The effects of practice and delay on motor skill learning and retention

The present study assessed the effects of amount of practice and length of delay on the learning and retention of a timed motor sequence task. Participants learned to reproduce ten-element visual sequences by tapping in synchrony with the stimulus. Participants were randomly assigned to a varied-practice condition or a varied-delay condition. In the varied-practice condition, participants received either one, three, or six blocks of practice followed by a fixed 4-week delayed-recall. In the varied-delay condition, participants received three blocks of practice followed by a varied delay of either 3 days, or 2, 4, or 8 weeks. Learning was assessed by changes in accuracy, response variance, and percent response asynchrony. Our results showed that amount of practice per se did not affect learning and retention of the task. Rather, distribution of practice over several days was the most important factor affecting learning and retention. We hypothesize that passage of time is essential for a maximum benefit of practice to be gained, as the time delay may allow for consolidation of learning, possibly reflecting plastic changes in motor cortical representations of the skill. With regards to delay, our findings suggest that explicit and motoric components of a motor sequence are likely to be learned and maintained in separate but interacting systems. First, only the longest delay group showed decrements in percent correct, indicating that longer lengths of delay might hinder retrieval of explicit aspects of the task. Second, all groups showed a decrement in percent response asynchrony, suggesting that synchronization may be a more difficult parameter to maintain because it relies heavily on sensorimotor integration.     

Alterations in short-term retention, conditioned avoidance response acquisition and motivation following aluminum induced neurofibrillary degeneration

Aluminum chloride induced neurofibrillary degeneration may provide a useful model for the study of a human dementia process. This possibility was assessed in cats trained to perform on a delayed-response task, a conditioned avoidance task, visual and temporal discrimination tasks and a motivational task involving rewarding intracranial electrical stimulation. After an initial asymptomatic period short term retention and acquisition of a conditioned avoidance response were selectively impaired. The associated ultrastructural abnormalities plausibly implicate the cytoplasmic streaming mechanism in the cellular substrate for some retention and acquisition phenomena.     

Retention of a backward classically conditioned reflex response in spinal cat

Summary Retention of a backward classically conitioned reflex response was investigated in the spinal cat preparation. Facilitation of the flexion reflex was induced by the pairing of superficial peroneal nerve stimulation (30 Hz, 0.5 s), the US (unconditioned stimulus), with saphenous nerve stimulation (10 Hz, 1.5 s), the CS (conditioned stimulus). Both the US and CS were supramaximal for activation of A cutaneous afferent fibers. Experimental animals received 30 paired trials (US preceded CS by 0.25 s) with an intertrial interval (ITI) of three min. Control animals received the same stimuli but in an explicitly unpaired manner. Following acquisition, all animals received 30 additional CS-alone trials at five min intervals. This paradigm, which incorporated ITIs longer than those which had been used previously in backward conditioning studies, induced a long-lasting potentiation of the flexion reflex which appeared to be specific to spinal reflex pathways activated by A cutaneous fibers. The relevancy of these results to a more specific understanding of backward and forward classical conditioning in the spinal cat is discussed.Supported by NSF grants 8415917 and 8808495     

Observations on the therapeutic effect of acupuncture plus tuina on retention of urine

将118例尿潴留患者随机分为2组,即针灸推拿治疗组和药物注射治疗组分别进行治疗观察.结果2组疗效有显著差异.并对2组治疗效果、治疗次数、疗效影响等比较分析,提示针灸推拿组显效率明显优于药物注射组.反映针灸配合推拿治疗尿潴留是临床一种较好的治疗方法.     

药对陈皮—生姜与其单味药挥发油共有组分的比较分析

目的:利用气相色谱—质谱法分离检测药对陈皮—生姜及其单味药陈皮、生姜的挥发油成分。方法:采用交互移动窗口因子分析法(AMWFA)对药对与单味药挥发油成分的共有组分进行比较分析。用质谱库结合保留指数进行定性,并采用总体积积分法定量。结果:分别定性了陈皮、生姜、药对陈皮—生姜挥发油成分57、32和44种,分别占总含量的95.79%、82.80%、91.78%。结论:药对与陈皮、生姜的共有组分分别为28、21种,三者的共有组分为12种。     

头针不同留针时间治疗脑卒中偏瘫疗效观察

目的观察头针疗法留针时间长短对脑卒中偏瘫疗效的影响,为临床头针治疗脑卒中偏瘫提供依据。方法将82例脑卒中偏瘫患者随机分为对照组（22例）、短时留针组（30例）、长时留针组（30例）。对照组采用Bobath疗法为主的常规康复训练,短时留针组和长时留针组在康复训练基础上加留针时间分别为0．5h和24h的常规头针治疗。三组均分别在康复治疗1个月和3个月时以简式Fugl—Meyer运动功能评分表（FMMS）、Fugl—Meyer平衡功能评分表（FMA—B）和改良Barthel指数评分（MBI）进行治疗前后的功能评价。结果长时留针组治疗后在肢体运动功能、日常生活能力（ADL）等方面的功能明显优于对照组和短时留针组（P〈0．05）,而短时留针组与对照组相比差异无统计学意义。结论留针时间长短对头针治疗腑卒中偏瘫有明显影响,应采用长时间留针。     

宫、腹腔镜手术联合中药治疗输卵管阻塞性不孕的临床观察

目的：探讨宫、腹腔镜手术联合中药治疗输卵管阻塞性不孕的疗效。方法：我院2006年9月至2007年12月收治输卵管阻塞性不孕患者52例,利用宫腔镜直接观察子宫腔内膜及输卵管开口,在直视下行输卵管插管回压推注美蓝和疏通液体,同时在腹腔镜下行盆腔粘连松解、输卵管造口、内异病灶电灼术。术后给予中药保留灌肠治疗,随访受孕情况。结果：52例患者,输卵管复通有效率为74.5%。治疗后受孕率32.7%。结论：宫、腹腔镜手术联合中药治疗可大大提高输卵管阻塞的治愈率,缩短治疗周期,减少患者的经济和心理负担,值得推广应用。     

海洛因成瘾者社区美沙酮维持治疗脱失和保持的定性研究

目的:了解四川省西昌市海洛因成瘾者社区美沙酮维持治疗脱失和保持情况及其影响因素。方法:2005年12月-2006年1月,从四川省西昌市美沙酮维持治疗社区中分别选取87名参加维持治疗的吸毒者和50名相关社区人员进行美沙酮维持治疗脱失和保持情况及影响因素的个人深入访谈。结果:西昌市参加社区美沙酮维持治疗的吸毒者脱失的主要原因是因偷吸而被强制戒毒和外出;保持的主要影响因素是参加治疗的吸毒者主动与吸毒伙伴减少来往和积极工作。社区对美沙酮的主要影响因素是美沙酮维持治疗的知晓和了解程度低、对参加治疗的吸毒者仍存在偏见。结论:应对美沙酮维持治疗的参加者开展干预服务提高保持率,同时加大社区宣传减少社会偏见。     

中药保留灌肠治疗溃疡性结肠炎疗效的系统评价

目的评价中药保留灌肠治疗溃疡性结肠炎的疗效。方法应用国际Cochrane协作网系统评价方法，对中药保留灌肠治疗溃疡性结肠炎的随机对照试验（RCT）进行系统评价。计算机检索（1995～2005年）EMBASE、中国生物医学文献数据库、中国期刊网等。手工检索发表与未发表的文献，纳入中药与传统西药治疗措施相比较的随机对照试验，统计学处理采用Cochrane协作网的Rev Man 4.2软件。结果共纳入23个RCT试验。短期结果显示中药灌肠组比对照组的疗效好，8个RCT结果显示中药灌肠组有效率（92.8%）高于口服柳氮磺吡啶组（89.9%），3个RCT结果显示中药灌肠组有效率（93.1%）高于庆大霉素加皮质激素灌肠组（71.6%），4个RCT结果显示中药灌肠组有效率（94.2%）高于柳氮磺吡啶加皮质激素组（74.9%）。中药灌肠治疗未发现明显不良反应。结论该研究所纳入试验的方法学质量均较低，虽显示中药灌肠疗法在改善溃疡性结肠炎近期临床疗效指标方面优于常规西药疗法，但因无评价远期疗效的试验，尚不能对其疗效得出可靠的结论。     

二相厌氧—生物接触氧化工艺处理四环素废水的研究

本文以二相厌氧-生物接触氧化工艺对四环素废水的处理进行了试验研究,并考察了各反应器的运行特性。在进水COD浓度≤3500mg/L,四环素浓度≤230mg/L,二相厌氧中产酸相、产甲烷相及后续生物接触氧化反应器的水力停留时间分别为3、24h和10h时,COD去除率93％,四环素去除率96％,出水COD<230mg/L,生物接触氧化对氨氮的去除率为75％。试验结果表明二相厌氧-生物接触氧化工艺用于处理四环素废水是可行的。