1,300 research outputs found
A Mirror Neuron Inspired Model for Goal Inference
No full textThe human mirror neuron system (MNS) refers to brain regions becoming
active both when an action is performed, and when a similar action is being observed.
Several functions have been attributed to the MNS. It is argued that the
MNS is responsible for goal inference, and could be involved in learning by imitation.
Here we investigated an existing neural network model which exhibits
mirror properties, the RecurrentNeuralNetworkwith Parametric Bias (RNNPB).
However, this model fails to account for goal inference, when the body of the
actor and observer are dissimilar. The RNNPB model is extended such that it is
able to explain this general goal inference. This is achieved by ignoring bodily
parameters as a direct input to the model, and instead use the perceived state
of the world as a body-invariant input for the model.
First, the RNNPB model is tested for robustness against noise and parametric
noise in the original signals. It is demonstrated that the model is able to generalize,
which means that the extended RNNPB model does not demand strict
requirements on the features used for representing the state of the world. Furthermore,
we demonstrated the present model in a toy world example, in which
it is shown that observation of multiple goal-directed actions and generation of
a goal directed action achieving the same goal both leads to equal activation of
an additional input layer of the network. This layer contains the so called parametric
bias nodes, which is an essential part of the RNNPB architecture. This
exemplifies the goal related mirror properties of the model
Interview : robots come of age
No full textKey medical advances along with secure and stable societies means people have longer and more active lives. In Europe, fertility rates are on the decline. Yet life expectancy is increasing two and half years for each passing decade and nearly 25 % of the population will be over 65 by 2020. Because of it, the European Commission is funding research projects to address the socioeconomic
challenges of an ageing population
Consistent haptic feedback is required but it is not enough for natural reaching to virtual cylinders
No full textIn virtual reality it is easy to control the visual cues that tell us about an object’s shape. However, it is much harder to provide realistic virtual haptic feedback when grasping virtual objects. In this study we examined the role of haptic feedback when grasping (virtual) cylinders with an elliptical circumference. In Experiment 1 we placed the same circular cylinder at the simulated location of virtual elliptical cylinders of varying shape, so that the haptic feedback did not change when the visually specified shape changed. We found that the scaling of maximum grip aperture with the diameter of the nearest principal axis (.14 ± .04) was much weaker than when grasping real cylinders (.54 ± .04, Cuijpers, Brenner, & Smeets, 2006 Grasping reveals visual misjudgements of shape. Experimental Brain Research, 175, 32-44). For the scaling of grip orientation with the orientation of the cylinder we found large individual differences: the range is .07-.82 (average .42 ± .07) as compared to .55-.79 (average .67 ± .03) for grasping real cylinders. In Experiment 2 we provided consistent haptic feedback by placing real cylinders that matched the location, shape and orientation of the virtual cylinders. The scaling gains of both maximum grip aperture (.39 ± .04) and grip orientation (.56 ± .08) were substantially higher than in Experiment 1, but still lower than for grasps to real cylinders. The variability between participants for the scaling of grip orientation was also much reduced. These results showed that although haptic feedback must be consistent with visual information, it is not sufficient for natural prehension. We discuss the implications of these findings in terms of the integration of visual information with haptic feedback
Comparing performance and situation awareness in USAR unit tasks in a virtual and real environment
Full text linkA convenient way to test Urban Search And Rescue (USAR) robots would be in virtual environments (VEs). Evaluations in VEs are generally accepted as alternative for real scenarios. There are obvious differences between operation in a real and virtual environment. Nonetheless, the current experiment showed no significant differences in situation awareness (SA) and performance during several elementary tasks (e.g. slalom) between a virtual world and a previous experiment in reality (Mioch, Smets, & Neerincx, 2012). Only small dependencies between the unit tasks were found. The effect of individual differences (like gender, km driven per year, and gaming experience), were significant for certain elementary tasks. Testing robots in virtual environments could still be useful even if differences between VE and reality exist, since comparisons of different conditions in VE seems to have the same results as the same comparison in the field (Bishop & Rohrmann, 2003; Van Diggelen, Looije, Mioch, Neerincx, & Smets, 2012).Intelligent SystemsElectrical Engineering, Mathematics and Computer Scienc
Interpersonal movement coordination in jointly moving a rocking board
No full textIn this study, we investigate how two persons (dyads) coordinate their movements when performing cyclical motion patterns on a rocking board. In keeping with the Leading Joint Hypothesis (Dounskaia, 2005), the movement dynamics of the collaborating participants were expected to display features of a prime mover with low movement variability. Fourteen subject pairs performed the task in nine amplitude-frequency combinations that were presented in the form of a to-be-tracked stimulus on a computer display. Participants were asked to track the stimulus by jointly rocking the Board sideways while receiving continuous visual feedback of its rotations. Displacements of 28 IREDS that were attached to the rocking board, both ankles, knees, hips, shoulders and heads of both actors, were sampled at 75 Hz by means of a 3D-motion tracking system. From these data, we derived body-segment angular excursions as well as the continuous relative phase and time-lagged cross-correlations between relevant joint excursions. The results show that, at the intrapersonal level, knee rotations initially led all other joints in time while the antiphase coordination between the knees displayed relative low variability. At the interpersonal level, dyads adopted a leader-follower strategy with respect to the coordination demands of the task. We take that knee rotations create a dynamic foundation at both intra- and interpersonal levels involving subordination of individual action to joint performance thereby allowing for lowdimensional control of joint action in a high-dimensional, repetitive motor task
Revealing unexpected effects of rescue robots’ team-membership in a virtual environment
Full text linkIn urban search and rescue (USAR) situations resources are limited and workload is high. Robots that act as team players instead of tools could help in these situations. A Virtual Reality (VR) experiment was set up to test if team performance of a human-robot team increases when the robot act as such a team player. Three robot settings were tested ranging from the robot as a tool to the robot as a team player. Unexpectedly, team performance seemed to be the best for the tool condition. Two side-effects of increasing robot’s teammembership could explain this result: mental workload increased for the humans who had to work with the team-playing robot, whereas the tendency to share information was reduced between these humans. Future research should, thus, focus on team-memberships that improve communication and reduce cognitive workload.Intelligent SystemsElectrical Engineering, Mathematics and Computer Scienc
Evaluation of unimodal and multimodal communication cues for attracting attention in human–robot interaction
Full text linkOne of the most common tasks of a robot companion in the home is communication. In order to initiate an information exchange with its human partner, the robot needs to attract the attention of the human. This paper presents results of two user studies ( N=12 ) to evaluate the effectiveness of unimodal and multimodal communication cues for attracting attention. Results showed that unimodal communication cues which involve sound generate the fastest reaction times. Contrary to expectations, multimodal communication cues resulted in longer reaction times with respect to the unimodal communication cue that produced the shortest reaction time
Combining robotic persuasive strategies : the persuasive power of a storytelling robot that uses gazing and gestures
Full text linkEarlier theorizing suggested that an (artificial) agent that combines persuasive strategies will be more persuasive. Therefore, the current research investigated whether a robot that uses two persuasive strategies is more persuasive than a robot that uses only one. Two crucial persuasive strategies that humans use in face-to-face persuasion are gazing and gestures, and therefore we studied the combined and individual contribution of these two persuasive strategies (gestures and gazing) on the persuasiveness of a storytelling robot. A robot told a classical persuasive story about the consequences of lying to forty-eight participants, and was programmed to use (persuasive) gestures (or not) and gazing (or not). Next, we asked participants to evaluate the character in the story thereby assessing the robot’s persuasiveness. Results presented evidence a robot’s persuasiveness is increased when gazing is used. When the robot used gestures, its persuasiveness only increased when it also used gazing. When the robot did not use gazing, using gestures diminished the robot’s persuasiveness. We discuss the implications for theory and design of robots that are more persuasive
Interview : robots come of age
No full textKey medical advances along with secure and stable societies means people have longer and more active lives. In Europe, fertility rates are on the decline. Yet life expectancy is increasing two and half years for each passing decade and nearly 25 % of the population will be over 65 by 2020. Because of it, the European Commission is funding research projects to address the socioeconomic challenges of an ageing population
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