[A study of information processing of cognitive conflict using event-related potentials].

This study examined whether cognitive conflict, reported by Eriksen and Eriksen (1974), could be explained by a model of reciprocal inhibition between correct and incorrect response preparation. Subjects responded selectively to a central target letter with flanking compatible (e.g., HHHHH) or incompatible (e.g., SSHSS) noise letters. In the mixed condition all four stimuli were mixed randomly in a block, and in the blocked condition only two stimuli with identical noises were used. The results showed that the reaction times to incompatible stimuli were delayed in the mixed condition compared with that to compatible stimuli, while the delay was significantly reduced in the blocked condition. This blocking effect was also shown on P3 latencies, an event-related potential measure of stimulus evaluation, but not on lateralized readiness potentials (LRPs), a measure of response preparation. Furthermore, irrespective of blocked/mixed conditions, LRPs indicating incorrect preparation were observed. These findings suggest that cognitive conflict could not be explained by the reciprocal inhibition model based on response preparation, but by a model based on stimulus evaluation.

[Long-term follow-up of neonatal hyperbilirubinemia when phototherapy was withheld because of low bilirubin levels in the spinal fluid--growth, intelligence and soft neurological signs in school children].

The significance of cerebrospinal fluid (CSF) bilirubin levels on the outcome of neonatal jaundice has been investigated by correlations between kernicterus or brain damage and CSF bilirubin levels (Torii 1974, 1981, Meisels 1984), This study is designed to clarify the significance of CSF bilirubin levels in the long-term prognosis of neonatal hyperbilirubinemia. Sixteen full-term newborn babies with hyperbilirubinemia (serum bilirubin level 20.0-30.0 mg/dl) who did not receive phototherapy because of low bilirubin in their spinal fluid (usually under 0.5 mg/dl in normal neonates) were followed in this study of growth, intelligence and neurobehavior. The subjects' neurobehavior was compared with that of a matched control group. The physical growth of the children with a history of hyperbilirubinemia was within normal limits except for one girl whose weight was less than-2 SD from the average. Verbal IQ's were lower than performance IQ's in 10 out of 14 children with a history of hyperbilirubinemia. However, no mental retardation was noted. No significant difference was found between the two groups in mean positive scores on the Garfield test. In the Prechtl test, mean score of the finger-touching test was significantly higher in the children with a history of hyperbilirubinemia than in the control group. The soft sign coefficient and the occurrence of attention deficit hyperactivity disorder were not significantly different in the two groups. In summary, a low bilirubin level (less than 0.5 mg/dl) in the spinal fluid seems to be a good prognostic sign in infants with neonatal bilirubinemia.

Motor response information influence on CNV shape and resolution time.

This study systematically investigates changes in CNV waveform shape and resolution time that result from the presentation of facilitatory, inhibitory, or no motor response (MR) information simultaneously with the warning (S1) or imperative (S2) stimulus of the S1-S2-MR CNV paradigm. Analyses indicate that the simultaneous presentation of S1 and information to produce or inhibit a MR attenuates initial CNV development. Further, when the S1 information is inhibitive, CNV development is retarded throughout. The contribution of an inhibitory psychological process during CNV development is proposed. The data also indicate that CNV resolution time is not dependent on the presence of a motor response. It is suggested that CNV resolution time is indicative of psychological completion or closure.