Adaptive motor control during experiments with

ABSTRACT Recent experiments with Brain Machine Interfaces indicate that the extent of neural modulations increases abruptly upon starting to operate the interface. In contrast, neural modulations due to the trajectory profile remain relatively unchanged. Furthermore, the enhanced modulations subside with further training, mirroring the trend in task performance, which degraded upon starting to operate the interface and improved gradually with training. Here we investigate the hypothesis that the enhanced modulations reflect internal representation of trajectory errors, which results in corrective commands in the short term and adaptive modifications of internal models in the long term. A simplified uni-dimensional model is analyzed to demonstrate the observed transient enhancement in neural modulations during the operation of Brain machine Interfaces. Identifying the source of the transient enhancement in neural modulation would provide insight into adaptive motor control and facilitate the improvement of future Brain Machine Interfaces. INTRODUCTION The firing rates of cortical motor neurons represent a diversity of motor, sensory, and cognitive signals. The representation of movement direction and speed has been characterized extensively using tuning curve

Inflammatory Processes in Kawasaki Disease Reach their Peak at the Sixth Day of Fever Onset: Laboratory Profiles According to Duration of Fever

We evaluated the inflammatory indices according to the fever duration in children with Kawasaki disease (KD), and determined duration when the inflammatory processes in KD reach their peak. Children with KD (n=152) were classified into 7 groups according to fever duration: at the third day or earlier (n=20), fourth (n=33), fifth (n=46), sixth (n=15), seventh (n=15), eighth (n=9), and at the ninth day or later after fever onset (n= 14). The levels of various laboratory indices were determined 3 times: before, 24 hr and 7 days after intravenous immunoglobulin administration (2 g/kg). WBC and neutrophil counts, and C-reactive protein level were the highest at the sixth day. Levels of hemoglobin, albumin, and high density lipoprotein cholestrol were the lowest at the sixth day. Although these indices were not significant statistically between groups, the indices showed either bell-shaped or U-shaped distribution of which peak or trench were at the sixth day. These findiugs showed that the inflammatory processes in KD reach peak on the sixth day of fever onset. This finding is important because a higher single-dose intravenous immunoglobulin treatment before the peak day may help reduce the coronary artery lesions in KD

Kawasaki Disease

Kawasaki disease is an acute febrile, systemic vasculitic syndrome of an unknown etiology that primarily occurs in children younger than five years of age. The principal presentations of Kawasaki disease include fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy. Coronary artery aneurysms or ectasia develops in 15% to 25% of untreated children with the disease, which may later lead to myocardial infarction, sudden death, or ischemic heart disease. Treatment with intravenous gamma globulin (IVIG) is effective, but the mode of action is still unclear. The development of a diagnostic test, a more specific therapy, and ultimately the prevention of this potentially fatal illness in children are all dependent upon the continued advances in determining the etiopathogenesis of this fascinating disorder

Metacognitive functioning predicts positive and negative symptoms over 12 months in first episode psychosis

The negative symptoms of schizophrenia are a major source of impairment and distress but both pharmacological and psychological treatment options provide only modest benefit. Developing more effective psychological treatments for negative symptoms will require a more sophisticated understanding of the psychological processes that are implicated in their development and maintenance. We extended previous work by demonstrating that metacognitive functioning is related to negative symptom expression across the first 12 months of first episode psychosis (FEP). Previous studies in this area have either been cross-sectional or have used much older participants with long-standing symptoms. In this study, forty-five FEP participants were assessed three times over 12 months and provided data on PANSS rated symptoms, premorbid adjustment, metacognitive functioning, and DUP. Step-wise linear regression showed that adding metacognition scores to known predictors of negative symptoms (baseline symptom severity, gender, DUP, and premorbid academic and social adjustment) accounted for 62% of the variance in PANSS negative symptom scores at six months and 38% at 12 months. The same predictors also explained 47% of the variance in positive symptoms at both six and 12 months. However, exploration of the simple correlations between PANSS symptom scores and metacognition suggests a stronger univariate relationship between metacognition and negative symptoms. Overall, the results indicate that problems with mental state processing may be important determinants of negative symptom expression from the very early stages of psychosis. These results provide further evidence that metacognitive functioning is a potentially relevant target for psychological interventions