• Science of Emotion and Sensibility
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• v.16 no.1
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• pp.107-116
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• 2013

In the implementation of a P300 speller, rows and columns paradigm (RCP) is most commonly used. However, the RCP remains subject to adjacency-distraction error and double-flash problems. This study suggests a novel P300 speller stimuli presentation-the sub-block paradigm (SBP) that is likely to solve the problems effectively. Fifteen subjects participated in this experiment where both SBP and RCP were used to implement the P300 speller. Electroencephalography (EEG) activity was recorded from Fz, Cz, Pz, Oz, P3, P4, PO7, and PO8. Each paradigm consisted of a training phase to train a classifier and a testing phase to evaluate the speller. Eighteen characters were used for the target stimuli in the training phase. Additionally, 5 subjects were required to spell 50 characters and the rest of the subjects were to spell 25 characters in the testing phase. Classification accuracy results show that average accuracy was significantly higher in SBP as of 83.73% than that of RCP as of 66.40%. Grand mean event-related potentials (ERPs) at Pz show that positive peak amplitude for the target stimuli was greater in SBP compared to that of RCP. It was found that subjects tended to attend more to the characters in SBP. According to the participants' ratings on how comfortable they were with using each type of paradigm on 7-point Likert scale, most subjects responded 'very difficult' in RCP while responding 'medium' and 'easy' in SBP. The result showed that SBP was felt more comfortable than RCP by the subjects. In sum, the SBP was more correct in P300 speller performance as well as more convenient for users than the RCP. The actual limitations in the study were discussed in the last part of this paper.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.1
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• pp.68-74
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• 2000

Purpose: This study was to investigate the clinical manifestations of FTT in children. Methods: From March 1997 to July 1999, clinical observations were made on patients with FTT who had visited to Samsung Medical Center. Detailed histories and through physical examinations were taken, and when suspected organic FTT, basic laboratory studies were done. Results: Upon the review of medical records, we investigated the clinical manifestations of 74 children, aged 1 month and 13 year 1 month. The causes of FTT were composed of either physiologic (47.8%) or pathologic (52.2%) ones. Among the physiologic FTT, were there familial short stature (FSS, 14.5%), intrauterine growth retardation (IUGR, 14.5%), constitutional growth delay (CGD, 11.6%), idiosyncrasy and prematurity. Among pathologic causes, neurologic disorders (20%) are the most common causes of FTT, and then follow by GI (13.4%), allergic and infectious disorders in decreasing order. The data showed that average caloric intake in patients with FTT was 76,2% of recommended amount. FTT patients with CGD, IUGR, and idiosyncrasy had tendency to take small foods. The FTT children with prematurity, IUGR and pathologic FTT, were short and thin for their ages. However FTT children with CGD and FSS had tendency to be thin with relatively normal heights for their ages, in comparison with those of the children with prematurity, IUGR and pathologic FTT. Conclusion: The diagnosis of FTT was easily obtained with simple and through medical history, physical examination, and minimal laboratory tests. In this study, organic FTT was more prevalent than physiologic one. This results indicate that early intervention is mandatory, because children may develop significant long-term sequelae from nutritional deficiency.

• Clinical and Experimental Pediatrics
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• v.45 no.11
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• pp.1373-1380
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• 2002

Purpose : Acute measles encephalitis(ME) is characterized by an abrupt onset of fever and obtundation, frequently accompanied by seizures and multifocal neurological signs. The aim of this study was to clarify the clinical manifestation, progression and the brain SPECT patterns in patients with acute ME. Methods : This study included 11 children with acute ME admitted to Chonbuk National University Hospital. Ten patients received a first dose of measles vaccine, one patient did not receive a first dose, and no patients received a second dose. ME was diagnosed based on characteristic clinical pictures, measles antibodies by ELISA and abnormal CSF findings. Brain MRI and brain SPECT were performed in 11 patients with acute ME. Results : There were four males and seven females whose ages at onset ranged between 18 months and 14 years(mean : 10.5 years). The main clinical neurologic pictures were loss of consciousness( 10) and seizure(five). The titer of IgG and IgM antimeasles antibodies in serum were positive in 10 patients. In CSF, nine patients had IgG antibodies and one patient had IgM antibodies. The concentration of protein(mean : $124{\pm}60mg/dL$) and WBC counts(mean : $158{\pm}157/{\mu}L$) in CSF were elevated in all patients. In electroencephalographic examination, nine patients showed increased slow waves. Seven of 11 patients(63.6%) revealed high signal intensity on the brain MRI. In contrast, all patients showed hypoperfusion in brain SPECT examination. According to brain SPECT, the perfusion deficits were frequently observed in the frontal lobe(nine), temporal (nine), parietal(eight) and thalamus(eight). Conclusion : Brain SPECT is more sensitive than MRI for the evaluation of brain damage in early stages of acute ME.