Long-latency auditory evoked potentials with verbal and nonverbal stimuli

IntroductionLong-latency auditory evoked potentials represent the cortical activity related to attention, memory, and auditory discrimination skills. Acoustic signal processing occurs differently between verbal and nonverbal stimuli, influencing the latency and amplitude patterns.ObjectiveTo describe the latencies of the cortical potentials P1, N1, P2, N2, and P3, as well as P3 amplitude, with different speech stimuli and tone bursts, and to classify them in the presence and absence of these data.MethodsA total of 30 subjects with normal hearing were assessed, aged 18–32 years old, matched by gender. Nonverbal stimuli were used (tone burst; 1000 Hz – frequent and 4000 Hz – rare); and verbal (/ba/ – frequent; /ga/, /da/, and /di/ – rare).ResultsConsidering the component N2 for tone burst, the lowest latency found was 217.45 ms for the BA/DI stimulus; the highest latency found was 256.5 ms. For the P3 component, the shortest latency with tone burst stimuli was 298.7 with BA/GA stimuli, the highest, was 340 ms. For the P3 amplitude, there was no statistically significant difference among the different stimuli. For latencies of components P1, N1, P2, N2, P3, there were no statistical differences among them, regardless of the stimuli used.ConclusionThere was a difference in the latency of potentials N2 and P3 among the stimuli employed but no difference was observed for the P3 amplitude.     

The relationship of paroxysmal ventricular tachycardia complicating the acute phase and ventricular arrhythmia during the late hospital phase of myocardial infarction to long-term survival

The long-term prognosis of paroxysmal ventricular tachycardia (PVT) complicating acute myocardial infarction remains unevaluated. Significant ventricular arrhythmia in the patient after infarction is said to carry a poor prognosis with regard to survival. To evaluate these two important aspects of myocardial infarction in man, 56 patients with documented myocardial infarction had Holter monitoring performed during the initial 24 hours and prior to hospital discharge. In 38 of the 45 survivors, Holter monitoring was repeated an average of 19 months after infarction. There were eight cardiac deaths during follow-up. Data analysis revealed that of 18 patients with PVT during the acute phase, one died during follow-up and 17 survived long-term. Even though the incidence of complex PVCs prior to hospital discharge and at long-term follow-up was higher in patients with PVT during the acute phase than in those without PVT, survival appeared unaffected. Thus, PVT during the acute phase of myocardial infarction and complex PVCs at the time of hospital discharge are not incompatible with long-term survival.     

P300, Disinhibited Personality, and Early-Onset Alcohol Problems

BACKGROUND: Recent research suggests that a reduced P300 amplitude of the event-related potential is associated with a vulnerability to alcoholism. This study tested the hypothesis that reductions in the P300 amplitude would be associated with specific dimensions of disinhibited personality (social deviance proneness and impulsivity) and that these personality traits would mediate the association between P300 and alcohol problems in a young adult sample that varied widely in disinhibitory traits. METHODS: Alcohol problems, personality (impulsivity, social deviance, harm avoidance, and excitement seeking), and event-related potentials were measured in a sample of 190 subjects (87 men, 103 women) with a mean age of 20.7 +/- 1.9 years. RESULTS: Social deviance, impulsivity, and alcohol problems were associated with reductions in the P300, but only in male subjects. A structural model suggested that social deviance, impulsivity, and alcohol problems were all strongly related to P300 amplitude at Fz. Further analyses indicated that for male subjects, social deviance mediated the association between P300 at Fz and alcohol problems as well as the association between impulsivity and alcohol problems. CONCLUSIONS: This study suggests that reduced P300s are strongly associated with a general tendency toward antisocial, defiant, and impulsive traits, which might, in turn, increase the risk for alcohol abuse. The lack of an association between reduced P300s and personality or alcohol problems in women was unexpected and deserves further study.     

不同剂量拉莫三嗪治疗老年癫痫的比较研究

目的 探讨不同剂量拉莫三嗪治疗老年癫痫患者的临床疗效。方法 选择2014年7月—2018年2月洛阳市第三人民医院神经内科诊治的老年癫痫患者88例作为研究对象,根据拉莫三嗪使用剂量分为对照组（40例）和观察组（48例）。对照组患者给予大剂量拉莫三嗪片治疗,拉莫三嗪起始剂量25 mg/d,2周后为50 mg/d,第5周以后为目标剂量100 mg/d,维持100 mg/d治疗观察至第8周。观察组患者给予小剂量拉莫三嗪片治疗,起始剂量25 mg/d,2周后为50 mg/d,第5周以后为目标剂量50 mg/d,维持50 mg/d治疗观察至第8周。观察两组患者的临床疗效,同时比较两组患者蒙特利尔认知评估量表（MoCA）评分、P300潜伏期、波幅和不良反应情况。结果 治疗后,对照组和观察组总有效率分别为97.5%、97.9%,两组对比差异无统计学意义。治疗后,两组患者的MoCA评分均显著高于治疗前,同组治疗前后比较差异具有统计学意义（P<0.05）;且观察组治疗后的MoCA评分显著高于对照组,两组比较差异具有统计学意义（P<0.05）。治疗后,观察组的P300潜伏期显著降低,波幅明显升高,同组治疗前后比较差异具有统计学意义（P<0.05）;且观察组治疗后P300潜伏期及波幅显著优于对照组,两组比较差异具有统计学意义（P<0.05）。观察组治疗期间的不良反应发生率为6.3%,显著低于对照组的32.5%,两组比较差异具有统计学意义（P<0.05）。结论 相对于大剂量,小剂量拉莫三嗪治疗老年癫痫患者能达到很好的疗效,能减少不良反应的发生,改善患者的神经电生理功能与认知功能。     

Differentiating event‐related potential components sensitive to emotion in middle childhood: Evidence from temporal–spatial PCA

Event‐related potentials (ERPs) may be particularly useful for examining emotional processing across development. Though a number of ERP components are sensitive to emotional content in adults, previous studies have yet to systematically examine the components sensitive to emotion in children. The current study used temporal–spatial principal components analysis (PCA) to identify ERP components in response to complex emotional images in 9‐year‐old children. Three components were modulated by emotional content and were similar to those previously observed in adults, including: the early posterior negativity, the P300, and a sustained relative positivity similar to the late positive potential (LPP). Compared to those previously observed in adults, the components sensitive to emotion in children were maximal over more occipital regions and the LPP component appeared to be less protracted in time, perhaps indicative of less elaborative processing of emotional stimuli. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 539–550, 2013     

Cortical potentials in an auditory oddball task reflect individual differences in working memory capacity

This study determined whether auditory cortical responses associated with mechanisms of attention vary with individual differences in working memory capacity (WMC) and perceptual load. The operation span test defined subjects with low versus high WMC, who then discriminated target/nontarget tones while EEG was recorded. Infrequent white noise distracters were presented at midline or ±90° locations, and perceptual load was manipulated by varying nontarget frequency. Amplitude of the N100 to distracters was negatively correlated with WMC. Relative to targets, only high WMC subjects showed attenuated N100 amplitudes to nontargets. In the higher WMC group, increased perceptual load was associated with decreased P3a amplitudes to distracters and longer‐lasting negative slow wave to nontargets. Results show that auditory cortical processing is associated with multiple facets of attention related to WMC and possibly higher‐level cognition.