Biology subjects

Dzianok, P.

Publications and source records attributed to Dzianok, P..

4 recordsLinked to original sources

bioRxiv2025

Common but different: An ERP study of single- and multi-source interference processing in MSIT

Flexible behavior often requires processing of complex, interfering information. Research has investigated conflict-related brain processes mostly using single tasks which hindered direct comparison of different interference types. Thus, the question if they are resolved by a common mechanism or by a set of different, task-specific mechanisms remains open. In this study, we used event-related potentials (ERPs) to examine the spatio-temporal dynamics of cognitive control across Simon, flanker, multi-source and no-conflict conditions. Our findings reveal that all trial types engaged the same sequence of processing stages, as indicated by common ERP waveforms and consistent number and order of microstates across conditions. However, the intensity and duration of these common stages scaled with difficulty of the conflict task (as measured by RTs and accuracy) from Simon to flanker to multi-source interference. Flanker conflict uniquely influenced early ERP components strongly engaging the dorsal attentional system and visual areas, likely due to demands posed by the presence of flanker distractors. Later ERP components (with sources including ventral attention and somatomotor network areas) were affected by both conflicts. Accordingly, when flanker and Simon conflicts were presented together, early processes lineary summed up, but there was an interaction at the later stage of processing paralleling nonlinear drop of accuracy in a multi-conflict condition. Our study provides novel insights into the neural dynamics underlying cognitive control engaged across different conflict types and their interaction. The use of source analysis allowed us to ground ERP-based findings in the wider context of studies, including those using neuroimaging techniques. Highlights- The same processing stages, in same order are evoked in control and conflict trials - Their intensity/duration scale with conflict behavioral difficulty - Flanker conflict demands enhanced early attentional (DAN) and visual processing - Flanker and Simon interact at the late-stage processing involving VAN and SM networks - Flanker and Simon interaction is sublinear

neuroscience↗

bioRxiv2025

Cortical thinning in temporal pole, a core region in Alzheimer's disease, in non-demented, middle-aged APOE-e4 and PICALM-AA/AG carriers

The symptoms of Alzheimers disease (AD) are caused by neurodegeneration and atrophy in particular brain regions, especially in the temporal cortex. However, the influence of genetic risk on cortical thickness in non-demented individuals prior to disease onset remains unclear. This study aimed to explore the relationship between two AD risk genes (APOE/PICALM) and cortical thickness in selected regions of interest (ROIs) in non-demented, middle-aged individuals. Sixty-nine (N = 69) participants (34 females, 35 males; age: 55.45{+/-}3.19) underwent magnetic resonance imaging (MRI). They were divided into three groups based on their AD risk. Cortical thickness was analyzed using CAT12 software (surface-based morphometry with the Destrieux atlas) based on T1-weighted MR images in five ROIs referred as "the cortical signature of AD" in previous studies. APOE-{varepsilon}4 with PICALM-AA/AG carriers (A+P-) are characterized by a thinner cortex in the right temporal pole compared to non-carriers, controlling for sex. No other differences in cortical thickness were found in the selected ROIs. The direction of the findings aligns with existing literature reporting cortical thinning in amyloid-positive individuals, as well as in patients with mild cognitive impairment and Alzheimers disease when compared to control groups.

neuroscience↗

bioRxiv2024

Alzheimer's disease-like features in resting state EEG/fMRI of cognitively intact and healthy middle-aged APOE/PICALM risk carriers

IntroductionGenetic susceptibility is a primary factor contributing to etiology of late-onset Alzheimers disease (LOAD). The exact mechanisms and timeline through which APOE/PICALM influence brain functions and contribute to LOAD remain unidentified. This includes their effects on individuals prior to the development of the disease. MethodsAPOE/PICALM alleles were assessed to determine the genetic risk of LOAD in 79 healthy, middle-aged participants who underwent EEG and fMRI recordings. The resting-state signal was analyzed to estimate relative spectral power, complexity (Higuchis algorithm), and connectivity (coherence in EEG and ICA-based connectivity in fMRI). ResultsThe main findings indicated that individuals at risk for LOAD exhibited reduced signal complexity and the so-called "slowing of EEG" which are well-known EEG markers of AD. Additionally, these individuals showed altered functional connectivity in fMRI (within attention related areas). DiscussionRisk alleles of APOE/PICALM may affect brain integrity and function prior to the onset of the disease

neuroscience↗

bioRxiv2023

Common and distinct BOLD correlates of Simon and flanker conflicts which can(not) be reduced to time-on-task effects

The ability to identify and resolve conflicts between standard, well trained behaviors, and behaviors required by the current context is an essential feature of cognitive control. To date, no consensus has been reached on the brain mechanisms involved in exerting such control: while some studies identified diverse patterns of activity across different conflicts, other studies reported common resources across conflict tasks or even across simple tasks devoid of conflict component. The latter reports attributed the entire activity observed in the presence of conflict to longer time spent on the task (i.e. to the so-called time-on-task effects). Here we used an extended Multi-Source Interference Task (MSIT) which combines Simon and flanker types of interference to determine shared and conflict-specific mechanisms of conflict resolution in fMRI, and their separability from the time-on-task effects. Large portions of the activity in the dorsal attention network and decreases of activity in the default mode network were shared across the tasks and scaled in parallel with increasing reaction times. Importantly, activity in the sensory and sensorimotor cortices, as well as in the posterior medial frontal cortex (pMFC)-a key region implicated in conflict processing-could not be exhaustively explained by the time-on-task effects.

neuroscience↗