Neurophysiological investigations for the clinical usability of endogeneously modulated ECoG signals from striate and extrastriate visual cortex by estimating the focus of attention at the level single trials

• Applicant: Dr. Detlef Wegener
• Subject Area: Cognitive, Systems and Behavioural Neurobiology
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 341162354

• Final Report Year: 2024

Final Report Abstract

The epidural measurement of neuronal activity represents a minimally invasive method for future clinical and basic scientific applications. Epidurally placed microelectrode arrays allow to simultaneously measure signals from multiple cortical areas with a high number of electrodes, without penetrating neural tissue or the dura mater. However, potential drawbacks of epidural measurements include i) lower selectivity, as the signals collected represent the integrated activity of a large number of neurons, ii) poorer signal-to-noise ratio, as the electrodes are farther from the neural signal sources and the dura mater serves as an additional barrier, iii) the high volume of data to be handled, and iv) the relatively unexplored long-term functionality of the used multi-electrode arrays. Within the framework of the funded research project, epidural measurements were conducted in the primary visual cortex of the macaque, and the selectivity of sensory and endogenously modulated signals was investigated. Analytical methods were developed to optimize the extractable information content, and the long-term functionality of the utilized multi-electrode arrays was examined using receptive field mapping approaches. The results of the research project indicate that with the aid of appropriate analysis algorithms, i) the amount of data to be considered can be significantly reduced, ii) high information content can be extracted from initially noisy signals, iii) epidural signals represent highly specific spatial and non-spatial stimulus information. Results further indicate that future research is needed to improve the further improve the long-term integrity and functionality of the currently available electrode arrays. As part of the cost-neutral extension of the project, additional preliminary work was carried out for subsequent investigations. These investigations are necessary for the statistical examination of various technical aspects of epidural multi-electrode arrays and the combination of epidural measurements with optogenetic stimulation. Furthermore, they serve the preparation of studies for the in-depth characterization of epidural signals in the context of fundamental scientific research on attention and decision processes, for which mesoscale epidural measurements provide possibilities which are either not investigable or difficult to study using conventional intraparenchymal measurements.

Publications

• Emphasizing the “positive” in positive reinforcement: using nonbinary rewarding for training monkeys on cognitive tasks. Journal of Neurophysiology, 120(1), 115-128.
  Fischer, Benjamin & Wegener, Detlef
  
• Optimizing the Yield of Multi-Unit Activity by Including the Entire Spiking Activity. Frontiers in Neuroscience, 13.
  Drebitz, Eric; Schledde, Bastian; Kreiter, Andreas K. & Wegener, Detlef
  
• Visual epidural field potentials possess high functional specificity in single trials. Journal of Neurophysiology, 122(4), 1634-1648.
  Fischer, Benjamin; Schander, Andreas; Kreiter, Andreas K.; Lang, Walter & Wegener, Detlef
  
• „About the specificity of epidural field potentials recorded with highdensity multi-electrode arrays from the primary visual cortex”, Promotionsschrift (Dr. rer. nat.), Universität Bremen
  Fischer B.
  
• Blood Analysis of Laboratory Macaca mulatta Used for Neuroscience Research: Investigation of Long-Term and Cumulative Effects of Implants, Fluid Control, and Laboratory Procedures. eneuro, 8(5), ENEURO.0284-21.2021.
  Wegener, Detlef; Oh, (胡箪棋) Dan Qi Priscilla; Lukaß, Herbert; Böer, Michael & Kreiter, Andreas K.
  
• Dynamic divisive normalization circuits explain and predict change detection in monkey area MT. PLOS Computational Biology, 17(11), e1009595.
  Ernst, Udo A.; Chen, Xiao; Bohnenkamp, Lisa; Galashan, Fingal Orlando & Wegener, Detlef
  
• Monkey V1 epidural field potentials provide detailed information about stimulus location, size, shape, and color. Communications Biology, 4(1).
  Fischer, Benjamin & Wegener, Detlef
  
• An Open-Source, Fully Customizable 5-Choice Serial Reaction Time Task Toolbox for Automated Behavioral Training of Rodents. Journal of Visualized Experiments, 179.
  Morais, Gancz Julia; El Jundi, Nada; Strippelmann, Eva; Koch, Michael & Wegener, Detlef
  
• Generalised exponential-Gaussian distribution: a method for neural reaction time analysis. Cognitive Neurodynamics, 17(1), 221-237.
  Marmolejo-Ramos, Fernando; Barrera-Causil, Carlos; Kuang, Shenbing; Fazlali, Zeinab; Wegener, Detlef; Kneib, Thomas; De Bastiani, Fernanda & Martinez-Flórez, Guillermo
  
• Monitoring and immunogenicity of SARS-CoV-2 vaccination of laboratory rhesus monkeys (Macaca mulatta). Scientific Reports, 13(1).
  Oh, Dan Qi Priscilla; Grothe, Iris; Lukaß, Herbert; Kreiter, Andreas K.; Hoffmann, Markus & Wegener, Detlef