- Titel
- Detection of sensorimotor perturbations in grasping and walking
- Zitierfähige Url:
- https://nbn-resolving.org/urn:nbn:de:bsz:ch1-qucosa2-1005407
- Übersetzter Titel (DE)
- Erkennbarkeit sensomotorischer Perturbationen beim Greifen und Gehen
- Datum der Einreichung
- 26.06.2025
- Datum der Verteidigung
- 06.11.2025
- DOI
- https://doi.org/10.60687/2025-0213
- Abstract (EN)
- 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.
- Andere Ausgabe
- Sensorimotor adaptation impedes perturbation detection in grasping
DOI: 10.3758/s13423-024-02543-y - Perceiving inter-leg speed differences while walking on a split-belt treadmill
DOI: 10.1038/s41598-024-85091-8 - Can pupillometry reveal perturbation detection in sensorimotor adaptation during grasping?
DOI: 10.1152/jn.00259.2025 - Freie Schlagwörter (EN)
- perception and action, sensorimotor adaptation, just-noticeable differences, haptic perception, pupillometry
- Klassifikation (DDC)
- 500
- 150
- 152.1
- Normschlagwörter (GND)
- Kognitive Psychologie, Augenbewegung, Handlung, Greifen, Gehen
- GutachterIn
- Prof. Dr. Alexandra Bendixen
- Prof. Dr. Rouwen Cañal Bruland
- BetreuerIn Hochschule / Universität
- Prof. Dr. Alexandra Bendixen
- Den akademischen Grad verleihende / prüfende Institution
- Technische Universität Chemnitz, Chemnitz
- Version / Begutachtungsstatus
- angenommene Version / Postprint / Autorenversion
- URN Qucosa
- urn:nbn:de:bsz:ch1-qucosa2-1005407
- Veröffentlichungsdatum Qucosa
- 28.11.2025
- Dokumenttyp
- Dissertation
- Sprache des Dokumentes
- Englisch
- Lizenz / Rechtehinweis
CC BY 4.0- Inhaltsverzeichnis
Bibliographische Beschreibung 1 Abstract 2 Acknowledgements 4 1 General introduction 7 1.1 Development of action improvement 8 1.1.1 Adjustments to sensory errors 9 1.1.2 Sensorimotor adaptation to perturbations 10 1.1.3 Sensory errors in computational models of adaptation 14 1.1.4 Implicit and explicit adaptation processes 17 1.1.5 Including awareness in models of adaptation 20 1.2 Detecting perturbations 22 1.2.1 Making a perturbation detectable 22 1.2.2 Constraints in changing perturbation properties 24 1.2.3 Dissociating mismatch and error signal 25 1.3 Measuring perturbation detection 25 1.3.1 Report-based measures of perturbation detection 26 1.3.2 No-report measures of perturbation detection 27 1.4 Summary and overall goal 29 2. Perturbation detection in grasping based on sensory mismatch and error signal 30 2.1 Size-perturbations in grasping 30 2.2 Study 1: Sensorimotor adaptation impedes perturbation detection in grasping 32 2.2.1 Abstract 32 2.2.2 Introduction 33 2.2.3 Methods 35 2.2.4 Results 42 2.2.5 Discussion 50 2.3 Contributions in a wider perspective I 52 3. Detecting perturbations in different actions 54 3.1 Sensorimotor perturbations in walking 54 3.1.1 Perceiving information in grasping and walking 54 3.1.2 Gait parameters and treadmill walking 55 3.1.3 Detecting split-belt speed perturbations 57 3.1.4 Manipulating gait speed – the QUEST procedure 59 3.2 Study 2: Perceiving inter-leg speed differences while walking on a split-belt treadmill 60 3.2.1 Abstract 60 3.2.2 Introduction 61 3.2.3 Methods 63 3.2.4 Results 68 3.2.5 Discussion 72 3.3 Perception thresholds in grasping and walking 76 3.4 Contributions in a wider perspective II 77 4. Pupillometry as a no-report marker for perturbation detection 78 4.1 Limitations of psychophysical measures in the context of perturbation detection 78 4.2 Pupil diameter in sensorimotor adaptation tasks 79 4.3 Combining psychophysics and pupillometry 81 4.4 Study 3: “Can Pupillometry Reveal Perturbation Detection in Sensorimotor Adaptation during Grasping?' 82 4.4.1 Abstract 82 4.4.2 Introduction 83 4.4.3 Methods 88 4.4.4 Results 96 4.4.5 Discussion 105 4.4.6 Appendix 109 4.5 Contributions in a wider perspective III 112 5. General Discussion 113 5.1 Detecting and reporting perturbations 114 5.1.1 Is reporting just the plain response of a detected perturbation? 114 5.1.2 Perception of sensory errors in real-world behavior 116 5.1.3 Dealing with uncertainty 117 5.1.4 Properties of perturbation detection 119 5.2 Future perspectives 120 5.2.1 Implications on perturbation procedures 120 5.2.2 Pupillometry and properties of perturbation detection in walking 121 5.2.3 Importance of the sensory error signal 123 5.2.4 Contributions on naturalistic actions and applications 124 5.3 Conclusion 126 6. References 128 Publication list 153