Over the last two decades, a significant discovery in systems neuroscience has been the realization that spontaneous activity is not random "noise". Still, brain regions are correlated, even in the absence of sensory stimuli or motor tasks. Whereas classical neuroscientific models argued that brain functions primarily depend upon stimulus-related processing, the current view is that the cognitive operations of the brain are mainly intrinsic. Recent studies suggest that this intrinsic structure is optimized to switch to a variety of possible states in individuals with high cognitive functioning. However, whether and how this stable structure adapts to novel conditions is unknown. This project addresses this issue by testing how cognitive flexibility influences the intrinsic brain organization and its adaptation to extreme manipulations of the body.
The body, particularly the hand, is the primary means of interaction with the environment. Neurological, psychiatric, and other clinical conditions (e.g., body amputation) can modify the body image and, therefore, how individuals interact with the surroundings. In the course of the development and the experience, the biomechanics of the human body movements generates distributions of highly probable states that are internalized by the brain. A new theoretical framework posits that the spontaneous oscillations of the brain may function as long-term prior of frequent behaviors that constrain the recruitment of task-driven activity.
Through high-density Electroencephalography (Hd-EEG) and virtual reality, this multidisciplinary project addresses how and whether cognitive flexibility influences how the brain reorganizes when there is not a match between prior expectations and incoming input, regarding the body. This study has far-reaching implications not only for neuroscience but also for psychology, psychopathology, and neurology.
At the theoretical level, most of what we know about brain functions comes from studies using static and extremely constrained sensory stimuli briefly flashed on the screen. At the same time, the participants maintain fixation on a small central target and then act when a specific condition is satisfied. The activation of brain areas during these goal-directed behaviors is typically compared to a state of control; by contrast, the spontaneous brain activity, e.g., not attributed to an experimental paradigm, is viewed as "noise". This classical approach has strongly shaped the field of cognitive neuroscience and has generated two main biases. Firstly, simplified experiments do not guarantee that the principles and concepts established within that framework will apply more generally; second, brain functions primarily depend upon stimulus-related processing.
In the present project, the combined usage of VR and electrophysiological techniques is considered a step change, both at a theoretical and practical level. Indeed, VR environments generate strong emotional and physical responses, by simulating realistic and ecological contexts, despite guaranteeing the control needed in the laboratory experiments. By testing and implementing free-flowing behavior protocols, this project proposes innovative methodological approaches to advance our understanding of how and whether neural priors bias sensory and motor processing, in the face of the potentially high dimensionality of real-life events and individual differences in cognitive flexibility.
In particular, our project will advance existing literature on the influence of specific personality traits and/or cognitive abilities on the reorganization of the intrinsic brain connectivity in response to extreme manipulations of the body. The rationale underlying the idea to use extreme manipulation of the body to investigate putative reorganizations of the intrinsic network structure is clear and based on specific empirical evidence. Firstly, the body is the primary means of interaction with the environment. Using our hands, we can manipulate objects, explore the surroundings, or change the world around us. Secondly, neurological, psychiatric, and other clinical conditions (e.g., amputation) can strongly modify our body image and, therefore how individuals interact with the external environment. The understanding of how individual differences influence the way we react to these dramatic, and often sudden, events is crucial to implement targeted therapeutic interventions.
In the field of the neuroprosthesis and robotic-assisted technology, understanding which resources are used by the brain for controlling the body and, particularly the hand, in natural settings is crucial for the development of biomedical technology, that use robotic systems to perform new and more precise operations possible (as those implemented in micro-surgery). Over time this technology could make its entrance in industry and daily life, with positive effects on the physical burden of the users. However, less is known on how individual differences can influence their usage. Perhaps the most interesting example is represented by amputees. A recent fMRI study shows stable topography of the cortical representation of the fingers decades after arm amputation (Kikkert et al., 2016). This implies that a stable intrinsic structure obstructs the functional reorganization of the brain, despite classical neuroscientific models arguing that after brain lesions or peripheral injury, cortical plasticity mechanisms permit such reorganization. Our project tests how and whether individual differences in cognitive functioning can drive a possible brain change.