RAB-PPS · Reactive adaptive behaviour elicited by events in close proximity of the body

Reactive adaptive behaviour elicited by events in close proximity of the body

The main research goal was to systematically explore how the brain copes with sudden transient events (perceived as threats) in close proximity of our body, within the Peripersonal Space (PPS). Here we could carry out research on healthy human subjects, on a clinical population (patients affected by Parkinson’s disease (PD), a severe movement disorder (Poewe et al., 2017), and on non-human primates. Several, challenging, research techniques (e.g. behavioural methods, electroencephalography (EEG), electromyography (EMG), intracranial electrophysiology (iEEG) on non-human primate and neuromodulation, such as transcranial electrical stimulation (tES) (Paulus, 2011) were involved to address the research questions. The project systematically investigated how the human cortex modulates subcortical defensive reflexes, focusing on the Hand Blink Reflex (HBR) as a model for rapid, adaptive defensive behaviour within peripersonal space (PPS). The HBR, a brainstem-mediated blink response to somatosensory stimulation of the hand, was chosen because its magnitude is strongly influenced by the hand’s proximity to the face, reflecting the nervous system’s estimation of threat value. This multidisciplinary project had ambitious goals to achieve in a short time. However, data collection was completed within the two-year timeframe. We are now at the stage of drafting the first two papers that will be ready for submission in the next few months. We are currently finalising data analysis on both patients affected by Parkinson’s Disease and non-human primates. The final phase of the project experienced delays due to reliance on external institutions for patient recruitment and access to non-human primate data, which proved challenging within the project's timeframe. Problems and Needs Addressed * Scientific gap: The precise mechanisms and cortical areas responsible for modulating subcortical defensive reflexes in humans are still unclear, limiting our understanding of how the brain integrates sensory, motor, and contextual information to generate adaptive responses. * Clinical need: Early and accurate differentiation between PD and atypical parkinsonism remains a major challenge in neurology, often leading to delayed diagnosis and suboptimal care45. There is a pressing need for objective, neurophysiological markers and innovative diagnostic tools. * Societal relevance: As Europe’s population ages, the prevalence of neurodegenerative diseases is increasing, with significant societal and economic costs. Improving early diagnosis and rehabilitation strategies for PD and related disorders aligns with EU policy priorities, including “Economy that works for people” and “Europe for the digital age”. Overall Objectives and Pathway to Impact This project set out to: * Systematically characterize the neural mechanisms underlying defensive behaviours (with a primary focus on the HBR) in both healthy individuals and clinical populations, using a multidisciplinary approach that combines behavioural testing, electrophysiology, and non-invasive brain stimulation. * Identify the cortical substrates and oscillatory dynamics (especially in Brodmann area 7, BA7) that modulate subcortical defensive reflexes, providing direct causal evidence of top-down control in humans. * Develop and validate neuromodulation-based protocols (e.g., tDCS, tACS) as potential diagnostic and rehabilitative tools for movement disorders, with a special focus on differentiating PD from atypical parkinsonism. * Bridge basic neuroscience with clinical and social sciences by integrating psychological assessments (e.g., anxiety questionnaires), collaborating with clinicians and psychologists, and engaging in public outreach and education. Scale and Significance of Expected Impact * Scientific impact: The project advances the state of the art by providing new insights into the cortical control of defensive reflexes, revealing the frequency-specific role of beta oscillations in modulating the HBR, and establishing BA7 as a key hub in these processes. * Clinical impact: Preliminary results suggest that neuromodulation protocols can distinguish PD from atypical parkinsonism, supporting earlier and more accurate diagnoses, and paving the way for novel rehabilitation strategies. * Societal and policy impact: By improving diagnostic tools and rehabilitation approaches, the project addresses urgent healthcare needs, supports healthy aging, and contributes to EU priorities on innovation and societal well-being. * Interdisciplinary integration: The project brings together neuroscience, clinical neurology, psychology, and social sciences, fostering a holistic understanding of defensive behaviour and its modulation in health and disease. Setting the Scene This research responds to the urgent need for a deeper understanding of how the human brain generates and controls defensive behaviours, and how these mechanisms break down in disease. By combining cutting-edge neuroscience with clinical translation and public engagement, the project aims to deliver tangible benefits for science, medicine, and society.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз