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1.
Electro- and magnetoencephalography studies have suggested that increased gamma-band activity (GBA) is a correlate of activated neural stimulus representations. In this study, a delayed matching-to-sample paradigm for auditory spatial information was employed to investigate the role of magnetoencephalographic gamma-band activity in the differentiation between matching and nonmatching stimulus pairs. Twelve subjects made same-different judgments about the lateralization angle of pairs of filtered noise stimuli (S1 and S2) presented with 0.8-s delays. One half of the subjects had to respond to matching stimulus pairs, the other half to nonmatching stimulus pairs. Cortical oscillatory activity in the memory task was compared to a control task requiring the detection of background noise intensity changes. Memory-related GBA increases were revealed over midline parietal areas in the middle of the delay phase and during the presentation of S2 and over frontocentral areas at the end of the delay phase. This replicated previous findings. In addition, nonmatching trials were associated with increased GBA over right parietal areas in response to S2. The midline parietal GBA increase during S2 in the memory condition may have reflected the representation of S1 needed for a comparison between S1 and S2. When S1 and S2 were identical, no further representation was required. In contrast, for nonmatching pairs, a second representation was activated over right parietal areas. 相似文献
2.
The aim of this study was to investigate the mechanisms involved in the perception of perceptually salient frequency modulation (FM) using auditory steady-state responses (ASSRs) measured with magnetoencephalography (MEG). Previous MEG studies using frequency-modulated amplitude modulation as stimuli (Luo et al., 2006, 2007) suggested that a phase modulation encoding mechanism exists for low (< 5 Hz) FM modulation frequencies but additional amplitude modulation encoding is required for faster FM modulation frequencies. In this study single-cycle sinusoidal FM stimuli were used to generate the ASSR. The stimulus was either an unmodulated 1-kHz sinusoid or a 1-kHz sinusoid that was frequency-modulated with a repetition rate of 4, 8, or 12 Hz. The fast Fourier transform (FFT) of each MEG channel was calculated to obtain the phase and magnitude of the ASSR in sensor-space and multivariate Hotelling's T2 statistics were used to determine the statistical significance of ASSRs. MEG beamformer analyses were used to localise the ASSR sources. Virtual electrode analyses were used to reconstruct the time series at each source. FFTs of the virtual electrode time series were calculated to obtain the amplitude and phase characteristics of each source identified in the beamforming analyses. Multivariate Hotelling's T2 statistics were used to determine the statistical significance of these reconstructed ASSRs. The results suggest that the ability of auditory cortex to phase-lock to FM is dependent on the FM pulse rate and that the ASSR to FM is lateralised to the right hemisphere. 相似文献
3.
Purpose: The study examined the relationship between verbal short-term memory (STM) and language impairment in Cantonese speakers after stroke. It is hypothesised that Cantonese speakers with left-hemisphere (LH) stroke would perform worse than those with right hemisphere (RH) stroke and normal controls. Specific linguistic factors of Cantonese might affect results in the tasks. Method: Fifteen participants with LH stroke, 10 with RH stroke and 25 healthy controls were tested with auditory–verbal immediate serial recall (ISR) tasks and auditory linguistic tasks. All stroke participants were assessed with the Cantonese version of Western Aphasia Battery (CAB). Result: The LH group performed significantly worse than the RH and healthy control groups in the auditory verbal ISR and auditory linguistic tasks. There were significant lexicality, frequency and imageability effects in most tasks. Auditory discrimination and word comprehension tasks, but not the auditory word recognition task had correlations with ISR tasks. Conclusion: Verbal STM and language performance of Cantonese-speakers with history of LH stroke were inferior to RH stroke and healthy controls. The effects of lexicality, word frequency and imageability on verbal STM memory performance were found. Cantonese tones have effects on performance in auditory word recognition task, similar to onset, nucleus and rime. 相似文献
4.
The early visual gamma-band response is an oscillatory signal evoked approximately 100 ms after stimulation. While some studies have found effects of various cognitive processes on this signal, such effects could not be replicated in other studies. Accordingly, some authors have claimed that evoked gamma-band activity reflects merely sensory functions. To resolve these conflicting positions, we conducted a target detection experiment in which the feature that defined the target could be distributed over a large or a small part of the entire stimulus. Only targets covering a larger area of the entire stimulus evoked stronger gamma-band activity than standards although the over-all stimulus size was identical for all stimuli. This increase in evoked activity resulted from stronger oscillatory power and not exclusively from stronger phase-locking. In contrast, N1 and P3 amplitudes were larger for target stimuli irrespective of the distribution of the relevant stimulus feature. These results are consistent with the notion that early gamma-band activity is generated by feature-selective neural assemblies the activity of which can in fact be modulated by top-down processes. This interaction, however, may be only detectable in scalp-recorded EEG if it affects a sufficient number of neural assemblies. 相似文献
5.
摘要
目的:探讨听觉剥夺对幼鼠学习记忆的影响及听皮质细胞超微结构的变化。
方法:将36只SD幼鼠随机分为听觉剥夺组和正常对照组。听觉剥夺组在生后第7天用阿米卡星500mg/kg·d皮下注射,直到生后第16天,建立听觉剥夺模型。分别于生后第3周、5周、7周进行Morris 水迷宫测试,检测各组幼鼠的学习记忆能力。行为学测试完毕后,观察听皮质超微结构的变化。对照组只进行等容量生理盐水皮下注射。
结果:①定位航行实验:3周龄听觉剥夺组和对照组每天逃避潜伏期差异均无显著性意义(P值均>0.05);5周龄听觉剥夺组幼鼠自第2天起,每天的逃避潜伏期均较同龄对照组延长,差异有显著性意义(P值分别P<0.05、P<0.01、P<0.01);7周龄听觉剥夺组幼鼠每天逃避潜伏期均较同龄正常鼠延长,差异有显著性意义(P值分别P<0.05、P<0.01、P<0.01、P<0.01)。②空间探索实验:生后3周龄幼鼠听觉剥夺组及对照组在目标象限游泳时间及跨越平台次数差异无显著性意义(P>0.05);5周龄、7周龄听觉剥夺组在目标象限的游泳时间均短于正常对照组(P<0.05、P<0.01),跨越平台次数较对照组减少,差异均有显著性意义(P值均<0.05)。③对照组神经元形态完整,结构清晰,细胞器丰富;突触丰富,突触前膜、后膜结构及突触间隙清晰,突触囊泡多。听觉剥夺组神经元肿胀,细胞器明显减少;突触囊泡数量减少,突触前、后膜结构模糊不清,突触间隙融合。
结论:听觉剥夺幼鼠学习记忆能力下降,并与听皮质神经元及突触超微结构改变密切相关。 相似文献
6.
In recent years, it has been pointed out that epigenetic changes affect learning and memory formation. Particularly, it has been shown that histone acetylation and DNA methylation work in concert to regulate learning and memory formation. We aimed to examine whether acetylation of H2B within the rat hippocampus alters by trainings in the Morris water maze test. Male, 2–3 months old, Sprague Dawley rats were trained in Morris water maze task. Animals were given four trials per day for five consecutive days to locate a hidden platform. On the sixth day, the platform was removed and the animals were swum for 60 s. The effects of sodium butyrate, histone deacetylase inhibitor, were tested on normal and scopolamine-induced memory-impaired rats. The histone deacetylase inhibitor, sodium butyrate, increased histone H2B acetylation in normal rats. Sodium butyrate had no effect on learning and memory performance of normal rats; however, it partially ameliorated learning and memory disruption induced by scopolamine. So, the histone deacetylase inhibitors can be new treatment agent for cognitive disorders. 相似文献
7.
目的:探讨学习记忆训练对全脑缺血大鼠空间学习记忆能力的影响及其胆碱能机制。方法:选用健康雄性SD大鼠90只随机分为假手术组、对照组、训练组。采用改良Pulsinelli’s 4血管闭塞法制作全脑缺血大鼠模型。术后1周以Y型电迷宫训练大鼠,分别在训练7d、14d、21d后应用Y型电迷宫检测比较i组大鼠的空间学习记忆能力的差异。结果:训练21d后,对照组与假手术组和训练组比较,Y型电迷宫全天总反应时间和潜伏期明显延长(P〈0.05),错误反应次数明显增多(P〈0.05)。对照组神经元明显水肿,细胞器明显减少。训练组神经元细胞大、圆,细胞质丰富。对照组CA1区乙酰胆碱转移酶的光密度值明显低于假手术组和训练组(P〈0.05),而训练组和假手术组之间差异无显著性意义(P〉0.05)。结论:学习记忆训练可以改善全脑缺血大鼠的空间学习记忆能力,其机制可能是训练增加了乙酰胆碱转移酶的活性或训练抑制了乙酰胆碱转移酶活性的降低。 相似文献
8.
One of the most amazing aspects of the human brain is its ability to learn information and use it to change behaviour. A key neurotrophin that influences memory function is brain‐derived neurotrophic factor (BDNF). This review briefly discusses the mechanistic role that BDNF may play in facilitating learning and memory. We also describe the role of exercise on this relationship. As discussed herein, BDNF may influence memory via BDNF‐induced alterations in membrane receptor expression and translocation, as well as activating several pathways ( PLC‐y, PI3K, ERK) that act together to facilitate cellular effects that influence synaptic plasticity. Exercise may help to facilitate BDNF expression and its downstream cellular pathways from both direct and indirect mechanisms. 相似文献
9.
目的:研究重复经颅磁刺激(rTMS)对脑梗死大鼠空间记忆功能的影响,并探讨其可能机制。方法:45只大鼠随机分为假手术组、对照组和rTMS组各15只,采用大脑中动脉栓塞再灌注(tMCAO)法制作脑梗死大鼠模型。采用Morris水迷宫评定学习记忆功能变化,通过实时定量聚合酶链式反应(qRT-PCR)观察患侧海马白细胞白介素1β(IL-1β)、诱导型一氧化氮合酶(iNOS)、肿瘤坏死因子(TNF-α)以及梗死灶区(IL-1β)mRNA表达量。结果:与假手术组相比,对照组及rTMS组大鼠逃避潜伏期显著延长(P0.01),而rTMS组较对照组的逃避潜伏期则明显缩短(P0.05)。对照组、rTMS组IL-1βmRNA在患侧海马及皮层的表达量均较假手术组增高(P0.01),rTMS组患侧海马IL-1βmRNA表达较对照组显著增高(P0.01),患侧皮层IL-1βmRNA表达较对照组无明显变化。对照组、rTMS组iNOS、TNF-αmRNA表达量均较假手术组增高(P0.01),rTMS组与对照组无明显差异。结论:rTMS治疗可促进脑梗死后空间学习记忆功能恢复,并可能通过增加患侧海马区IL-1βmRNA表达来实现。 相似文献
10.
Working memory (WM) capacity increases across childhood, peaks in young adulthood, and declines thereafter. Developmental and aging theories suggest that deficient inhibitory control processes in children and older adults may underlie the lower performance relative to younger adults. Recently, oscillatory alpha power (7-13 Hz) of the electroencephalogram (EEG) has been suggested as a neural marker of inhibition processes contributing to WM performance (Sauseng et al., 2009). We examined 20 children (10-13 years), 12 younger adults (20-26 years), and 20 older adults (70-76 years) in a cued change-detection paradigm. Behaviorally, we observed the expected lifespan peak in younger adults. EEG alpha power was generally reduced in older adults compared to children and younger adults. In line with previous research, hemispheric differences in alpha power related to attention and WM processes during the retention interval increased with load in younger adults. In children and older adults, lateralized alpha power increased from low to medium load conditions, but decreased for high load conditions. Furthermore, older adults showed higher inter-trial phase stability shortly after stimulus onset compared to children and younger adults. Our results show that inhibitory control processes as indexed by local alpha power modulations can be observed in children and older adults but seem to break down when WM load is high. In addition, older adults are more entrained by external stimulation what may increase a need for inhibitory control during later processing. We conclude that differences in inhibitory control processes and information uptake as reflected in amplitude modulations and inter-trial phase stability of alpha rhythms interactively determine WM constraints across the lifespan. 相似文献
12.
目的:探讨手术室短期综合干预对经尿道前列腺电切术(TURP)老年患者焦虑及术中配合的影响.方法:将160例行TURP老年患者随机分为对照组和实验组各80例,对照组实施常规护理,实验组给予心理干预、行为干预、提醒告知等手术室短期综合干预,干预前后运用焦虑自评量表(SAS)对两组进行评估,记录操作配合(静脉置管、硬膜外置管)一次成功率、术中不适(体位不适、恶心、呕吐、胸闷、呼吸困难)的情况.结果:两组入手术室后焦虑评分比较差异无统计学意义(P>0.05),干预后比较差异有统计学意义(P<0.05);实验组静脉置管一次成功率高于对照组(P<0.01),体位不适发生率低于对照组(P<0.05);两组硬膜外置管一次成功率及恶心、呕吐、胸闷、呼吸困难发生率比较差异无统计学意义(P>0.05).结论:手术室短期综合干预能减轻患者焦虑程度,使静脉通路建立与麻醉穿刺操作更顺利,术中经过更平稳,为患者术后恢复打下良好基础. 相似文献
13.
目的 :探讨睡眠呼吸暂停综合征 (SAS)病人治疗前后记忆功能和情绪障碍的变化。方法 :SAS25例 ,单纯鼾症12例 ,以标准的记忆和情绪测试量表评分。SAS患者中12例接受持续正压气道通气 (CPAP)治疗 ,治疗后复查评分。结果 :SAS组记忆功能评分显著低于对照组 ,25例SAS中12例以抑郁和焦虑为主的情绪变化 ,12例SAS经CPAP治疗后评分明显改善。结论 :SAS病人有记忆功能的损害和情绪变化 ,并与低氧血症和睡眠结构有关 ,CPAP治疗能明显改善。 相似文献
14.
This study examined evidence for the role of selective memory for stressful events in women with headache. Previous studies have reported that on retrospective measures of stress, those with tension-type headache report more stressful events and rate the events as more stressful than did headache-free controls. However, when ratings are made concurrently, participants with headache and controls did not differ in their ratings of equivalent stressors presented in the laboratory. One theory for why differences are found in stress ratings made retrospectively, but not concurrently, is that selective memory biases recollection of past events in patients with headache. This study compared self-report ratings of stressful events and their perceived impact made either concurrently or retrospectively to determine if selective memory might explain the discrepancies found in earlier studies. Participants included 20 patients with tension-type headache and 22 headache-free controls. Participants were compared on hourly, daily, and weekly measures of stressors and their perceived impact via hourly and nightly visual analog scale ratings, the Daily Stress Inventory, and the Weekly Stress Inventory. If support was to be offered to the hypothesis that selective memory biases the retrospective memory of patients with headache, then an interaction between group assignment (ie, headache versus control group) and time of rating would be expected. No such interaction occurred. Results from the study suggest that all participants have a tendency to overestimate stress on retrospective measures, but that patients with headache do not do so at a significantly different rate than do headache-free controls. The alternative hypothesis that patients with headache tend to appraise everyday events as more stressful is supported. 相似文献
15.
目的探讨阿立哌唑与氟哌啶醇对首发精神分裂症智力和记忆力的影响。方法对60例首发精神分裂症患者随机分为阿立哌唑组30例和氟哌啶醇组30例,系统治疗8周。用阳性和阴性症状量表(PANSS)、韦氏成人智力量表(WAIS-RC)、韦氏记忆量表(WMS)进行评估。结果治疗后,患者PANSS总分明显下降,但两组间无显著性差异(P〉0.05),阿立哌唑组与氟哌啶醇组治疗前后WAIS-RC也无显著性差异(P〉0.05)。阿立哌唑组WMS的100→1、积累、图片、再生、再认、触觉、理解、记忆商(MQ)治疗前后有显著改善(P〈0.05~0.01),MQ的平均增值为18.46;氟哌啶醇组MQ增值为11.15,且有较多项目与治疗前无显著性差异,两组治疗前后各项目增值比较以阿立哌唑组显著。结论阿立哌唑对首发精神分裂症记忆力的影响明显好于氟哌啶醇。 相似文献
16.
目的 探究甲状旁腺激素(1-34)(PTH1-34)对大鼠下颌骨骨折愈合的短期和长期影响。方法 选择60只雄性SD大鼠构建下颌骨骨折模型,并根据随机数字表法分为5组:阴性对照组、地塞米松组、PTH1-34低剂量组、PTH1-34中剂量组和PTH1-34高剂量组,每组各12只。阴性对照组肌内注射等剂量0.9%氯化钠溶液,地塞米松组肌内注射1 mg/kg地塞米松,3个PTH1-34剂量组分别肌内注射15、30和60μg/kg,共连续治疗28 d。分析各组第1、2、3、4周骨折愈合处平均骨密度值、骨折愈合平均灰度值、骨小梁面积百分比和骨小梁厚度、骨痂形成评分、骨痂区骨保护素(OPG)水平以及血清骨形态发生蛋白(BMP-7)、转化生长因子β1(TGF-β1)和碱性成纤维生长因子(b FGF)浓度。结果随着时间的延长,3个PTH1-34剂量组不同时间段骨折愈合处平均骨密度值、骨折愈合平均灰度值、骨小梁面积百分比和骨小梁厚度、骨痂形成评分、骨痂区OPG水平以及血清BMP-7、TGF-β1及b FGF浓度均显著高于阴性对照组和地塞米松组,差异均有统计学意义(P <0.05),且中剂量PTH1-... 相似文献
17.
目的:观察植物性雌激素三羟异黄酮(GST)对脑缺血大鼠学习记忆的影响。方法:雌性大鼠,行双侧卵巢切除手术后,皮下注射三羟异黄酮治疗,10天后结扎双侧颈总动脉,制备脑缺血动物模型。2个月后,用水迷宫法测定大鼠学习记忆能力的改变,并取海马组织作超薄切片电镜分析。结果:①水迷宫测试结果:GST组与去卯巢对照组比较,游完全程的时间明显缩短,错误反应次数明显减少。②形态学观察:去卵巢对照组海马神经元超微结构有明显损害,而GST组能明显改善海马神经元的损伤。结论:GST通过对脑缺血动物脑神经元保护作用,提高卯巢去势大鼠学习记忆的能力。 相似文献
18.
ObjectiveThis study investigated the effects of three auditory interventions; white noise, recorded mother's voice, and MiniMuffs, applied during a heel lance on pain and comfort in premature infants in the neonatal intensive care units. Design and methodsThis experimental, parallel, randomised controlled research was conducted in a state hospital tertiary-level neonatal intensive care unit. The sample comprised sixty-four premature infants with gestational ages of 31–36 weeks. The infants were randomly assigned to four groups: i) white noise, ii) recorded mother’s voice, iii) MiniMuffs, and iv) control. Pain and comfort of newborns were evaluated according to the Neonatal Infant Pain Scale (NIPS) and the COMFORTneo scale. Oxygen saturation, heart rate, and crying time were also measured. ResultsThe mean of oxygen saturation levels in the white noise, recorded mother's voice, and MiniMuffs group were higher than the control group. The heart rate, crying time, mean NIPS score, COMFORTneo score of the premature neonates in the white noise, recorded mother’s voice, and MiniMuffs groups were significantly lower than the control group (p < .001). ConclusionAuditory interventions used during heel lance reduce the pain and increase the comfort of the premature infants. White noise is extremely effective in preventing infants’s pain. 相似文献
19.
目的 研究尼莫通对缺氧缺血性脑损伤(HI)后大鼠学习和记忆能力的影响,并探讨其作用机理.方法 7日龄大鼠行右侧颈总动脉接扎后吸入8%氧气2 h建立HI模型.随机取13只予尼莫通腹腔注射,每日1次,共5天;至80 d左右行Y迷宫测试,然后用胶质纤维酸性蛋白(GFAP)免疫组化染色标记星形胶质细胞.结果 HI组学习记忆能力明显低于正常对照组(P〈0.01),尼莫通可提高学习能力,但对记忆无明显作用.HI组海马结构辐射层GFAP阳性细胞数密度高于对照组和治疗组(P〈0.05),其他各层差异不显著.结论 缺氧缺血性脑损伤可致大鼠学习记忆障碍,可能与缺氧缺血后海马结构中胶质细胞改变导致神经元微环境调节能力减退有关,尼莫通对脑缺氧缺血有一定的改善作用. 相似文献
20.
目的 探究不同放疗剂量对局部晚期肺癌患者近远期疗效、血清肿瘤标志物水平与不良反应发生率的影响.方法 前瞻性选取2014年1月至2017年11月南通市肿瘤医院收治的接受放疗的局部晚期肺癌患者60例.根据随机数字表法分为高剂量组(n=31)和低剂量组(n=29),高剂量给予等效生物剂量为76~86 Gy,低剂量为60~66... 相似文献
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