Normal Young Adults Research Articles

Erythropoietin levels in geriatric anemia

ABSTRACT Background: Defects in the production or action of erythropoietin (EPO) are important contributing factors in anemia. However, the exact impact of aging on levels of EPO and its role in the development of geriatric anemia is still underexplored. Moreover, the specific pattern of EPO in etiological subcategories such as nutritional anemia (NA), anemia of chronic disease (ACD), and unexplained anemia (UA) is not entirely known. Objective: The aim of the study was to determine the serum EPO levels in geriatric anemia and compare them across NA, ACD, UA, and NA with ACD. Materials and Methods: Ninety anemic geriatric patients (cases) along with 30 non-anemic geriatric controls were evaluated for serum EPO levels. A correlation between S.EPO and inflammatory markers was also done. Results: Serum EPO levels were higher in cases as compared to controls (P < 0.00). After adjusting for outliers, the reference range of EPO in controls was the same as in normal young adults (2.21–20.95 mU/mL). The majority (37/58, 63.7%) of NA patients had increased S.EPO levels (highest among all four subcategories and controls). S.EPO also correlated inversely with high-sensitivity CRP (hsCRP) and serum ferritin (SF), reinforcing that the inflammatory state suppresses S.EPO levels. Conclusion: Geriatric anemic patients have elevated S.EPO as compared to non-anemic controls (observed reference range similar to young adults). Raised EPO levels were detected more frequently in NA, while they were the lowest in UA.

Effects of Stimulus Rate and Periodicity on Auditory Cortical Entrainment to Continuous Sounds.

The neural mechanisms underlying the exogenous coding and neural entrainment to repetitive auditory stimuli have seen a recent surge of interest. However, few studies have characterized how parametric changes in stimulus presentation alter entrained responses. We examined the degree to which the brain entrains to repeated speech (i.e., /ba/) and nonspeech (i.e., click) sounds using phase-locking value (PLV) analysis applied to multichannel human electroencephalogram (EEG) data. Passive cortico-acoustic tracking was investigated in N = 24 normal young adults utilizing EEG source analyses that isolated neural activity stemming from both auditory temporal cortices. We parametrically manipulated the rate and periodicity of repetitive, continuous speech and click stimuli to investigate how speed and jitter in ongoing sound streams affect oscillatory entrainment. Neuronal synchronization to speech was enhanced at 4.5 Hz (the putative universal rate of speech) and showed a differential pattern to that of clicks, particularly at higher rates. PLV to speech decreased with increasing jitter but remained superior to clicks. Surprisingly, PLV entrainment to clicks was invariant to periodicity manipulations. Our findings provide evidence that the brain's neural entrainment to complex sounds is enhanced and more sensitized when processing speech-like stimuli, even at the syllable level, relative to nonspeech sounds. The fact that this specialization is apparent even under passive listening suggests a priority of the auditory system for synchronizing to behaviorally relevant signals.

38 Real-World Goal Setting and Follow Through in Young and Older Adults

Objective:The ability to generate, plan for, and follow through with goals is essential to everyday functioning. Compared to young adults, cognitively normal older adults have more difficulty on a variety of cognitive functions that contribute to goal setting and follow through. However, how these age-related cognitive differences impact real-world goal planning and success remains unclear. In the current study, we aimed to better understand the impact of older age on everyday goal planning and success.Participants and Methods:Cognitively normal young adults (18-35 years, n= 57) and older adults (60-80 years, n= 49) participated in a 10-day 2-session study. In the first session, participants described 4 real-world goals that they hoped to pursue in the next 10 days. These goals were subjectively rated for personal significance, significance to others, and vividness, and goal descriptions were objectively scored for temporal, spatial, and event specificity, among other measures. Ten days later, participants rated the degree to which they planned for and made progress in their real-world goals since session one. Older adults also completed a battery of neuropsychological tests.Results:Some key results are as follows. Relative to the young adults, cognitively normal older adults described real-world goals which navigated smaller spaces (p=0.01) and that they perceived as more important to other people (p=0.03). Older adults also planned more during the 10-day window (p<0.001). There was not a statistically significant age group difference, however, in real-world goal progress (p=0.65). Nonetheless, among older participants, goal progress was related to higher mental processing speed as shown by the Trail Making Test Part A (r=0.36, p=0.02) and the creation of goals confined to specific temporal periods (r=0.35, p=0.01). Older participants who scored lower on the Rey Complex Figure Test (RCFT) long delay recall trial reported that their goals were more like ones that they had set in the past (r= -0.34, p=0.02), and higher episodic memory as shown by the RCFT was associated with more spatially specific goals (r=0.32, p=0.02), as well as a greater use of implementation intentions in goal descriptions(r=0.35, p=0.02).Conclusions:Although older adults tend to show decline in several cognitive domains relevant to goal setting, we found that cognitively normal older adults did not make significantly less progress toward a series of real-world goals over a 10-day window. However, relative to young adults, older adults tended to pursue goals which were more important to others, as well as goals that involved navigating smaller spaces. Older adults also appear to rely on planning more than young adults to make progress toward their goals. These findings reveal age group differences in the quality of goals and individual differences in goal success among older adults. They are also in line with prior research suggesting that cognitive aging effects may be more subtle in real-world contexts.

Saliva insulin tracks plasma insulin across the day following high-carbohydrate and low-carbohydrate meals.

Non-invasive monitoring of insulin could hold promise to identify those with, or at risk for developing, insulin resistance. We aimed to examine saliva insulin responses across the day following high- and low-carbohydrate meals and evaluate whether changes in saliva insulin might accurately reflect changes in plasma insulin. In two randomized crossover studies, young normal weight men (NW; n=8; Study 1) and adults with overweight/obesity (OO; n=8; Study 2) completed two 9-h experimental trials in which the participants consumed isocaloric mixed high-carbohydrate (HC) or low-carbohydrate (LC) meals at 0, 3, and 6 h. Plasma and saliva samples were collected at fasted baseline and every 30 min for a total of 19 samples across 9 h. Overall, findings revealed a similar trend for postprandial saliva and plasma insulin responses regardless of the time of the day with a ∼30-45 min lag between saliva and plasma insulin responses. In both NW and OO groups, saliva and plasma insulin area under the curve (AUC) and incremental AUC were significantly higher in HC condition as compared to LC condition (all P≤0.002). Nine-hour plasma and saliva insulin total AUCs were strongly and very strongly correlated in both HC (r=0.68; P=0.007) and LC (r=0.84, P<0.001) conditions, respectively. Saliva insulin is proportionate to and appears to reasonably track plasma insulin across the day with a ∼30-45 min delay. Saliva insulin shows promise as a non-invasive method to discern between low and high plasma insulin and may have utility in predicting the degree of insulin resistance (NCT03374436).

Interrater and Intrarater Reliability of the Intra-Abdominal Pressure Test in Young Adults

BACKGROUND: Diaphragm is not used correctly to its fullest potential which can lead to injury provoking compensations. If recruited properly, the diaphragm aids in the production of intra-abdominal pressure, which is necessary for core and spinal stabilization. Intra-abdominal pressure is a key component of our dynamic stability system. OBJECTIVE: The purpose of this study was to determine the interrater and intrarater reliability of the intra-abdominal pressure test in young adults. METHODOLOGY: It is a non-experimental design of test-retest type. 80 subjects (50 women and 30 men) aged 18-28 years with the BMI of &lt; 23.05-24.9 kg/m2 were conveniently included. Subjects with the history of low back pain for past 3 months, any hip or knee surgery for last 1 year, thoracic or thoracoabdominal surgery, postural deformities, cardiorespiratory diseases, pregnancy and pelvic floor dysfunction was excluded. The intra- abdominal pressure test had been carried to the subjects on the same day for the interrater reliability and 1 week later for the intrarater reliability. The signs of proper stabilization with the correct and incorrect activation of the chest and abdominal movements of the subjects were documented independently between the raters and scoring had been done. RESULTS: The results of the study showed an overall excellent interrater reliability of ICC=0.957 and intrarater reliability of ICC= 0.903 of the test. CONCLUSION: The study concludes that there is an overall excellent interrater and intrarater reliability of the intra-abdominal pressure test in normal young adults and hence it can be used in clinical practice. Keywords: Diaphragm, Intra-abdominal pressure, Intra-abdominal pressure test, Core stability, Spinal stability.

Eye-Tracker Study of the Developmental Eye Movement Test in Young People without Binocular Dysfunctions.

The purpose of this study was to evaluate ocular motility in normal young adults when performing the Developmental Eye Movement (DEM) test using an infrared eye-tracker in a sample of young subjects without visual dysfunctions. An optometric evaluation was carried out on 52 participants with a mean age of 21.00 ± 3.22 years to verify they did not have any binocular dysfunction, by completing a computerized version of the DEM test while their eye movements were recorded with an eye-tracker. A custom-written software was developed to analyse some specific parameters of ocular motility while performing each subtest (Test A, Test B and Test C) of the complete DEM test. The mean duration of the fixations was shorter in Test C (243.56 ± 46.18 s) than in Test A (493.52 ± 171.41 s) and Test B (484.20 ± 156.59 s). The mean adjusted horizontal (AdjHT: 35.24 ± 6.68 s) and vertical (VT: 33.58 ± 5.56 s) times were at the 45th and at the 40th percentile, respectively. In Test C, there was a high positive significant correlation between the saccadic speed (cc: 0.77; p < 0.001) and the saccadic length (cc: 0.74; p < 0.001) of both eyes. The eye-tracker is an objective method to evaluate the DEM test in subjects without binocular dysfunctions, measuring and quantifying ocular motility parameters that are impossible with the traditional subjective method. The eye movements of both eyes are conjugated in each subject, having saccades of the same length and speed.

Brain aerobic glycolysis and resilience in Alzheimer disease

The distribution of brain aerobic glycolysis (AG) in normal young adults correlates spatially with amyloid-beta (Aβ) deposition in individuals with symptomatic and preclinical Alzheimer disease (AD). Brain AG decreases with age, but the functional significance of this decrease with regard to the development of AD symptomatology is poorly understood. Using PET measurements of regional blood flow, oxygen consumption, and glucose utilization-from which we derive AG-we find that cognitive impairment is strongly associated with loss of the typical youthful pattern of AG. In contrast, amyloid positivity without cognitive impairment was associated with preservation of youthful brain AG, which was even higher than that seen in cognitively unimpaired, amyloid negative adults. Similar findings were not seen for blood flow nor oxygen consumption. Finally, in cognitively unimpaired adults, white matter hyperintensity burden was found to be specifically associated with decreased youthful brain AG. Our results suggest that AG may have a role in the resilience and/or response to early stages of amyloid pathology and that age-related white matter disease may impair this process.

True grit and brain: Trait grit mediates the connection of DLPFC functional connectivity density to posttraumatic growth following COVID-19

BackgroundThere is increasing interest in identifying factors to predict posttraumatic growth (PTG), a positive psychological response following traumatic events (e.g., the COVID-19 pandemic). Grit, a psychological trait of perseverance and passion to pursue long-term goals, has emerged as a promising predictor for PTG. This study aimed to examine the functional connectivity markers of grit and the potential brain-grit mechanism in predicting PTG. MethodsBaseline brain imaging scans and grit scale and other controlling measures were administered in 100 normal young adults before the COVID-19 pandemic, and follow-up PTG measurement was obtained during the period of community-level outbreak. Whole-brain correlation analysis and prediction analysis were used to identify the brain regions whose functional connectivity density (FCD) related to individuals' grit scores. Mediation analyses were performed to explore the mediation relation between FCD, grit and PTG. ResultsGrit was positively related to FCD in the right dorsolateral prefrontal cortex (DLPFC), a core hub implicated in self-regulation and reward-motivation processes. Furthermore, grit mediated the effect of right DLPFC FCD on COVID-related PTG. These results survived controlling for self-control and family socioeconomic status. LimitationsOur study is limited by only one-session neuroimaging data and self-reported behavioral measures in a sample of normal adults. ConclusionsThis study indicates grit and right DLPFC FCD as neuropsychological contributors for the development of PTG. It deepens our understanding of the neural bases of grit, and may have clinical potential to develop targeted brain interventions aimed at improving grit to raise PTG and mental health during the pandemic.

Using Complete Blood Count Examination General Health Status Study of Normal Young Male Adult

Using Complete Blood Count Examination General Health Status Study of Normal Young Male Adult

Movement pattern and upper extremity muscle activation during fast and slow continuous steering movement

Continuous steering movement (CSM) is an essential component of the upper extremity (UE) task during vehicle driving, and could be a suitable candidate for multi-joint rehabilitation programs for patients with UE disabilities. This study aims to evaluate the UE muscle activation during CSM and how the rotating speed and direction affect CSM's kinematic and kinetic performance. Surface electromyography (EMG), hand contact information, and steering torque were measured under fast (180°/s) and slow (60°/s) constant-velocity CSM to reveal the activation of shoulder and elbow muscles, temporal characteristics, and force exertion during the stance and swing phases of a CSM cycle. Data from 24 normal young adults showed that shorter contact duration but higher force exertion occurred in the hand moving in an outward steering direction during only fast CSM in either the clockwise (CW) or counterclockwise (CCW) direction. During a steering cycle (either fast or slow speed), the triceps brachii, sternal part of the pectoralis major (PS), and posterior deltoid play major roles in generating steering torque in the CW direction of the CSM. In contrast, the PS, clavicular part of the pectoralis major (PC), and anterior deltoid (AD) largely contribute to torque generation during the CCW CSM. During the swing phase of CSM, AD, PC, and PS are the major muscles that move the hand for the next grasping of the steering wheel in all four conditions. Using the mean activation profiles of the major contributing muscles, the functional roles of these elbow and shoulder muscles were analyzed and are discussed herein. These findings help us to further understand the activation patterns of UE muscles and the kinematic and kinetic changes during two rotating directions and two speeds of CSM, and suggest important implications for future practice in clinical training.

Three-dimensional wideband absorbance immittance findings in young adults with large vestibular aqueduct syndrome.

To investigate the effect of large vestibular aqueduct syndrome (LVAS) on middle ear sound transmission using wideband absorbance immittance (WAI). WAI results from young adult LVAS patients and normal adults were compared. Averaged energy absorbance (EA) at ambient and peak pressure in the LVAS group showed differences to the normal group. Under ambient pressure, the average EA of the LVAS group was significantly higher than the normal group at frequencies 472-866 Hz and 6169-8000 Hz (p< .05) and lower at frequencies 1122-2520 Hz (p< .05). Under peak pressure, absorbance was increased at frequencies 515-728, 841, and 6169-8000 Hz (p< .05) and decreased at 1122-1374Hz and 1587-2448 Hz (p< .05). An investigation into the effect of external auditory canal pressure on EA across frequencies in the pressure-frequency domain, showed that EA differed significantly in the low-frequency region of 707and 1000 Hz from 0 to 200 daPa and 500 Hz at 50 daPa (p< .05). There was also a significant difference in EA between the two groups at 8000 Hz (p< .05) in the pressure range -200-300 daPa. WAI is a valuable tool to measure the effect of LVAS on middle ear sound transmission. LVAS has a significant effect on EA at low and mid frequencies under ambient pressure, while the frequencies affected are mainly at low frequencies when positive pressure is presented. Level 3a.

Assessing everyday functioning using a novel smartphone app in cognitively normal adults: A pilot study of the Assessment of Smartphone Everyday Tasks (ASSET)

AbstractBackgroundCognitively complex everyday tasks may be affected in early stages of Alzheimer’s disease. Performance‐based digital assessments could facilitate more precise measurement of subtle changes in everyday functioning. We piloted a novel smartphone app ‘Assessment of Smartphone Everyday Tasks’ (ASSET), to investigate its utility for measuring everyday functioning in cognitively normal older adults. ASSET consists of Patient Portal and Calendar tasks for renewing prescriptions, making payments, and scheduling urgent and recurring appointments (Figure1). It tracks response time and accuracy.MethodASSET was piloted in 34 participants (n = 20 cognitively normal young adults (YN): 21.3±2.6 years, 85%female, median 14.5 years of education; n = 14 cognitively normal older adults (ON), 75.1±4.8 years, 71%female, median 18 years of education). At baseline, participants completed the first version of ASSET and the Preclinical Alzheimer’s Cognitive Composite (PACC5) in the research clinic. ON participants and their study partners completed the Alzheimer’s Disease Cooperative Study Activities of Daily Living – Prevention Instrument (ADCS ADL‐PI). We calculated accuracy rates (correct responses/task duration) for both tasks and computed Pearson’s r correlation coefficients between subtasks (internal consistency) and with PACC5 and ADCS ADL‐PI (construct validity). To investigate test‐retest reliability, participants subsequently completed the first and five alternate versions of ASSET remotely on a fixed, biweekly schedule.ResultAt baseline, the Patient Portal and Calendar tasks were highly correlated (r = 0.78, 95% confidence interval (95%CI) = [0.60,0.89]). YN performed better on both tasks than ON, completing them faster and making fewer errors (Patient Portal: Cohen’s d = ‐3.0, 95%CI = [‐4.2, ‐1.8]; Calendar: d = ‐1.6, 95%CI = [‐2.4, ‐0.7]). Performance was moderately correlated with PACC5 (Patient Portal: r = 0.59, 95%CI = [0.49,0.67]; Calendar: r = 0.48, 95%CI = [0.37,0.58]). Among ON, performance on ASSET was not significantly correlated with either self‐ or study partner‐reported ADCS ADL‐PI. Over repeated assessments, Patient Portal accuracy increased, while Calendar accuracy increased but dropped at the last assessment among all participants (see Figure2).ConclusionInitial results show that ASSET may have good internal consistency and good ability to distinguish young from older cognitively normal adults. Future research should aim to corroborate current findings and extend with Alzheimer’s disease biomarkers to better understand the value of ASSET in detecting early changes in everyday functioning.

Binaural temporal coding and the middle ear muscle reflex in audiometrically normal young adults

Noise exposure may damage the synapses that connect inner hair cells with auditory nerve fibers, before outer hair cells are lost. In humans, this cochlear synaptopathy (CS) is thought to decrease the fidelity of peripheral auditory temporal coding. In the current study, the primary hypothesis was that higher middle ear muscle reflex (MEMR) thresholds, as a proxy measure of CS, would be associated with smaller values of the binaural intelligibility level difference (BILD). The BILD, which is a measure of binaural temporal coding, is defined here as the difference in thresholds between the diotic and the antiphasic versions of the digits in noise (DIN) test. This DIN BILD may control for factors unrelated to binaural temporal coding such as linguistic, central auditory, and cognitive factors. Fifty-six audiometrically normal adults (34 females) aged 18 – 30 were tested. The test battery included standard pure tone audiometry, tympanometry, MEMR using a 2 kHz elicitor and 226 Hz and 1 kHz probes, the Noise Exposure Structured Interview, forward digit span test, extended high frequency (EHF) audiometry, and diotic and antiphasic DIN tests. The study protocol was pre-registered prior to data collection. MEMR thresholds did not predict the DIN BILD. Secondary analyses showed no association between MEMR thresholds and the individual diotic and antiphasic DIN thresholds. Greater lifetime noise exposure was non-significantly associated with higher MEMR thresholds, larger DIN BILD values, and lower (better) antiphasic DIN thresholds, but not with diotic DIN thresholds, nor with EHF thresholds. EHF thresholds were associated with neither MEMR thresholds nor any of the DIN outcomes, including the DIN BILD. Results provide no evidence that young, audiometrically normal people incur CS with impacts on binaural temporal processing.

The Influence of Near Vision Tasks on Intraocular Pressure in Normal Subjects and Glaucoma Patients.

To investigate the effect of static accommodative tasks on intraocular pressure (IOP) of glaucomatous and normal eyes. Four groups of subjects categorized as primary open-angle glaucoma (POAG), primary angle-closure suspects (PACS), normal age-matched controls, and normal young adults (NYA; age 40 years) were enrolled. The baseline IOPs were measured after the subjects were looking at a distant target for 15 min. Static accommodation was obtained by execution of near vision tasks (reading at 33 cm in daylight [300 lux] for 60 min). IOPs were measured at 15, 30, 45, and 60 min intervals while accommodating and then measured again after 15 min of relaxing accommodation while looking at a distant target. One-hundred and eighteen eyes of 98 subjects were recruited. The study groups consisted of the following categories: 25 POAG (46 eyes), 24 PACS (47 eyes), 25 matched controls (50 eyes), and 24 NYA (48 eyes). Within all groups, the mean IOP decreased throughout the accommodation period at all time points. Maximum IOP reduction after accommodation was detected at the 30-min time among the POAG subjects, at the 45-min time in the PACS and matched control groups, and at 15 min after the relaxation of accommodation in the NYA group. IOP reduction levels showed no statistically significant difference among POAG, PACS, and the normal matched groups in their response to accommodation. However, NYA had significantly lower IOP and greater IOP reduction after the resting period (relaxation of accommodation). Static accommodative tasks can significantly reduce IOP in normal, POAG, and PACS individuals. Encouraging glaucoma patients to practice periodical near vision tasks could be viewed as an adjunctive measure for glaucoma management.

Investigation of the Appropriate Reverberation Time in Learning Spaces for Elderly People Using Speech Intelligibility Tests

The Republic of Korea is currently an aging society, and it will enter an ultra-aging society in 2025. This study aimed to investigate the undesignated appropriate reverberation time of learning spaces for elderly people in Korea. For this purpose, a virtual sound field was created, and the anechoic sounds were convoluted with the virtual sound field to control the reverberation time via absorption rate adjustments. Using a virtual sound field, auralized materials were made which have five different conditions with a reverberation time ranging from 0.4 s to 1.2 s. Speech intelligibility tests were conducted in both elderly and young people using headphones. Consonant–Vowel–Consonant (CVC) tests were undertaken. Preliminary experiments were performed to adjust the difficulty levels of speech intelligibility via normal young adults. The test order was nonsequential, and the sound output level was 60 dB(A). As a result, the test scores were found to decrease with an increase in the reverberation time. In addition, it was revealed that the test scores fell by 32.4% compared with the scores of normal adults under the same reverberation conditions. When the reverberation time was longer than 0.8 s, the test score was reduced by up to 13.3%; therefore, learning spaces for elderly people may require reverberation times shorter than 0.8 s. If the proposed reverberation time were applied to learning spaces for the elderly, it is believed that it could provide an appropriate sound environment for the elderly.

An intergenerational analysis of cognitive impairment in healthy elders

Cognitive disorders are common in elderly population and are becoming an increasingly important public health problem, partly because of the rapid aging of the population. This study was conducted to find out the differences between cognitive ability between normal adults and healthy elders of north region. The mild cognitive impairment (MCI) resulting in limitations and delayed treatment of dementia, should be considered an entry point for researching recent changes in the lives of healthy elderly. In this study we have applied MoCA test on the 36 normal healthy elders belonging to high socioeconomic status and normal young adults. Results have shown that there was no significant difference amongst the young normal adults; all the participants had normal MoCA scores. The MoCA scores were significantly impaired in all the healthy elders and there was a significant difference between the normal young adults and healthy elders. Age has a significant influence on MOCA score in older adults. Hence there is a need for age specific stratification in cut-off scores.

Clinical Applications of Facial Sensor Biofeedback: Implications for Voice Therapy or Vocal Training

Objectives: Biofeedback therapy is a training technique that has a positive effect on the voice. In order to conduct resonant voice therapy or tube phonation more effectively, it is important for the patient to feel the vibration sensation in a specific part of the facial structures. Therefore, in this study, the clinical basis for facial vibration was presented by quantifying the vibration site and magnitude using vibration sensors during various semi-occluded vocal tract phonations.Methods: A total of 38 normal young adults without dysphonia participated in this study. Recording was performed a total of 6 times for each type of phonation, in the order of /a/ phonation, Kazoo, lip trill, humming, straw phonation, and tube phonation in water at the comfortable level using newly developed facial vibration sensor.Results: There was a significant difference in the magnitude of vibration according to body parts (cheek, nose, neck) during resonant voice or tube phonation; the largest amplitude presented in the nose during humming whereas lip trill, straw, kazoo, and tube phonation in water presented in the cheek. There were also significant differences in the magnitude of vibration among the voice therapy exercises or vocal training techniques (/a/ phonation, Kazoo, lip trill, humming, straw phonation, and tube phonation in water; with greater amplitude in dual sources such as lip trill and water resistance phonation than in single source phonations.Conclusion: The facial vibration sensor could provide clinical evidence for facial vibration sensation during semi-occluded vocal tract phonation. It can also provide biofeedback and monitor whether patients can perform semi-occluded vocal tract phonation properly.

The effect of EMG magnitude on the masseter vestibular evoked myogenic potential (mVEMP)

IntroductionThe masseter vestibular evoked myogenic potential (mVEMP) is a bilaterally generated, electromyographically (EMG)-mediated response innervated by the trigeminal nerve. The purpose of the present investigation was to 1) determine whether subjects could accurately achieve and maintain a range of EMG target levels, 2) to examine the effects of varied EMG levels on the latencies and amplitudes of the mVEMP, and 3) to investigate the degree of side-to-side asymmetry and any effects of EMG activation. MethodsSubjects were nine neurologically and otologically normal young adults. A high-intensity tone burst was presented monaurally while subjects were seated upright and asked to match a range of EMG target levels by clenching their teeth. Recordings were made from the ipsilateral and contralateral masseter muscles referenced to the ear being monaurally stimulated. ResultsWe found that the tonic EMG target had no effect on mVEMP latency. Additionally, although mVEMP amplitudes “scaled” to the EMG target, there was a tendency for the subjects’ EMG level to “undershoot” the EMG target levels greater than 50 μV. While some individuals did generate differences in EMG activation between sides, there were no significant differences on average EMG activation between sides. Further, while average corrected amplitude asymmetry was similar across EMG targets, some individuals demonstrated large, corrected amplitude asymmetry ratios. ConclusionsThe results of this investigation suggest that, as with cVEMP recordings, the underlying EMG activation may vary between subjects and could impact mVEMP amplitudes, yet could be mitigated by amplitude correction techniques. Further it is important to be aware that even young normal subjects have difficulty maintaining large, tonic EMG activity during the mVEMP recording.

INFLUENCE OF BLOOD GROUP ON EVOKED OTOACOUSTIC EMISSIONS

OAE testing is more sensitive in the detection of the early onset of cochlear pathologies before a change in hearing thresholds. In the development of cochlear hair cells in the foetus human blood group antigens were involved. The present study is aimed to investigate the effect of blood group on evoked otoacoustic emissions amongAim: young adults in the Indian context. A total of 120 normal young adults of age 18 – 30 years were selected and groupedMethod: according to the ABO system of blood group, each consists of 30 participants and recorded both DPOAE and TEOAE. Results: The DPOAE and TEOAE amplitude showed signicant difference across frequencies and ears which do not follow a uniform pattern of signicance in all blood groups indicating no effect of blood group in OAE amplitude. The present studyConclusion: revealed no effect of blood group over evoked otoacoustic emission, though the results report a signicant difference among the majority of the test frequencies which is not uniform indicating any inuence, and this opens the possibility of other factors inuencing the OAE response.

Negative emotions and brain: Negative emotions mediates the association between structural and functional variations in emotional-related brain regions and sleep quality

Importance and study objectiveEmotion plays an important role in sleep quality, meanwhile, poor sleep quality is usually correlated with high negative emotions (NES). However, less is known about the neural basis for NES and the underlying mechanism for how NES affect individuals’ sleep quality in the health brain. The present study combined voxel-based morphometry and resting-state functional connectivity analysis to identify the relationship between brain regions and NES, and then explored how NES-related brain structures are related to sleep quality in a large sample of normal young adults. Design and participantsThe present study used a fMRI procedure. Participants were 339 normal young adults. The NES was represented by the principal components of four measures: the Self-rating Anxiety Scale, Self-rating Depression Scale, Negative Affect Schedule, and Psychosomatic Tension Relaxation Inventory. Sleep quality was measured using the Pittsburgh Sleep Quality Index. ResultsResults showed that higher NES scores were associated with larger regional gray matter volume (rGMV) in the left parahippocampal gyrus, right superior temporal gyrus, and right postcentral gyrus. Further functional connectivity analysis demonstrated that the connectivity between these three brain regions and a specific set of emotion-related regions was also significantly associated with NES scores. Moreover, NES acted as a mediator of the relationship between the rGMV of the left parahippocampal gyrus, right superior temporal gyrus, and right postcentral gyrus and sleep quality. NES also mediated the relationship between the connectivity between the right superior temporal-supplementary motor area and the right superior temporal-right precentral gyrus and sleep quality. ConclusionThe present study provides the further evidence for neural substrates of NES and reveals a potential mechanism that NES mediates the effect of spontaneous brain activity on sleep quality. Meanwhile, these findings indicate that negative emotions share a common brain structure and function based on sleep quality.