Symposium
From Synapses to Cognition: Neural Communication and Brain Dynamics in Health and Disease
Chair
María Victoria Oberholzer
Instituto de Neurociencia Cognitiva y Traslacional Fundación Favaloro (INECO-CONICET)
Understanding how the brain coordinates activity across distributed networks is key to explainingcognition in both health and disease. This symposium brings together complementary approaches—from systems neuroscience to clinical research and neurotechnology—to examine how neuralcommunication dynamically supports behavior across multiple levels of organization.
Jean-Christophe Comte will present evidence from freely moving rats showing that synapticstrength across hippocampal pathways fluctuates with the sleep–wake cycle, highlighting the roleof brain states in memory processes. Bridging to human cognition, Juan Kamienkowski will explorehow neural dynamics support visual search in naturalistic environments, revealing how attentionand memory are integrated over time.
Lucia Alba Ferrara will address how distributed brain networks support social communication andreorganize under pathological conditions. Finally, Victoria Peterson will discuss how understandingbrain dynamics can inform the development of brain–computer interfaces for motor rehabilitation.
Together, these contributions illustrate how neural communication operates across scales, linkingsynaptic mechanisms with cognition and clinical applications.
Jean-Christophe Comte
Université Claude Bernard Lyon 1, Francia
Modulation of Brain States Duration Encode Synaptic Strength Dynamics .
Interactions among brain areas are essential for most cognitive functions. Neuronal interactionsbetween these areas depend on the modulation of synaptic strength; however, this modulationremains poorly understood. We recorded evoked responses in four hippocampal pathways in freelymoving male rats over a 24-hour period. We show that synaptic strength in these pathwaysoscillates with a very slow periodicity and correlates with the duration of vigilance states. A modelbased on hypnogram data and synaptic strength in one pathway was able to predict the evolutionof synaptic strength in most pathways, except for one. These results suggest that the temporalsuccession of vigilance states may contribute to memory processes through rapid modulation ofsynaptic strength across several pathways during the sleep–wake cycle. This further suggests thatmemory processes depend not only on sleep duration but also on sleep architecture, as well as oncardiac and respiratory rhythms.
Juan Kamienkowski
Laboratorio de Inteligencia Artificial Aplicada, Instituto de Cs de la Computación, UBA - CONICET
Parsing Brain's Algorithms During Resolution of Visual Search Tasks
Understanding how the human brain orchestrates visual search in naturalistic environmentsrequires moving beyond highly constrained laboratory settings. This talk presents a comprehensiveresearch programme investigating the neural dynamics of active visual exploration by co-registeringeye movements with electroencephalography (EEG) and magnetoencephalography (MEG). We willfirst discuss earlier work demonstrating that target detection during free-viewing elicits reliablefixation-related potentials, including early sensory markers and a robust P3 component akin toclassical fixed-gaze paradigms. Expanding on this, we explore how the brain parses a mentalprogramme of visual routines, showing that low-frequency oscillatory activity and baseline shiftstrack the integration of evidence and task progression across multiple fixations. Furthermore, weaddress the transition towards more ecologically valid hybrid search tasks, where attention andmemory continuously interact. By applying advanced deconvolution models to disentangleoverlapping neural responses, we reveal how memory load modulates early visual processing andfrontoparietal beta-band activity. Ultimately, this line of research bridges the gap between activevision and cognitive electrophysiology, offering a spatiotemporal map of the brain's algorithmsduring naturalistic search.
Victoria Peterson
IMAL-CONICET-UNL, Argentina
The neurophysiology behind the development of brain-computer interfaces for rehabilitation
Brain-computer interfaces (BCI) allow the control of external devices through real-time brain signaldecoding. When aiming to use these devices as tools for motor rehabilitation, the development ofmachine learning algorithms for decoding movement intention or imagination requires a suitableand accurate framework based on the underlying neurophysiology of the mental task to bedecoded. In this talk, we will seek to understand the neurophysiology in electroencephalographysignals that must be captured to promote effective neurofunctional motor rehabilitation. Challengesin the construction of such algorithms as well as in the certification of proper signal generation fromthe BCI users will also be discussed.
Lucía Alba Ferrara
ENyS - CONICET
Understanding Brain Communication Through Social Cognition: Evidence from Clinical Neuroscience
Understanding how the brain supports social communication requires integrating evidence fromaffective and pragmatic language processing as well as clinical models of neural reorganization. Thistalk will present converging findings from functional neuroimaging studies on emotional prosody,idiomatic expressions, and sarcasm comprehension. Results show that while basic affectiveprocessing relies on temporal and lateral frontal regions, more complex socio-cognitive demands—such as mental state attribution—engage medial prefrontal and fronto-parietal networks. Similarly,pragmatic language processing recruits bilateral fronto-temporal systems, with contributions fromboth hemispheres depending on semantic complexity and contextual integration. Evidence frompatients with temporal lobe epilepsy further demonstrates that these networks are dynamic andcapable of functional reorganization, recruiting alternative regions to preserve socialcommunicative abilities. Altogether, these findings support a model of brain communication as adistributed, flexible system shaped by both cognitive demands and neural plasticity, highlighting theclose interaction between social cognition and language in health and disease.