Biology subjects

Schinazi, V. R.

Publications and source records attributed to Schinazi, V. R..

3 recordsLinked to original sources

bioRxiv2026

Long-term reliability and stability of parameterized resting state EEG: Evidence from a five-year follow-up

Several aspects of parameterized neural activity, including the aperiodic exponent and individual peak alpha frequency, have emerged as promising biomarkers for ageing, pathology, and cognitive decline. Their potential clinical application is tempered by a lack of evidence on long-term temporal stability. Existing investigations have largely relied on cross-sectional designs or considered stability for up to 90 days. Here, we examined five-year reliability, stability, and age-related changes in periodic and aperiodic neural activity using electroencephalography in adults aged 20-70 years. Resting-state EEG was recorded in two sessions, approximately five years apart. We extracted the aperiodic exponent, aperiodic offset, peak alpha power, and individual alpha peak frequency and examined test-retest reliability at both the channel and cluster levels. All parameters demonstrated fair to excellent test-retest reliability (intraclass correlations = 0.51-0.88). Linear mixed models revealed that individual peak alpha frequency decreased, the aperiodic exponent flattened, and parameterized alpha power remained unchanged. There were no interactions between time and age. Our findings suggest that parameterized activity is reliable over long timeframes, and demonstrates changes consistent with ageing-related processes. Spectral parameterization may provide a means of characterizing within-person neurophysiological changes across adulthood. Future research should explore the utility of identifying deviations that may indicate pathology.

neuroscience↗

bioRxiv2025

Hypoxia and Cognitive Ability in Humans: A Systematic Review and Meta-Analysis

This systematic and meta-analytical review examined how a reduction in oxygen availability to tissue (hypoxia) affects cognitive function. Hypoxia had a moderate-to-large detrimental effect on general cognitive ability and across domains, including memory, attention, executive function, processing speed, and psychomotor speed. Increased hypoxic severity was associated with greater declines in general cognitive ability and executive function, while longer duration of exposure was associated with greater declines in executive function and psychomotor speed. Participant age was a moderator for executive function and psychomotor speed, with older adults experiencing greater impairments. For executive function and psychomotor speed, the magnitude of these effects was less pronounced during intermittent and hypobaric exposures, potentially due to adaptive physiological mechanisms. While our models accounted for exposure characteristics and age of participants, substantial unexplained variance remained. These findings highlight hypoxias impact on cognition and emphasize the need to investigate underlying neurophysiological mechanisms that may influence individual vulnerability.

neuroscience↗

bioRxiv2024

Lower Aperiodic Activity is Associated with Reduced Verbal Fluency Performance Across Adulthood

Age-related cognitive decline associations with human electroencephalography (EEG) have previously focused on periodic activity. However, EEG primarily consists of non-oscillatory aperiodic activity, characterised with an exponent and offset value. In a secondary analysis of a cohort of 111 healthy participants aged 17 - 71 years, we examined the associations of the aperiodic exponent and offset in resting EEG with a battery of cognitive tests consisting of the Colour-Word Interference Test, Wechsler Adult Intelligence Scale IV Digit Span Test, Rey Auditory Learning Test, Delis-Kaplan Executive Function System Trail Making Test, and the Verbal Fluency Test. Using Principal Component Analysis and K-Means Clustering, we identified clusters of electrodes that exhibited similar aperiodic exponent and offset activity during resting-state eyes-closed EEG. Robust linear models were then used to model how aperiodic activity interacted with age and their associations with performance during each cognitive test. Offset by age interactions were identified for the Verbal Fluency Test, where smaller offsets were associated with poorer performance in adults as early as 33 years of age. Greater aperiodic activity is increasingly related to better verbal fluency performance with age in adulthood.

neuroscience↗