Biology subjects

Casamento-Moran, A.

Publications and source records attributed to Casamento-Moran, A..

4 recordsLinked to original sources

bioRxiv2026

The State of Motion: Demographic and representational consequences of motion-based exclusion in fMRI

Large-scale neuroimaging datasets are increasingly used to map relationships between brain structure, function, and behavior across the human lifespan. Routinely, analyses exclude participants who moved too much during imaging. While this decision is framed as quality control, it is increasingly recognized that head motion is not randomly distributed across individuals within a study, and so motion-based exclusion may preferentially remove people with particular characteristics relevant to the scientific goals of the study. Here we survey head motion and how it relates to participant characteristics across six large, publicly available datasets spanning nearly the entire human lifespan, namely the Human Connectome Project (HCP) Young Adult, HCP in Development, HCP in Aging, Adolescent Brain Cognitive DevelopmentSM Study, UK Biobank, and Spatial Topology project. These six datasets comprise more than 50,000 unique participants and 300,000 scans. We further benchmark our findings against motion distributions aggregated by MRIQC across more than 1.5 million scans. Under commonly applied strict exclusion thresholds, large fractions of participants would be removed (exceeding 80 % in the UK Biobank task data), and these removals were demographically structured, disproportionately excluding younger and older participants, those with higher BMI, and those with motion-associated clinical conditions. Respiratory pseudo-motion inflated estimates of head motion in adult cohorts, and applying notch filtering to remove respiratory frequencies from these estimates meaningfully reduced exclusion rates. Exclusion also carried downstream consequences. Strict thresholds reduced statistical power, inflated study costs, and altered the apparent predictability of behavioral phenotypes by removing a non-random, behaviorally distinct subgroup. These findings demonstrate that motion exclusion thresholds are not neutral quality-control decisions but structured selection mechanisms that reshape the composition of neuroimaging samples. We recommend that studies report the demographic characteristics of excluded participants, prefer data-driven censoring methods over fixed motion cutoffs, and clarify the target population while considering appropriate weighting techniques.

neuroscience↗

bioRxiv2026

Transformations of cognitive maps for sensorimotor control

Adaptive embodied behavior involves transforming structured knowledge about the relationship between environment and action into motor signals, but how these transformations are coordinated across brain networks remain unknown. Participants learned associations between visual cues and isometric exertions that varied in force and duration, forming a two-dimensional cognitive map of a force-time space. During behavior, this force-time space was expressed in several cortical regions using grid-like coding schemes, indicating sensorimotor cognitive maps. Importantly, while mnemonic regions such as the entorhinal cortex maintained an unwarped, task-relevant representation, the primary motor cortex encoded a force-time space distorted by perceived effort during motor execution. Dynamic causal modeling showed inhibitory motor-to-mnemonic coupling that predicted the transformation of effort-weighted motor signals into sensorimotor maps. Furthermore, individual differences in learning and navigating the force-time space independently shaped mnemonic map geometry and perceived effort. These findings demonstrate that sensorimotor cognitive maps emerge from dynamic interactions between motor and mnemonic systems and are shaped by individual differences during the learning and execution of movement.

neuroscience↗

bioRxiv2025

Neuromuscular Signals Shape Fatigue and Effort-Based Decision-Making in Humans

Physical fatigue influences our willingness to undertake effortful actions, yet the physiological signals driving this process are not well understood. We created a biofeedback paradigm to distinguish the effects of reduced muscle-force capacity from compensatory increases in neuromuscular activity on effort-based decision-making. Human participants made risky choices about prospective physical effort before and after repeated fatiguing exertions under two biofeedback conditions: force biofeedback, which required increased neuromuscular drive, and EMG biofeedback, which constrained the increase in neuromuscular drive. Both biofeedback conditions led to similar reductions in muscle strength and feelings of fatigue. However, we found that the Force biofeedback condition, which required compensatory neuromuscular activation, produced a significantly greater increase in the subjective cost of effort, thereby altering individuals effort-based decision-making more than EMG biofeedback. These findings demonstrate how muscle physiological processes influence feelings of fatigue and decisions to exert effort. Suggesting that fatigue may consist of separate components that collectively motivate behavior while simultaneously protecting and restoring bodily homeostasis during physical challenge.

neuroscience↗

bioRxiv2025

Striatal and cerebellar interactions during reward-based motor performance

Goal-directed motor performance relies on the brains ability to distinguish between actions that lead to successful and unsuccessful outcomes. The basal ganglia (BG) and cerebellum (CBL) are integral to processing performance outcomes, yet their functional interactions remain underexplored. This study scanned participants brains with functional magnetic imaging (fMRI) while they performed a skilled motor task for monetary rewards, where outcomes depended on their motor performance and also probabilistic events that were not contingent on their performance. We found successful motor outcomes increased activity in the ventral striatum (VS), a functional sub-region of the BG, whereas unsuccessful motor outcomes engaged the CBL. In contrast, for probabilistic outcomes unrelated to motor performance, the BG and CBL exhibited no differences in activity between successful and unsuccessful outcomes. Dynamic causal modeling revealed that VS-to-CBL connectivity was inhibitory following successful motor outcomes, suggesting that the VS may suppress CBL error processing for correct actions. Conversely, CBL-to-VS connectivity was inhibitory after unsuccessful motor outcomes, potentially preventing reinforcement of erroneous actions. Additionally, interindividual differences in task preference, assessed by having participants choose between performing the motor task or flipping a coin for monetary rewards, were related to inhibitory VS-CBL connectivity. These findings highlight a performance-mediated functional network between the VS and CBL, modulated by motivation and subjective preferences, supporting goal-directed behavior.

neuroscience↗