Fernandez, R. S. | bioRxiv Science

bioRxiv2025

Remoteness sensitive theta network dynamics during early autobiographical memory access

AO_SCPLOWBSTRACTC_SCPLOWAutobiographical memory (AM) is a crucial aspect of human cognition that aids in social understanding, decision-making, and future planning. Its inherent diversity provides a valuable framework for exploring the neural dynamics underlying the retrieval of memories of varying ages. This study aimed to determine whether the access phase of AM retrieval contains neural signatures sensitive to the remoteness of these memories. Forty-one participants engaged in an AM retrieval task while their brain activity was recorded using electroencephalography (EEG). We measured spectral power and time-resolved Granger Causality (GC) during the first 1500 ms following the onset of memory recovery. The results showed that remote autobiographical memories led to a significant increase in midline fronto-central theta power (6.5-8 Hz) around 900 ms after retrieval, compared to recent memories. Additionally, GC analyses revealed that both recent and remote memories showed an anterior-to-posterior flow of information, but the remote network present a denser and more efficient connectivity pattern in the theta band between 800 and 1100 milliseconds. These findings suggest that the remoteness of memories influences the early stages of autobiographical memory access. They also highlight theta power and its directed interactions as temporally precise markers of the neural mechanisms that support autobiographical memory retrieval.

animal behavior and cognition↗

bioRxiv2020

A working memory intervention weakens the reconsolidation of a threat memory and its biases processing towards threat.

BACKGROUNDThreat-conditioning (TC) memory plays a central role in anxiety disorders, but not in a simple way. This memory impacts on complex cognitive systems by modifying behavioral responses with a bias to fearful stimuli and overestimating potential threats. In this study we proposed a global approach analyzing the scope of disrupting TC memory reconsolidation in the implicit memory, the declarative contingency and the cognitive biases. METHODSDay 1: Subjects were trained on TC. Day 2: after Threat-memory reactivation, one group performed a high demanding working memory task (HWM) and the other a low demanding working memory task (LWM). The last group, only performed the HWM task. Day 3: TC memory was tested by an extinction session followed by reinstatement. Finally, all subjects completed tasks targeting stimuli representation, valuation and attentional bias towards threat. RESULTSDisrupting reconsolidation of TC memory with a HWM weakened the implicit memory retention and faded the representation and valuation towards threat but it had no effect on attentional bias. Moreover, we revealed that subjects performance during the working memory task was specifically associated in TC memory retention. CONCLUSIONSOur findings reveal a strong impairment of the threat-memory restabilization and associated emotional biases. This may result from the competition between defensive survival and central-executive control networks. Our results fits with Experimental Psychopathology approach, disentangling the relation between the implicit memory, cognitive, valenced systems and the possibility to weaken both the threatening memory and the systems associated with the maintenance of anxiety profile.

neuroscience↗