基于多尺度特征融合与反向注意力的COVID-19病灶分割

针对新型冠状病毒肺炎（COVID-19）分割问题中感染区域具有高变异性以及病灶与背景对比度低等问题,提出一种基于多尺度特征融合与反向注意力的COVID-19感染分割网络。首先,利用残差网络作为主干网络进行特征提取,并使用全局上下文聚合策略对不同层次特征进行融合得到粗略的分割结果;其次,在网络瓶颈处添加多尺度特征融合模块,利用空洞卷积与多核池化增强网络分割不同尺度病变的能力;最后,设计一种级联结构的反向注意力模块,利用互补区域的细节特征增强背景与目标的对比度。本文方法在COVID-19 CT分割测试集上的准确率、特异性、灵敏度分别达到0.714、0.700和0.958,误检和漏检区域明显减少,细小病灶的分割能力显著提升。     

Joint Attention and Toddler Characteristics: Race, Sex and Socioeconomic Status

In studies of joint attention and sequences of interaction that foster joint attention, limited focus has been placed on toddler characteristics such as race, sex and socioeconomic status (SES). The purpose of the present study was to investigate the relationship between joint attention and toddler's race, sex and SES. Eighty-four dyads of diverse race, sex and SES were videotaped playing, and joint attention and initiating matemal bid sequences were coded. Joint attention related to a “persisting” mother, whether or not the toddler accepted the initial maternal bid. No race differences were found; however, females engaged in more frequent bouts of joint attention and had more frequent nonpersistent maternal responses after the bid was accepted. Finally, SES was generally unrelated to joint attention. The manner in which bids for joint attention transpired and the amount of joint attention that occurred was largely independent of the dyad's SES as measured here.     

Electrophysiological indices of acute effects of ethanol on involuntary attention shifting

Dose-related effects of ethanol (placebo, 0.30, and 0.60 g/kg) on behavioral and event-related brain potential (ERP) indices of involuntary attention shifting of audition were investigated. ERPs were recorded from 11 healthy social drinkers during a forced-choice reaction-time (RT) task. Subjects were presented with 100 and 200 ms tones (P = 0.50 for each) with a constant inter-stimulus interval (ISI) of 1 s. The task was to press either of two buttons, depending on the tone duration. The majority of the tones (“standards”) were of 700 Hz (P = 0.82). Occasionally, however, the frequency of the tones changed, deviating either slightly (750 Hz), moderately (900 Hz), or widely (1200 Hz; P = 0.06 for each) from the standard frequency. In accordance with previous findings, the task-irrelevant frequency deviations prolonged the RT. This RT prolongation was attenuated by alcohol with the 0.3 g/kg dose, thus suggesting less distraction by irrelevant stimulus deviations under the influence of ethanol. Furthermore, the P3a, reflecting involuntary attention shifting, was suppressed by alcohol even with the 0.3 g/kg dose. These findings demonstrate a detrimental effect of alcohol on involuntary attention shifting, evident with doses considerably smaller than previously described, and still juridically acceptable in road traffic in most countries. Received: 19 December 1997/Final version: 26 May 1998     

Scopolamine Effects on Visual Information Processing, Attention, and Event-Related Potential Map Latencies

We measured performance and event-related brain potential (ERP) map latencies in 12 subjects during four visual discrimination tasks to compare the timing of scopolamine effects on information processing and attention. "Topographic component recognition" found ERP map latencies at times of best fit with a component model map. This "common topography" criterion minimized topographic differences among conditions to facilitate latency interpretations. Scopolamine slowed N1 latency in all tasks, and P3 and reaction time in some tasks. The drug delayed responses to easy targets more than to hard targets. It also induced a disproportionate N1 delay for unilateral high spatial frequency gratings. Both effects reflect a scopolamine-induced impairment when processing targets that usually capture attention. Scopolamine also impaired accuracy for unilateral high spatial frequency gratings, and for gratings presented at probable locations, confirming and extending previous findings. Scopolamine-induced P1 and N1 delays showed that visual processing was affected. Several results were inconsistent with a serial stage model. We suggest that scopolamine both delays selected processes and impairs a processing mode based on automatic capture of attention, inducing more serial processing.     

Differences in muscle activity before, during, and after responding in a simple reaction time task: schizophrenics vs. normals.

Schizophrenics and normals were presented with a series of simple reaction time (RT) trials. Electromyographic techniques were used to partition RT into peripheral and central components. It was observed that contrary to the previously held assumption of "neuromuscular sameness," schizophrenics displayed a qualitatively different pattern of muscle activity in their motor responding. Differences of the observed sort could account, in part, for differences previously thought to be due solely to central dysfunction.     

Neuroanatomical correlates of the near response: voluntary modulation of accommodation/vergence in the human visual system

This study identifies brain regions participating in the execution of eye movements for voluntary positive accommodation (VPA) during open-loop vergence conditions. Neuronal activity was estimated by measurement of changes in regional cerebral blood flow (rCBF) with positron emission tomography and 15O-water. Thirteen naive volunteers viewed a checkerboard pattern with their dominant right eye, while a lens interrupted the line of gaze during alternate 1.5 s intervals. Three counterbalanced tasks required central fixation and viewing of a stationary checkerboard pattern: (i) through a 0.0 diopter (D) lens; (ii) through a -5.0-D lens while avoiding volitional accommodation and permitting blur; and (iii) through a -5. 0-D lens while maintaining maximal focus. The latter required large-amplitude, high-frequency VPA. As an additional control, seven of the subjects viewed passively a digitally blurred checkerboard through a 0.0-D lens as above. Optometric measurements confirmed normal visual acuity and ability to perform the focusing task (VPA). Large-amplitude saccadic eye movements, verified absent by electro-oculography, were inhibited by central fixation. Image averaging across subjects demonstrated multifocal changes in rCBF during VPA: striate and extrastriate visual cortices; superior temporal cortices; and cerebellar cortex and vermis. Decreases in rCBF occurred in the lateral intraparietal area, prefrontal and frontal and/or supplementary eye fields. Analysis of regions of interest in the visual cortex showed systematic and appropriate task dependence of rCBF. Activations may reflect sensorimotor processing along the reflex arc of the accommodation system, while deactivations may indicate inhibition of systems participating in visual search.     

威斯康星卡片分类测验用于注意缺陷多动障碍的meta分析

目的　分析注意缺陷多动障碍 (ADHD)患儿与正常儿童在威斯康星卡片分类测验 (WCST)中各指标成绩的差异。方法　复习国外 14篇有关文献 ,对ADHD患儿和正常儿童WCST的 4个指标 (持续性错误数、分类完成数、非持续性错误数和持续性反应数 )进行meta分析。结果　ADHD和正常对照组在WCST的持续性错误数、完成分类数和非持续性错误数的成绩差异有统计学意义 ,且可靠性较好。两组的持续性反应数也有统计学意义 ,但其可靠性较差。ADHD患儿的平均持续错误数比正常儿童高 0 4 6倍标准差。正常儿童的平均完成分类数比ADHD组高 0 37倍标准差。ADHD患儿的平均非持续性错误数比正常儿童高 0 37倍标准差。ADHD患儿的平均持续性反应数比正常儿童高 0 30倍标准差。 4个指标的效应尺度均在小至中的范围。结论　WCST值得推广应用于ADHD患儿 ,较敏感的指标包括持续性错误数、完成分类数和非持续性错误数。ADHD患儿可能存在前额叶功能缺陷。     

利培酮对精神分裂症的疗效及对记忆和注意功能的影响

目的 :探讨利培酮对精神分裂症 (SC)的疗效及对认知功能的影响。方法 :对 45例首发精神分裂症及分裂样精神障碍病人在利培酮治疗前后分别进行临床记忆量表、数字划销测验、阳性与阴性症状量表 (PANSS)和不良反应量表评定。疗程 8wk。结果 :利培酮治疗SC的临床总有效率为 91 % ,显效率 78%。治疗后记忆商、指向记忆、无意义图象再认及数字划销测验净分均高于治疗前 ,数字划销测验的失误率低于治疗前 (P <0 .0 5或P <0 .0 1 )。PANSS的阳性症状量表分下降与记忆商呈负相关 ,与数字划销测验的失误率呈正相关 ;而阴性症状量表分的下降与记忆和数字划销测验各项指标间无明显相关性。结论 :利培酮能有效地治疗SC病人的阳性和阴性症状 ,改善记忆及注意功能。     

Thyroid function in a population of children with attention deficit hyperactivity disorder

To determine the prevalence of thyroid hormone abnormalities and generalized resistance to thyroid hormone in a population of children with attention deficit hyperactivity disorder (ADHD) as compared to reference ranges determined from a control population and hence to determine if routine thyroid hormone screening in children with non-familial ADHD is indicated.

Method:

Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.

Results:

The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.

Conclusion:

Routine thyroid hormone screening is not indicated in children with non-familial ADHD.