Alpha Peak Frequency Research Articles

Task demands modulate pre-stimulus alpha frequency and sensory template during bistable apparent motion perception.

Despite ambiguous environmental inputs, top-down attention biases our subjective perception toward the preferred percepts, via modulating prestimulus neural activity or inducing prestimulus sensory templates that carry concrete internal sensory representations of the preferred percepts. In contrast to frequent changes of behavioral goals in the typical cue-target paradigm, human beings are often engaged in a prolonged task state with only 1 specific behavioral goal. It remains unclear how prestimulus neural signals and sensory templates are modulated in the latter case. To answer this question in the present electroencephalogram study on human subjects, we manipulated sustained task demands toward one of the 2 possible percepts in the bistable Ternus display, emphasizing either temporal integration or segregation. First, the prestimulus peak alpha frequency, which gated the temporal window of temporal integration, was effectively modulated by task demands. Furthermore, time-resolved decoding analyses showed that task demands biased neural representations toward the preferred percepts after the full presentation of bottom-up stimuli. More importantly, sensory templates resembling the preferred percepts emerged even before the bottom-up sensory evidence were sufficient enough to induce explicit percepts. Taken together, task demands modulate both prestimulus alpha frequency and sensory templates, to eventually bias subjective perception toward the preferred percepts.

Cerebral Peak Alpha Frequency Is Not Associated with Emotional Modulation of Pain

Chronic pain is a tremendous burden, resulting in increased psychological distress and disability. To prevent and address chronic pain before it develops, more research into chronic pain risk markers is needed. Cerebral peak alpha frequency (PAF) is a promising risk marker as it is associated with pain sensitivity, postsurgical pain outcomes, and several chronic pain conditions. However, it is still unclear how cerebral PAF is related to nociceptive processing and pain modulation. The purpose of this study was to examine the relationship between PAF and one type of pain modulation, emotional modulation of pain. To this end, a well validated affective picture viewing paradigm was used during which 24 IAPS pictures (8 mutilation, 8 neutral, 8 erotica pictures) were presented and painful electric stimulations were delivered. In addition to subjective pain ratings, physiological responses to electric stimulations were recorded at the spinal level (assessed by the nociceptive flexion reflex [NFR]) and the supraspinal level (assessed by the pain-evoked potentials [N2 & P2]). EEG was recorded during a 3-minute period of rest and PAF was extracted using the center of gravity method. The sample consisted of 37 (23 women) healthy, right-handed, pain-free participants. The degree of pain inhibition during erotica was assessed using a change score calculating the difference in pain, NFR, and N2/P2 during erotica relative to neutral pictures. Conversely, the degree of pain facilitation during mutilation was assessed using a change score calculating the difference in pain, NFR, and N2/P2 during mutilation relative to neutral pictures. PAF was entered as predictor in multiple regression analyses that controlled for age and sex, with change scores (erotica-neutral; mutilation-neutral) as outcome variables. Results found no significant association between PAF and emotional modulation. This suggests that any relationship between PAF and chronic pain risk is not due to emotional modulation of pain.

P558. Alpha Phase Coherence and Desynchronization During the Degraded-Stimulus Continuous Performance Task in Schizophrenia

Alpha oscillations are relevant to visual perceptual processes that support attention and higher-order cognition. Our previous work demonstrated that resting state alpha peak frequencies were slower in schizophrenia, and corresponded to impairments on a visual attention task (Degraded-Stimulus Continuous Performance Task; DS-CPT). In the current study we examine EEG during the DS-CPT to clarify whether alpha phase coherence and synchronization are aberrant during visual attention.

Altered alpha and theta oscillations correlate with sequential working memory in Parkinson's disease.

Daily activities such as preparing a meal rely on the ability to arrange thoughts and actions in the right order. Patients with Parkinson’s disease have difficulties in sequencing tasks. Their deficits in sequential working memory have been associated with basal ganglia dysfunction. Here we demonstrate that altered parietal alpha and theta oscillations correlate with sequential working memory in Parkinson’s disease. We included 15 patients with Parkinson’s disease (6 women, mean age: 66.0 years), 24 healthy young (14 women, mean age: 24.1 years), and 16 older participants (7 women, mean age: 68.6 years). All participants completed a picture ordering task with scalp electroencephalogram (EEG) recording, where they arranged five pictures in a specific order and memorized them over a delay. When encoding and maintaining picture sequences, patients with Parkinson’s disease showed a lower baseline alpha peak frequency with higher alpha power than healthy young and older participants. Patients with a higher baseline alpha power responded more slowly for ordered trials. When manipulating picture sequences, patients with Parkinson’s disease showed a lower frequency of maximal power change for random versus ordered trials than healthy young and older participants. Healthy older participants showed a higher frequency of maximal power change than healthy young participants. Compared with patients with frequency of maximal power change in the alpha band (8–15 Hz), patients with frequency of maximal power change in the theta band (4–7 Hz) showed a higher ordering-related accuracy cost (random versus ordered) in the main task and tended to respond more slowly and less accurately in an independent working memory test. In conclusion, altered baseline alpha oscillations and task-dependent modulation of alpha and theta oscillations may be neural markers of poor sequential working memory in Parkinson’s disease.

Timing of adoption is associated with electrophysiological brain activity and externalizing problems among children adopted internationally.

This study investigated middle childhood resting electroencephalography (EEG) and behavioral adjustment in 35 internationally adopted children removed from early caregiving adversity between 6 and 29 months of age. Older age of adoption was associated with more immature or atypical profiles of middle childhood cortical function, based on higher relative theta power (4-6Hz), lower relative alpha power (7-12Hz), lower peak alpha frequency, and lower absolute beta (13-20Hz) and gamma (21-50Hz) power. More immature or atypical EEG spectral power indirectly linked older age of adoption with increased risk for externalizing problems in middle childhood. The findings add to existing evidence linking duration of early adverse exposures with lasting effects on brain function and behavioral regulation even years after living in a stable adoptive family setting. Findings underscore the need to minimize and prevent children's exposures to early caregiving adversity, especially in the first years of life. They call for innovative interventions to support neurotypical development in internationally adopted children at elevated risk.

Alpha and theta peak frequency track on- and off-thoughts

Our thoughts are highly dynamic in their contents. At some points, our thoughts are related to external stimuli or tasks focusing on single content (on-single thoughts), While in other moments, they are drifting away with multiple simultaneous items as contents (off-multiple thoughts). Can such thought dynamics be tracked by corresponding neurodynamics? To address this question, here we track thought dynamics during post-stimulus periods by electroencephalogram (EEG) neurodynamics of alpha and theta peak frequency which, as based on the phase angle, must be distinguished from non-phase-based alpha and theta power. We show how, on the psychological level, on-off thoughts are highly predictive of single-multiple thought contents, respectively. Using EEG, on-single and off-multiple thoughts are mediated by opposite changes in the time courses of alpha (high in on-single but low in off-multiple thoughts) and theta (low in on-single but high in off-multiple thoughts) peak frequencies. In contrast, they cannot be distinguished by frequency power. Overall, these findings provide insight into how alpha and theta peak frequency with their phase-related processes track on- and off-thoughts dynamically. In short, neurodynamics track thought dynamics.

Investigating the Potential Use of EEG for the Objective Measurement of Auditory Presence

Presence is the sense of being in a virtual environment when physically situated in another place. It is one of the key components of the overall virtual reality (VR) experience, as well as other immersive audio applications. However, there is no standardized method for measuring presence. In our previous study, we explored the possibility of using electroencephalography (EEG) to measure presence by using questionnaires as a reference. It was found that an increase in the subjective presence level was correlated with an increase in the theta/beta ratio (an index derived from EEG). In the present study, we re-analyzed the original data and found that the peak alpha frequency (PAF), another EEG index, may also have the potential to reflect the change in the subjective presence level. Specifically, an increase in the subjective presence level was found to be correlated with a decrease in PAF. Together with our previous study, these results indicate the potential use of EEG for the objective measurement of presence in the future.

Impact of impaired cerebral blood flow autoregulation on electroencephalogram signals in adults undergoing propofol anaesthesia: a pilot study.

Cerebral autoregulation actively maintains cerebral blood flow over a range of MAPs. During general anaesthesia, this mechanism may not compensate for reductions in MAP leading to brain hypoperfusion. Cerebral autoregulation can be assessed using the mean flow index derived from Doppler measurements of average blood velocity in the middle cerebral artery, but this is impractical for routine monitoring within the operating room. Here, we investigate the possibility of using the EEG as a proxy measure for a loss of cerebral autoregulation, determined by the mean flow index. Thirty-six patients (57.5 [44.25; 66.5] yr; 38.9% women, non-emergency neuroradiology surgery) anaesthetised using propofol were prospectively studied. Continuous recordings of MAP, average blood velocity in the middle cerebral artery, EEG, and regional cerebral oxygen saturation were made. Poor cerebral autoregulation was defined as a mean flow index greater than 0.3. Eighteen patients had preserved cerebral autoregulation, and 18 had altered cerebral autoregulation. The two groups had similar ages, MAPs, and average blood velocities in the middle cerebral artery. Patients with altered cerebral autoregulation exhibited a significantly slower alpha peak frequency (9.4 [9.0, 9.9] Hz vs 10.5 [10.1, 10.9] Hz, P<0.001), which persisted after adjusting for age, norepinephrine infusion rate, and ASA class (odds ratio=0.038 [confidence interval, 0.004, 0.409]; P=0.007). In this pilot study, we found that loss of cerebral autoregulation was associated with a slower alpha peak frequency, independent of age. This work suggests that impaired cerebral autoregulation could be monitored in the operating room using the existing EEG setup. NCT03769142.

Brainmarker-I Differentially Predicts Remission to Various Attention-Deficit/Hyperactivity Disorder Treatments: A Discovery, Transfer, and Blinded Validation Study

BackgroundAttention-deficit/hyperactivity disorder is characterized by neurobiological heterogeneity, possibly explaining why not all patients benefit from a given treatment. As a means to select the right treatment (stratification), biomarkers may aid in personalizing treatment prescription, thereby increasing remission rates. MethodsThe biomarker in this study was developed in a heterogeneous clinical sample (N = 4249) and first applied to two large transfer datasets, a priori stratifying young males (<18 years) with a higher individual alpha peak frequency (iAPF) to methylphenidate (N = 336) and those with a lower iAPF to multimodal neurofeedback complemented with sleep coaching (N = 136). Blinded, out-of-sample validations were conducted in two independent samples. In addition, the association between iAPF and response to guanfacine and atomoxetine was explored. ResultsRetrospective stratification in the transfer datasets resulted in a predicted gain in normalized remission of 17% to 30%. Blinded out-of-sample validations for methylphenidate (n = 41) and multimodal neurofeedback (n = 71) corroborated these findings, yielding a predicted gain in stratified normalized remission of 36% and 29%, respectively. ConclusionsThis study introduces a clinically interpretable and actionable biomarker based on the iAPF assessed during resting-state electroencephalography. Our findings suggest that acknowledging neurobiological heterogeneity can inform stratification of patients to their individual best treatment and enhance remission rates.

Differences in the Course of Physiological Functions and in Subjective Evaluations in Connection With Listening to the Sound of a Chainsaw and to the Sounds of a Forest.

We explored differences in the course of physiological functions and in the subjective evaluations in response to listening to a 7-min recording of the sound of a chainsaw and to the sounds of a forest. A Biofeedback 2000x-pert apparatus was used for continual recording of the following physiological functions in 50 examined persons: abdominal and thoracic respiration and their amplitude and frequency, electrodermal activity (skin conductance level), finger skin temperature, heart rate (pulse, blood volume pulse and blood volume pulse amplitude) and heart rate variability (HRV). The group of 25 subjects listening to the sound of a chainsaw exhibited significantly lower values of blood volume pulse amplitude, lower values in peak alpha frequency HRV and higher values in peak high-frequency HRV. In the time interval from 80 s to 209 s, in which the two groups showed the greatest differences, lower values of blood volume pulse were also recorded while listening to the sound of a chainsaw. Listening to the sound of a chainsaw is associated with a greater feeling of fatigue and higher tension, while listening to the sounds of a forest is even considered to elicit feelings of improved learning abilities. The assumption that listening to the sound of a chainsaw results in higher defense arousal was confirmed. The greater variability which is exhibited by a majority of physiological functions while listening to the forest sounds may also be an innovative finding. It seems that there are two types of arousal (sympathetic and parasympathetic) following from correlations between physiological functions and subjective assessment. Low values of blood volume pulse amplitude are especially important from the health perspective. They correspond to the amount of vasoconstriction which occurs in the endothelial dysfunction related to increased mortality, incidence of myocardial infarction, leg atherosclerosis and topically to COVID-19.

Effect of Cervical Transcutaneous Spinal Cord Stimulation on Sensorimotor Cortical Activity during Upper-Limb Movements in Healthy Individuals.

Transcutaneous spinal cord stimulation (tSCS) can improve upper-limb motor function after spinal cord injury. A number of studies have attempted to deduce the corticospinal mechanisms which are modulated following tSCS, with many relying on transcranial magnetic stimulation to provide measures of corticospinal excitability. Other metrics, such as cortical oscillations, may provide an alternative and complementary perspective on the physiological effect of tSCS. Hence, the present study recorded EEG from 30 healthy volunteers to investigate if and how cortical oscillatory dynamics are altered by 10 min of continuous cervical tSCS. Participants performed repetitive upper-limb movements and resting-state tasks while tSCS was delivered to the posterior side of the neck as EEG was recorded simultaneously. The intensity of tSCS was tailored to each participant based on their maximum tolerance (mean: 50 ± 20 mA). A control session was conducted without tSCS. Changes to sensorimotor cortical activity during movement were quantified in terms of event-related (de)synchronisation (ERD/ERS). Our analysis revealed that, on a group level, there was no consistency in terms of the direction of ERD modulation during tSCS, nor was there a dose-effect between tSCS and ERD/ERS. Resting-state oscillatory power was compared before and after tSCS but no statistically significant difference was found in terms of alpha peak frequency or alpha power. However, participants who received the highest stimulation intensities had significantly weakened ERD/ERS (10% ERS) compared to when tSCS was not applied (25% ERD; p = 0.016), suggestive of cortical inhibition. Overall, our results demonstrated that a single 10 min session of tSCS delivered to the cervical region of the spine was not sufficient to induce consistent changes in sensorimotor cortical activity among the entire cohort. However, under high intensities there may be an inhibitory effect at the cortical level. Future work should investigate, with a larger sample size, the effect of session duration and tSCS intensity on cortical oscillations.

Individual resting-state alpha peak frequency and within-trial changes in alpha peak frequency both predict visual dual-pulse segregation performance.

Although sensory input is continuous, information must be combined over time to guide action and cognition, leading to the proposal of temporal sampling windows. A number of studies have suggested that a 10-Hz sampling window might be involved in the "frame rate" of visual processing. To investigate this, we tested the ability of participants to localize and enumerate 1 or 2 visual flashes presented either at near-threshold or full-contrast intensities, while recording magnetoencephalography. The inter-stimulus interval (ISI) between the 2 flashes was varied across trials. Performance in distinguishing between 1 and 2 flashes was linked to the alpha frequency, both at the individual level and trial-by-trial. Participants with a higher resting-state alpha peak frequency showed the greatest improvement in performance as a function of ISI within a 100-ms time window, while those with slower alpha improved more when ISI exceeded 100ms. On each trial, correct enumeration (1 vs. 2) performance was paired with faster pre-stimulus instantaneous alpha frequency. Our results suggest that visual sampling/processing speed, linked to peak alpha frequency, is both an individual trait and can vary in a state-dependent manner.

Periodic and aperiodic neural activity displays age-dependent changes across early-to-middle childhood

The neurodevelopmental period spanning early-to-middle childhood represents a time of significant growth and reorganisation throughout the cortex. Such changes are critical for the emergence and maturation of a range of social and cognitive processes. Here, we utilised both eyes open and eyes closed resting-state electroencephalography (EEG) to examine maturational changes in both oscillatory (i.e., periodic) and non-oscillatory (aperiodic, ‘1/f-like’) activity in a large cohort of participants ranging from 4-to-12 years of age (N = 139, average age=9.41 years, SD=1.95). The EEG signal was parameterised into aperiodic and periodic components, and linear regression models were used to evaluate if chronological age could predict aperiodic exponent and offset, as well as well as peak frequency and power within the alpha and beta ranges. Exponent and offset were found to both decrease with age, while aperiodic-adjusted alpha peak frequency increased with age; however, there was no association between age and peak frequency for the beta band. Age was also unrelated to aperiodic-adjusted spectral power within either the alpha or beta bands, despite both frequency ranges being correlated with the aperiodic signal. Overall, these results highlight the capacity for both periodic and aperiodic features of the EEG to elucidate age-related functional changes within the developing brain.

Electrophysiological signatures of brain aging in autism spectrum disorder

Recent evidence suggests that structural and functional brain aging is atypical in adults with autism spectrum disorder (ASD). However, it remains unclear if oscillatory slowing, a key marker of neurophysiological aging, follows an atypical trajectory in this population. This study examines patterns of age-related oscillatory slowing in adults with ASD, captured by reductions in the brain's peak alpha frequency (PAF). Resting-state electroencephalography (EEG) data from adults (18–70 years) with ASD (N = 93) and non-ASD controls (N = 87) were pooled from three independent datasets. A robust curve-fitting procedure quantified the peak frequency of alpha oscillations (7–13 Hz) across all brain regions. Associations between PAF and age were assessed and compared between groups. Consistent with characteristic patterns of oscillatory slowing, PAF was negatively associated with age across the entire sample (p < .0001). A significant group-by-age interaction revealed that this relationship was more pronounced in adults with ASD (p < .01). These findings invite further longitudinal investigations of PAF in adults with ASD to confirm if age-related oscillatory slowing is accelerated.

Covariate-adjusted hybrid principal components analysis for region-referenced functional EEG data.

Electroencephalography (EEG) studies produce region-referenced functional data via EEG signals recorded across scalp electrodes. The high-dimensional data can be used to contrast neurodevelopmental trajectories between diagnostic groups, for example between typically developing (TD) children and children with autism spectrum disorder (ASD). Valid inference requires characterization of the complex EEG dependency structure as well as covariate-dependent heteroscedasticity, such as changes in variation over developmental age. In our motivating study, EEG data is collected on TD and ASD children aged two to twelve years old. The peak alpha frequency, a prominent peak in the alpha spectrum, is a biomarker linked to neurodevelopment that shifts as children age. To retain information, we model patterns of alpha spectral variation, rather than just the peak location, regionally across the scalp and chronologically across development. We propose a covariate-adjusted hybrid principal components analysis (CA-HPCA) for EEG data, which utilizes both vector and functional principal components analysis while simultaneously adjusting for covariate-dependent heteroscedasticity. CA-HPCA assumes the covariance process is weakly separable conditional on observed covariates, allowing for covariate-adjustments to be made on the marginal covariances rather than the full covariance leading to stable and computationally efficient estimation. The proposed methodology provides novel insights into neurodevelopmental differences between TD and ASD children.

Analytic consistency and neural correlates of peak alpha frequency in the study of pain

BackgroundSeveral studies have found evidence of reduced resting-state peak alpha frequency (PAF) in populations with pain. However, the stability of PAF from different analytic pipelines used to study pain has not been determined and underlying neural correlates of PAF have not been validated in humans. New methodFor the first time we compare analytic pipelines and the relationship of PAF to activity in the whole brain and thalamus, a hypothesized generator of PAF. We collected resting-state functional magnetic resonance imaging (rs-fMRI) data and subsequently 64 channel resting-state electroencephalographic (EEG) from 47 healthy men, controls from an ongoing study of chronic prostatitis (a pain condition affecting men). We identified important variations in EEG processing for PAF from a review of 17 papers investigating the relationship between pain and PAF. We tested three progressively complex pre-processing pipelines and varied four postprocessing variables (epoch length, alpha band, calculation method, and region-of-interest [ROI]) that were inconsistent across the literature. ResultsWe found a single principal component, well-represented by the average PAF across all electrodes (grand-average PAF), explained > 95% of the variance across participants. We also found the grand-average PAF was highly correlated among the pre-processing pipelines and primarily impacted by calculation method and ROI. Across methods, interindividual differences in PAF were correlated with rs-fMRI-estimated activity in the thalamus, insula, cingulate, and sensory cortices. ConclusionsThese results suggest PAF is a relatively stable marker with respect to common pre and post-processing methods used in pain research and reflects interindividual differences in thalamic and salience network function.

Cortical oscillatory dysrhythmias in visual snow syndrome: a magnetoencephalography study.

Visual snow refers to the persistent visual experience of static in the whole visual field of both eyes. It is often reported by patients with migraine and co-occurs with conditions such as tinnitus and tremor. The underlying pathophysiology of the condition is poorly understood. Previously, we hypothesized that visual snow syndrome may be characterized by disruptions to rhythmical activity within the visual system. To test this, data from 18 patients diagnosed with visual snow syndrome, and 16 matched controls, were acquired using magnetoencephalography. Participants were presented with visual grating stimuli, known to elicit decreases in alpha-band (8–13 Hz) power and increases in gamma-band power (40–70 Hz). Data were mapped to source-space using a beamformer. Across both groups, decreased alpha power and increased gamma power localized to early visual cortex. Data from the primary visual cortex were compared between groups. No differences were found in either alpha or gamma peak frequency or the magnitude of alpha power, p > 0.05. However, compared with controls, our visual snow syndrome cohort displayed significantly increased primary visual cortex gamma power, p = 0.035. This new electromagnetic finding concurs with previous functional MRI and PET findings, suggesting that in visual snow syndrome, the visual cortex is hyperexcitable. The coupling of alpha-phase to gamma amplitude within the primary visual cortex was also quantified. Compared with controls, the visual snow syndrome group had significantly reduced alpha–gamma phase–amplitude coupling, p < 0.05, indicating a potential excitation–inhibition imbalance in visual snow syndrome, as well as a potential disruption to top-down ‘noise-cancellation’ mechanisms. Overall, these results suggest that rhythmical brain activity in the primary visual cortex is both hyperexcitable and disorganized in visual snow syndrome, consistent with this being a condition of thalamocortical dysrhythmia.

Peak alpha frequency and N200 latency as predictors of neuropsychological performance in a memory disorders clinic

AbstractBackgroundElectrophysiological measures including alpha peak power and frequency, and N200 latency are potential biomarkers of Alzheimer’s Disease (AD) pathology. It is still unclear how these measures can be used in clinical settings to better diagnose AD and differentiate it from other cognitive neurodegenerative disorders. As an initial step towards better understanding clinical utility of electrophysiological measures within a dementia population, this study aims to determine how alpha and gN200 measures can help predict neuropsychological status among an heterogenous sample of patients from memory disorders clinic.MethodData was collected using a seven electrodes COGNISION™ rig. Older veterans with memory complaints aged 50‐100 were recruited from a memory disorders clinic at the VA Boston Healthcare system (N= 185) with a MMSE score of 13 and above. EEG/ERP data was recorded while participants completed a three‐tone auditory oddball task. Participants who failed an audiometry screening test and those with a BPA below 35% were excluded. All subjects were administered a neuropsychological battery to assess degree of cognitive impairment. Amyloid PET results were also available for a small subset of subjects (N=49).ResultLinear regressions were computed for all cognitive measures that correlated with alpha peak frequency and N200 latency. Alpha peak frequency is a significant predictor of encoding (p=0.048) and delayed recall (p=0.014) in the CERAD list learning task, and of verbal category fluency (p=0.033). N200 target latency is a significant predictor of number of intrusions (p=0.0379) of the CERAD recognition task, and of Trails Making Test A (p=0.006) and B (p=0.048) time. Alpha peak frequency is also associated with amyloid PET status (p=0.040) using logistic regression.ConclusionAlpha peak frequency and N200 latency are useful predictors of cognitive status, especially of memory and executive function, among a memory disorders population. Alpha peak frequency is also an important factor in the prediction of amyloid PET status. Overall, alpha peak frequency and N200 latency represent a novel tool to better assess memory disorders patients, and characterize the cognitive profile of their underlying pathology in an heterogenous clinical setting.

Effects of fitness and sedentarism on a biomarker of early AD progression

AbstractBackgroundGiven the lack of an effective treatment for Alzheimer’s Disease (AD), research on factors that might prevent it or delay its symptoms is needed. Physical activity (PA) stands as a means for favourably altering cognitive performance and neuropathologic processes and has been identified as a relevant and easily modifiable lifestyle factor against AD progression. This study thrives to understand the effects of both cardiorespiratory fitness (CRF) and sedentary behaviours (SB) in adult controls through the assessment of magnetoencephalography (MEG).Method30 healthy adults (age between 50 and 70 years) participated in the study. The sample underwent a five minutes of eyes‐closed resting MEG recording (NMEG = 24), a cycloergometer incremental exercise test to evaluate CRF through VO2peak (Nstress = 17), and carried an accelerometer for one week to estimate SB (NACC = 26). The alpha peak frequency at posterior brain areas was extracted, and then its partial correlation to VOpeak and the relative sedentary time from the accelerometer data were calculated, respectively, while also controlling for age. Partial correlation between VO2max and relative sedentary time was calculated as well.ResultStatistical analysis yielded a significant direct correlation between VO2peak and Alpha peak frequency (N=17, rho = 0.504, p‐value = 0.023), while relative sedentary time and Alpha peak frequency showed a significant inverse correlation (N = 20, rho = ‐0.435, p‐value = 0.032). Partial correlation between VO2peak and relative sedentary time was not significant (N = 17, rho = ‐0.404, p‐value = 0.120).ConclusionDespite the small cohort, results pinpoint a strong influence of both CRF and SB. Greater CRF, described as higher VO2peak, appears associated with increased alpha frequency in posterior brain regions, a robust biomarker of brain health which is negatively affected in AD. At the same time, higher levels of sedentarism show a strong relation to decreased alpha peak frequency, indicating that low levels of PA might put subjects entering old age at risk.

Genetic association of APOE epsilon2 genotype with neurophysiological characteristics in healthy adults

AbstractBackgroundThe association of apolipoprotein E genotype with late‐onset AD (LOAD) is well established. APOE e4 allele is the major common risk factor for LOAD (Saunders et al., 1993), and the rare APOE e2 allele appears to confer protective effect for LOAD (Goldberg et al., 2020). The mechanisms underlying the impact of the APOE e2 allele on LOAD development remain largely unknown. The study was aimed at determining the possible APOE e2 genotype effect on EEG and cognitive event‐related potentials (ERP) in non‐demented adults.MethodThe enrolled cohort included 135 healthy volunteers, age range 20‐69 years, stratified by APOE genotype. APOE e2/e3 subgroup included 21 subjects, APOE e3/e3 subgroup ‐ 76 subjects, APOE e4/e3 subgroup ‐ 38 subjects. Informed written consent was obtained from all participants. All subjects underwent a neurological examination and cognitive screening. The significance of the differences between the EEG and cognitive ERP characteristics in different subgroups was estimated using ANOVA in the general linear modelResultThe presence of the APOE e2/e3 genotype was associated with higher individual alpha peak frequency (IAPF) relative to the presence of APOE e3/e3 and APOE e4/e3 genotypes. IAPF a stable neurophysiological 'trait' marker which has been shown to correlate with better memory scores (Grandy et al., 2013). In the carriers of APOE e2 allele P300 latency remained stable during aging, while in the carriers of APOE e3/e3 as well as APOE e4/e3 genotypes P300 latency showed positive correlation with age.ConclusionAPOE e2 genotype is associated with higher EEG IAPF and stable P300 latency during aging that can underlie better cognitive reserve and protective effect against LOAD. The effect may be related to larger hippocampal volume and better maintenance of neuronal connections in APOE e2 healthy carriers compared to non‐carriers.