The digital motor output: a conceptual framework for a meaningful clinical performance metric for a motor neuroprosthesis.

In recent years, the majority of the population has become increasingly reliant on continuous and independent control of smart devices to conduct activities of daily living. Upper extremity movement is typically required to generate the motor outputs that control these interfaces, such as rapidly and accurately navigating and clicking a mouse, or activating a touch screen. For people living with tetraplegia, these abilities are lost, significantly compromising their ability to interact with their environment. Implantable brain computer interfaces (BCIs) hold promise for restoring lost neurologic function, including motor neuroprostheses (MNPs). An implantable MNP can directly infer motor intent by detecting brain signals and transmitting the motor signal out of the brain to generate a motor output and subsequently control computer actions. This physiological function is typically performed by the motor neurons in the human body. To evaluate the use of these implanted technologies, there is a need for an objective measurement of the effectiveness of MNPs in restoring motor outputs. Here, we propose the concept of digital motor outputs (DMOs) to address this: a motor output decoded directly from a neural recording during an attempted limb or orofacial movement is transformed into a command that controls an electronic device. Digital motor outputs are diverse and can be categorized as discrete or continuous representations of motor control, and the clinical utility of the control of a single, discrete DMO has been reported in multiple studies. This sets the stage for the DMO to emerge as a quantitative measure of MNP performance.

Narcissistic and dependent traits and behavior in four archetypal 2-person, 2-choice games.

Introduction: The characteristic behaviors we use to define personality pathology arise from specific interpersonal interactions. In an effort to create a laboratory-based context in which behavior might be expected to be influenced by particular personality traits, we used four 2-person, 2-choice games (the Prisoner's Dilemma, Chicken, Leader, and Hero games) to create a simulated interaction and focused specifically on narcissism and dependency. Method: An online sample of 1137 (35% male, M age = 38.46 years, SD age = 13.20) participants completed brief, self-reported measures of trait narcissism and dependency and played one of the four games. Before deciding how to act or react, participants received either no message, a promise to cooperate, or a threat to defect from a (confederate) partner. Results: When receiving no message, those who cooperated in the Prisoner's Dilemma had lower trait narcissism, while those who defected in the Chicken and Leader games had higher trait narcissism. Also with no message, participants who cooperated in the Hero game had higher trait dependency. Promises only affected the relationship between trait narcissism in the Leader game while threats only affected the relationship between trait dependency in the Chicken game. Discussion: These findings add to the limited behavioral research on personality pathology and largely support established interpersonal conceptualizations and models. Future work might extend these findings using even more ecologically valid approaches to explore the behavioral correlates of personality traits that have important implications for interpersonal interactions.