As is well known, Japanese adults who have just begun to learn English often err in producing /r/ and /l/ because their native language does not possess such liquid consonants. The aim of this study was to determine if Japanese adults eventually learn to produce /r/ and /l/ accurately in words like read and lead. Liquids spoken by 12 native Japanese speakers who had lived in the United States for an average of two years were often misidentified by native English-speaking listeners. Their productions of /r/ and /l/ also received much lower (and thus foreign-accented) ratings than did the native English speakers' liquids. On the other hand, liquids produced by native Japanese speakers who had lived in the United States for an average 21 years were identified correctly in forced-choice tests. This held true for liquids in words that had been read from a list as well as for words that had been spoken spontaneously. The ratings of liquids produced by 10 of the 12 experienced Japanese speakers fell within the range of ratings obtained for the 12 native English speakers. These findings challenge the widely accepted view that segmental production errors in a second language arise from the inevitable loss of ability to learn phonetic segments not found in the native language.

Adult↗

PubMedDate not supplied

Beneficial effect on nebracetam on energy metabolism after microsphere-induced embolism in rat brain.

The present study was undertaken to examine the possible therapeutic effects on nebracetam on the energy metabolism of rat brain regions in microsphere-induced, sustained ischemia. Microsphere embolism was induced by injection of 900 microspheres (48 microns in diameter) into the right internal carotid artery of rats, and changes in the energy metabolism of the cerebral cortex, striatum and hippocampus of the right hemisphere were determined without and with nebracetam treatment. Microsphere embolism induced increases in lactate and glucose contents and decreases of ATP and creatine phosphate contents in these regions, suggesting that sustained impairment of cerebral energy metabolism occurred. These changes were gradually reversed with time after the operation. Treatment of microsphere-injected rats with 30 mg/kg of nebracetam, p.o., twice a day, was started one day after the onset of cerebral ischemia. The effects of treatment with nebracetam on cerebral energy metabolites were determined on the 3rd and 7th day after operation. Treatment of microsphere-injected rats with nebracetam significantly improved these variables on the 3rd day after the onset of ischemia, but the improvement was small on the 7th day, except for reversal of the hippocampal ATP content. These results suggest that nebracetam is a possible therapeutic agent for the restoration of cerebral energy metabolism against microsphere-induced, sustained cerebral ischemia.

Adenosine Triphosphate↗