Biology subjects

Moccia, A.

Publications and source records attributed to Moccia, A..

4 recordsLinked to original sources

bioRxiv2022

Selective retrieval revealed by electroencephalographic (EEG) neural pattern reinstatement

1.For past experiences to guide our actions we need to retrieve the relevant memories. Here, we used electroencephalography (EEG) to investigate how memories are selected for retrieval, and to test how current goals and external retrieval cues drive selection during the retrieval cascade. We analysed data from two studies in which people studied objects in picture or auditory word formats and later recalled them using either written words (Experiment 1, n = 28) or line drawings (Experiment 2, n = 28) as retrieval cues. We used multivariate decoding to quantify the reinstatement of study phase neural patterns when people successfully identified items that had been studied in a format currently designated as targeted, compared with non-targeted items. Neural reinstatement emerged at around 500 ms post-stimulus, like the established left parietal event-related potential (ERP) signature of recollection. Reinstatement was target-selective (greater for targets than non-targets) when test cues overlapped more with targets, a pattern previously shown for the left parietal ERP (Moccia & Morcom, 2021). In contrast, when cues overlapped more with non-targets, neural reinstatement was reversed - greater for non-targets - unlike the left parietal ERP. We also tested for goal-directed mental reinstatement proposed to guide selection prior to retrieval cues. When words were cues there was strong evidence of this proactive reinstatement, but it was not detected when pictures were cues. Together, the data suggest that selection can act at multiple stages of memory retrieval and depends on both external cues and goal-directed control.

neuroscience↗

bioRxiv2021

ASXL3 controls cortical neuron fate specification through extrinsic self-renewal pathways

During corticogenesis, transcription plasticity is fundamental to the restriction of neural progenitor cell (NPC) multipotency and production of cortical neuron heterogeneity. Human and mouse genetic studies have highlighted the role of Polycomb transcriptional regulation in this process. ASXL3, which encodes a component of the Polycomb repressive deubiquitination (PR-DUB) complex, has been identified as a high confidence autism spectrum disorder (ASD) risk gene. Genetic inactivation of Asxl3, in a mouse model that carries a clinically relevant ASXL3 frameshift (Asxl3fs) variant, disrupts lateral expansion of NPCs and delays cortical neuron differentiation. Single-cell RNA sequencing analysis implicates Notch signaling, which alters the composition of excitatory neurons and fidelity of cortical layer deposition. Our data provides a new link between extrinsic signaling cues and intrinsic epigenetic regulation that together control the timing of cell fate programs. Furthermore, transcriptomic analysis revealed dysregulation of other known ASD risk genes indicating that a convergent developmental pathway is affected. Collectively our work provides important insights about developmental mechanisms that contribute to ASD neuropathology.

neuroscience↗

bioRxiv2021

Selective remembering: Cue overlap enables pre-retrieval control of recollection

People often want to recall only currently relevant events, but this selective remembering is not always possible. We contrasted two candidate mechanisms: the overlap between retrieval cues and stored memory traces, and the ease of recollection. In two preregistered experiments (Ns = 28) we used event-related potentials (ERPs) to quantify pre-retrieval selection and the goal states - retrieval orientations - thought to achieve this selection. Participants viewed object pictures or heard object names, and one of these sources was designated as targets in each memory test. We manipulated cue overlap by probing memory with visual names (Experiment 1) or line drawings (Experiment 2). Results revealed that regardless of which source was targeted, the left parietal ERP effect indexing recollection was selective when test cues overlapped more with the targeted than non-targeted information, despite consistently better memory for pictures. ERPs for unstudied items were also more positive-going when cue overlap was high, suggesting that engagement of retrieval orientations reflected availability of external cues matching the targeted source. The data support the view that selection can act prior to recollection if there is sufficient overlap between retrieval cues and targeted versus competing memory traces.

neuroscience↗

bioRxiv2020

Aging Reduces EEG Markers of Recognition Despite Intact Performance: Implications for Forensic Memory Detection

ERP-based forensic memory detection is based on the logic that guilty suspects will hold incriminating knowledge about crimes they have committed, and therefore should show parietal ERP positivities related to recognition when presented with reminders of their crimes. We predicted that such forensic memory detection might however be inaccurate in older adults, because of changes to recognition-related brain activity that occurs with aging. We measured both ERPs and EEG oscillations associated with episodic old/new recognition and forensic memory detection in 30 younger (age < 30) and 30 older (age > 65) adults. EEG oscillations were included as a complementary measure which is less sensitive to temporal variability and component overlap than ERPs. In line with predictions, recognition-related parietal ERP positivities were significantly reduced in the older compared to younger group in both tasks, despite highly similar behavioural performance. We also observed ageing-related reductions in oscillatory markers of recognition in the forensic memory detection test, while the oscillatory effects associated with episodic recognition were similar across age groups. This pattern of results suggests that while both forensic memory detection and episodic recognition are accompanied by ageing-induced reductions in parietal ERP positivities, these reductions may be caused by non-overlapping mechanisms across the two tasks. Our findings suggest that EEG-based forensic memory detection tests are invalid in older populations, limiting their practical applications.

neuroscience↗