Neural Sensor Fusion for Spatial Visualization on a Mobile Robot

An ARTMAP neural network is used to integrate visual information and ultrasonic sensory information on a B 14 mobile robot. Training samples for the neural network are acquired without human intervention. Sensory snapshots are retrospectively associated with the distance to the wall, provided by on~ board odomctry as the robot travels in a straight line. The goal is to produce a more accurate measure of distance than is provided by the raw sensors. The neural network effectively combines sensory sources both within and between modalities. The improved distance percept is used to produce occupancy grid visualizations of the robot's environment. The maps produced point to specific problems of raw sensory information processing and demonstrate the benefits of using a neural network system for sensor fusion.Office of Naval Research and Naval Research Laboratory (00014-96-1-0772, 00014-95-1-0409, 00014-95-0657

ARTMAP-FTR: A Neural Network For Fusion Target Recognition, With Application To Sonar Classification

ART (Adaptive Resonance Theory) neural networks for fast, stable learning and prediction have been applied in a variety of areas. Applications include automatic mapping from satellite remote sensing data, machine tool monitoring, medical prediction, digital circuit design, chemical analysis, and robot vision. Supervised ART architectures, called ARTMAP systems, feature internal control mechanisms that create stable recognition categories of optimal size by maximizing code compression while minimizing predictive error in an on-line setting. Special-purpose requirements of various application domains have led to a number of ARTMAP variants, including fuzzy ARTMAP, ART-EMAP, ARTMAP-IC, Gaussian ARTMAP, and distributed ARTMAP. A new ARTMAP variant, called ARTMAP-FTR (fusion target recognition), has been developed for the problem of multi-ping sonar target classification. The development data set, which lists sonar returns from underwater objects, was provided by the Naval Surface Warfare Center (NSWC) Coastal Systems Station (CSS), Dahlgren Division. The ARTMAP-FTR network has proven to be an effective tool for classifying objects from sonar returns. The system also provides a procedure for solving more general sensor fusion problems.Office of Naval Research (N00014-95-I-0409, N00014-95-I-0657

ARTMAP-FTR: A Neural Network for Object Recognition Through Sonar on a Mobile Robot

ART (Adaptive Resonance Theory) neural networks for fast, stable learning and prediction have been applied in a variety of areas. Applications include automatic mapping from satellite remote sensing data, machine tool monitoring, medical prediction, digital circuit design, chemical analysis, and robot vision. Supervised ART architectures, called ARTMAP systems, feature internal control mechanisms that create stable recognition categories of optimal size by maximizing code compression while minimizing predictive error in an on-line setting. Special-purpose requirements of various application domains have led to a number of ARTMAP variants, including fuzzy ARTMAP, ART-EMAP, ARTMAP-IC, Gaussian ARTMAP, and distributed ARTMAP. A new ARTMAP variant, called ARTMAP-FTR (fusion target recognition), has been developed for the problem of multi-ping sonar target classification. The development data set, which lists sonar returns from underwater objects, was provided by the Naval Surface Warfare Center (NSWC) Coastal Systems Station (CSS), Dahlgren Division. The ARTMAP-FTR network has proven to be an effective tool for classifying objects from sonar returns. The system also provides a procedure for solving more general sensor fusion problems.Office of Naval Research (N00014-95-I-0409, N00014-95-I-0657

Two-spin subsystem entanglement in spin 1/2 rings with long range interactions

We consider the two-spin subsystem entanglement for eigenstates of the Hamiltonian $$H= \sum_{1\leq j< k \leq N} (\frac{1}{r_{j,k}})^{\alpha} {\mathbf \sigma}_j\cdot {\mathbf \sigma}_k$$ for a ring of $N$ spins 1/2 with asssociated spin vector operator $(\hbar /2){\bf \sigma}_j$ for the $j$-th spin. Here $r_{j,k}$ is the chord-distance betwen sites $j$ and $k$. The case $\alpha =2$ corresponds to the solvable Haldane-Shastry model whose spectrum has very high degeneracies not present for $\alpha \neq 2$. Two spin subsystem entanglement shows high sensistivity and distinguishes $\alpha =2$ from $\alpha \neq 2$. There is no entanglement beyond nearest neighbors for all eigenstates when $\alpha =2$. Whereas for $\alpha \neq 2$ one has selective entanglement at any distance for eigenstates of sufficiently high energy in a certain interval of $\alpha$ which depends on the energy. The ground state (which is a singlet only for even $N$) does not have entanglement beyond nearest neighbors, and the nearest neighbor entanglement is virtually independent of the range of the interaction controlled by $\alpha$.Comment: 16 figure

Brain Differently Changes Its Algorithms in Parallel Processing of Visual Information

Feedback from the visual cortex (Vl) to the Lateral Geniculate Nucleus (LGN) in macaque monkey increase contrast gain of LGN neurons for black and white (B&W) and for color (C) stimuli. LGN parvocellular cells responses to B&W gratings are enhanced by feedback multiplicatively and in contrast independent manner. However, in magnocellular neurons corticofugal pathways enhance cells responses in a contrast~dependent non-linear manner. For C stimuli cortical feedback enhances parvocellular neurons responses in a very strong contrast-dependent manner. Based on these results [13] we propose a model which includes excitatory and inhibitory effects on cells activity (shunting equations) in retina and LGN while taking into account the anatomy of cortical feedback connections. The main mechanisms related to different algorithms of the data processing in the visual brain are differences in feedback properties from Vl to parvocellular (PC) and to magnocellular (MC) neurons. Descending pathways from Vl change differently receptive field (RF) structure of PC and MC cells. For B&W stimuli, in PC cells feedback changes gain similarly in the RF center and in the RF surround, leaving PC RF structure invariant. However, feedback influence MC cells in two ways: directly and through LGN interneurons, which together changes gain and sizes of their RF center differently than gain and size of the RF surround. For C stimuli PC cells operate like MC cells for B&W. The first mechanism extracts from the stimulus an important features in a independent way from other stimulus parameters, whereas the second channel changes its tuning properties as a function of other stimulus attributes like contrast and/or spatial extension. The model suggests novel idea about the possible functional role of PC and MC pathways

Acceptance and commitment therapy for psychosis: current status, lingering questions and future directions

Purpose Acceptance and Commitment Therapy for psychosis (ACTp) is a contextual behavioural intervention that promotes psychological flexibility by fostering active acceptance, cognitive defusion, values construction and committed action to enhance well-being and recovery. Multiple studies have shown that ACTp is acceptable and efficacious, but questions remain as to its distinction from similar approaches and the conditions under which it would be implemented most effectively. Methods We present the current evidence for processes and outcomes of ACTp and summarise the qualitative findings of experiences of service users in ACT programmes. We compare ACTp with other cognitive behavioural therapies and mindfulness-informed interventions for psychosis. Results Acceptance and commitment therapy for psychosis is promising as a pragmatic, process-driven intervention model. Further efforts are needed to investigate psychological flexibility in the context of psychosis with observational, experimental and intervention studies that will inform model scope and treatment refinement. Additionally, implementation research is the necessary next step, including how support persons can be trained in ACTp. Lower intensity and technology-assisted approaches have the potential to reduce barriers to accessing ACTp and extend impact. Conclusions Over the last 20 years, ACTp has demonstrated meaningful effects in individual and group formats in a range of settings, targeting outcomes such as rehospitalisation, depression, psychotic symptom distress and impact. Future work should focus on how best to integrate ACTp with other current evidence-based interventions for psychosis

Integrating Storytelling into the Theory and Practice of Contextual Behavioral Science

The practice of generating and interpreting stories can be examined through a behavioral lens and has many potential implications for clinical practice. However, storytelling has for the most part yet to be integrated into the field of contextual behavioral science (CBS). A bedrock of human culture, storytelling has influenced both individual behavior and intergroup cooperation for millennia. Basic principles of relational frame theory, such as those pertaining to coherence, perspective-taking, and the transformation of stimulus function, may help to reveal how stories derive their psychological impact. In turn, understanding storytelling from a CBS perspective can facilitate the broader integration of narrative methods into clinical interventions, which may help in expanding the reach and impact of individual, group, and self-help interventions. Suggestions for integrating storytelling into practice are provided as are future directions for studying the behavioral mechanisms of storytelling

Believability of hallucinations as a potential mediator of their frequency and associated distress in psychotic inpatients

Behavioural and Cognitive Psychotherapy, 34(4): pp. 497-502.The aim of the current study was to examine how belief in the validity of hallucinations relates to the association between hallucination frequency and associated distress. In a sample of inpatients with psychotic symptoms, results demonstrated that hallucination believability predicted later distress after controlling for symptom frequency. In addition, results were consistent with the hypothesis that hallucination believability mediated the frequencydistress link. Recent randomized controlled trials have supported the efficacy of cognitive behavior therapy for schizophrenia and related psychotic disorders. Further evidence suggests that cognitive behavioral approaches that incorporate mindfulness and acceptance-based strategies may be effective in reducing the believability of positive symptoms. Future trials incorporating longitudinal designs and more detailed assessments of these variables are needed

Self-efficacy for social situations in adolescents with generalized social anxiety disorder

Behavioural and Cognitive Psychotherapy, 35(2): pp. 209-223.Self-efficacy is a potentially useful concept when applied to Social Anxiety Disorder (SAD). The aims of the current study were to examine the psychometric properties of the Self- Efficacy for Social Situations Scale (SESS; Gaudiano and Herbert, 2003) and to investigate the relationship between self-efficacy and anxiety in an adolescent sample with generalized SAD. Results replicated those found in a previous adult SAD sample. The SESS showed high internal consistency and good construct and criterion-related validity. The SESS also predicted subjective anxiety and perceived performance in social role play tests after controlling for social anxiety severity. Furthermore, self-efficacy more clearly predicted self-ratings in contrast to observer ratings of performance in social role play tests. Finally, changes in social selfefficacy were strongly associated with changes in social anxiety symptoms following treatment, even after controlling for changes in fear of negative evaluation. Treatment implications for adolescent SAD are discussed

Onset of illness and developmental factors in social anxiety disorder: Preliminary findings from a retrospective interview

Journal of Psychopathology and Behavioral Assessment, 29(2): pp. 101-110.Although many advances have been made in the treatment of Social Anxiety Disorder (SAD), less is known about its onset and factors related to its course and severity. The current study aimed to investigate developmental factors (e.g., onset of illness, behavioral inhibition, socially 12 traumatic experiences) that research has suggested are related to the course and severity of SAD in a sample of adults diagnosed with generalized SAD. Results showed behavioral inhibition to be the only consistent predictor of current severity. Results for age of onset were consistent with previous studies suggesting an early childhood and later adolescent pattern. In addition, an earlier age of onset negatively impacted improvement in cognitive behavior therapy for SAD, but no other developmental factors were related to treatment outcome. Future research using longitudinal designs and multiple informants is needed to confirm findings from retrospective reports