Biology subjects

Buzi, G.

Publications and source records attributed to Buzi, G..

3 recordsLinked to original sources

bioRxiv2026

Aging effects on retrospective and naturalistic encoding of time and their relationship with memory.

In everyday life, attention is not explicitly directed toward time. Yet, we can reconstruct how long an experience lasted from the memory traces it left behind, a process intertwined with episodic memory and subjective experience. As both memory and temporal processing change with advancing age, investigating aging effects could provide critical insights on these reconstructive processes. In this study, 31 younger (aged 24{+/-}3) and 36 older (aged 69{+/-}6) healthy adults completed two EEG sessions: 1) a resting-state recording followed by an unexpected retrospective time estimation, and 2) a video-based prospective duration estimation task where participants encoded and judged the duration of 50 naturalistic videos (2-32s) varying in eventfulness. Using a cycle-by-cycle burst analysis of alpha (: 8-12 Hz), we examined oscillatory correlates of both retrospective temporal judgement and prospective temporal processing. Behaviorally, both groups reconstructed short intervals similarly, but older adults produced longer prospective duration estimates than younger adults for longer video clips (16-32s), particularly under low-eventfulness. Regression analyses also showed that individual differences in older adults' prospective duration judgments were influenced by both their retrospective time estimation and episodic memory abilities, especially for longer videos. At the neural level, resting-state -burst dynamics were higher in older adults and predicted, with -power, longer retrospective estimates in older adults. Additionally, resting-state -burst activity predicted -burst during video encoding in both groups. Together, these findings reveal that individual -power and -burst dynamics could constitute memory-based time-tracking mechanism that aging reshapes in ways that manifest behaviorally under naturalistic conditions.

neuroscience↗

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↗

bioRxiv2021

Default Mode Network spatial configuration varies across task domains

Recent developments in network neuroscience suggest reconsidering what we thought we knew about the Default Mode Network (DMN). Although this network has always been seen as unitary and associated with the resting state, a new deconstructive line of research is pointing out that the DMN could be divided into multiple subsystems supporting different functions. By now, it is well known that the DMN is not only deactivated by tasks, but also involved in affective, mnestic, and social paradigms, among others. Nonetheless, it is starting to become clear that the array of activities in which it is involved, might also be extended to more extrinsic functions. The present meta-analytic study is meant to push this boundary a bit further. The BrainMap database was searched for all experimental paradigms activating the DMN, and their activation maps were then computed. An additional map of task-induced deactivations was also created. A Multidimensional Scaling indicated that such maps could be arranged along an anatomo-psychological gradient, which goes from midline core activations, associated with the most internal functions, to the involvement of lateral cortices in more external tasks. Further investigations suggested that such extrinsic mode is especially related to reward, semantic, and emotional functions. However, an important finding was that the variability of task-induced DMN anatomic redistribution was hard to recapitulate, as none of the maps, or any linear combination of them, could represent the whole space of its dynamical reconfiguration. Altogether, our findings suggest that the DMN may be characterized by a richer functional diversity and a more spatial complexity than previously suggested.

neuroscience↗