Biology subjects

Dornier, V.

Publications and source records attributed to Dornier, V..

3 recordsLinked to original sources

bioRxiv2026

How aging reshapes implicit learning: behavioral and oscillatory evidence from an EEG-adapted Fast Mapping paradigm.

Most of everyday memory formation occurs without deliberate intent, yet the neural mechanisms supporting implicit encoding and their reorganization with age remain poorly understood. The present study investigated age-related changes in implicit learning using an EEG-adapted Fast Mapping paradigm (the Disjunctive Inference Implicit Learning Test, DIILT) in 31 younger and 35 older adults, paired with a comprehensive neuropsychological assessment and a one-month delayed recognition measure. Behaviorally, younger adults rapidly acquired novel implicit associations across the learning phase, whereas older adults showed persistent reliance on familiar items and limited improvement for novel associations. Critically, both groups successfully retained novel associations after one month, with implicitly learned associations showing greater long-term stability than explicitly encoded ones regardless of age. At the neural level, younger adults exhibited early posterior theta engagement for novel compared to familiar items, which disappeared by the end of learning, consistent with novelty-driven associative encoding. Older adults showed no such theta modulation for novel items, pointing to reorganization of the neural mechanisms supporting implicit encoding. Theta dynamics predicted immediate recognition in younger adults but not in older adults who rather showed theta association with processing speed, suggesting an age-related shift from memory-specific binding to domain-general cognitive resource allocation, consistent with neural maintenance frameworks of cognitive aging. These findings demonstrate that implicit encoding produces durable memory traces across the lifespan but relies on reorganized oscillatory dynamics in aging, with implications for understanding how cognitive aging reshapes everyday memory formation.

neuroscience↗

bioRxiv2026

A learning-evoked slow-oscillatory architecture paces population activity for offline reactivation across the human medial temporal lobe

Memory processing requires the coordinated engagement of neuronal populations across distributed brain networks and across time. How such coordination is organized in the human medial temporal lobe (MTL) remains unclear. Here, we show that MTL population activity is dynamically structured by a transient slow-oscillatory architecture that emerges during online learning to promote offline consolidation and later recall. Using intracranial recordings that combine single-neuron spiking activity and local field potentials in human participants, we find that mnemonic engagement evokes on-demand slow-oscillatory bursts in the hippocampus. These hippocampal bursts synchronize gamma-band patterns across MTL regions, defining discrete coordination events that pace cross-regional coactivity motifs during learning. These learning-time population motifs are then selectively reactivated during hippocampal ripples in post-learning rest, and the strength of their reactivation predicts subsequent recall accuracy. Together, these findings identify a multi-scale coordination mechanism that links distributed population activity across learning, consolidation, and recall in humans.

neuroscience↗

bioRxiv2025

Reading about sensations recruits the posterior insula: An intracranial EEG study

When we read, how do words and sentences become concepts? Contrary to theoretical perspectives that conceptualize meaning and concepts as symbolic and abstract, embodied approaches propose that semantic access relies on mental simulations of bodily experiences□associated with the word’s meaning (e.g., simulating the act of running when we read the word ‘run’ or feeling pain when reading the word ‘burn’). If this view of cognition underpins conceptual processing, then sensory and motor cortices should play an early role during language comprehension. To test this idea, we recorded intracranial neural activity (High-Frequency Activity, 50–150 Hz) in epileptic patients while they read short sentences from different semantic categories: abstract-, action- and sensation-related. We hypothesized that reading sensation-related sentences (e.g., “he burns me”) would preferentially involve the posterior insula — a key region for processing affective and painful sensations. Our results, revealed an early functional dissociation between the anterior and posterior insula: the anterior insula showed a non-selective response across all semantic categories, whereas the posterior insula presented an early selective response (around 170 ms) for the sensation-related ones. Furthermore, the intensity of this selective neural response in the posterior insula correlated with the intensity of subjective perceived pain. These results provide direct intracranial evidence suggesting that language is deeply rooted in body-environment interactions.

neuroscience↗