Project Sakkadische Unterdrückung: von Zebrafischen zu Primaten

Basic data

Title:
Sakkadische Unterdrückung: von Zebrafischen zu Primaten
Duration:
01/03/2020 to 28/02/2023
Abstract / short description:
Active sensation is the mode of operation for most behaving organisms. While there are a multitude of computational advantages to active sensation, moving the sensor, such as the eyes for the visual modality, invariably introduces complexities in processing of the input sensory streams. This is so because, during active sensation, information may be sensed by the organism that is the consequence of the sensor movement itself, as opposed to being a result of a genuine novel event in the outside world. Here, we focus on vision and eye movements. We study a robust perceptual phenomenon, called “saccadic suppression”, in which perceptual detection thresholds for brief visual stimulus presentations are dramatically elevated when the brief visual stimuli appear near the time of rapid saccadic eye movements. Despite the robustness of saccadic suppression as a phenomenon, countless debates have emerged, and remain, about its mechanisms and origins. Our goal in the proposed research is to approach saccadic suppression from the perspective of evolutionary convergence and optimization, and we will do so by studying saccadic suppression in two organisms that are almost at two opposite ends of the evolutionary spectrum: zebrafish on the one hand and non-human primates on the other. While saccadic suppression has been observed in the latter, this phenomenon is completely unexplored in the former. We will exploit the known similarities in the oculomotor systems of zebrafish larvae and non-human primates to demonstrate the existence of saccadic suppression in the fish. We will focus on the optic tectum (OT) in fish and the homologous superior colliculus (SC) in non-human primates. The OT of larval zebrafish only contains a few thousand neurons. We will therefore characterize saccade-dependent changes of visual responses for all tectal neurons and relate saccadic suppression to the concept of efficient sensorimotor estimation, in which the OT shares computational resources for both motor control and visual perception. We will use our experimental results to obtain quantitative, predictive estimates about the performance limits of vision with and without saccades in both species. Critically, the identification of anatomically and functionally defined cell types involved in saccadic suppression in the fish will help resolve outstanding debates about this phenomenon in non-human primates (and even human primates). Our approach is unique in the sense that the same scientific personnel will directly work with both species, in a close collaboration across two neighboring laboratories, allowing the deepest insights that we can get about saccadic suppression. The transformative aspect of our proposed research is that we will study active vision in zebrafish OT, and that we will use the anatomical and functional circuit mechanisms uncovered in the fish OT to clarify long-lasting debates about the involvement of mammalian SC in the same phenomenon.
Keywords:
Optisches Tektum
Superiorer Colliculus
Sakkaden und sakkadische Unterdrückung
Aktives Sehen
Sensorische Informationsschätzung
Motorkontrolle
Effiziente Enkodierung

Involved staff

Managers

University Department of Neurology
Hospitals and clinical institutes, Faculty of Medicine

Contact persons

Faculty of Science
University of Tübingen
Department of Biology
Faculty of Science
Werner Reichardt Center for Integrative Neuroscience (CIN)
Centers

Local organizational units

Department of Cognitive Neurology
University Department of Neurology
Hospitals and clinical institutes, Faculty of Medicine

Funders

Bonn, Nordrhein-Westfalen, Germany
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