Visual evoked potentials relating to imagery: Words for concrete objects versus absolute concepts

Summary We recorded visual evoked potentials (VEPs) elicited with high or low imaginable Chinese characters (HIC or LIC), representing concrete objects or absolute concepts, respectively. A closed circle (CC) acts as control stimulus. These were displayed (at 1.6° visual angle) for 35 ms on a TV monitor. Twenty-one channel VEPs (band-pas filter: 0.05–60 Hz), using balanced non-cephalic electrodes, were recorded from –100 to 924 ms for 11 right-handed male volunteers. The VEPs were analyzed by multivariate analysis of variance (MANOVA) and comparison of topographies at four remarkable peaks (P110, N160, P230 and N320). MANOVA showed significant differences (p< 0.001) for both conditions of channel and stimuli (HIC, LIC or CC). P100 for the CC-VEPs, N160 for the HIC-and LIC-VEPs, P230 for the CC-VEPs, and N320 for the HIC-VEPs were remarkable in the posterior scalp regions. Topographies at P100 and N160 showed no difference between the HIC-and LIC-stimuli. However, those at N320 showed difference between the HIC-and LIC-stimuli over the occipital and posterior temporal areas. Those results suggest that the responses at P100 and N160 might segregate Chinese characters from non Chinese characters. N320 suggested certain processes in imagery on recognizing Chinese characters over the occipital and posterior temporal areas.We are grateful to Dr. Yoshiji Kojima of Hamamatsu University for helpful comments.     

Holistic processing of impossible objects: Evidence from Garner’s speeded-classification task

Holistic processing, the decoding of the global structure of a stimulus while the local parts are not explicitly represented, is a basic characteristic of object perception. The current study was aimed to test whether such a representation could be created even for objects that violate fundamental principles of spatial organization, namely impossible objects. Previous studies argued that these objects cannot be represented holistically in long-term memory because they lack coherent 3D structure. Here, we utilized Garner’s speeded classification task to test whether the perception of possible and impossible objects is mediated by similar holistic processing mechanisms. To this end, participants were asked to make speeded classifications of one object dimension while an irrelevant dimension was kept constant (baseline condition) or when this dimension varied (filtering condition). It is well accepted that ignoring the irrelevant dimension is impossible when holistic perception is mandatory, thus the extent of Garner interference in performance between the baseline and filtering conditions serves as an index of holistic processing. Critically, in Experiment 1, similar levels of Garner interference were found for possible and impossible objects implying holistic perception of both object types. Experiment 2 extended these results and demonstrated that even when depth information was explicitly processed, participants were still unable to process one dimension (width/depth) while ignoring the irrelevant dimension (depth/width, respectively). The results of Experiment 3 replicated the basic pattern found in Experiments 1 and 2 using a novel set of object exemplars. In Experiment 4, we used possible and impossible versions of the Penrose triangles in which information about impossibility is embedded in the internal elements of the objects which participant were explicitly asked to judge. As in Experiments 1–3, similar Garner interference was found for possible and impossible objects. Taken together, these findings emphasize the centrality of holistic processing style in object perception and suggest that it applies even for atypical stimuli such as impossible objects.     

Highly Chlorinated Toxic Contaminants in Pesticide-Treated Wooden Art Objects

Although the contamination of wooden art objects with pesticides is well known, to the authors' knowledge no attempt has yet been made to investigate the eventual presence of other toxic compounds that have been produced during the degradation of pesticides or that may be present in the technical formulations. Here, the authors report on the presence of polychlorinated biphenyls (PCBs) and polychlorinated terphenyls (PCTs) in scrapings from wooden antique art objects, namely printing blocks, sculptures, and masks. These antiques belong to 2 fine art museums in Belgium—Antwerp's Ethnographic Museum and the Plantin-Moretus Museum. It is documented that these art objects were treated with pesticides in the 1950s. In addition, 2-heptachlorodibenzo-p-dioxin (HpCDD) isomers and octachlorodibenzo-p-dioxin (OCDD) were also identified. The presence of these toxic compounds in these antiques requires a better understanding of safety for the persons (conservators, museum employees, restorers, and visitors) coming in contact with these objects.     

ICU物体表面的消毒效果监测

目的了解ICU医护人员手频繁接触物体表面的消毒质量,提高管理者对ICU物体表面消毒重要性的认识,为加强医院感染的预防与控制提供科学依据。方法 2013年3-8月对重症医学科、急诊和神经外科重症监护病房医务人员手频繁接触物体表面的消毒效果进行目标性监测,数据分析应用SPSS 19.0软件处理。结果共采集各类标本468份,合格393份,合格率84.0%,其中消毒后2h304份,合格249份,合格率81.9%;消毒后8h164份,合格144份,合格率87.8%,二者之间消毒效果差异无统计学意义;目标性病原菌监测结果显示,以多药耐药菌为主,共检出病原菌80株,检出率较高的病原菌为鲍氏不动杆菌39株、金黄色葡萄球菌29株,分别占48.8%、36.3%,其中泛耐药鲍氏不动杆菌34株、MRSA 28株,分别占87.2%、96.6%,肺炎克雷伯菌9株占11.2%。结论 ICU医护人员手频繁接触物体表面的日常清洁消毒质量有待提高,应强化医务人员手卫生管理,制定医务人员手频繁接触物体表面清洁与消毒的标准化操作规程,并加强规范的落实与监管。     

Maternal attachment influences mother–infant styles of regulation and play with objects at nine months

We examined the association between the quality of maternal representations of attachment evaluated by the Adult Attachment Interview (AAI) and mother styles of regulating attention and emotion during free play with objects in 41 mother dyads when infants were nine months old. The secure mother dyads showed a greater duration of engagement matches, with more positive matches, and a greater capacity to move from non-matched to matched states. Secure mother dyads demonstrated greater involvement in play with objects than insecure mother dyads. Insecure mother dyads showed a greater duration of mismatches and spent more time in negative matches. Correlations between maternal AAI scores and the variables studied also showed that the maternal Passivity and Unresolved scales were associated with less adequate dyadic attention and emotion regulation, while the maternal Coherence scale was associated with more adequate dyadic attention and emotion regulation.     

Nonverbal imitation skills in children with specific language delay

Research in children with language problems has focussed on verbal deficits, and we have less understanding of children's deficits with nonverbal sociocognitive skills which have been proposed to be important for language acquisition. This study was designed to investigate elicited nonverbal imitation in children with specific language delay (SLD). It is argued that difficulties in nonverbal imitation, which do not involve the processing of structural aspects of language, may be indicative of sociocognitive deficits. Participants were German-speaking typically developing children (n = 60) and children with SLD (n = 45) aged 2–3½ years. A novel battery of tasks measured their ability to imitate a range of nonverbal target acts that to a greater or lesser extent involve sociocognitive skills (body movements, instrumental acts on objects, pretend acts). Significant group differences were found for all body movement and pretend act tasks, but not for the instrumental act tasks. The poorer imitative performance of the SLD sample was not explained by motor or nonverbal cognitive skills. Thus, it appeared that the nature of the task affected children's imitation performance. It is argued that the ability to establish a sense of connectedness with the demonstrator was at the core of children's imitation difficulty in the SLD sample.     

The electrophysiological correlate of contour integration is similar for color and luminance mechanisms

Contour integration perceptually links together similarly oriented line elements hidden between randomly oriented distracters. To investigate how contour integration depends on early sensory processing, we compared the electrophysiological correlate of contour integration of elements defined by luminance (black-and-white) or isoluminant color (red-and-green) contrasts. Detection performance for color- and luminance-defined contours (both open and closed) was matched. Detectable contours elicited a negative shift over posterior electrodes starting 220 ms after stimulus onset. The shift occurred for both color and luminance contrasts, even when possible luminance artifacts in red-and-green stimuli were masked. This indicates a common physiological processing stream for orientation-based contour integration of red-and-green and black-and-white elements.     

一种视觉假体的视觉显著图提取新方法

目的 一幅图像或场景的显著性区域代表它们的主要内容（显著目标）.由于视觉假体可植入电极的数量有限,只有低分辨率的图像对其才有用,因此提取显著性区域有助于视觉假体捕捉到场景中的显著目标.方法 Itti模型是一个显著性检测模型,它检测到的显著性区域与人的视觉感知有差异,显著目标的边界不明确.笔者去除了Itti模型提取的方向和色彩特征,将红（R）、绿（G）、蓝（B）三基色（RGB）图像转换到对应于HSI颜色空间上的色调（H）、纯度（S）、亮度（I）3个新特征分量,对hti模型进行优化改进.在显著图中,将落在显著目标内的显著点面积与总显著点面积的比值定义为显著图精确度;以显著图精确度为提取显著图方法的测度,对改进前后2种方法进行比较.结果 利用改进方法提取的显著图比Itti模型显著图精确度提高了约20％;在检测显著性区域时所用时间减少近50％.结论 提出了一种用于人工视觉的获取显著目标的方法,本算法可以得到更加精确的显著性结果,且可缩短运行时间.     

Complications of lost needle after suture of vaginal tear following delivery

We present a case of a lost broken needle during repair of a vaginal tear following delivery. The woman was not informed at that time. Only twenty years later a pelvic X-ray visualised the fragment by chance. From that day on she complained about lower abdominal chronic pain and insisted on a hysterectomy. The case considers moving of foreign bodies and as a cause of chronic pain and relates to open information even 20 years later. Received: 25 March 2000 / Accepted: 8 April 2000