Perturbing human thalamocortical loops to understand their contribution to visual perception

• Applicants: Dr. Jorge Jaramillo; Privatdozentin Dr. Elisabeth Kaufmann; Professor Dr. Tobias Staudigl; Professor Dr. Tino Zaehle, Ph.D.
• Subject Area: Human Cognitive and Systems Neuroscience ; Biological Psychology and Cognitive Neuroscience ; Cognitive, Systems and Behavioural Neurobiology
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 520139811

The contribution of the thalamus to human cognition has long been underestimated. The reasons for this are, on the one hand, a traditionally cortex-focused view that explains higher cognitive functions exclusively in terms of neural circuits at the cortical level. Moreover, recording neural data from subcortical areas is complicated by their deep location in the human brain, especially when both spatial and temporal precision are required. Recent developments in deep brain stimulation for treatment of psychiatric and neurological disorders now open the possibility of direct electrophysiological recordings from the human subcortex and the manipulation of these areas by electrical stimulation to test possible causal relationships for their involvement in cognitive processes. In the present project, we take advantage of this unique opportunity by studying thalamocortical loops in patients who have had a deep brain stimulator implanted to treat their epilepsy. This allows us to record intracranial EEG directly from the mediodorsal thalamus and stimulate it electrically, to investigate whether and how human visual perception depends on thalamocortical loops. In addition to this external modulation of thalamocortical networks by electrical stimulation, we will investigate whether thalamocortical networks can also be internally modulated by eye movements. Again, we will investigate the effect of such an internal modulation of thalamocortical networks on human visual perception. Computational modeling will provide a unified framework to compare the effects of external and internal modulation of the thalamocortical network. First, we will model the dynamical activity of interconnected thalamic and cortical neurons to understand their contributions to perceptual processing. Next, we will design a deep brain stimulation protocol to model the effects of perturbing the thalamocortical network via deep brain stimulation to the mediodorsal thalamus and to evaluate the causal role of the mediodorsal thalamus for visual detection. Finally, we will augment the thalamocortical circuit model by including behavioral feedback from the eye movement system to model potential contributions of small eye movements to attention and visual detection. Thus, computational modeling will be key to interpret the experimental results at a neural circuit level and formulate predictions that can be tested within the current experimental design, as well as translational predictions that can be tested in animal models.

• DFG Programme: Priority Programmes
• Subproject of: SPP 2411: Sensing LOOPS: cortico-subcortical interactions for adaptive sensing
• International Connection: USA