Research

Goal


Our main research project addresses the question of how it is that we come to feel that we own our body. This question is fundamental because the feeling of body ownership is a basic aspect of self-awareness. Our goal is to identify the multisensory mechanisms whereby the central nervous system distinguishes between sensory signals from within one's own body and sensory signals from the environment. The long-term goal of the project is to develop a physiological model of the central representation of one's body.

We are currently extending this line of research to include questions related to how signals from within the body influence one's visuospatial perception of objects in the external world and how these signals influence one's higher self-related cognitive functions (e.g., episodic memory, body satisfaction).

Research


Our core line of research focuses on the question of how it is that we come to feel ownership over our bodies. This problem can be formulated in terms of a multisensory binding problem: how is visual, tactile, and proprioceptive information combined to obtain a single coherent object that is one's limb? Another line of questioning addresses how the brain represents the position, movement and relative size of different limbs and body parts. We also want to improve our understanding of why people experience phantom limbs after amputation and how experience and training can change one's central body representation.

Perceptual illusions are used in combination with state-of-the-art neuroimaging techniques to address these questions in humans. These illusions allow the controlled manipulation of specific aspects of body representation in healthy individuals. Neuroimaging and focal neurodisruption methods then allow us to probe the underlying brain mechanisms.

This research has important clinical and industrial applications. The projection of ownership onto external objects represents a new direction in man-machine interfacing, neuroprosthetics, and computer science. We collaborate with engineers and hand surgeons to develop advanced prostheses that feel more like real limbs, and we are also developing our own humanoid robotic hand for fMRI experiments.

The Lab


Our laboratory is located in the Department of Neuroscience, Karolinska Institutet. We have a large virtual reality lab (four sets of head-mounted displays, analogue and digital video cameras, video editing software), a behavioral testing room with physiological recording devices (e.g., skin conductance responses, multichannel electromyograms, skin temperature recording sensors, magnetic motion capturing system), and a state-of-the-art transcranial magnetic stimulation (TMS) lab with Neuronavigation (Magstim). For functional magnetic resonance imaging, we have full access to one 3 T Tim Trio scanner at Karolinska Hospital's Huddinge MR-Centre (Head of MR-physics: Prof. Tie-Qiang Li) and one 3 T GE Scanner at the hospital's Solna MR-Centre (Head Prof. Martin Ingvar).

Funding and Partnerships


The lab is funded by Ehrsson's five-year (2008-2013) Starting Investigator Grant from the European Research Council (Neuroscience panel), a five-year "Future Research Leader" grant from the Swedish Foundation for Strategic Research (2008-2013) and a 21st Century Science Initiative Grant, Understanding Human Cognition, from the James S. McDonnell Foundation (USA). (http://www.jsmf.org/grants/d.php?id=2010009).

The lab has also received important start-up support from the Human Frontier Science Programme (2009-2011) (http://www.hfsp.org/frontier-science/hfsp-success-stories/body-self-perception). Our lab is a partner of the Stockholm Brain Institute (www.stockholmbrain.se), a consortium for Cognitive and Computational Neuroscience in Stockholm.

External Research Quality Assessment


Our lab received the highest grade ("outstanding; 6/6") in the recent external research assessment of the Karolinska Institutet (ERA 2010). That put us among the top 12% of labs at the Karolinska Institutet that received this grade.