinnitus and HCs by using a total of 18 features in both sensor- and source-level. This study demonstrated that patients with tinnitus exhibited significantly altered neural processing during the cognitive-related oddball paradigm, including lower P3 amplitudes, delayed N2 latency, and reduced source activities in specific brain regions in cognitive-related oddball paradigm. The correlations between N2 source activities and Hospital Anxiety and Depression Scale-Depression scores suggest a potential link between the physiological symptoms of tinnitus and their neural impact on patients with tinnitus. Such findings underscore the potential diagnostic relevance of N2- and P3-related features in tinnitus, while also highlighting the interplay between the temporal lobe and occipital lobe in tinnitus. Furthermore, the application of machine learning techniques has shown reliable results in distinguishing tinnitus patients from HCs, reinforcing the viability of N2 and P3 features as biomarkers for tinnitus.

Effect of induced astigmatism on vestibulo-ocular reflex

ABSTRACT Clinical relevance The vestibular-ocular reflex stabilises the retinal image and maintains balance during head movement. Astigmatism is one of the common refractive errors that can reduce the quality of visual inputs. Background The purpose of this study was to investigate the effect of induced astigmatism on the function of the vestibular-ocular reflex. Methods This prospective semi-experimental study was conducted on 48 participants aged 20 to 40 years who had no history of neurological, vestibular, or eye disorders. Simple myopic astigmatism was induced using three positive cylindrical lens powers of + 0.50D, +1.50D, and + 2.50D at three axes of 180, 45, and 90 degrees in both eyes. The vestibular-ocular reflex was evaluated by the ocular Vestibular Evoked Myogenic Potential (oVEMP) through acoustic stimulation (a 500 hz tone burst at an intensity of 95 dBnHL) of the ear, with potentials recorded from the lower oblique muscle. The latency of the N1 and P1 waves and the amplitude of N1-P1 were recorded for all participants in the baseline condition (without any induced astigmatism) and under different induced astigmatism conditions. Results The latencies of N1 and P1 significantly increased with the increasing power of induced astigmatism; however, the powers of astigmatism had no effect on the amplitude of N1-P1. The axes of induced astigmatism did not have a significant effect on the latencies and amplitude of N1-P1. Conclusions Induced astigmatism due to retinal image blur can deteriorate the function of the vestibular-ocular reflex by increase in the latencies of N1 and P1 oVEMP waves.

Preliminary evaluation of the FastCAP for users of the Nurotron cochlear implant.

Electrically evoked compound action potential (ECAP) can be used to measure the auditory nerve's response to electrical stimulation in cochlear implant (CI) users. In the Nurotron CI system, extracting the ECAP waveform from the stimulus artifact is time-consuming. We developed a new paradigm ("FastCAP") for use with Nurotron CI devices. In electrically evoked compound action potential in fast mode (FastCAP), N recordings are averaged directly on the CI hardware before data transmission, significantly reducing data transmission time. FastCAPs and ECAPs were measured across five electrodes and four stimulation levels per electrode. The FastCAP stimulation rate (33.3 Hz) is also faster than the ECAP rate (2.5 Hz). Results showed strong correlations between ECAPs and FastCAPs for N1 latency (r = 0.84, p < 0.001) and N1 amplitude (r = 0.97, p < 0.001). Test-retest reliability for FastCAPs was also high, with intraclass correlation coefficients of r = 0.87 for N1 latency (p < 0.001) and r = 0.96 for N1 amplitude (p < 0.001). The mean test time was 46.9 ± 1.4 s for the FastCAP and 340.3 ± 6.3 s for the ECAP. The FastCAP measurement time was significantly shorter than the ECAP measurement time (W = -210.0, p < 0.001). FastCAP thresholds were significantly correlated with behavioral thresholds in 7/20 participants and with comfortable loudness levels in 11/20 participants. The time required to measure FastCAPs was significantly lower than that for ECAPs. The FastCAP paradigm maintained the accuracy and reliability the ECAP measurements while offering a significant reduction in time requirements. This preliminary evaluation suggests that the FastCAP could be an effective clinical tool to optimize CI processor settings (e.g., threshold stimulation levels) in users of the Nurotron CI device.

Clinical Features Evaluation of Myopic Fundus tessellation from OCTA and MfERG.

To evaluate the differences in fundus tessellation among various severities using multifocal visual electrophysiology (MfERG) and optical coherence tomography angiography (OCTA) for clinical grading and treatment. This study included 52 patients totaling 87 eyes. The Early Treatment Diabetic Retinopathy Study (ETDRS) grid division method was utilized to assess Grade of fundus tessellation. Data obtained via OCTA and ImageJ software included macular foveal thickness (MT), subfoveal choroidal thickness (SFCT), superficial retinal capillary layer vascular density (SVD), deep retinal capillary layer vascular density (DVD), and choroidal blood capillary layer blood flow density (CFD). Multifocal visual electrophysiology equipment provided latency and amplitude of N1 and P1 waves. Differences and changes among the four Grade of fundus tessellation grading were compared, and ROC curve analysis was performed to identify the optimal choroidal thickness indicators for predicting the grading of fundus tessellation. SFCT tends to decrease as the grade of fundus tessellation increases. and the amplitudes of N1 and P1 waves in multifocal electroretinography reduce, with an elongation in their latency periods. Correlation analysis showed that SFCT positively correlated with N1 and P1 amplitudes (r=0.270, 0.246; P<0.05) and negatively correlated with their latency periods (r=-0.219, -0.248; P<0.05). The ROC curve results indicated the cutoff values for SFCT were 192.75µm between Grade 1 and 2, 162µm between Grade 2 and 3, and 130.75µm between Grade 3 and 4. Assessment in fundus tessellation using MfERG and OCTA contributes to objective grading of fundus tessellation and further help to clinical prediction and treatment. Assessment in fundus tessellation morphologically and functionally using MfERG and OCTA contributes to classification and clinical prediction of fundus tessellation.

Objective Neurophysiological Measures of Cognitive Performance in Elite Ice Hockey Players.

Athletic peak performance is increasingly focused on cognitive and mental factors. In the current study, cognitive performance was measured by neurophysiological responses in elite Junior-A hockey players. Neurophysiological brain vital signs were extracted from event-related potentials (ERPs) to evaluate auditory sensation (the N100), basic attention (the P300), and cognitive processing (the N400). In total, we evaluated 348 athletes, across 17 teams, throughout different hockey arenas in British Columbia, Canada. While brain vital signs were collected to help manage concussion, the current investigation focused on a retrospective performance analysis of cognitive processing differences. The results revealed three interesting findings: 1) Player position differences were detectable in sensory N100 latency, with significantly faster responses for forwards compared to defense; 2) Goalies showed significantly higher attention P300 amplitude compared to all other positions; and 3) Cognitive N400 processing differences were detectable only during competitive combine testing, showing 60ms latency differences between forwards and defense on average. The current findings suggest that neurophysiological responses, which are also sensitive to concussion, may be used to identify sensory, attentional, and cognitive processing differences to help optimize peak performance.

Acute effects of different physical activity on executive function and regulation role of beta oscillation in sedentary youth frontal region

Chronic sedentary behavior can have a negative impact on the executive function (EF) of young people. While physical activity (PA) has been shown to improve this phenomenon, the effects of different types of PA on EF vary. In this study, we compared the effects of moderate-intensity continuous training (MICT) (60–70% HRmax, 30 min), body weight training (BWT) (2 sets tabata, 20 min), and mind-body exercise (MBE) (2 sets Yang style shadowboxing, 20 min) on EF in 59 sedentary youth (n = 59, age = 20.36 ± 1.78, BMI = 24.91 ± 1.82, P>0.05) to identify the optimal dose of PA for improving EF. Metrics related to the EF task paradigm included stop signal, electroencephalogram (EEG), event-related potential (ERP), P300, N200, error-related negativity (ERN), and error positivity (Pe). error positivity (Pe), and β-wave in frontal lobe; training monitoring, including heart rate (HR), rating of perceived exertion (RPE), feeling scale (FS), and dual-mode model (DMM); load assessment, including Edward’s TRIMP (TRIMP) and session-RPE (s-RPE). The study results indicate that BWT significantly improved accuracy in terms of EF (F = 16.84, P = 0.0381) and was comparable to MICT in terms of shortening reaction time (F = 58.03, P = 0.0217; F = 75.49, P = 0.0178). Regarding ERP, BWT reduced the amplitude values of N200 compared to ERN (F = 44.35, P = 0.0351; F = 48.68, P = 0.0317), increased P300 compared to Pe (F = 97.72, P<0.01; F = 29.56, P = 0.0189), and shortened P300 latency (F = 1.84, P = 0.0406). In contrast, MICT was only effective for P300 with Pe (F = 66.59, P = 0.0194; F = 21.04, P = 0.0342) and shortened N200 latency (F = 27.29, P = 0.0411). The increase in total amplitude and β-oscillation in terms of EEG was proportional to the exercise intensity, with the difference between MICT and BWT being present at 5–20 Hz, and MBE at 10–15 Hz. Regarding training load, the order of HR, RPE, TRIMP, and s-RPE was BWT > MICT > MBE (F = 202.69; F = 114.69; F = 114.69; P = 0.0342). The latency of N200 was also shortened (F = 27.29, P = 0.0411). The results showed that PA improves EF in sedentary youth, although BWT works best, it leads to a decrease in motor perception. Initially, MICT was scheduled alongside MBE and later replaced with BWT. This may help establish an exercise habit while improving EF.

Otolith Function in Young Skilled Football Players

Background and Aim: Regular physical activities, including sports, are associated with improved balance function. The objectives of our study were to conduct cervical Vestibular Evoked Myogenic Potentials (cVEMPs) and ocular VEMPs (oVEMPs) in young adult football players and to compare the test results with those who are not involved in regular physical activities as the control group. Methods: We recruited 11 young football players (9 right-leg and two left-leg dominant) who have been playing football regularly since childhood and have participated in inter-school or college/university-level football tournaments. The age-matched control group consisted of 11 healthy participants not involved in any physical activities regularly or as a hobby. Participants in both groups underwent cVEMP and oVEMP tests in both ears. Results: The peak-to-peak amplitude of both cVEMP and oVEMP were higher in football players than in the control group. The amplitude for left ear stimulation was higher than the right ear for both cVEMP and oVEMP in football players and it reached statistical significance for oVEMP in left ear stimulation (p&lt;0.05). The n10 latency of oVEMP in both right and left ear stimulations and the p13 latency of cVEMP in left ear stimulation was significantly shorter in football players compared to the control group (p&lt;0.05). Conclusion: Regular football players have stronger vestibule-collic and translational Vestibulo-Ocular Reflexes (t-VOR). The reflex strength, measured as the higher peak-to-peak amplitude of VEMPs, might also be influenced by factors like leg/eye dominance.Keywords: Vestibular function; football; adults; vestibular evoked myogenic potentials; balance function

The characteristics of event-related potentials in generalized anxiety disorder: A systematic review and meta-analysis.

Previous studies have reported inconsistent findings regarding event-related potentials (ERPs) abnormalities in individuals with generalized anxiety disorder (GAD). This meta-analysis aimed to systematically review and synthesize the existing evidence on ERP alterations in individuals with GAD. A comprehensive literature search was conducted in PubMed, the Cochrane Library, Excerpta Medica Database, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Database (VIP), Wanfang database, and China Biology Medicine (CBM) databases from inception to November 11, 2024. Gray literature and reference lists were also manually searched. Studies investigating ERP component differences between individuals with GAD and healthy controls were included. Two independent reviewers conducted study selection, data extraction, and risk of bias assessment. Influence and sensitivity analyses were performed to assess the robustness of the pooled results. Effect sizes (SMD, Hedge's g) were calculated for latency and amplitude differences. Heterogeneity was assessed using the I2 statistic. Meta-regression and subgroup analyses were conducted to explore the source of heterogeneity. Trim-and-fill analyses were applied to assess potential publication bias. Data synthesis was performed using R (version 4.2.3) software. A total of 37 studies involving 1086 individuals with GAD and 1315 healthy controls were included. The overall risk of bias was rated as low for 25 studies and moderate for 12 studies. Ten ERP components were included in the quantitative meta-analysis: P3, N2, N1, P2, Error Related Negativity (ERN), Correction Related Negativity (CRN), Mismatch Negativity (MMN), P1 (amplitude), Pe, and LPP. Pooled results indicated that individuals with GAD exhibited decreased P3 amplitude (g=-0.54, 95% CI: -0.70 to -0.38, I2=20%, P=0.22) and increased ERN amplitude (g=-0.42, 95% CI: -0.72 to -0.12, I2=40%, P=0.11) compared to healthy controls. In addition, delayed latency of P3 (g=0.43, 95% CI: 0.09 to 0.78, I2=75%, P<0.01), N2 (g=0.36, 95% CI: 0.11 to 0.62, I2=30%, P=0.20), and MMN (g=0.63, 95% CI: 0.52 to 0.75, I2=0%, P<0.0001) was observed in individuals with GAD. Due to the limited number of included studies, the results of N170, N1/P2, N270, N400, VPP, BAEP, P1 (latency), P50, EPN and Nf were summarized narratively. Individuals with GAD were reported to have increased N170, N400, and VPP amplitude and delayed P1 latency compared to healthy controls. Age, sex ratio, sample size, diagnostic criteria, task-related modality, and paradigm were identified as potential influencing factors of ERP characteristics. Individuals with GAD exhibit increased ERN amplitude and decreased P3 amplitude in contrast with healthy controls. In addition, delayed latency of P3, N2, and MMN is detected in individuals with GAD. The identified ERP components in individuals with GAD are associated with attention, cognition, visual perception, error or conflict monitoring, semantic information integration, and auditory sensory memory processes. Due to the limited number of included studies and high heterogeneity, further studies with high quality are needed to confirm these findings.

Neuromodulatory Effect of Lactate on Visual Evoked Potential After Acute Exercise in Healthy Adult Males.

Background Lactate, once considered merely a byproduct of anaerobic metabolism, is now recognized as a crucial neuromodulator in the brain, particularly during high-energy demands. Recent studies have explored its role in neuroprotection, cognitive enhancement, and neural plasticity. This study investigates the effects of elevated blood lactate levels, induced by acute exercise, on visual evoked potentials (VEPs), which reflect neural activity in the visual cortex. Methodology This interventional study was performed in theDepartment of Physiology, Indira Gandhi Institute of Medical Sciences, Patna, BR, IND. Fifty healthy male subjectsaged 18 to 40 years, participated in the study. Baseline blood lactate levels and VEP were recorded after 30 minutes of rest. Subjects then performed aerobic exercise until exhaustion, following the Bruce protocol. Blood lactate levels and VEPs were measured immediately at the end of exercise and again at 10 and 20 minutes post-exercise. Visual evoked potentials (the N75, P100, and N145 waves) were recorded according to the International 10-20 system, using the MEP Neurosoft four-channel machine (Neurosoft, Ivanovo, RUS). Data were analyzed using repeated measures ANOVA, Pearson's correlation, and linear regression via SPSS Statistics version 29.0.2.0 (IBM Corp, Armonk, NY, USA). Results Post-exercise, blood lactate levels were raised, which was statistically significant. The VEP analysis showed a statistically significant decrease in P100 latency immediately after exercise, which correlated with the rise in lactate levels having a p-value <0.001. The increase in N145 latencyat 10 minutes post-exercise was statistically significant, whichcorrelated with changes in lactate levels. The N75 latency exhibited a statistically significant decrease at 10 minutes post-exercise, though it had no statistically significant correlation with lactate levels. Conclusion The study demonstrates that elevated blood lactate levels post-exercise influence VEPs, particularly by decreasing P100 latency and increasing N145 latency. These findings suggest that elevated lactate levels post-exercise may enhance primary visual cortex activity, possibly as a protective mechanism to maintain essential visual processing. However, this enhancement may impair communication with extrastriate areas, potentially reducing the accuracy of perceiving complex visual features such as color, depth, and motion.

Understanding the effects of different transcranial magnetic stimulation control protocols: a behavioral and neural perspective.

Transcranial magnetic stimulation (TMS) is a noninvasive stimulation technique for modulating brain activity. However, selecting optimal control protocols to account for their neural and non-neural effects remains a challenge. To this end, the present event-related potential (ERP) study investigated the behavioral and neural effects of three commonly used control protocols, namely, sham stimulation and real stimulation with continuous theta burst stimulation (c-TBS) over the vertex and primary visual cortex (V1), on a given task manipulating pitch in voice auditory feedback. The results showed no significant differences in vocal and ERP responses to pitch perturbations among the three TMS control protocols, suggesting their comparable neural and non-neural influences on vocal feedback control. Compared with the baseline condition (no TMS), all three TMS control protocols led to intact vocal compensations but prolonged N1 latencies and reduced P2 amplitudes, potentially linked to nonspecific stimulation effects or placebo-like responses. These findings provide the first neurobehavioral evidence for comparable effects across different TMS control protocols on vocal pitch regulation, offering insights for selecting optimal control strategies to explore the causal mechanisms of auditory-vocal integration. They also emphasize the importance of including a baseline condition to disentangle genuine TMS effects.NEW & NOTEWORTHY This is the first study to provide neurobehavioral evidence comparing the effects of three transcranial magnetic stimulation (TMS) control protocols on vocal feedback control. The findings suggest that sham stimulation and real stimulation [continuous theta burst stimulation (c-TBS) over vertex and V1] produce similar neural and non-neural effects on vocal pitch regulation. Despite no differences in vocal responses, all protocols led to prolonged N1 latencies and reduced P2 amplitudes, emphasizing the importance of including a baseline condition to isolate genuine TMS effects.

Early Impairment of Face Perception in Post-Stroke Depression: An ERP Study.

Objective: Face recognition is an important cognitive function of the human brain. Post stroke depression (PSD) is a common mental complication after stroke, which has a serious impact on individual physical function recovery and quality of life. This study aims to explore the face perception characteristics of PSD through electrophysiological indicators N170 and VPP, and provide an objective basis for the early evaluation of facial cognitive dysfunction in PSD. Methods: 58 patients in the cerebral small vessel disease (CSVD) with depressive symptoms (PSD) and 188 patients in the pure CSVD (NPSD). At the same time, 30 healthy subjects were selected as the healthy controls (HC). The differences of N170 and VPP components between the three groups were compared under the stimulation of inverted faces and upright faces. Results: PSD patients exhibited significantly longer peak latency and lower amplitude of N170 and VPP under both inverted and upright face stimulation compared to HC and NPSD. These results suggest that PSD patients have defects in early face recognition, there are abnormalities in the early perception and structural encoding of face information, and both the "overall mechanism" and "feature mechanism" of face recognition are damaged. Conclusions: These findings provide neuroelectrophysiological evidence for impaired emotionless face recognition in PSD patients.

Exploring the Relationship between Masseter and Cervical Vestibular-Evoked Myogenic Potentials in Young Adults with Hearing Thresholds Less Than or Equal to 15 dB HL.

Cervical vestibular-evoked myogenic potentials (cVEMPs) and masseter vestibular-evoked myogenic potentials (mVEMPs) are considered to have a common saccular origin. While a few studies have examined both vestibular-evoked myogenic potentials (VEMPs) in individuals with brainstem disorders as part of a test battery, the relation between these two potentials has rarely been the subject of discussion. The present study explored the relation between mVEMPs and cVEMPs using electromyography (EMG)-scaled parameters in normal-hearing young adults. Within-subject study design. Twenty young adults between 18 and 39 years of age (11 males, 9 females) participated in the study. cVEMP and mVEMP were performed on all the participants at 95 dBnHL with 500 Hz tone burst stimuli. Various VEMP parameters were evaluated including P13 and N23 peak latencies, the amplitude of the P13-N23 complex, and the Interaural Amplitude Asymmetry Ratio in EMG-scaled and unscaled conditions. All participants exhibited a 100% response rate for cVEMP and mVEMP responses. There were no significant ears and gender effect for both cVEMP and mVEMP. No correlation was found between cVEMP and mVEMP. There was no significant difference found between P1 and N1 latency values of cVEMP and mVEMP; however, a significant variation was observed for peak-to-peak amplitude both in EMG-scaled and unscaled conditions between cVEMP and mVEMP. Minimal to no association between any parameters of cVEMPs and mVEMPs suggests no significant relationship between these two VEMPs.

VEP Latency Delay Reflects Demyelination Beyond the Optic Nerve in the Cuprizone Model.

Remyelination therapies are advancing for multiple sclerosis, focusing on visual pathways and using visual evoked potentials (VEPs) for de/remyelination processes. While the cuprizone (CZ) model and VEPs are core tools in preclinical trials, many overlook the posterior visual pathway. This study aimed to assess functional and structural changes across the murine visual pathway during de/remyelination. One group of C57BL/6 mice underwent a CZ diet for 6 weeks to simulate demyelination, with a subset returning to a regular diet to induce remyelination. An additional group was fed a protracted CZ diet for 12 weeks to maintain chronic demyelination. Visual function was evaluated using electrophysiological recordings, including scotopic threshold responses (STRs) and electroretinograms (ERGs), with VEPs serving as a key biomarker for overall pathway health. Tissues from eyes, brains, and optic nerves (ONs) were collected at different time points for structural analysis. Our results demonstrated significant effects on VEPs, including increased N1 latencies and reduced amplitudes in the CZ mouse model. However, retinal function remained unaffected, as evidenced by unchanged STRs, ERGs, and retinal ganglion cell counts. Analysis of ONs revealed morphological changes, characterized by a significantly decreased axon diameter in the core region compared to the subpial region. Additionally, there was a significant increase in the g-ratio of the core region at 12 weeks CZ compared to controls. Immunofluorescence further demonstrated a decrease in myelin basic protein levels at 6 and 12 weeks in CZ animals. Interestingly, the dorsal lateral geniculate nucleus and primary visual cortex (V1) exhibited similar myelin changes, correlating with VEP latency alterations. These data reveal that interpreting VEP latency solely as a marker for ON demyelination is incomplete. Previous preclinical studies have overlooked the posterior visual pathways, necessitating a broader interpretation of VEP latency to cover the entire visual pathway.

Shared Patterns of Cognitive Control Behavior and Electrophysiological Markers in Adolescence.

Behavioral parameters obtained from cognitive control tasks have been linked to electrophysiological markers. Yet, most previous research has investigated only a few specific behavioral parameters at a time. An integrated approach with simultaneous consideration of multiple aspects of behavior may better elucidate the development and function of cognitive control. Here, we aimed to identify shared patterns between cognitive control behavior and electrophysiological markers using stop-signal task data and EEG recordings from an adolescent sample (n = 193, aged 11-25 years). We extracted behavioral variables covering various aspects of RT, accuracy, inhibition, and decision-making processes, as well as amplitude and latency of the ERPs N1, N2, and P3. To identify shared patterns between the two sets of variables, we employed a principal component analysis and a canonical correlation analysis. First, we replicated previously reported associations between various cognitive control behavioral parameters. Next, results from the canonical correlation analysis showed that overall good task performance was associated with fast and strong neural processing. Furthermore, the canonical correlation was affected by age, indicating that the association varies depending on age. The present study suggests that although distributional and computational methods can be applied to extract specific behavioral parameters, they might not capture specific patterns of cognitive control or electrophysiological brain activity in adolescents.

Prolonged Visual Evoked Potential Latencies in Dogs Naturally Infected with Canine Distemper Virus.

Canine distemper (CD) is a deadly, multi-system infection caused by a Morbillivirus. The canine distemper virus (CDV) frequently affects the nervous system with demyelinating leukoencephalitis, the most common neurological lesion. The disease has been linked to multiple sclerosis (MS) in humans due to similar clinical presentation and pathophysiological mechanisms. In MS, visual evoked potentials (VEPs) have been identified as a reliable marker for disease progression, enabling the early detection of clinically suspected lesions. The aim of this study was to determine if there are any abnormalities in VEP responses in dogs with neurological CD. Visual evoked potentials and electroretinogram (ERG) were recorded at both the cranial and spinal levels in dogs naturally infected with CDV and in healthy dogs. The results in the CDV-infected group revealed a bilateral increase in the latency of N1, P1, N2, P2, and N3 waves of the VEPs, without any alterations in their amplitudes. No significant differences were observed in the ERG between the groups. These results suggest that altered VEP responses could serve as an early diagnostic indicator of neurological damage caused by distemper. Therefore, conducting these studies could potentially aid in the detection of central nervous conduction disorders during the subclinical phases of the disease.

Reading Disability in Children: Exploring the N400 and its Associations with Set-For-Variability

ABSTRACT The N400 event-related potential (ERP), a marker of lexical-semantic processing, can assess the neural basis of reading difficulties. This study examines 1) semantic processes in typically developing (TD) children and children with reading disabilities (RD) using N400 and Set-for-Variability (SfV) profiles and 2) correlations between N400 and SfV. Fifty-one children read congruent and incongruent sentences during EEG. Results showed RD children lacked an N400 effect and had delayed SfV. A negative correlation between SfV and N400 latency in the RD group indicated distinct semantic processing delays in these children.

Study on the event-related potential in recognition of emotional words between typical “five-state personality”

Objective: To explore the event-related potential (ERP) differences of people with typical traditional Chinese medicine (TCM) “five-state personality” in the task of judging the emotional attributes (positive, neutral, and negative) of Chinese words. Methods: The “five-state personality test” was applied to screen the typical TCM “five-state personality”, and three groups were established including positive personality, negative personality, and atypical personality. The differences of electroencephalogram (EEG) components in the task of judging the emotional attributes of Chinese words were collected using ERPs. The 3 personality groups ×3 words with emotional attributes were analyzed by two-way analysis of variance (ANOVA). Results: The N1 and P300 components were induced successfully. The analysis on the mean values of corresponding electrodes in left frontal lobe, right frontal lobe, frontal lobe and parietal lobe showed that in the typical negative personality group, the absolute value of N1 amplitude was smaller in the prefrontal and frontal lobes, and the latency was shorter in the left frontal lobe, while in the typical positive personality group, the absolute value of N1 amplitude was larger in the left frontal lobe. In the prefrontal and frontal lobes, the N1 peak absolute value of negative words was higher and the latency was longer, and the N1 latency of neutral words was shorter. The N1 latency of positive words was shorter in the parietal lobe. In the right frontal and frontal lobes, the P300 peak of negative words was higher and the latency was longer, while the latency of positive words was longer in the parietal lobe. In addition, there was some interaction between personality groups and emotional attributes of words. Conclusion: When people with typical “five-state personality” judge the emotional attributes of words, the absolute value of N1 amplitude in left prefrontal lobe of typical positive personality group is high, while that of typical negative personality group was small and the latency is short. The P300 latency of negative words is longer in the right frontal and frontal lobes, and that of positive words is longer in the parietal lobes, with more significant difference in the positive personality group.

Assessment of Sacculocollic and Vestibulomasseteric Reflex Pathways in Individuals With Migraine and Vestibular Migraine.

The study's objective was to evaluate the functioning of sacculocollic and vestibulomasseteric reflex pathways in individuals with vestibular migraine and migraine. Seventy-five participants aged 18-50 years were selected for the study. Participants were divided into three groups. Group 1 consisted of 25 healthy individuals, Group 2 consisted of 25 migraine individuals, and Group 3 consisted of 25 individuals with vestibular migraine. Cervical vestibular-evoked myogenic potential (cVEMP) and masseter vestibular-evoked myogenic potential (mVEMP) were recorded using a 500-Hz tone burst stimulus presented at 125 dB peSPL for all participants. The cVEMP test results showed a delayed p13 and n23 latency for both migraine and vestibular migraine individuals when compared to healthy individuals. Also, the amplitude of the p13-n23 peak was reduced compared to healthy individuals in both migraine and vestibular migraine. Similarly, the mVEMP test results showed a delayed p11 and n21 latency for both migraine and vestibular migraine individuals. No difference was observed in the amplitude of the p11-n21 peak complex between the three groups. Spearman's rho correlation revealed no significant (p > .05) correlation between cervical and masseter VEMP latency and amplitude parameters between healthy, migraine, and vestibular migraine individuals. The results of the study are suggestive of the pathology of the sacullocollic and vestibulomasseteric reflex pathways in individuals with migraine and vestibular migraine. Individuals with migraine and vestibular migraine should undergo a detailed vestibular evaluation.