Human echolocation: pitch versus loudness information

Blind persons emit sounds to detect objects by echolocation. Both perceived pitch and perceived loudness of the emitted sound change as they fuse with the reflections from nearby objects. Blind persons generally are better than sighted at echolocation, but it is unclear whether this superiority is related to detection of pitch, loudness, or both. We measured the ability of twelve blind and twenty-five sighted listeners to determine which of two sounds, 500 ms noise bursts, that had been recorded in the presence of a reflecting object in a room with reflecting walls using an artificial head. The sound pairs were original recordings differing in both pitch and loudness, or manipulated recordings with either the pitch or the loudness information removed. Observers responded using a 2AFC method with verbal feedback. For both blind and sighted listeners the performance declined more with the pitch information removed than with the loudness information removed. In addition, the blind performed clearly better than the sighted as long as the pitch information was present, but not when it was removed. Taken together, these results show that the ability to detect pitch is a main factor underlying high performance in human echolocation.     

加强我国卫生领域科研诚信建设的重要性

近几年来,我国的科研不端案例呈不断上升趋势.科技部、教育部、中国科学院,国家自然科学基金委员会、中国科学技术协会等部门或机构已发布了关于科研不端行为的处理规定,然而在我国卫生领域科研不端行为的处理和科研诚信建设方面尚未出台相关政策或指导意见.加强我国卫生领域的科研诚信建设具有重要意义.     

早期归隐现象与管晏的隐逸观

我国古代的隐逸发生很早,至迟在商周之际就有不少可信的例子,到春秋时期成为一种普遍社会现象。对于隐逸,管、晏进行了具体分析,给予隐士客观评价,并主张国家积极征召隐士。管、晏的隐逸观与他们自身经历有关,也是其“举贤授能”人才思想的一部分。管、晏招隐士的主张,对于当时诸侯笼络人才、赢取民心、稳定社会具有积极作用。     

重视直肠癌术后局部复发的防治

直肠癌术后局部复发是临床关注的重点与难点问题。术前准确分期、评估,选择合理治疗方案和术式,是防治局部复发的先决条件。手术遵循全直肠系膜切除(TME)原则,保证断端切缘和环周切缘完整、无癌细胞残留是防治局部复发的关键。新辅助治疗可降低T3、T4期直肠癌局部复发率。发挥直肠癌多学科综合治疗模式优势对防治直肠癌局部复发有重要作用。     

道教劝善书的和谐理念——以《关圣帝君觉世真经》为例

《关圣帝君觉世真经》在对人们"诸恶莫作,众善奉行"的劝诫中渗透着诸多和谐的理念,它的生命伦理、家庭伦理、社会伦理、生态伦理、经济伦理及道德赏罚观,反映出道教对社会和谐的追求,为我们构建和谐社会提供了宝贵的思想理论资粮。     

无意识信息加工中的“完型”——无意识捆绑假说的新证据

采用连续闪烁范式(Continuous Flash Suppression,CFS)考察了无意识状态下完型能否发生.研究通过2(线条完整性)×2(意义破坏)×2(熟悉性)的被试内实验设计考察了8种条件下图片的突破抑制时间(Suppression Time,ST).结果发现:线条完整和意义未破坏的图片能更快地克服噪音图片的抑制进入意识;熟悉性不影响突破抑制时间.重要的是,不完整的图片也可以出现意义破坏效应.这表明即使在被抑制的状态下,不完整图形的信息也能够传达至与完型相关的高级视觉区域形成客体表征.研究为无意识捆绑假说(The Unconscious Binding Hypothesis)提供了新的实验证据.     

Chinese Philosophy Education at Peking University

1 Introduction Philosophy is no more a favorite subject for students at Peking University than it is for students at other universities around the world,even if many of them enjoy philosophy courses.Presently,the Department of Philosophy at Peking University enrolls an average of forty-five freshmen1 each year,though most of them do not take philosophy as their major.     

线索类型对阈下注视线索效应的影响

实验结合连续闪烁抑制范式和线索化范式, 通过操纵直视面孔和斜视面孔的呈现方式, 考察了动静线索类型对注视线索效应的影响。结果表明：两种线索在阈上条件都能产生注视线索效应, 且动态线索诱发的效应更大; 无意识条件下有且仅有动态注视线索能诱发注视线索效应。这说明眼睛运动是产生阈下注视线索效应的必要条件; 眼睛运动会增强阈上注视线索效应, 静态注视线索效应依赖于意识。研究结果支持了社会知觉与心理理论交互模型。     

11~14岁超常儿童与普通儿童问题解决能力的发展比较

以北京市某中学和某小学11~14岁之间294名学生为被试, 其中超常儿童131人, 普通儿童163人。采用推箱子任务, 结合横向比较和纵向追踪数据, 从认知能力、元认知能力和认知效率三个维度来考察超常儿童与普通儿童问题解决能力的发展差异。结果发现超常儿童在问题解决能力的三个维度上均优于普通儿童, 两类儿童问题解决能力的发展模式不一致：超常儿童的问题解决能力发展先快后慢, 快速发展期在11~12岁半之间; 普通儿童的问题解决能力发展先慢后快, 快速发展期在12岁半~14岁之间。超常儿童与普通儿童的问题解决能力差异随年龄增大逐渐减小。