N1 Latency Research Articles

Assessment of balance after recovery from Covid-19 disease

ObjectiveTo answer the question whether balance related systems have been affected in adults who recovered from Covid-19 disease. This is the first case-control study to assess balance objectively and quantitatively in Covid-19 disease. MethodsThirty-seven patients who recovered from Covid-19 disease and 30 healthy controls were compared using Dizziness Handicap Inventory (DHI), Computerized Dynamic Posturography (CDP), Vestibular Evoked Myogenic Potentials(VEMP) and Video Head Impulse Test (v-HIT). ResultsOn CDP, the composite and visual general scores of the patients were significantly lower than controls (p<0.01). The v-HIT gains of the patients significantly decreased in the vertical semicircular canals compared to controls (p<0.01).There was a significant difference between the patients and controls regarding the absence of o-VEMPs (p<0.01) while the amplitudes and latencies were similar between the groups (p>0.05). Decreased P1/N1 amplitudes and elongated N1 latencies were found on c-VEMP testing (p<0.05). Anosmia, taste disorder and gender were not associated with subjective and objective test results (p>0.05). ConclusionThe Covid-19 disease can cause dizziness rather that incapacitating vertigo. Dizziness can be seen in almost one-fifth of the adult covid19 out-patients, which may be due to involvement of vestibular and visual systems,ortheir central connections. The squeals created in the balance related systems may be irreversible as they have persisted after the recovery of the patients. It is also plausible to anticipate more severe condition in the older patients who were treated in the intensive care units. In the long term follow up of the survivors, the need for balance rehabilitation programs should be remembered in order to minimize risks of falling down.

Persistence of Neuronal Alterations in Alcohol-Dependent Patients at Conclusion of the Gold Standard Withdrawal Treatment: Evidence From ERPs.

Background: One of the main challenges for clinicians is to ensure that alcohol withdrawal treatment is the most effective possible after discharge. To address this issue, we designed a pilot study to investigate the efficacy of the rehabilitation treatment on the main stages of information processing, using an electroencephalographic method. This topic is of main importance as relapse rates after alcohol withdrawal treatment remain very high, indicating that established treatment methods are not fully effective in all patients in the long run.Method: We examined in alcohol-dependent patients (ADP) the effects of the benzodiazepine-based standard detoxification program on event-related potential components at incoming (D0) and completion (D15) of the treatment, using tasks of increasing difficulty (with and without workload) during an auditory oddball target paradigm. Untreated non-alcohol-dependent-volunteers were used as matching controls.Results: At D0, ADP displayed significantly lower amplitude for all ERP components in both tasks, as compared to controls. At D15, this difference disappeared for the amplitude of the N1 component during the workload-free task, as well as the amplitude of the P3b for both tasks. Meanwhile, the amplitude of the N2 remained lower in both tasks for ADP. At D0, latencies of N2 and P3b in both task conditions were longer in ADP, as compared to controls, whilst the latency of N1 was unchanged. At D15, the N2 latency remained longer for the workload condition only, whereas the P3b latency remained longer for the workload-free task only.Conclusion: The present pilot results provide evidence for a persistence of impaired parameters of ERP components, especially the N2 component. This suggests that neural networks related to attention processing remain dysfunctional. Longitudinal long-term follow-up of these patients is mandatory for further assessment of a link between ERP alterations and a later risk of relapse.

Assessment of event-related evoked potentials and China-Wechsler intelligence scale for cognitive dysfunction in children with obstructive sleep apnea

ObjectiveTo explore the relationship between obstructive sleep apnea (OSA) and cognitive impairment by combining event-related evoked potentials (ERPs) and China-Wechsler Younger Children Scale (C-WISC) in children with sleep-disordered breathing (SDB) with vs. without OSA. MethodsThis was a retrospective case-control study of all consecutive children (n = 148) with adenoid tonsil hypertrophy between July 2017 and March 2019 at the Hospital. ResultsThe children were divided into the OSA (n = 102) and non-OSA (n = 46) groups. The apnea-hypopnea index (AHI), obstructive apnea index (OAI), and obstructive apnea-hypopnea index (OAHI) in the OSA group were elevated compared with those of the non-OSA group (all P < 0.001). The mean oxygen saturation (SaO2) and SaO2 nadir were lower in the OSA group compared with the non-OSA group (both P < 0.001). The respiratory arousal index (RAI) values in the OSA group were larger than those of the non-OSA group (P < 0.001). The P300 and N100 latencies in the OSA group were longer than those of the non-OSA group (both P < 0.001). Pearson's correlation analysis revealed correlations of the P300 peak latency with full-scale intelligence quotient (FIQ) (P < 0.001 and r = −0.527), verbal intelligence quotient (VIQ) (P < 0.001 and r = −0.448), and performance intelligence quotient (PIQ) (P < 0.001 and r = −0.515). There was a correlation between the N100 peak latency and PIQ (P = 0.026 and r = −0.183). ConclusionERPs, as an objective measurement, might help assess cognitive impairment in children with OSA.

Comparison of Visual Evoked Potentials in Patients Affected by Optic Neuritis From Multiple Sclerosis or Neuromyelitis Optica Spectrum Disorder.

To compare the visual evoked potentials (VEPs) of optic neuritis (ON) patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and controls. To evaluate correlations between VEP and optical coherence tomography (OCT), contrast sensitivity (CS), and automated perimetry. Fifty-five eyes with ON from 29 patients (MS = 14 and NMOSD = 15) and 57 eyes from 29 controls were evaluated using VEP, automated perimetry, CS, and optical coherence tomography. Three groups were analyzed: 1) MS eyes with history of ON (ON-MS), 2) NMOSD eyes with ON (ON-NMOSD), and 3) healthy controls. Groups were compared and associations between the parameters were tested. Compared to controls, ON-MS eyes showed significantly delayed N75 and P100 latencies when using a medium-sized stimulus (30'), and delayed P100 latency when using a large stimulus (1.5°), but similar amplitudes. Compared to controls, ON-NMOSD eyes showed significantly lower N75/P100 amplitudes (both stimulus sizes) and P100/N135 amplitudes (with the 30' stimulus), but latencies did not differ, except for a delayed P100 latency with the 30' stimulus. When comparing the 2 ON groups using the 1.5° stimulus, there was significant delay in P100 latency in ON-MS eyes and a reduction in N75/P100 amplitude in ON-NMOSD eyes. Peripapillary retinal nerve fiber layer, macular inner retinal layers, and CS measurements were significantly smaller in ON patients than in controls. A strong correlation was found between VEP parameters and inner retinal layer thickness in ON-NMOSD eyes. ON-MS eyes had normal amplitude and delayed VEP latency, whereas ON-NMOSD eyes displayed reduced amplitude and preserved latency when elicited by checkerboard stimulus with large 1.5° checks. Under such conditions, VEP may help distinguish resolved MS-related ON from resolved NMOSD-related ON.

Development of motion speed perception from infancy to early adulthood: a high-density EEG study of simulated forward motion through optic flow

This study investigated evoked and oscillatory brain activity in response to forward visual motion at three different ecologically valid speeds, simulated through an optic flow pattern consisting of a virtual road with moving poles at either side of it. Participants were prelocomotor infants at 4–5 months, crawling infants at 9–11 months, primary school children at 6 years, adolescents at 12 years, and young adults. N2 latencies for motion decreased significantly with age from around 400 ms in prelocomotor infants to 325 ms in crawling infants, and from 300 and 275 ms in 6- and 12-year-olds, respectively, to 250 ms in adults. Infants at 4–5 months displayed the longest latencies and appeared unable to differentiate between motion speeds. In contrast, crawling infants at 9–11 months and 6-year-old children differentiated between low, medium and high speeds, with shortest latency for low speed. Adolescents and adults displayed similar short latencies for the three motion speeds, indicating that they perceived them as equally easy to detect. Time–frequency analyses indicated that with increasing age, participants showed a progression from low- to high-frequency desynchronized oscillatory brain activity in response to visual motion. The developmental differences in motion speed perception are interpreted in terms of a combination of neurobiological development and increased experience with self-produced locomotion. Our findings suggest that motion speed perception is not fully developed until adolescence, which has implications for children’s road traffic safety.

Short-term lithium treatment protects the brain against ischemia–reperfusion injury by enhancing the neuroplasticity of cortical neurons

ABSTRACT Objectives Lithium exerts a broad neuroprotective effect on the brain. This study examined whether lithium exerts therapeutic effects on stroke by restoring neural connections at the ischemic core of cortices post brain insult. Methods We treated rats with lithium or vehicle (saline) every 24 h for the first 72 h, starting at the beginning of reperfusion after inducing middle cerebral artery occlusion (MCAO) in rats. Somatosensory evoked potential (SSEP) recording and behavioral testing were employed to evaluate the beneficial effects of lithium treatment. To examine the effects of lithium-induced neuroplasticity, we evaluated the dendritic morphology in cortex pyramidal cells and the primary neuronal cell culture that underwent brain insults and oxygen and glucose deprivation (OGD), respectively. Results The results demonstrated that rats subjected to MCAO had prolonged N1 latency and a decreased N1/P1 amplitude at the ipsilateral cortex. Four doses of lithium reduced the brain infarction volume and enhanced the SSEP amplitude. The results of neurobehavioral tests demonstrated that lithium treatment improved sensory function, as demonstrated by improved 28–point clinical scale scores. In vitro study results showed that lithium treatment increased the dendritic lengths and branches of cultured neurons and reversed the suppressive effects of OGD. The in vivo study results indicated that lithium treatment increased cortical spine density in various layers and resulted in the development of the dendritic structure in the contralateral hemisphere. Conclusion Our study confirmed that neuroplasticity in cortical neurons is crucial for lithium-induced brain function 50 recovery after brain ischemia.

Normative and Pathological Ranges of Cervical Vestibular Evoked Myogenic Potentials in Normal Subjects and Patients with Complete Compensated Unilateral Vestibular Loss: A Cross Sectional Study.

To know the normative ranges of VEMP response metrics in healthy young adults. To know the pathological cutoff of VEMP metrics in unilateral vestibular loss patients. To compare our VEMP metrics with the normative values of other studies from the western world. Prospective cross-sectional study. Tertiary care audiovestibular laboratory. 30 healthy subjects and 15 cases with a unilateral complete compensated loss. Various VEMP parameters-p1 latency, n1 latency, p1-n1 amplitude and Interaural asymmetry ratio (IAR) were entered into databases and analyzed. We compared our parameters with the most cited scientific data on VEMP available in the PubMed database, and we analyzed the results. 90% of controls and 80% of cases got VEMP responses at 95dB HL threshold, 500Hz with subject/patient placed in sitting upright with head turned to opposite side position. The normative data of VEMP response metrics in young adults for p1, n1 latencies, p1-n1 amplitude, and IAR are 13 ± 2ms, 21 ± 2ms, 91 ± 33 uV, and 9.25 ± 7.3, respectively. As the VEMP test has 100% sensitivity and 100% (95% CI 87-100%) negative predictive value in detecting the saccular dysfunction, we recommend the VEMP test as a mandatory tool in the vestibular test battery. There is no statistically significant difference in various VEMP parameters between the control and normal sides of the case group.

Axon regeneration after optic nerve injury in rats can be improved via PirB knockdown in the retina

BackgroundIn the central nervous system (CNS), three types of myelin-associated inhibitors (MAIs) exert major inhibitory effects on nerve regeneration: Nogo-A, myelin-associated glycoprotein (MAG), and oligodendrocyte-myelin glycoprotein (OMgp). MAIs have two co-receptors, Nogo receptor (NgR) and paired immunoglobulin-like receptor B (PirB). Existing studies confirm that inhibiting NgR only exerted a modest disinhibitory effect in CNS. However, the inhibitory effects of PirB on nerve regeneration after binding to MAIs are controversial too. We aimed to further investigate the effect of PirB knockdown on the neuroprotection and axonal regeneration of retinal ganglion cells (RGCs) after optic nerve injury in rats.MethodsThe differential expression of PirB in the retina was observed via immunofluorescence and western blotting after 1, 3, and 7 days of optic nerve injury (ONI). The retina was locally transfected with adeno-associated virus (AAV) PirB shRNA, then, the distribution of virus in tissues and cells was observed 21 days after AAV transfection to confirm the efficiency of PirB knockdown. Level of P-Stat3 and expressions of ciliary neurotrophic factor (CNTF) were detected via western blotting. RGCs were directly labeled with cholera toxin subunit B (CTB). The new axons of the optic nerve were specifically labeled with growth associated protein-43 (GAP43) via immunofluorescence. Flash visual evoked potential (FVEP) was used to detect the P1 and N1 latency, as well as N1-P1, P1-N2 amplitude to confirm visual function.ResultsPirB expression in the retina was significantly increased after ONI. PirB knockdown was successful and significantly promoted P-Stat3 level and CNTF expression in the retina. PirB knockdown promoted the regeneration of optic nerve axons and improved the visual function indexes such as N1-P1 and P1-N2 amplitude.ConclusionsPirB is one of the key molecules that inhibit the regeneration of the optic nerve, and inhibition of PirB has an excellent effect on promoting nerve regeneration, which allows the use of PirB as a target molecule to promote functional recovery after ONI.

Brain Vital Signs in Elite Ice Hockey: Towards Characterizing Objective and Specific Neurophysiological Reference Values for Concussion Management.

Background: Prior concussion studies have shown that objective neurophysiological measures are sensitive to detecting concussive and subconcussive impairments in youth ice-hockey. These studies monitored brain vital signs at rink-side using a within-subjects design to demonstrate significant changes from pre-season baseline scans. However, practical clinical implementation must overcome inherent challenges related to any dependence on a baseline. This requires establishing the start of normative reference data sets.Methods: The current study collected specific reference data for N = 58 elite, youth, male ice-hockey players and compared these with a general reference dataset from N = 135 of males and females across the lifespan. The elite hockey players were recruited to a select training camp through CAA Hockey, a management agency for players drafted to leagues such as the National Hockey League (NHL). The statistical analysis included a test-retest comparison to establish reliability, and a multivariate analysis of covariance to evaluate differences in brain vital signs between groups with age as a covariate.Findings: Test-retest assessments for brain vital signs evoked potentials showed moderate-to-good reliability (Cronbach’s Alpha > 0.7, Intraclass correlation coefficient > 0.5) in five out of six measures. The multivariate analysis of covariance showed no overall effect for group (p = 0.105), and a significant effect of age as a covariate was observed (p < 0.001). Adjusting for the effect of age, a significant difference was observed in the measure of N100 latency (p = 0.022) between elite hockey players and the heterogeneous control group.Interpretation: The findings support the concept that normative physiological data can be used in brain vital signs evaluation in athletes, and should additionally be stratified for age, skill level, and experience. These can be combined with general norms and/or individual baseline assessments where appropriate and/or possible. The current results allow for brain vital sign evaluation independent of baseline assessment, therefore enabling objective neurophysiological evaluation of concussion management and cognitive performance optimization in ice-hockey.

Cervical vestibular-evoked myogenic potentials in patients with essential tremor

Although different neuroanatomical structures and pathways are emphasized as possible explanations for essential tremor (ET), there is still an ongoing debate. This study aimed to assess the role of brainstem and reflex pathways with cervical vestibular-evoked myogenic potentials (VEMP) in patients with ET. This prospective study included 34 patients with ET and 25 healthy controls. Cervical VEMP was performed in both groups and latencies, inter-peak latency intervals, peak-to-peak amplitudes and asymmetry ratios were recorded. There was statistically no significant difference between the groups in terms of age (38.9 ± 14.9 years vs. 38.9 ± 14.9 years, p = 0.673) and gender (female to male ratio: 14/11 vs. 20/14, p = 0.828). Right N1 latency and right N1–P1 interval were significantly longer in the patient group (p < 0.05). There was a significant positive correlation between the duration of disease and the right N1–P1 interval (p < 0.05). There was no significant difference between the patient and control groups in terms of bilateral P1 latency, left N1 latency, left N1–P1 interval, and bilateral N1 and P1 amplitudes (p˃0.05). Cervical VEMP may reveal the involvement of brainstem and associated reflex pathways in ET.

The reference intervals of intraoperative posterior tibial nerve somatosensory evoked potentials

BackgroundA reference interval exists for posterior tibial nerve somatosensory evoked potentials (PTN-SEPs) in awake. However, the reference interval for intraoperative- PTN-SEPs (I-PTN-SEPs) remains unclear. As a substitute for PTN-SEPs in awake, we considered I-PTN-SEPs can provide functional information about the dorsal somatosensory system. No report evaluated the physiologic and analytical issues in the measurement of I-PTN-SEPs. We investigated the sources of variation and reference intervals for I-PTN-SEPs. MethodsWe studied 143 patients with unilateral radiculopathy and without neurologic deficit who underwent surgery. Stimulation was delivered to the PTN at the ankle. The scalp recording electrode was placed at the Cz with a reference electrode located on the forehead at the Fz. SEPs were recorded from patients during electrical stimulation of the I-PTN. ResultsP1 and N1 latencies showed significant positive linear correlations with age (P1 latency = 36.52 + 0.0814 × age, P = 0.00003; N1 latency = 46.21 + 0.081 × age, P = 0.00022), and body height (P1 latency = 16.94 + 14.91 × body height, P = 0.00000; N1 latency = 25.42 + 15.64 × body height, P = 0.00002). In contrast, I-PTN-SEPs amplitude showed no correlation with age or body height. The 95% confidence interval for I-PTN-SEPs amplitude, or the reference interval, was determined as 0.31–5.91 μV. ConclusionsThe lower normal limit value was 0.31 μV, and this reference interval may be useful to evaluate function of the posterior funiculus, such that as during surgery for patients with intramedullary tumor.

Effects on cervical vestibular-evoked myogenic potentials of four clinically used head and neck measurement positions in healthy subjects

Background The most reliable head and neck position for cervical vestibular-evoked myogenic potentials (cVEMPs) measurements yet to be determined. Aims/objectives To assess how four body positions used during clinical recordings of cVEMPs affect cVEMP parameters. Material and method cVEMPs of 10 healthy subjects (26-50 years old) were recorded in four body positions: A. sitting/head rotated; B. supine/head rotated; C. semi-recumbent/head rotated and elevated; D. supine/head elevated. Results Mean background sternocleidomastoid muscle (SCM) electrical activity was significantly higher in positions C and D than in positions A and B. The latencies of p13 and n23 differed significantly among the four positions. Raw p13-n23 complex amplitude was significantly greater in positions C and D than in A and B. These differences were reduced when amplitudes were corrected by SCM activity. For positions A and B, one and two subjects, respectively, had an abnormal raw asymmetry ratio (AR). After correction, all subjects had normal ARs in all positions. Conclusions and significance Body positions in which the head is elevated produce a quicker and larger cVEMP response compared to positions in which the head is not elevated. The difference in ARs among positions can be ignored as long as the correction is made.

Characteristic manifestation of ocular and cervical vestibular evoked myogenic potentials findings in severe obstructive sleep apnea patients

Background Studies of saccular and utricular function in patients with obstructive sleep apnea (OSA) are rare. We noticed that some OSA patients also had positive results in vestibular function tests, and this inspired our interest in exploring the vestibular function patterns of OSA patients. Objectives To investigate otolithic organ function in severe OSA patients who lack vestibular symptoms and systemic disease. Material and methods 32 patients (64 ears) with severe OSA and 22 healthy controls (44 ears) were enrolled. The ocular and cervical vestibular-evoked myogenic potentials (oVEMP and cVEMP) and the caloric test were recorded and analyzed. Results The response rates of oVEMP (73.4%) and cVEMP (82.8%) in patients with severe OSA were significantly lower than those in controls. In oVEMP, elevated thresholds (p = .002), decreased n1-p1 amplitudes (p < .001), prolonged n1 latencies (p < .001) were observed. In cVEMP, the elevation of thresholds (p < .001), decrease in p1-n1 amplitudes (p < .001), and n1-p2 amplitudes (p < .001), prolongation of p1 latencies (p = .003) were observed. No significant difference in the caloric test was found between the two groups. Conclusions and significance Disappearance or impairment of VEMPs could be observed in patients with severe OSA, and reflects different degrees of impairment in the utricle and saccule.

Intraoperative Monitoring (IOM) P-IM002. Somatosensory evoked potentials in cervical and cerebellopontine angle Neurosurgical procedures: Experience from a tertiary care center in india

Introduction . The role of Intraoperative neuromonitoring (IONM) as a guiding technique in neurosurgical procedures is well established. Somato-Sensory Evoked Potentials (SSEPs) are an important modality in IONM. We report our experience with SSEPs in surgeries of Cervical Spine, Cranio-Vertebral junctions and Cerebellopontine angle at our centre. Methods . Sixty two patients underwent surgery in the cervical region and cerebellopontine angle under IONM guidance at the Department of Neurosurgery from May 2018 and September 2018. Out of which SSEPs were not performed in 22 patients and SSEPs could not be recorded in 20 patients due to technical reasons, therefore 20 patients were included in the study. SSEPs were recorded during the surgical procedures to provide information about neural integrity. Median nerves in both the limbs were stimulated at the level of the wrist using sterile transdermal needle electrodes. SSEP recordings were obtained using corkscrew needle electrodes placed at the scalp in Cp3, Cp4 and Fz, according to the 10-20 recording system. Signals were acquired using Medtronics NimEclipse© and Natus Protektor© system. The cortical recordings were taken from Cp3-Fz and Cp3-Cp4 montage for right sided SSEP and Cp4-Fz and Cp4-Cp3 montage for left sided SSEP. Results . The stimulation intensity was decided on a case-to-case basis. Range of stimulation varied from 10 - 23 mA with frequency of 4.70 Hz and stimulation duration of 0.2 ms. Real time averaging of 1000 waveforms was done. N20 and P22 latencies were checked pre-operatively just after induction, intra-operatively and post-operatively just before closure. In all the 20 patients, intra-operative period was uneventful. All cases showed normal recovery in the post- operative period. Conclusion . SSEP monitoring is a very useful tool for intraoperative sensory tract monitoring in the patients undergoing Cervical and Cerebellopontine region surgery. Change in the latency or amplitude in the cortical SSEP recordings can predict injury to the vital structures which can be reversed by surgeons if early warning is raised by Neurophysiologists.

Aging Effects on Cortical Responses to Tones and Speech in Adult Cochlear-Implant Users.

Age-related declines in auditory temporal processing contribute to speech understanding difficulties of older adults. These temporal processing deficits have been established primarily among acoustic-hearing listeners, but the peripheral and central contributions are difficult to separate. This study recorded cortical auditory evoked potentials from younger to middle-aged (< 65years) and older (≥ 65years) cochlear-implant (CI) listeners to assess age-related changes in temporal processing, where cochlear processing is bypassed in this population. Aging effects were compared to age-matched normal-hearing (NH) listeners. Advancing age was associated with prolonged P2 latencies in both CI and NH listeners in response to a 1000-Hz tone or a syllable /da/, and with prolonged N1 latencies in CI listeners in response to the syllable. Advancing age was associated with larger N1 amplitudes in NH listeners. These age-related changes in latency and amplitude were independent of stimulus presentation rate. Further, CI listeners exhibited prolonged N1 and P2 latencies and smaller P2 amplitudes than NH listeners. Thus, aging appears to degrade some aspects of auditory temporal processing when peripheral-cochlear contributions are largely removed, suggesting that changes beyond the cochlea may contribute to age-related temporal processing deficits.

Recognition Characteristics of Facial and Bodily Expressions: Evidence From ERPs.

In the natural environment, facial and bodily expressions influence each other. Previous research has shown that bodily expressions significantly influence the perception of facial expressions. However, little is known about the cognitive processing of facial and bodily emotional expressions and its temporal characteristics. Therefore, this study presented facial and bodily expressions, both separately and together, to examine the electrophysiological mechanism of emotional recognition using event-related potential (ERP). Participants assessed the emotions of facial and bodily expressions that varied by valence (positive/negative) and consistency (matching/non-matching emotions). The results showed that bodily expressions induced a more positive P1 component and a shortened latency, whereas facial expressions triggered a more negative N170 and prolonged latency. Among N2 and P3, N2 was more sensitive to inconsistent emotional information and P3 was more sensitive to consistent emotional information. The cognitive processing of facial and bodily expressions had distinctive integrating features, with the interaction occurring in the early stage (N170). The results of the study highlight the importance of facial and bodily expressions in the cognitive processing of emotion recognition.

Visual prediction cues can facilitate behavioural and neural speech processing in young and older adults

The ability to process speech evolves over the course of the lifespan. Understanding speech at low acoustic intensity and in the presence of background noise becomes harder, and the ability for older adults to benefit from audiovisual speech also appears to decline. These difficulties can have important consequences on quality of life. Yet, a consensus on the cause of these difficulties is still lacking. The objective of this study was to examine the processing of speech in young and older adults under different modalities (i.e. auditory [A], visual [V], audiovisual [AV]) and in the presence of different visual prediction cues (i.e., no predictive cue (control), temporal predictive cue, phonetic predictive cue, and combined temporal and phonetic predictive cues). We focused on recognition accuracy and four auditory evoked potential (AEP) components: P1–N1–P2 and N2. Thirty-four right-handed French-speaking adults were recruited, including 17 younger adults (28 ± 2 years; 20–42 years) and 17 older adults (67 ± 3.77 years; 60–73 years). Participants completed a forced-choice speech identification task. The main findings of the study are: (1) The faciliatory effect of visual information was reduced, but present, in older compared to younger adults, (2) visual predictive cues facilitated speech recognition in younger and older adults alike, (3) age differences in AEPs were localized to later components (P2 and N2), suggesting that aging predominantly affects higher-order cortical processes related to speech processing rather than lower-level auditory processes. (4) Specifically, AV facilitation on P2 amplitude was lower in older adults, there was a reduced effect of the temporal predictive cue on N2 amplitude for older compared to younger adults, and P2 and N2 latencies were longer for older adults. Finally (5) behavioural performance was associated with P2 amplitude in older adults. Our results indicate that aging affects speech processing at multiple levels, including audiovisual integration (P2) and auditory attentional processes (N2). These findings have important implications for understanding barriers to communication in older ages, as well as for the development of compensation strategies for those with speech processing difficulties.

Brief Report: Preliminary Evidence of the N170 as a Biomarker of Response to Treatment in Autism Spectrum Disorder.

Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by primary difficulties in social function. Individuals with ASD display slowed neural processing of faces, as indexed by the latency of the N170, a face-sensitive event-related potential. Currently, there are no objective biomarkers of ASD useful in clinical care or research. Efficacy of behavioral treatment is currently evaluated through subjective clinical impressions. To explore whether the N170 might have utility as an objective index of treatment response, we examined N170 before and after receipt of an empirically validated behavioral treatment in children with ASD.Method: Electroencephalography (EEG) data were obtained on a preliminary cohort of preschool-aged children with ASD before and after a 16-week course of PRT and in a subset of participants in waitlist control (16-weeks before the start of PRT) and follow-up (16-weeks after the end of PRT). EEG was recorded while participants viewed computer-generated faces with neutral and fearful affect.Results: Significant reductions in N170 latency to faces were observed following 16 weeks of PRT intervention. Change in N170 latency was not observed in the waitlist-control condition.Conclusions: This exploratory study offers suggestive evidence that N170 latency may index response to behavioral treatment. Future, more rigorous, studies in larger samples are indicated to evaluate whether the N170 may be useful as a biomarker of treatment response.

Electrophysiological Studies of Reception of Facial Communication in Autism Spectrum Disorder and Schizophrenia.

Autism spectrum disorder (ASD) and schizophrenia spectrum disorders (SZ) are characterized by difficulty with social cognition and atypical reception of facial communication - a key area in the Research Domain Criteria framework. To identify areas of overlap and dissociation between ASD and SZ, we review studies of event-related potentials (ERP) to faces across ASD and SZ populations, focusing on ERPs implicated in social perception: P100, N170, N250, and P300. There were many inconsistent findings across studies; however, replication was strongest for delayed N170 latency in ASD and attenuated N170 amplitude in SZ. These results highlight the challenges of replicating research findings in heterogeneous clinical populations and the need for transdiagnostic research that continuously quantifies behavior and neural activity across neurodevelopmental disorders.

The Time Course of Event-Related Brain Potentials in Athletes' Mental Rotation With Different Spatial Transformations.

Studies have found that athletes outperformed non-athletes in mental rotation tasks with both object-based and egocentric transformations (ET), but the effect of sport expertise on the processing stages (i.e., perceptual stage, rotation stage, and decision stage) remains conflicted. Bearing the view that the stages occur sequentially and the high temporal resolution of event-related brain potentials, this study focused on brain processing during mental rotation and was designed to determine the time course of electrophysiological changes in athletes and non-athletes. A total of 42 divers and non-athletes were recruited for the study. A mental body rotation task with object-based and egocentric transformation conditions was conducted, and the reaction time (RT), accuracy, performance stages, N2 latency, amplitude, and the amplitude of rotation-related negativity (RRN) were recorded. Behavioral results demonstrated higher accuracy for athletes at 120° and 180°. Moreover, as compared to non-athletes, the enlarged amplitude of N2 and RRN were confirmed in both transformations for athletes and were correlated with the performance stages and athletes’ professional training years. The present study provided a deeper insight into the relationship between sports training, behavior performance, and brain activity.