Biology subjects

Skolasinska, P.

Publications and source records attributed to Skolasinska, P..

3 recordsLinked to original sources

bioRxiv2026

Longitudinal changes in control energy of brain networks in older adults at familial risk for Alzheimers disease

The ability of structural brain networks to control neural dynamics is affected by healthy and pathological aging, including Alzheimers disease (AD). According to network control theory, transitions between functional brain states incur energetic costs. How these costs change longitudinally with aging remains unknown. Here, in 279 older adults at familial risk for AD, control energy increased longitudinally for state maintenance and transitions between sensorimotor and attentional networks, while decreasing for another sensorimotor--attentional transition. Changes in transition costs between higher-order networks were associated with cognitive performance: greater DorsAttn--Executive cost was associated with poorer immediate memory, while lower Executive--Def+Lim cost was associated with poorer attention. Higher plasma p-tau181 was associated with lower DorsAttn--Def+Lim transition cost. These findings reveal transition-specific alterations in the energetic landscape of aging and distinct relationships with cognition and AD pathology. Together, they highlight energetic constraints on brain network reconfiguration as a complementary perspective on neurocognitive aging.

neuroscience↗

bioRxiv2026

Using HD-DOT in precision accuracy microgenetic research designs to measure change over time in speech, language, and hearing clinical populations

Documenting change is fundamental to understanding the process of intervention among individuals with communication disorders. This technical report demonstrates the clinical applicability of wearable fNIRS systems and the NeuroDOT processing pipelines for examining within-person cortical dynamics of learning. Using a microgenetic research design and a dense sampling approach, we examined changes in the prefrontal cortical hemodynamic response in an adult female participant who completed the same spoken sentence repetition and auditory fixation tasks across eight sessions. In addition to behavioral accuracy, hemodynamic data were collected with a continuous-wave, multi-channel fNIRS system (NIRSport2) using a prefrontal 20-channel optode montage. Data were processed using NeuroDOT (https://www.nitrc.org/projects/neurodot) (Eggebrecht & Culver, 2019) to: (i) standardize signal quality across the sessions to quantify motion levels and to ensure standardized brain map specificity, (ii) to examine both channel space fluctuations in the hemodynamic response and map changes in cortical activation patterns over the sessions. The signal quality met the predefined criteria for only the first five sessions. Participants repetition accuracy did not improve over the five sessions. Channel-wise analysis revealed that HbO concentration differs significantly over right and left hemisphere channels over the course of the five sessions for the Sentence Repetition task, but not for the Auditory Fixation condition. Brain maps revealed qualitative differences in the pattern of prefrontal cortical activation across the five sessions. Behavioral assessments do not fully capture what occurs during speech repetition tasks, and leveraging neuroimaging can help identify and discriminate between disordered and neurotypical populations.

neuroscience↗

bioRxiv2025

Functional Connectivity Graph Theory Analysis of Spoken Word Processing Efficiency in Prefrontal Cortical Activation

PurposeNetwork science models of real-time spoken word processing predict that word frequency and sublexical phonotactic probability directly influence verbal working memory. Behavioral accuracy and speed of processing suggest that high frequency words differ in cognitive processing effort as compared to low frequency words. Cognitive processing effort, assessed indirectly through changes in prefrontal oxygenated (HbO) and deoxygenated (HbR) hemoglobin concentrations, also suggest that high and low frequency words differ in cognitive effort. This novel study examines potential differences in linguistic processing effort and efficiency directly, using measures of functional connectivity (FC) strength, modularity, and global efficiency, derived from the listeners prefrontal cortex hemodynamic responses using a paradigmatic verbal working memory paradigm. MethodA total of 20 neurologically typical participants (age 18-21 years) completed an auditory n-back working memory task comparing performance for words differing in whole-word frequency and sub lexical phonotactic probability. Changes in HbO and HbR hemoglobin concentration were recorded with a continuous-wave, multi-channel fNIRS system (TechEn, Inc., Milford, MA) using a 20-channel optode montage across the prefrontal cortex. Partial correlation coefficients were calculated between each channel pair to produce 20 x 20 FC matrices for each participant. Prefrontal networks were constructed as a graph where nodes in the graph are the fNIRS measurements and edges are partial correlations between pairs of measurements. ResultsWord frequency effects were evident in both in the behavioral and functional connectivity measures. Task performance, regardless of word frequency, was related to brain measures, such that higher prefrontal FC strength was negatively correlated with accuracy (d) and high modularity was negatively correlated with response times for low frequency words. In keeping with the direction of the brain-behavior correlations, the highest performing participant had lower FC strength and higher efficiency whereas the lowest performing participant had higher modularity and lower global efficiency. ConclusionsWe identified network properties that are linked to lexical indices of cognitive processing effort in typical participants. These preliminary results point to strategies that could assess language function in atypical populations in future studies.

neuroscience↗