Can our brain perceive a sense of ownership towards an independent supernumerary limb; one that can be moved independently of any other limb and provides its own independent movement feedback? Following the rubber-hand illusion experiment, a plethora of studies have shown that the human representation of "self" is very plastic. But previous studies have almost exclusively investigated ownership towards "substitute" artificial limbs, which are controlled by the movements of a real limb and/or limbs from which non-visual sensory feedback is provided on an existing limb. Here, to investigate whether the human brain can own an independent artificial limb, we first developed a novel independent robotic "sixth finger." We allowed participants to train using the finger and examined whether it induced changes in the body representation using behavioral as well as cognitive measures. Our results suggest that unlike a substitute artificial limb (like in the rubber hand experiment), it is more difficult for humans to perceive a sense of ownership towards an independent limb. However, ownership does seem possible, as we observed clear tendencies of changes in the body representation that correlated with the cognitive reports of the sense of ownership. Our results provide the first evidence to show that an independent supernumerary limb can be embodied by humans.
Artificial Limbs/psychology , Brain/physiology , Cognition/physiology , Extremities/physiology , Adult , Behavior/physiology , Fingers/physiology , Humans , Male , Movement/physiology , Robotics/standards , Young Adult
Cell-based microarrays are emerging as a tool for analyzing the functions of genes in cells. However, partly due to the difficulty of cell immobilization, the application of this method has been limited to adherent cells. We previously reported a method that rapidly and strongly attached living nonadherent cells to glass slides modified with a cell membrane anchoring reagent, designated a biocompatible anchor for membrane (BAM). Here we demonstrate that plasmid DNA deposited in a defined area on BAM-modified glass slides was transfected into nonadherent K562 cells immobilized on the DNA-deposited and BAM-modified slides. This method allowed the transfection of K562 cells not only with plasmid cDNA expression vectors but also with small interfering RNA (siRNA) at a defined location on the BAM-modified slides. We expect this methodology to greatly expand the scope of current cell microarray technology.
Biocompatible Materials/chemistry , Cells, Immobilized , Indicators and Reagents , Oligonucleotide Array Sequence Analysis/methods , Polyethylene Glycols/chemistry , Cloning, Molecular , DNA, Complementary , Ether/chemistry , Gene Expression , Glass , Humans , K562 Cells , Lipids , Membranes, Artificial , Oligonucleotide Array Sequence Analysis/instrumentation , Plasmids , RNA, Small Interfering , Surface Properties , Transfection
Microarrays of living cells are an emerging tool in systems such as reverse transfection. These studies are limited to adherent cells partly because of the difficulty of cell immobilization. Using a newly developed reagent, the biocompatible anchor for membrane (BAM), we show herein the rapid and strong attachment of living nonadherent cells and adherent cells on BAM-modified surfaces. Normal cellular growth was observed for over 7 days on BAM-modified surfaces. We expect this methodology to greatly expand the scope of current cell microarray technology.
Biocompatible Materials/chemical synthesis , Cell Adhesion/physiology , Cell Culture Techniques/methods , Cell Division/physiology , Cells, Immobilized/physiology , Ether/chemistry , Polyethylene Glycols/chemistry , Animals , Biocompatible Materials/chemistry , Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Cell Survival/physiology , Humans , Jurkat Cells , K562 Cells , Membranes, Artificial , Mice , NIH 3T3 Cells , Surface Properties
