Neural correlates of action effects anticipation – towards ecological more relevant paradigms
Dissertation
Datum der mündl. Prüfung:2022-12-07
Erschienen:2023-12-07
Betreuer:Prof. Dr. Alexander Gail
Gutachter:Prof. Dr. Alexander Gail
Gutachter:Prof. Dr. Stefan Treue
Dateien
Name:Thesis_ZurnaAhmed_2022_PublishedVersion.pdf
Size:7.72Mb
Format:PDF
Zusammenfassung
Englisch
Imagine it is Saturday morning and you are going for groceries with your car. Once you arrive at the supermarket, you attempt to reverse park your car in a narrow parking space. You have learned in school, if you want the backend of your car to go to the left (action effect), you need to rotate the steering wheel to the left (action) and vice versa. Clearly, you have an internal representation of the action effects before initiating the action as otherwise you might easily bump into a neighboring car. But how these anticipated action effects are encoded in the brain remains an open and heavily debated question up to date. This dissertation addresses this controversial question in 5 chapters. At first, we advanced the field of systems neuroscience by providing an open source video tutorial to custom-design and -fit your own (wireless) neural implants without any prior experience (Chapter 2). We then introduced a novel touchscreen paradigm (AEA task), which links actions to its effects immediately. Existing paradigms were criticized for rather using arbitrary action and effect associations as this immediate link has been missing. Our neural recordings collected across the brain areas of the fronto-parietal reach region using custom-fitted implants provide clear first-time evidence that action effect anticipation is encoded on a single neuron level and at the population level during action planning, so in other words before the initiation of the action itself (Chapter 3). However, as many of our everyday movements go beyond sitting and simple reaches on a touchscreen, this thesis also focused on developing closer to real-life task paradigms for unrestrained rhesus macaques, which up to date remains a challenge in systems neuroscience. I first developed a novel haptic device, which allows a direct translation of the previously developed AEA task to a free experimental environment (Chapter 4). While the animal was sitting unrestrained and interacting with this device, we recorded neural data using wireless systems. Our preliminary findings show that monkeys adopt to a different strategy when placed in an unconstrained environment (Suppl. Chapter 1). In the last chapter (Chapter 5), we pushed existing limits further. Studying full-body behaviors going beyond sitting and walking or social interactions while recording neural data in non-human primates was technologically not possible. To overcome this limitation, I developed the Exploration Room (ExR), which is a ~2.5 x 4.5 x 2.5 m (W x L x H) modular experimental setup. Additionally a full- body marker less motion tracking system was developed and neural recording systems were integrated. We used the ExR’s modularity to record different types of full-body behaviors and tasks across five rhesus macaques. We demonstrated how these complex neural and behavioral data can be analyzed to answer research questions, which could not be addressed so far as it was technologically not possible such as does reach encoding differ between a two-leg and four-leg stand? To conclude, this dissertation addressed the open question of action effect anticipation in a conventional setting by introducing a novel task paradigm as well in a less constrained setup, in which the animals could move freely. We provide first-time evidence that action effects are encoded on a single neuron level prior to action execution. We also developed a large-scale environment for rhesus macaques with full body motion tracking and wireless neural recordings and provide proof that the ExR is suited for neuroscience studies therefore pushing existing limitations of systems neuroscience.
Keywords: non-human primates; neuroscience; action effect anticipation; freely moving rhesus macaques; sensorimotor control