ELAPS: Embodied Latency Adaptation and the Perception of Simultaneity

• Applicant: Dr. Marieke Rohde
• Subject Area: Human Cognitive and Systems Neuroscience
• Term: from 2010 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 191674407

The human brain continually compensates for latencies between the senses and between action and perception. The previous project "ELAPS: Embodied Latency Adaptation and the Perception of Simultaneity" investigated the plasticity of visuomotor delay compensation mechanisms. This is a topic of great relevance for the design and use of digital interfaces (e.g., virtual reality, remote manipulation), where feedback delays are often inevitable. The project results show that humans adapt their motor behavior and time perception to additional feedback delays (sub-second range) given the right circumstances, e.g., a predictable task environment.The continuation proposal "ELASTiC: Embodied Latencies in Agency, Space, Time and Causation" extends these results with targeted additional experiments for a better understanding of the underlying mechanisms. This work will pay additional attention to the concept of agency (self-initiated action) in the context of visual feedback latencies. The results from the project ELAPS show, on the one hand, that agency is a key factor in delay adaptation and processing. On the other hand, sensorimotor timing determines the sense of agency (e.g., an action has to happen before a sensory event for humans to perceive a causal link). The project ELASTiC will investigate these interdependencies between agency and visuomotor timing using different strands of experiments on human behavior. (1) Experiments on motor control in the closed sensorimotor loop.Firstly, simple and controlled motor tasks (manual tracking) will be used to study the basic components of latency adaptation and processing. Secondly, experiments on delay adaptation in freely moving participants provide a more ecologically valid complement to this work. For this research, participants wear a portable virtual reality glasses. This work tests for generalization of delay adaptation, such as: If participants adapt to a visual delay on hand movements, will this learning transfer to the control of whole body movements with feedback delays?(2) Experiments on perceptionChanges in time and agency perception are studied using a multisensory psychophysics approach. Human perceptual judgments (e.g., on sensed agency or temporal order) are recorded and described as a function of a continuously varied physical variable (e.g., visuomotor latencies), in order to extract parameters that characterize the perceptual world.Especially the interface between these two approaches (perceptual learning in motor control; active agency perception) will increase our understanding of the plastic neural processes involved in action and perception. The theoretical framework of these results (multisensory integration, control theory) makes the project results suitable for engineering applications (e.g., interface design, human-machine-interaction) or even in medicine (e.g., disruptions of the sense of agency in schizophrenic patients).

• DFG Programme: Research Grants