Biology subjects

Cignetti, F.

Publications and source records attributed to Cignetti, F..

3 recordsLinked to original sources

bioRxiv2026

Beyond gait speed: a multidimensional motor signature of Motoric Cognitive Risk syndrome identified through domain-specific anomaly detection

Motoric Cognitive Risk (MCR) syndrome, defined by subjective cognitive complaints and slow gait speed, identifies older adults at increased risk of major neurocognitive disorders (NCDs). Yet, gait speed reflects a composite output shaped by heterogeneous neuromusculoskeletal and cognitive processes, limiting its clinical specificity. This study aimed to refine the motor signature of MCR by quantifying domain-specific gait deviations relative to a normative reference cohort using an anomaly detection approach. Ninety-seven adults ([≥] 55 years) completed two 3-minute treadmill walking bouts at their preferred speed. Participants were categorized into three groups: older adults with MCR (n = 20), healthy older adults with slow gait (sHOA; n = 20) matched to MCR for age and gait speed, and healthy older adults (HOA; n = 57). Linear spatiotemporal and nonlinear trunk acceleration-derived variables were organized into ten functional gait domains, conceptually grouped into gait pattern (pace, rhythm, phases, postural control, symmetry), fluctuation amplitude (variability), and temporal structure of fluctuations (regulation, signal complexity, divergence of movement trajectories, and attractor complexity). For each domain, a Gaussian mixture model trained on HOA data defined a normative reference space, from which individual anomaly scores quantified deviations across groups. Both sHOA and MCR showed higher deviations in gait pattern domains (pace and phases) than HOA, consistent with their slower gait speed. Only MCR exhibited additional deviations in domains related to fluctuation amplitude and temporal structure, reflected by increased step-to-step variability and trunk acceleration fluctuations that were more divergent, more predictable, and less complex. These findings reveal a multidimensional motor signature of MCR. Domain-specific anomaly scores may provide individualized, clinically interpretable biomarkers to support early detection and monitoring of older adults at increased risk of major NCDs. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/716304v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@3b2e52org.highwire.dtl.DTLVardef@15e4101org.highwire.dtl.DTLVardef@fdb9c4org.highwire.dtl.DTLVardef@1af0d03_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2024

Savings in visuomotor learning is associated with connectivity changes within a cerebello-thalamo-cortical network encoding movement errors

Savings refers to faster relearning upon re-exposure to a previously experienced movement perturbation. One theory suggests that the brain recognizes past errors and is therefore more able to learn from them. If true, there should be a modification of the neural response to errors during re-exposure to a perturbation. To test this idea, we imaged the brains of participants who underwent two sessions (1 day apart) of adaptation to a visuomotor perturbation and investigated brain responses to movement errors. The magnitude of movement error was entered into different types of GLMs to study error-related activation and coactivation (or functional connectivity). We identified a cerebello-thalamo-cortical network involved in the processing of movement errors during adaptation. We found that connectivity between regions of this network (i.e., between the cerebellum and the thalamus, and between the primary somatosensory cortex and the anterior cingulate cortex) became stronger during re-adaptation. Importantly, participants with the largest increases in connectivity strength were those who demonstrated the largest amounts of savings. These results establish a relationship between the ability of the brain to represent errors and the phenomenon of savings.

neuroscience↗

bioRxiv2020

Action Observation Network activity related to object-directed and socially directed actions in Adolescents

The Action Observation Network (AON) encompasses brain areas consistently engaged when we observe others actions. Although the core nodes of the AON are present from childhood, it is not known to what extent they are sensitive to different action features during development. As social cognitive abilities continue to mature during adolescence, the AON response to socially-oriented actions, but not to object-related actions, may differ in adolescents and adults. To test this hypothesis, we scanned with functional magnetic resonance imaging (fMRI) 28 typically-developing teenagers and 25 adults while they passively watched videos of hand actions varying along two dimensions: sociality (i.e. directed towards another person or not) and transitivity (i.e. involving an object or not). We found that observing actions recruited the same fronto-parietal and occipito-temporal regions in adults and adolescents. The modulation of voxelwise activity by the social or transitive nature of the action was similar in both groups of participants. Multivariate pattern analysis, however, revealed that the accuracy in decoding the social dimension from the brain activity patterns, increased with age in lateral occipital and parietal regions, known to be involved in semantic representations of actions, as well as in posterior superior temporal sulcus, a region commonly associated with perception of high level features necessary for social perception. Change in decoding the transitive dimension was observed only in the latter region. These findings indicate that the representation of others actions, and in particular their social dimensions, in the adolescent AON is still not as robust as in adults. Significance statementThe activity of the action observation network in the human brain is modulated according to the purpose of the observed action, in particular the extent to which it involves interaction with an object or another person. How this conceptual representation of actions is implemented during development is largely unknown. Here, using multivoxel pattern analysis of fMRI data, we discovered that, while the action observation network is in place in adolescence, the fine-grain organization of its posterior regions is less robust than in adults to decode the social or transitive dimensions of an action. This finding highlights the late maturation of social processing in the human brain.

neuroscience↗