Eintrag in der Universitätsbibliographie der TU Chemnitz
Volltext zugänglich unter
URN: urn:nbn:de:bsz:ch1-qucosa2-1005407
Müller, Carl
Bendixen, Alexandra (Prof. Dr.) ; Cañal Bruland, Rouwen (Prof. Dr.) (Gutachter)
Detection of sensorimotor perturbations in grasping and walking
Erkennbarkeit sensomotorischer Perturbationen beim Greifen und Gehen
Kurzfassung in englisch
Living in a dynamic environment requires continuous adjustments of our actions to interact efficiently with our dynamic world. However, learning how to adjust motor actions is inherently complex and relies on multiple sources of information, initiating various processes of a gradual improvement of motor actions. One such process on a sensory based level is called sensorimotor adaptation, a form of sensorimotor learning. Some of these adjustments can occur automatically, without being detected by the actor, others however are consciously initiated as the actor becomes aware of the need to correct their action. Thus, identifying the underlying properties and mechanisms making people aware of sensorimotor differences between informational inputs – that is, perturbation detection – and therefore making sensorimotor adaptation explicit is the core of this thesis. Having outlined the latest findings on potential properties and suitable measurements of perturbation detection, I present a first study examining the impact of two candidate factors in the detection of motor perturbations – on the one hand, the magnitude of a perturbation (i.e., physical mismatch between two stimuli) and on the other hand, the size of the perceived sensory error signal. Using grasping, a well-studied motor action with respect to sensorimotor adaptation, I developed an experimental setup allowing participants to grasp real-world cuboids while manipulating these two perturbation properties. Results highlighted the importance of the sensory error signal on perturbation detection, suggesting that adaptation impedes the perturbation detection in grasping. To improve the generalizability of the reported properties, mismatch and error signal, on detectability of perturbations, the next step was to examine other real-world actions like walking that engage different effectors, thus providing different error feedback to adapt to. Since the current literature is lacking precise threshold estimates in walking and barely discusses the differences in increasing versus decreasing speed perturbations, I first focused on filling this gap in study 2. This would be a necessary foundation for replicating the effects found in grasping of sensory error signals on perturbation detection also in walking. Using adaptive psychophysical methods, customized to a naturalistic walking environment, I report precise and reliable measurements for just-noticeable differences of increased- and deceased-speed split-belt perturbations. Comparing variability of these threshold estimates emphasizes the importance of considering individual differences for measuring perturbation detection while walking. Enhancing the understanding of perturbation detection across different modalities and actions also revealed some methodological difficulties that are further addressed in study 3. Psychophysical discrimination tasks have been reported to change the attention towards perturbations, which in turn changes the error signal as it enables cognitive adjustments. To overcome this problem, I added confidence estimation to the discrimination task in the grasping experiment and included pupillometry as a potential physiological no-report measure of perturbation detection. I found similar results compared to study 1, underlining the importance of the sensory error signal on perturbation detection while considering the special role of uncertainty. Moreover, pupil parameters responded to experimental manipulations as well as the grasping error, providing a promising methodological approach for a measurement of perturbation detection without relying on participant’s direct report. Finally, I discuss the implication of these results embedded in the wider context of sensorimotor adaptation and perturbation detection. I present perspectives on how these findings contribute to open questions of perception and action as well as future directions on how these could further be implemented in a more applied framework.
| Universität: | Technische Universität Chemnitz | |
| Institut: | Professur Struktur und Funktion kognitiver Systeme | |
| Fakultät: | Fakultät für Naturwissenschaften | |
| Dokumentart: | Dissertation | |
| Betreuer: | Bendixen, Alexandra (Prof. Dr.) | |
| DOI: | doi:10.60687/2025-0213 | |
| SWD-Schlagwörter: | Kognitive Psychologie , Augenbewegung , Handlung , Greifen , Gehen | |
| Freie Schlagwörter (Englisch): | perception and action , sensorimotor adaptation , just-noticeable differences , haptic perception , pupillometry | |
| DDC-Sachgruppe: | Naturwissenschaften und Mathematik, Psychologie, 152.1 | |
| Sprache: | englisch | |
| Tag der mündlichen Prüfung | 06.11.2025 | |
| OA-Lizenz | CC BY 4.0 |
