|Titel:||Dynamic coding of body-related and spatial information during tactile sensorimotor processing and continuous bimanual coordination||Sonstige Titel:||Dynamische Kodierung körperbezogener und räumlicher Informationen während taktiler sensomotorischer Verarbeitung und kontinuierlicher bimanueller Koordination||Sprache:||Englisch||Autor*in:||Brandes, Janina||Schlagwörter:||tactile remapping; motor control; multisensory processing; symmetry bias; mirror||Erscheinungsdatum:||2017||Tag der mündlichen Prüfung:||2017-10-27||Zusammenfassung:||
Flexible interaction with the external world, as squatting a mosquito or applauding at a concert for example, depends on processing information about the body and the environment. This information is sampled through different senses that code it relative to native anchors, such as the retina in vision or the skin in touch. Some body-related and spatial aspects are redundantly coded in multiple senses, as body posture or movement direction in vision and proprioception for instance. Others are uniquely coded in one sense, such as color in vision or tickling in touch. Successful interaction with the environment relies on combining redundant and complementary information across the senses. The three studies of the present thesis investigate the organizing principles of this process for different kinds of action. The first two studies examined how body-related information is processed in 3D space. For instance, to squat a mosquito, a tactile stimulus, natively coded relative to the skin, has to be recoded into an external movement target by integrating multisensory information about body posture. This process presumably encompasses coordinate transformation from skin-based into external coordinates and subsequent integration of both location codes. The first study investigated how both of these processes contribute to goal-directed action toward a touch using motion tracking of hand movements during a sensorimotor decision task (Chapter 2). The results showed that flexibly weighted integration of skin-based and spatial coordinates, as well as prior probabilities signaling previous movement goal locations, is the prime computational mechanism underlying touch localization for action. The second study investigated the neural implementation of this process using functional Magnetic Resonance Imaging (fMRI; Chapter 3). The results revealed that dynamically employed body-related and spatial codes differ depending on the stage of movement planning and are implemented in posterior parietal cortex (PPC). Other kinds of action, as applauding at a concert for example, also rely on processing body-related and spatial information. The third study examined how both aspects are coded across vision and proprioception using motion tracking of bimanual index finger adduction and abduction movements (Chapter 4). The results showed that coordinative movements are most stable if homologous muscles were used in both hands. Moreover, vision exclusively contributed to spatial (i.e., movement direction), but not to body-related (i.e., posture, muscle) movement coding. Taken together, the results of the present thesis show that body-related and spatial coding is flexibly employed according to the task context across different kinds of action. On a neural level, PPC appears to play a key role for spatial processing of body-related information. More generally, sensorimotor processing and continuous bimanual coordination have been investigated in two largely separate research fields to date, in part because studies on these different kinds of actions were motivated by distinct theoretical concepts. Building on the results of the present thesis, future investigations of tactile sensorimotor processing and continuous bimanual coordination could further characterize unique and shared processing principles against a common theoretical background, such as Optimal Feedback Control (OFC). Collectively, the present thesis advances our understanding of how perceptual and motor aspects of behavior interact during seemingly ordinary movements, such as squatting a mosquito or applauding at a concert.
|URL:||https://ediss.sub.uni-hamburg.de/handle/ediss/7422||URN:||urn:nbn:de:gbv:18-88155||Dokumenttyp:||Dissertation||Betreuer*in:||Heed, Tobias (Prof. Dr.)|
|Enthalten in den Sammlungen:||Elektronische Dissertationen und Habilitationen|