[ti:Can Language Learning Happen During Sleep?] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]A new study suggests some language learning [00:04.72]can take place during sleep. [00:08.50]Researchers from Switzerland's University of Bern [00:14.00]say they discovered people were able to learn [00:18.40]new language words during deep levels of sleep. [00:23.57]Results of the study recently appeared [00:28.04]in the publication Current Biology. [00:33.48]Sleeping hours are generally considered unproductive time. [00:39.64]But several studies have suggested [00:42.68]some learning activity can happen. [00:46.72]Studies involving mice provided evidence [00:51.13]that sleep learning is possible in the brain of mammals. [00:58.24]Other human studies, the Swiss researchers said, [01:02.52]found that simple learning through sounds [01:06.04]may be possible during sleep. [01:09.18]But they added that "complex verbal learning" [01:13.68]has not yet been demonstrated. [01:18.04]Much of the earlier research found [01:21.16]that memories made when people were awake [01:24.56]were reinforced and strengthened during sleep. [01:29.01]This supported the idea that information learned while awake [01:35.44]is replayed and deeply embedded in the sleeping brain. [01:42.56]The researchers theorized that, [01:45.26]if replay during sleep improves the storage of information [01:50.36]that is learned while awake,the processing and storage [01:54.82]of new information should also be possible during sleep. [02:00.32]The research group was led by Katharina Henke, [02:06.28]a professor at the University of Bern [02:09.48]and founder of the school's Center for Cognition, Learning and Memory. [02:17.16]The researchers carried out experiments [02:20.49]on a group of young German-speaking men and women. [02:24.81]The experiments centered on periods of deep sleep called "up-states." [02:33.04]They identified these slow-wave peaks [02:36.84]as the best moments for sleep-learning. [02:41.40]During normal sleep, human brain cells [02:45.05]are commonly active for a short period of time [02:49.08]before they enter a state of brief inactivity, [02:53.20]the researchers said. [02:56.12]The two states are continuously changing. [03:00.72]The researchers observed individuals in a controlled environment [03:05.24]during brief periods of sleep. [03:08.72]They recorded brain activity as pairs of words [03:12.88]were played for the study subjects. [03:17.08]One word in the pair was a real German word. [03:21.40]The other was a made-up foreign word. [03:25.21]For later identification purposes, the German words chosen [03:31.04]were things clearly larger or smaller than a shoebox. [03:37.76]Each word pair was played four times, [03:41.32]with the order of the words changed each time. [03:46.24]The researchers said the word pairs were played at a rhythm [03:50.96]that is similar to actual brain activity during deep sleep. [03:57.36]The goal was to create a lasting memory link [04:01.44]between the false word and the German word [04:04.92]that individuals could identify when awake. [04:09.14]When the subjects woke, [04:12.32]they were presented with the false language words [04:16.32]– both by sight and sound. [04:19.20]They were then asked to guess [04:22.12]whether the false word played during sleep [04:25.33]represented an object smaller or larger than a shoebox. [04:31.96]During this part of the experiment, [04:34.24]some of the subjects had their brain activityrecorded [04:38.20]by magnetic imaging technology. [04:42.08]This was meant to measure brain activity [04:45.20]when the subjects were giving their answers to the questions. [04:50.72]Results of the study found that a majority of subjects [04:55.04]gave more correct answers about the sleep-learned words [04:59.48]than would be expected if they had only guessed at random. [05:04.95]The researchers said they measured increased signals [05:09.92]affecting a part of the brain known as the hippocampus. [05:15.12]This brain structure is very important [05:19.24]for building relational memory during non-sleep periods. [05:25.00]The researchers said memory was best for word pairs presented [05:30.08]during slow-wave peaks during sleep. [05:34.88]The study suggests that memory formation in sleep [05:39.32]appears to be caused by the same brain structures [05:43.12]that support vocabulary learning while awake. [05:47.94]The researchers say more studies are needed [05:52.04]to support their findings. [05:55.12]However, the experiments do provide new evidence [05:59.36]that memories can be formed and vocabulary learning can take place [06:04.96]in both conscious and unconscious states. [06:10.44]I'm Bryan Lynn. [06:12.04]更多听力请访问51VOA.COM