Bahadir Kasap
Donders Institute for Brain, Cognition and Behaviour, Radboud University
Biological naturalist Consciousness requires living metabolic hardware
Bahadir Kasap works on the superior colliculus at the level of individual spikes. With A. John van Opstal he built a spiking neural network of the midbrain gaze motor map in which each neuron follows adaptive exponential integrate-and-fire dynamics, with biophysical parameters that vary systematically across the map, and lateral center-surround connectivity that synchronizes the bursting of the recruited population. The model reproduces the experimentally observed burst profiles, the systematic variation of peak firing rate with saccade amplitude, and the linear ensemble decoding that downstream circuitry applies to the population spikes. The work was published in Biological Cybernetics in 2017, with a microstimulation extension in PLOS Computational Biology in 2019, and the code is public on Bitbucket.
The superior colliculus is the clearest biological case of a structure that holds a multisensory priority map and converts a selection into a precisely timed action. In Kasap’s models that conversion is carried by conductance-based spiking dynamics, a log-polar coordinate transform and population codes, all measurable quantities rather than verbal claims. Bjørn Merker’s selection triangle assigns the same structure the target selection vertex of conscious organization, and Kasap’s work shows that vertex is computable in biologically realistic terms.
For artificial systems the lesson is that a midbrain-style selection layer is an engineering specification, not a metaphor. The sensory tectum of this project’s architecture implements the same priority-map principle at a coarser granularity, and the spiking model defines what a closer approximation would require, including the complex-logarithmic coordinate frame and the population-level motor output.
Known for. Spiking neural network models of the superior colliculus, log-polar motor map dynamics, ensemble coding of saccade commands
Coverage on this site
Related researchers
- Bjørn MerkerIndependent researcher, SwedenConsciousness without a cerebral cortex, the subcortical midbrain candidate, striatum-based sensory integration, critique of cortical orthodoxy
- A. John van OpstalDonders Institute for Brain, Cognition and Behaviour, Radboud UniversitySuperior colliculus motor map theory, ensemble coding of saccadic commands, spiking network models of the midbrain gaze system
- František BaluškaUniversity of BonnCellular consciousness, subcellular nanobrains, plant neurobiology, sentient cells as units of physiology
- Tristan A. BekinschteinDepartment of Psychology / Consciousness and Cognition Lab, University of CambridgeClinical biomarkers of consciousness, local-global auditory paradigm, transitions from wakefulness to sedation, neural dynamics of awareness
- Tomas Berjaga-BuisanComputational Neuroscience Group, Center for Brain and Cognition, Universitat Pompeu Fabra, BarcelonaNon-equilibrium thermodynamics of whole-brain models, fluctuation-dissipation theorem violations as a non-invasive consciousness marker
- Douglas BlackistonAllen Discovery Center at Tufts UniversityMemory stability during brain remodeling, xenobot platform design, amphibian memory transplantation work
Bahadir Kasap is listed with the other biological naturalists, who hold that consciousness requires living metabolic hardware. The theory family behind that position is set out in the index of consciousness theories. Every researcher covered on this site is indexed in the directory of consciousness researchers.