Multisensory integration induces body ownership of a handtool, but not any handtool

Bodily boundaries are computed by integrating multisensory bodily signals and can be experimentally manipulated using bodily illusions. Research on tool use demonstrates that tools alter body representations motorically to account for changes in a user's action repertoire. The present experiment sought to unify perceptual and motoric accounts of tool embodiment using a modified Rubber Hand Illusion (RHI) that also addressed the skill and practice aspects of the tool use literature. In Experiment 1, synchronous multisensory stimulation induced perceptual embodiment of a tool, chopsticks. The embodiment of chopsticks was stronger for more skilled participants, and if the illusion was preceded by tool use. In Experiment 2, the illusion was not elicited with a different type of tool, a teacup, showing that not all objects can be incorporated. This experiment helps to clarify the role of perceptual and motoric embodiment and suggests future avenues for research into tools embodiment using this method

Tool Embodiment: The Tool’s Output Must Match the User’s Input

The embodiment of tools and rubber hands is believed to involve the modification of two separate body representations: the body schema and the body image, respectively. It is thought that tools extend the capabilities of the body’s action schema, whereas prosthetics like rubber hands are incorporated into the body image itself. Contrary to this dichotomy, recent research demonstrated that chopsticks can be embodied perceptually during a modified version of the rubber hand illusion (RHI) in which tools are held by the rubber hand and by the participant. In the present research, two experiments examined tool morpho-functional (tool output affordance, e.g., precision grasping) and sensorimotor (tool input, e.g., precision grip) match as a mechanism for this tool-use dependent change to the body image. Proprioceptive drift in the RHI occurred when the tool’s output and the user’s input matched, but not when this match was absent. This suggests that this factor may be necessary for tools to interact with the body image in the RHI

Concrete Interface Protocol

Study Protoco

Multisensory Integration Induces Body Ownership of an External Tool

Bodily self-consciousness (BS) refers to self-knowledge like body shape, position and ownership. BS relies on the integration of multisensory bodily signals and can be experimentally manipulated with the Rubber Hand Illusion (RHI). In this illusion, the incorporation of a rubber hand into the BS is facilitated by visual similarity to the participant’s hand. Neurophysiological research indicates that tool use alters neural networks mapping body shape and posture for coordinating motor actions. The present experiment sought to unify perceptual and motoric BS accounts using a modified RHI. We found that synchronous multisensory stimulation induced perceptual embodiment of an external tool. The RHI was stronger if multisensory stimulation was preceded by tool use, highlighting the motor system’s role in embodiment. The illusion, as measured by proprioceptive drift and questionnaires, was stronger for skilled individuals but also occurred for untrained participants. This experiment helps to clarify the role of perceptual and motoric embodiment

Pilot-testing a Multiplayer HIV and Sexually Transmitted Infection Prevention Video Game Intervention for Black Adolescent Girls: Protocol for a Randomized Controlled Trial

BackgroundBlack adolescent girls aged between 14 and 19 years are more likely than White girls to be diagnosed with a sexually transmitted infection (STI). As STI diagnosis is associated with an increase in the risk for HIV acquisition, an early intervention specifically tailored to Black adolescent girls is warranted. A web-based video game intervention has the potential to reach this demographic. Because studies of social and behavioral determinants of disease demonstrate the protective role of peer group structures on individual outcomes, a multiplayer game can facilitate opportunities to exchange and evaluate information, learn social norms, develop behavioral skills, and allow peers to influence attitudes and behavior. No prior research has examined the feasibility of a web-based multiplayer game intervention for this population. ObjectiveThis study describes the protocol for a randomized controlled trial (RCT) pilot-testing the feasibility, acceptability, and limited efficacy of a multiplayer game–based intervention for increasing HIV and STI testing and condom use in Black adolescent girls. MethodsWe enrolled 79 Black adolescent girls aged 14 to 19 years residing in the United States into a 2-arm parallel RCT. The intervention is a theory-based, community-informed, multiplayer game that can be played with peers on the web using videoconferencing software. The goal of the game is to empower Black adolescent girls to make healthy decisions regarding dating, relationships, and sex, thus reducing HIV and STI infection. Control condition participants received a list of resources after playing a time and attention control game. All study procedures were conducted via the internet. We conveniently sampled Black adolescent girls using web-based advertisements. Study assessments occurred at enrollment, 1 week, 1 month, and 4 months after enrollment. The primary outcome of this study is increased HIV and STI testing by Black adolescent girls. Secondary outcomes include increased condom use, self-efficacy to use condoms, positive attitudes toward condom use, intentions, harm perceptions, HIV and STI and pre-exposure prophylaxis knowledge, positive sexual norms, sexual communication with partners, and reduced incidence of sexual risk behaviors associated with HIV and STI transmission. Secondary outcomes also included assessment of intervention feasibility and acceptability. ResultsFrom February to April 2022, a total of 79 Black adolescent girls were enrolled, with 40 (51%) having been randomized into the intervention condition and 39 (49%) into the control condition. At baseline, participant ages ranged from 14 to 19 (mean 16.4, SD 1.23) years. ConclusionsWeb-accessible game interventions overcome common impediments of face-to-face interventions presenting a unique opportunity to reach Black adolescent girls and improve their sexual health and self-efficacy. Trial data will provide information about the limited efficacy of the intervention and inform future web-based studies and a larger RCT aimed at improving the sexual health of Black adolescent girls. Trial RegistrationClinicalTrials.gov NCT04108988; https://clinicaltrials.gov/ct2/show/NCT04108988 International Registered Report Identifier (IRRID)DERR1-10.2196/4366