Abstract Following surgical repair of major nerve trunks there is a rapid functional reorganisation in the brain, characterised by a changed cortical mapping of the hand secondary to incorrect reinnervation of peripheral targets. Sensory... more
Abstract Following surgical repair of major nerve trunks there is a rapid functional reorganisation in the brain, characterised by a changed cortical mapping of the hand secondary to incorrect reinnervation of peripheral targets. Sensory re-educational ...
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A reinforcement architecture is introduced that consists of three complementary learning systems with different generalization abilities. The ACTOR learns state-action associations, the CRITIC learns a goal-gradient, and the PUNISH system... more
A reinforcement architecture is introduced that consists of three complementary learning systems with different generalization abilities. The ACTOR learns state-action associations, the CRITIC learns a goal-gradient, and the PUNISH system learns what actions to avoid. The architecture is compared to the standard actor-crititc and Q-learning models on a number of maze learning tasks. The novel architecture is shown to be superior on all the test mazes. Moreover, it shows how it is possible to combine several learning systems with different properties in a coherent reinforcement learning framework.
The core deficit in attention deficit/hyperactivity disorder (ADHD) continues to present an enigma to scientists, professionals and parents alike. Medication with methylphenidate has to some extent proven successful, but it is still not... more
The core deficit in attention deficit/hyperactivity disorder (ADHD) continues to present an enigma to scientists, professionals and parents alike. Medication with methylphenidate has to some extent proven successful, but it is still not known exactly what parts of the deficits in ADHD medication influences. It is thus important to further delineate the nature of ADHD and thoroughly investigate the possible subtypes. In this paper we describe some experiments investigating the nature of inhibition, resource allocation, sustained and selective attention, distractibility and task switching among children with ADHD. The conclusions could be used to advocate for different models of ADHD, e.g., a model of deficient response inhibition or a model of non-optimal resource allocation. Below we present our first steps toward a robot model of ADHD. The computational model can reproduce some of the behaviors shown in children with ADHD in experimental situations. The model suggests that a defici...
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Introduction To act in an unknown and continously changing environment, an autonomous robot must be able to react instantaneously on changes and unexpected events in order to avoid collisions and to update its maps. Successful navigation... more
Introduction To act in an unknown and continously changing environment, an autonomous robot must be able to react instantaneously on changes and unexpected events in order to avoid collisions and to update its maps. Successful navigation requires that the robot reacts primarily on its immediate sensory information and secondarily on its internal mapping of the spatial layout of the environment. We have developed and constructed an experimental mobile robot equipped with a number of complementary sensory systems (Balkenius and Kopp 1994a). A video camera is mounted on a movable head that also contains a pair of microphones. Ultrasonic sensors are located around the body of the robot and a set of tactile sensors (whiskers) and a bumper are used to detect obstacles at a short range. The project aims at developing the attention and navigation systems of the robot to include vision for spatial orientation. The choice of vision is natural since this modality contains the richest informati
No current commercially available myoelectrically controlled prosthetic hands provide conscious sensory feedback to the user. A system aiming at relocation of sensory input from a prosthetic hand equipped with force sensors to the forearm... more
No current commercially available myoelectrically controlled prosthetic hands provide conscious sensory feedback to the user. A system aiming at relocation of sensory input from a prosthetic hand equipped with force sensors to the forearm skin of amputees, a tactile display, has been developed and constructed. The system consists of five piezoresistive force sensors or, alternatively, a prosthetic hand equipped with force sensors, five digital servomotors with a lever and a circular plastic disk pushing on the skin, control electronics based on an MSP430 microcontroller and a test application implemented in LabVIEW running on a PC. The tactile display system is intended to be integrated into the socket of a hand prosthesis and used as a conscious sensory feedback system for hand amputees using a myoelectrically controlled hand prosthesis. The system will provide continuous force feedback from sensors in the fingertips of each prosthetic finger and will likely improve the users' ...
BERRY III is an interactive tool for the construction and simulation of neural network controlled artificial creatures that can be considered either as biological models or as simulated robots. Environments and creatures can be built and... more
BERRY III is an interactive tool for the construction and simulation of neural network controlled artificial creatures that can be considered either as biological models or as simulated robots. Environments and creatures can be built and modified during simulation time using a large set of graphical editors and viewers. The simulator also includes an extensive package for generation of graphs and statistics. To let the neural network controllers improve automatically, it possible to invoke an evolution module that uses the genetic algorithm to create new neural networks using a large selection of evolution schemes. The simulator is in the public domain and suitable both as a research tool and in education.
We describe how a standard reinforcement learning algorithm can be changed to include a second contextual input that is used to modulate the learning in the original algorithm. The new algorithm takes the context into account during... more
We describe how a standard reinforcement learning algorithm can be changed to include a second contextual input that is used to modulate the learning in the original algorithm. The new algorithm takes the context into account during relearning when the previously learned actions are no longer valid. The algorithm was tested on a number of cognitive experiment and shown to reproduce the learning in both a task switching test and in the Wisconsin Card Sorting Test. In addition, the algorithm was...
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The Artificial Hand Project is a cross disciplinary cooperation project group that has the vision of building an artificial hand that will be accepted by the bearer as a part of the body and not as a tool as it is today. The investigation... more
The Artificial Hand Project is a cross disciplinary cooperation project group that has the vision of building an artificial hand that will be accepted by the bearer as a part of the body and not as a tool as it is today. The investigation of a control system for such an advanced prosthesis is carried out in this paper using
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By using a microfabricated nerve chip with integrated electrodes through which peripheral nerves can regenerate and make electrical connects, it should be possible to control a remote prosthesis by processing the detected nerve signals.... more
By using a microfabricated nerve chip with integrated electrodes through which peripheral nerves can regenerate and make electrical connects, it should be possible to control a remote prosthesis by processing the detected nerve signals. In this study different artificial neural networks have been employed for classification of such complex patterns of signals. The signals were obtained from four electrodes detecting muscle activity in a rat hindlimb as a consequence of applied stimulus to the rat right hindpaw. These signals recorded at four different sites resembles a situation of a nerve chip with four electrodes, which implies that one might be able to use the same strategy when analyzing data from a four-electrode chip to obtain information from the nervous system. Here, the authors address the usefulness of different network topologies for analyzing measured in vivo data from an implanted perforated nerve chip
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The Double Cone Model (DCM) is a model of how the brain transforms sensory input to motor commands through successive stages of data compression and expansion. We have tested a subset of the DCM on speech recog- nition, production and... more
The Double Cone Model (DCM) is a model of how the brain transforms sensory input to motor commands through successive stages of data compression and expansion. We have tested a subset of the DCM on speech recog- nition, production and imitation. The experi- ments show that the DCM is a good candidate for an articial speech processing system that can
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To accurately track a moving target despite delays in the visual processing, it is necessary to predict how the target will move in the future and to direct the gaze toward the anticipated location. We have ad-dressed this problem within... more
To accurately track a moving target despite delays in the visual processing, it is necessary to predict how the target will move in the future and to direct the gaze toward the anticipated location. We have ad-dressed this problem within a simulated visual scene were a ball is dropped from a random location and subsequently bounces or rolls on different objects be-fore it comes to rest. A developmental system has been designed that attempts to track the location of the ball as closely as possible despite a delay of 250 ms from the the visual input to the control of gaze. The system is an extension of an earlier model of gaze development (Balkenius and Johansson, 2005). A standard Kalman filter-based tracking frame-work is used that gradually develops a set of parallel predictive models of the environment. The use of multiple models is similar to the MOSAIC architec-ture (Wolpert et al., 2003). These models are used to predict the future position of a target object, and by generalizi...
This paper presents an experimental study using two robots. In the experiment, the robots navigated through an area with or without obstacles and had as their goal to shift places with each other. Four dif-ferent approaches (random,... more
This paper presents an experimental study using two robots. In the experiment, the robots navigated through an area with or without obstacles and had as their goal to shift places with each other. Four dif-ferent approaches (random, reactive, planning, anticipation) were used during the experiment and the times to accomplish the task were com-pered. The results indicate that the ability to anticipate the behavior of the other robot could be to an advantage. However, the results also clearly show that anticipatory behavior is not always better than a purely reactive strategy.
This report describes a fast method for finding regions with a particular color in a visual scene. The method is general enough to be used in any situations were a number of objects with known color need to be found in an image. We demon-... more
This report describes a fast method for finding regions with a particular color in a visual scene. The method is general enough to be used in any situations were a number of objects with known color need to be found in an image. We demon- strate how the algorithm can be used to find and track robots wi th colored markers, symbols with a particular color as well as for simple color-based face detection.
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A model of event driven anticipatory learn-ing is described and applied to a number of attention situations where one or several vi-sual targets need to be tracked while being intermittently occluded. The model combines covert tracking of... more
A model of event driven anticipatory learn-ing is described and applied to a number of attention situations where one or several vi-sual targets need to be tracked while being intermittently occluded. The model combines covert tracking of multiple targets with overt control of a single attention focus. The im-plemented system has been applied to both a simple scenario with a car that is occluded in a tunnel and a complex situation with six simu-lated robots that need to anticipate the move-ments of each other. The system is shown to learn very quickly to anticipate target move-ments. The performance is further increased when the simulated robots are allowed to co-operate in the tracking task.
We have implemented four bio-inspired self- organizing haptic systems based on proprioception on a 12 d.o.f. anthropomorphic robot hand. The four systems differ in the kind of self-organizing neural network used for clustering. For the... more
We have implemented four bio-inspired self- organizing haptic systems based on proprioception on a 12 d.o.f. anthropomorphic robot hand. The four systems differ in the kind of self-organizing neural network used for clustering. For the mapping of the explored objects, one system uses a Self- Organizing Map (SOM), one uses a Growing Cell Structure (GCS), one uses a Growing Cell
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We have experimented with a bio-inspired self- organizing texture and hardness perception system which automatically learns to associate the representations of the two submodalities with each other. To this end we have developed a... more
We have experimented with a bio-inspired self- organizing texture and hardness perception system which automatically learns to associate the representations of the two submodalities with each other. To this end we have developed a microphone based texture sensor and a hardness sensor that measures the compression of the material at a constant pressure. The system is based on a novel
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The Lucs Haptic Hand III has been built as a step in a project at LUCS aiming at studying haptic perception. In this project, several robot hands together with cog- nitive computational models of the corresponding hu- man neurophysiologic... more
The Lucs Haptic Hand III has been built as a step in a project at LUCS aiming at studying haptic perception. In this project, several robot hands together with cog- nitive computational models of the corresponding hu- man neurophysiologic systems will be built. Grasping tests with the LUCS Haptic Hand III were done with six different objects in order to
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We have developed an 8 d.o.f. robot hand which has been tested with three computational models of haptic perception. Two of the models are based on the tensor product of different proprioceptive and sensory signals and a self-organizing... more
We have developed an 8 d.o.f. robot hand which has been tested with three computational models of haptic perception. Two of the models are based on the tensor product of different proprioceptive and sensory signals and a self-organizing map (SOM), and one uses a novel self-organizing neural network, the T-MPSOM. The computational models have been trained andtested with a set
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We investigate four different methods for background estimation in calcium imaging of the insect brain and evaluate their performance on six data sets consisting of data recorded from two sites in two species of moths. The calcium... more
We investigate four different methods for background estimation in calcium imaging of the insect brain and evaluate their performance on six data sets consisting of data recorded from two sites in two species of moths. The calcium fluorescence decay curve outside the potential response is estimated using either a low-pass filter or constant, linear or polynomial regression, and is subsequently used to calculate the magnitude, latency and duration of the response. The magnitude and variance of the responses that are obtained by the different methods are compared, and, by computing the receiver operating characteristics of a classifier based on response magnitude, we evaluate the ability of each method to detect the stimulus type and conclude that a polynomial approximation of the background gives the overall best result.
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This paper outlines the epigenetic logic of the emergence and elaboration of symbolization. The account is based upon considerations arising from the study of the ontogenesis and phylogenesis of symbolic communication, abstraction from... more
This paper outlines the epigenetic logic of the emergence and elaboration of symbolization. The account is based upon considerations arising from the study of the ontogenesis and phylogenesis of symbolic communication, abstraction from which yields generalizations regarding the necessary developmental pre-requisites for the capacity for symbolization and the processes of the elaboration of symbolic capacity into language.
IntroductionA visually orienting mobile robot must cope with anumber of changes to its environment. Mostimportantly, it must be able to identify its locationeven when objects in the environment have beenmoved or when the illumination... more
IntroductionA visually orienting mobile robot must cope with anumber of changes to its environment. Mostimportantly, it must be able to identify its locationeven when objects in the environment have beenmoved or when the illumination conditions havechanged. We report experiments with a template-basedself-localization method that operates in real time on aPentium 133 MHz PC (Balkenius and Kopp 1996a, b;1997). The algorithm
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A mobile robot navigating in an unstructured environment faces many difficult problems for which vision may potentially offer useful solutions. The XT-1 (eXpectation based Template matching) architecture was developed in an attempt to... more
A mobile robot navigating in an unstructured environment faces many difficult problems for which vision may potentially offer useful solutions. The XT-1 (eXpectation based Template matching) architecture was developed in an attempt to address many of these problems with similar constructions. The current system handles such diverse problems as landmark and place recognition, the generation of orienting and anticipatory saccades,
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IntroductionThe abilities of the currently existing hand prostheses are typically limited toopening or closing the hand. This limits the usefulness of the prosthesisconsiderably compared to the many degrees of freedom in an intact hand.... more
IntroductionThe abilities of the currently existing hand prostheses are typically limited toopening or closing the hand. This limits the usefulness of the prosthesisconsiderably compared to the many degrees of freedom in an intact hand. In order todevelop more advanced hand prostheses two main problems have to be solved. Thefirst is to develop more advanced mechanical solutions that allows for more
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This paper shows how a representation at multiple scales can be used for generalization in instrumental learning. The use of such representations is an efficient way to code similarities and differences within a stimulus dimension, and... more
This paper shows how a representation at multiple scales can be used for generalization in instrumental learning. The use of such representations is an efficient way to code similarities and differences within a stimulus dimension, and allows a learning system to generalize easily between various situations. A neural network based model of classical and instrumental conditioning is presented and its
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Persons with autism, probably due to early sensory impairments, attend to and select for stimuli in an uncommon way. Inhibition of some features of a stimulus, such as location and shape, might be intact, while other features are not as... more
Persons with autism, probably due to early sensory impairments, attend to and select for stimuli in an uncommon way. Inhibition of some features of a stimulus, such as location and shape, might be intact, while other features are not as readily inhibited, for example color. Stimuli irrelevant to the task might be attended to. This results in a learning process
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ABSTRACT We investigating the role of anticipation and attention in a dynamic environment in a number of large scale simulations of an agent that tries to negotiate a number of gates that continuously open and close. In particular we have... more
ABSTRACT We investigating the role of anticipation and attention in a dynamic environment in a number of large scale simulations of an agent that tries to negotiate a number of gates that continuously open and close. In particular we have looked at learning mechanisms that can predict the future positions of the gates and control strategies that will allow the agent to pass through the gates unharmed. The simulations reported below use the AARC architecture [1]. This architecture combines a large number of different cognitive mechanisms. In Experiment 1, the task for the agent is to pass through a single gate and in Experiment 2, to pass through three successive gates. The results shows that the AARC architecture is flexible enough to handle very diverse situations. It is also somewhat surprising that linear predictors are sufficient in most cases.
ABSTRACT A novel model of role of conditioning in attention is presented and evaluated on a Nao humanoid robot. The model implements conditioning and habituation in interaction with a dynamic neural field where different stimuli compete... more
ABSTRACT A novel model of role of conditioning in attention is presented and evaluated on a Nao humanoid robot. The model implements conditioning and habituation in interaction with a dynamic neural field where different stimuli compete for activation. The model can be seen as a demonstration of how stimulus-selection and action-selection can be combined and illustrates how positive or negative reinforcement have different effects on attention and action. Attention is directed toward both rewarding and punishing stimuli, but appetitive actions are only directed toward positive stimuli. We present experiments where the model is used to control a Nao robot in a task where it can select between two objects. The model demonstrates some emergent effects also observed in similar experiments with humans and animals, including attentional blocking and latent inhibition.
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... e Telematica, Universita' di Genova, Via all'Opera Pia 13 - 16145 Genova, Italy 3 Lund University Cognitive Science, Kungshuset, Lundagård SE - 222 22 Lund, Sweden dimitri.ognibene@istc. cnr ... Whitehead, SD,... more
... e Telematica, Universita' di Genova, Via all'Opera Pia 13 - 16145 Genova, Italy 3 Lund University Cognitive Science, Kungshuset, Lundagård SE - 222 22 Lund, Sweden dimitri.ognibene@istc. cnr ... Whitehead, SD, Ballard, DH: Learning to perceive and act by trial and error. Mach. ...
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How can visual selective attention guide eye movements so as to collect information and identify targets potentially relevant for action? Many models have been proposed that use the statistical properties of images to create a dynamic... more
How can visual selective attention guide eye movements so as to collect information and identify targets potentially relevant for action? Many models have been proposed that use the statistical properties of images to create a dynamic bottom-up saliency map used to guide saccades to potentially relevant locations. Since the concept of saliency map was introduced, it has been incorporated in
Research Interests: Selective Attention, Reinforcement Learning, Visual attention, Neural Network, Information Flow, and 12 moreObject Recognition, Robot Arm, Instrumental Conditioning, Saliency Map, Top Down Processing, Learning Process, Statistical Properties, Eye Movement, Short Term Memory, Mechanism of action, Bottom Up, and Top Down
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The paper presents a general architecture for behaviour based control systems for autonomous agents. A number of archi tectural principles are proposed which make it possible to combine reactive control with learning and problem solving... more
The paper presents a general architecture for behaviour based control systems for autonomous agents. A number of archi tectural principles are proposed which make it possible to combine reactive control with learning and problem solving in a coherent way. In particular, I investigate the interaction between reinforcement learning, internal world models and dynamic action selection as well as a number
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This book has provided various theoretical perspectives on anticipatory processes in natural and artificial cognitive systems. Advantages have been proposed and confirmed in various detailed case studies, which may have given the reader... more
This book has provided various theoretical perspectives on anticipatory processes in natural and artificial cognitive systems. Advantages have been proposed and confirmed in various detailed case studies, which may have given the reader detailed insights into anticipatory processes and their importance in various cognitive systems tasks. To wrap up these advantages and give a concluding overview of various current anticipatory process advantages, this final chapter highlights a concise collection of precise success stories of ...
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ABSTRACT Although attention can be purely reactive, like when we react to an unexpected event, in most cases, attention is under deliberate control anticipating events in the world. Directing attention and preparing for action takes time,... more
ABSTRACT Although attention can be purely reactive, like when we react to an unexpected event, in most cases, attention is under deliberate control anticipating events in the world. Directing attention and preparing for action takes time, and it is thus useful to be able to predict where an important event will occur in the environment and direct attention to it even before it happens. Another reason for the need for anticipation is the processing delays in the visuomotor system. In the human system it takes at least 100 ms to detect a visual target (Lamme and Roelfsema, 2000) and to just look at a moving object, we need to anticipate its movement to control the muscles of the eyes to move our gaze to the location where the target will be (von Hofsten and Rosander, 1997). The role of anticipation in attention can also be seen in the close connection between attention and action (Balkenius, 2000).
The moth Macroglossum stellatarum can learn the colour and sometimes the odour of a rewarding food source. We present data from 20 different experiments with different combinations of blue and yellow artificial flowers and the two odours... more
The moth Macroglossum stellatarum can learn the colour and sometimes the odour of a rewarding food source. We present data from 20 different experiments with different combinations of blue and yellow artificial flowers and the two odours honeysuckle and lavender. The experiments show that learning about the odours depends on the colour used. By training on different colour-odour combinations and testing on others, it becomes possible to investigate the exact relation between the two modalities during learning. Three computational models were tested in the same experimental situations as the real moths and their predictions were compared to the experimental data. The average error over all experiments as well as the largest deviation from the experimental data were calculated. Neither the Rescorla-Wagner model or a learning model with independent learning for each stimulus component were able to explain the experimental data. We present the new categorisation model, which assumes that the moth learns a template for the sensory attributes of the rewarding stimulus. This model produces behaviour that closely matches that of the real moth in all 20 experiments.
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We describe an efficient algorithm for visual landmark recognition based on elastic template matching. Each landmark is represented by a set of features and their spatial relations. The matching procedure allows for visual transformations... more
We describe an efficient algorithm for visual landmark recognition based on elastic template matching. Each landmark is represented by a set of features and their spatial relations. The matching procedure allows for visual transformations such as translation and expansion, or even partial occlusion. Robot navigation in a natural environment calls for a sophisticated sensory system. In this paper we propose a method for visual landmark recognition based on elastic template matching that can be used for both positioning and navigation. We define positioning as a process that uses the sensory input of the robot to derive the location and orientation of the robot with respect to a map of the environment. Navigation, on the other hand, is the use of external cues and internal structures to derive a path through the environment. We will mainly be concerned with navigation, but the methods developed below can also be used for pure positioning. The landmark recognition method we describe be...
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In RoboCup, all objects in the game are color coded to allow easy segmentation and identification. However, color vision is very sensitive to the exact color of the illumination which makes the identification task much harder than is... more
In RoboCup, all objects in the game are color coded to allow easy segmentation and identification. However, color vision is very sensitive to the exact color of the illumination which makes the identification task much harder than is often anticipated. Algorithms that work in the lab in fluorescent light may not function at all in an actual game where incandescent lights are used. This article is intended as a short tutorial on color vi- sion and demonstrates a method for retrieving the color of image patches independently of the color of the illu- mination. The computational scheme is tested on a set of images of orange balls on a green background with varying illumination.
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When a stimulus reaches our sensory system, it evokes a perceptual schema. This schema, subsequently, produces a central neiral representation of the stimulus. I want to investigate what properties these neural representations must have... more
When a stimulus reaches our sensory system, it evokes a perceptual schema. This schema, subsequently, produces a central neiral representation of the stimulus. I want to investigate what properties these neural representations must have to support complex cognitive processes. To do this, I present a description of neural networks that makes it possible to bridge the gap between the neuronal and the conceptual level of description. Using this high level description , I state a hypothesis about neural representations that I have called the continuity hypothesis. It makes it possible to use knowledge of processes at the conceptual level at the neuronal level. Some properties of the representation of a stimulus are presented and it is shown that the central representation can be the result either of a categorisation or an associative process. Two minimal conditions on categorisation are suggested. These conditions are used to construct a new type of competitive learning that support rep...
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The goal of this paper is to develop the foundation for a spatial navigation without objective representations. Rather than building the spatial representations on a Euclidean space, a weaker conception of space is used which has a closer... more
The goal of this paper is to develop the foundation for a spatial navigation without objective representations. Rather than building the spatial representations on a Euclidean space, a weaker conception of space is used which has a closer connection to perception. A type of spatial representation is described that uses perceptual information directly to define regions in space. By combining such regions, it is possible to derive a number of useful spatial representations such as place-fields, paths and topological maps. Compared to other methods, the representations of the presented approach have the advantage that they are always grounded in the perceptual abilities of the robot, and thus, more likely to function correctly
Research Interests: Mechanical Engineering, Robotics, Computer Vision, Control, Motion control, and 13 moreSpatial Representation, Learning, Navigation, Visual Servoing, Image recognition, Spatial Learning, Learning Control, Object Representation, Euclidean space, Spatial navigation, Autonomous Braking System, Electrical And Electronic Engineering, and Visual navigation
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During the years 2005 and 2006 a robot system has been developed at Lund University Cognitive Science to run navigation ex- periments in a dynamic environment. The main aim of the system is to study anticipation during navigation, model... more
During the years 2005 and 2006 a robot system has been developed at Lund University Cognitive Science to run navigation ex- periments in a dynamic environment. The main aim of the system is to study anticipation during navigation, model building, color tracking, navigation algorithms, social robotics and children's games. This techni- cal report describes the hardware and software used in the system. The system consists of two small two-wheeled robots, which are tracked using color markers using an overhead camera. The robots are controlled by a computer that handles tracking, navigation, motor control and the ex- periment control for each robot. Two setups are presented with example of the implementation of the integrated parts which can be used to run the system either in simulation or with the real robots. Currently, only two robots are supported, but in the final phase the system will handle six robots.
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Is attention a purely perceptual process or is it in any way related to motor control? The aim of this article is to show that attention puts similar demands on a cognitive system as motor control and present evidence supporting the view... more
Is attention a purely perceptual process or is it in any way related to motor control? The aim of this article is to show that attention puts similar demands on a cognitive system as motor control and present evidence supporting the view that similar mechanisms operate in the two processes. A computational model of attention is presented that uses habituation as well as classical and instrumental conditioning to explain a number of attentional processes. Evi- dence from neurophysiology is reviewed that suggest that attention is con- trolled in a way similar to actions. This view makes it possible to adapt tradi- tional learning theoretical mechanisms to the control of attention. Computer simulations are presented that illustrates the operation of the model.
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Abstract: This memory can be seen as a generalization of the working memory for novel foods introduced in chapter 5. In that simple working memory, only the sickness sensor could recall the stored memory. For a more general working... more
Abstract: This memory can be seen as a generalization of the working memory for novel foods introduced in chapter 5. In that simple working memory, only the sickness sensor could recall the stored memory. For a more general working memory, any sufficiently specific subschema from any modality should recall the entire sensory schema with which it was stored. For example, the activation of a place representation will read out the expectations of the stimulus that will be perceived at that location. In...
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Research Interests: Computer Graphics, Biomedical Engineering, Computer Animation, Humans, Clothing, and 12 moreMovement, Computer Assisted Instruction, Feedback, Electromyography, Amputees, Computer User Interface Design, Hand, Tree Structure, Prosthesis Fitting, Artificial Neural Network, Medical, and Decision Support Techniques
Research Interests: Mechanical Engineering, Robotics, Cognitive Science, Cognitive Robotics, Tensor product semigroups, and 14 moreNeural Network, Proprioception, Haptic Interface Design, Unsupervised Learning, Shape, Tactile Sensor, Texture, Self Organization, Tactile Sensors, Self Organized Map, Self Organizing Maps, Manipulator, Tensile Stress, and Electrical And Electronic Engineering
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This study explores the possibilities of transferring peripheral tactile stimulations from an artificial hand to the forearm skin. A tactile display applied to the forearm skin was used to transfer tactile input to the forearm from... more
This study explores the possibilities of transferring peripheral tactile stimulations from an artificial hand to the forearm skin. A tactile display applied to the forearm skin was used to transfer tactile input to the forearm from various locations on a hand displayed on a computer screen. Discernment of location, levels of pressure and a combination of the two in simulated functional grips was tested to quantify the participants' ability to accurately perceive the tactile stimulations presented. Ten participants (5 forearm amputees and 5 able-bodied volunteers) unfamiliar with the equipment participated in the three-stage experiments comprising a learning session with vision, a reinforced learning session without vision and a validation session without vision. The location discernment accuracy was high in both groups (75.2% and 89.6% respectively). The capacity to differentiate between three different levels of pressure was also high (91.7% and 98.1% respectively in the two groups). Recognition of simulated grip was slightly more difficult with the groups scoring 58.7% and 68.0% respectively for accuracy in the validation session. This study demonstrates that it is possible, following a brief training period, to transfer tactile input from an artificial hand to the forearm skin. The level of accuracy was lower for the more complex task, simulated grip recognition, possibly because this represents a more complex task requiring higher order brain functions. These results could form the basis for developing sensory feedback in hand prostheses.
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In this work, we present a biologically inspired model for recognition of occluded patterns. The general architecture of the model is based on the two visual information processing pathways of the human visual system, i.e. the ventral and... more
In this work, we present a biologically inspired model for recognition of occluded patterns. The general architecture of the model is based on the two visual information processing pathways of the human visual system, i.e. the ventral and the dorsal pathways. The proposed hierarchically structured model consists of three parallel processing channels. The main channel learns invariant representations of the input patterns and is responsible for pattern recognition task. But, it is limited to process one pattern at a time. The direct channel represents the biologically based direct connection from the lower to the higher processing level in the human visual cortex. It computes rapid top-down pattern-specific cues to modulate processing in the other two channels. The spatial channel mimics the dorsal pathway of the visual cortex. It generates a combined saliency map of the input patterns and, later, segments the part of the map representing the occluded pattern. This segmentation process is based on our hypothesis that the dorsal pathway, in addition to encoding spatial properties, encodes the shape representations of the patterns as well. The lateral interaction between the main and the spatial channels at appropriate processing levels and top-down, pattern-specific modulation of the these two channels by the direct channel strengthen the locations and features representing the occluded pattern. Consequently, occluded patterns become focus of attention in the ventral channel and also the pattern selected for further processing along this channel for final recognition.
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Page 1. Robots with Anticipation and Attention Birger Johansson Christian Balkenius ... Most important, we have an ability to use previously learned knowledge to antic-ipate the outcome of an action even if we have never seen it being... more
Page 1. Robots with Anticipation and Attention Birger Johansson Christian Balkenius ... Most important, we have an ability to use previously learned knowledge to antic-ipate the outcome of an action even if we have never seen it being performed before. ...
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ABSTRACT
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We show that by introducing an appropriate schema concept and exploiting the higher-level features of a resonance function in a neural network it is possible to define a form of nonmonotonic inference relation between the input and the... more
We show that by introducing an appropriate
schema concept and exploiting the higher-level
features of a resonance function in a neural
network it is possible to define a form of nonmonotonic
inference relation between the input
and the output of the network. This inference
relation satisfies some of the most fundamental
postulates for nonmonotonic logics. The construction
presented in the paper is an example of
how symbolic features can emerge from the
subsymbolic level of a neural network.
schema concept and exploiting the higher-level
features of a resonance function in a neural
network it is possible to define a form of nonmonotonic
inference relation between the input
and the output of the network. This inference
relation satisfies some of the most fundamental
postulates for nonmonotonic logics. The construction
presented in the paper is an example of
how symbolic features can emerge from the
subsymbolic level of a neural network.
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We describe a number of research projects at Lund Univer- sity Cognitive Science. The first project focuses on visual attention. The second area is haptic perceptions by robots. The third area is anticipation in groups of robots. The... more
We describe a number of research projects at Lund Univer- sity Cognitive Science. The first project focuses on visual attention. The second area is haptic perceptions by robots. The third area is anticipation in groups of robots. The final research area concerns building computa- tional tools that can be used to design large-scale cognitive models which will ultimately allow results
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ABSTRACT A model of emotional conditioning is ex-tended with a cortical model where stimulus codes compete for activation. This system is combined with motivational inputs that mod-ulate both sensory and emotional processing. The extended... more
ABSTRACT A model of emotional conditioning is ex-tended with a cortical model where stimulus codes compete for activation. This system is combined with motivational inputs that mod-ulate both sensory and emotional processing. The extended model is able to reproduce the attentional blocking effect. It can also learn to switch between different sensory targets when the motivational state changes. The relation between motivation, emotion, and attention control is learned through the presentation of different stimuli in combination with reward. The model has also been used to control sac-cades in a stereo vision head that learns what object are compatible with what motivations.
ABSTRACT The Ikaros project started in 2001 with the aim at de- veloping an open infrastructure for system-level brain modeling. The system has developed into a general tool for cognitive modeling as well as robot control. This report... more
ABSTRACT The Ikaros project started in 2001 with the aim at de- veloping an open infrastructure for system-level brain modeling. The system has developed into a general tool for cognitive modeling as well as robot control. This report describes the main parts of the Ikaros system, in particular the simulation kernel, and sum- marizes the work done within the first five years of the project.
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The Ikaros project started in 2001 with the aim of developing an open infrastructure for system-level brain modeling. The system has developed into a general tool for cognitive modeling as well as robot control. Here we describe the main... more
The Ikaros project started in 2001 with the aim of developing an open infrastructure for system-level brain modeling. The system has developed into a general tool for cognitive modeling as well as robot control. Here we describe the main parts of the Ikaros system and how it has been used to implement various cognitive systems and to control a number
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ABSTRACT In behavioral experiments, the hawkmoth Deilephila elpenor can learn both the color and the position of artificial flowers. When very similar colors are used, moths select the correct color during the first test on a given day,... more
ABSTRACT In behavioral experiments, the hawkmoth Deilephila elpenor can learn both the color and the position of artificial flowers. When very similar colors are used, moths select the correct color during the first test on a given day, thus using a stimulus strategy, but after repeated rewards, they switch to a place strategy and choose the flower in the position where they received the reward. When dissimilar colors are used, the moths continue to select flowers based on color and ignore position. We show how a computational model can reproduce the behavior in the experimental situation. The aim of the model is to investigate which learning and behavior selection strategies are necessary to reproduce the behavior observed in the experiment. The model is based on behavioral data and the sensitivities of the moth photoreceptors. The model consists of a number of interacting behavior systems that are triggered by specific stimuli and control specific behaviors. The ability of the moth to learn the colors of different flowers and the adaptive processes involved in the choice between stimulus-approach and place-approach strategies are reproduced very accurately by the model. The model has implications both for further studies of the ecology of the animal and for robotic systems.
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We have experimented with proprioception in a bio-inspired self-organizing haptic system. To this end a 12 d.o.f. anthropomorphic robot hand with proprioceptive sensors was developed. The system uses a self-organizing map for the mapping... more
We have experimented with proprioception in a bio-inspired self-organizing haptic system. To this end a 12 d.o.f. anthropomorphic robot hand with proprioceptive sensors was developed. The system uses a self-organizing map for the mapping of the explored objects. In our experiments the system was trained and tested with 10 different objects of different sizes from two different shape categories. To
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A computational model of the context processing is presented. It is shown in computer simulations how a stable context representation can be learned from a dynamic sequence of attentional shifts between various stimuli in the environment.... more
A computational model of the context processing is presented. It is shown in computer simulations how a stable context representation can be learned from a dynamic sequence of attentional shifts between various stimuli in the environment. The mechanism can automatically create the required context representations, store memories of stimuli and bind them to locations. The model also shows how an
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Eye gaze is a window onto cognitive processing in tasks such as spatial memory, linguistic processing, and decision making. We present evidence that information derived from eye gaze can be used to change the course of individuals’... more
Eye gaze is a window onto cognitive processing in tasks such as spatial memory, linguistic processing, and decision making. We present evidence that information derived from eye gaze can be used to change the course of individuals’ decisions, even when they are reasoning about high-level, moral issues. Previous studies have shown that when an experimenter actively controls what an individual sees the experimenter can affect simple decisions with alternatives of almost equal valence. Here we show that if an experimenter passively knows when individuals move their eyes the experimenter can change complex moral decisions. This causal effect is achieved by simply adjusting the timing of the decisions. We monitored partici- pants’ eye movements during a two-alternative forced-choice task with moral questions. One option was randomly predetermined as a target. At the moment participants had fixated the target option for a set amount of time we terminated their deliberation and prompted them to choose between the two alternatives. Although participants were unaware of this gaze-contingent manipulation, their choices were systematically biased toward the target option. We conclude that even abstract moral cognition is partly constituted by interactions with the immediate environment and is likely supported by gaze-dependent decision processes. By tracking the interplay be- tween individuals, their sensorimotor systems, and the environment, we can influence the outcome of a decision without directly manipulating the content of the information available to them.
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We present two models of the behaviour of the hawkmoth Manduca sexta when it approaches an artificial flower with an olfactory, visual or multimodal cue. The first model treats each condition separately while the second model combines... more
We present two models of the behaviour of the hawkmoth Manduca sexta when it approaches an artificial flower with an olfactory, visual or multimodal cue. The first model treats each condition separately while the second model combines both types of sensory cues in a single model. Both models reproduce several characteristic properties of the hawkmoth behaviour including its goal direction
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Classical conditioning is a basic learning mechanism in animals and can be found in almost all organisms. If we want to construct robots with abilities matching those of their biological counterparts, this is one of the learning... more
Classical conditioning is a basic learning mechanism in animals and can be found in almost all organisms. If we want to construct robots with abilities matching those of their biological counterparts, this is one of the learning mechanisms that needs to be implemented first. This article describes a computational model of classical conditioning where the goal of learning is assumed
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We describe work in progress with the aim of constructing a computational model of emotional learning and processing inspired by neurophysiological findings. The main areas modelled are the amygdala and the orbitofrontal cortex and the... more
We describe work in progress with the aim of constructing a computational model of emotional learning and processing inspired by neurophysiological findings. The main areas modelled are the amygdala and the orbitofrontal cortex and the interaction between them. We want to show that (1) there exists enough physiological data to suggest the overall architecture of a computational model, (2) emotion
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Infants gradually learn to predict the motion of moving targets and change from a strategy that mainly depends on saccades to one that depends on anticipatory control of smooth pursuit. A model is described that combines three types of... more
Infants gradually learn to predict the motion of moving targets and change from a strategy that mainly depends on saccades to one that depends on anticipatory control of smooth pursuit. A model is described that combines three types of mechanisms for gaze control that develops in a way similar to infants. Initially, gaze control is purely reactive, but as the anticipatory models become more accurate, the gain of the pursuit will increase and lead to a larger fraction of smooth eye movements. Finally, a third system learns to predict changes in target motion, which will lead to fast retuning of the parameters in the anticipatory model.
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This paper describes a system for haptic object categorization. It consists of a robotic hand, the LUCS Haptic Hand I, together with software modules that to some extent simulate the functioning of the primary and the secondary... more
This paper describes a system for haptic object categorization. It consists of a robotic hand, the LUCS Haptic Hand I, together with software modules that to some extent simulate the functioning of the primary and the secondary somatosensory cortices. The haptic system is the first one in a project at LUCS aiming at studying haptic perception. In the project, several robotic hands together with cognitive computational models of the corresponding human neurophysiological systems will be built. The haptic system was trained and tested with a set of objects consisting of balls and cubes, and the activation in the modules corresponding to secondary somatosensory cortex was studied. The results suggest that the haptic system is capable of categorization of objects according to size, if the shapes of the objects are restricted to spheres and cubes.