Is the heart preadapted to hypoxia? Evidence from fractal dynamics of heartbeat interval fluctuations at high altitude (5,050 m)

The dynamics of heartbeat interval time series over large time scales were studied by a modifed random walk analysis introduced recently asDetrended Fluctuation Analysis. In this analysis, the intrinsic fractal long-range power-law correlation properties of beat-to-beat fluctuations generated by the dynamical system (i.e., cardiac rhythm generator), after decomposition from extrinsic uncorrelated sources, can be quantified by the scaling exponent (α) which, in healthy subjects, for time scales of ∼10⁴ beats is ∼1.0. The effects of chronic hypoxia were determined from serial heartbeat interval time series of digitized twenty-four-hour ambulatory ECGs recorded in nine healthy subjects (mean age thirty-four years old) at sea level and during a sojourn at 5,050 m for thirty-four days (Ev-K2-CNR Pyramid Laboratory, Sagarmatha National Park, Nepal). The group averaged α exponent (±SD) was 0.99±0.04 (range 0.93–1.04). Longitudinal assessment of α in individual subjects did not reveal any effect of exposure to chronic high altitude hypoxia. The finding of α∼1 indicating scale-invariant long-range power-law correlations (1/f noise) of heartbeat fluctuations would reflect a genuinely self-similar fractal process that typically generates fluctuations on a wide range of time scales. Lack of a characteristic time scale along with the absence of any effect from exposure to chronic hypoxia on scaling properties suggests that the neuroautonomic cardiac control system is preadapted to hypoxia which helps prevent excessive mode-locking (error tolerance) that would restrict its functional responsiveness (plasticity) to hypoxic or other physiological stimuli. Editorial Note: A philosopher is, by definition, a lover of wisdom. In the following article, Dr. Dimitrov, as a philosopher, examines the principles that underlie being and thinking as performed by the structures of the brain. He reports his thoughts in a “virtual context.” Virtual, a word enjoying great popularity today, is derived from the Latin word for man; it describes manliness and implies apparent, but not actual, power. In his analysis of how information is dealt with by the human being, the author uses theoretical physics and mathematics that may seem arcane to some readers. A major aspect of his thesis declares that the effective performance of information systems relies not on the structures involved, but on the way they interact.     

Feedback functions for variable-interval reinforcement

On a given variable-interval schedule, the average obtained rate of reinforcement depends on the average rate of responding. An expression for this feedback effect is derived from the assumptions that free-operant responding occurs in bursts with a constant tempo, alternating with periods of engagement in other activities; that the durations of bursts and other activities are exponentially distributed; and that the rates of initiating and terminating bursts are inversely related. The expression provides a satisfactory account of the data of three experiments.     

Coronavirus: does its activation of archetypes of evil cause added psychological suffering?

Fear and grief caused by the pandemic have produced a powerful unconscious narrative in the collective psyche that the coronavirus is driven by an innately evil, and possibly divine, force. The resulting archetypal dimension of fear causes an extra layer of psychological suffering in individuals. This paper discusses how and why this narrative was created and why it is so compelling by looking at 1) the myth-making nature of the human psyche, 2) the psychodynamics of fear that drive the narrative, 3) the properties of the coronavirus and the pandemic that activate negative poles of some archetypes, in particular, archetypes of evil, and 4) asking how analytical psychology can help ease psychological suffering caused by these negative narratives, where one possibility is to invoke the transcendent function. The author’s personal experiences as both biochemist and analytical psychologist elucidate how the transcendent function can promote healing.     

Anterior cingulate cortex and cognitive control: Neuropsychological and electrophysiological findings in two patients with lesions to dorsomedial prefrontal cortex

Whereas neuroimaging studies of healthy subjects have demonstrated an association between the anterior cingulate cortex (ACC) and cognitive control functions, including response monitoring and error detection, lesion studies are sparse and have produced mixed results. Due to largely normal behavioral test results in two patients with medial prefrontal lesions, a hypothesis has been advanced claiming that the ACC is not involved in cognitive operations. In the current study, two comparably rare patients with unilateral lesions to dorsal medial prefrontal cortex (MPFC) encompassing the ACC were assessed with neuropsychological tests as well as Event-Related Potentials in two experimental paradigms known to engage prefrontal cortex (PFC). These included an auditory Novelty Oddball task and a visual Stop-signal task. Both patients performed normally on the Stroop test but showed reduced performance on tests of learning and memory. Moreover, altered attentional control was reflected in a diminished Novelty P3, whereas the posterior P3b to target stimuli was present in both patients. The error-related negativity, which has been hypothesized to be generated in the ACC, was present in both patients, but alterations of inhibitory behavior were observed. Although interpretative caution is generally called for in single case studies, and the fact that the lesions extended outside the ACC, the findings nevertheless suggest a role for MPFC in cognitive control that is not restricted to error monitoring.     

DISCUSSION OF THE CONCEPTUAL BASIS OF BIOSEMIOTICS

Kalevi Kull and colleagues recently proposed eight theses as a conceptual basis for the field of biosemiotics. We use these theses as a framework for discussing important current areas of debate in biosemiotics with particular reference to the articles collected in this issue of Zygon.     

A Neuropsychological Investigation of Perfectionism

Perfectionism entails a burdensome preoccupation with one’s self-evaluation in the context of performance outcomes. Although perfectionism has been subject to extensive research, scant literature on its effect on cognitive functioning is available, let alone in nonclinical populations. The aim of the present study is to utilize a comprehensive neuropsychological battery to assess cognitive functions among college students with high and low levels of perfectionism. Participants were 98 college students who were screened for clinical status, completed a neuropsychological battery, and assessed for perfectionism and related symptomatology. Results revealed that the high negative perfectionism group had significantly higher levels of depression and stress compared to the low negative perfectionism group. However, no group differences were found across neuropsychological outcomes. Gradient differences on clinical outcome measures were found when three groups characterized by high adaptive, high maladaptive, and mixed perfectionism were compared. However, no differences were found on neuropsychological tests. These findings suggest that higher levels of negative perfectionism are associated with significant psychopathological burden, but with intact neuropsychological test performance. These results are important, particularly in the context of the need to identify and treat students struggling with high levels of perfectionism and related psychopathological burden, which can be overlooked given that they present with intact cognitive and academic performance.     

眼跳的研究范式及其主要认知功能

眼跳运动系统为研究者探索行为的认知控制机制提供了有力工具。已有研究发现,很多认知过程会影响不同类型眼跳任务中的眼跳参数。在系统梳理已有研究的基础上,从以下4个方面系统阐述和评价了眼跳运动的研究范式和主要认知功能：（1）视觉导向眼跳的研究范式和变式及其认知功能,包括空白/重叠效应、分心物效应、提示效应、学习效应等;（2）预测性眼跳的研究范式和认知控制,涉及神经生物钟理论、视空间工作记忆、指导语等;（3）记忆导向眼跳的研究范式和变式及其认知控制,包括分心物效应、年龄效应、视空间工作记忆的抑制效应、注意等;（4）反向眼跳的研究范式和变式及其认知控制,包括反向眼跳抑制、眼跳决策信号竞争整合模型、工作记忆容量、注意、错误监控、学习、奖励和年龄效应等。最后,结合已有研究范式对未来眼跳研究的趋势和需解决的问题进行了展望。     

创造性思维的脑机制

创造性思维是创造性的核心。近年来,脑电和脑成像技术的发展为研究创造性思维的神经基础提供了有力的技术支持,对创造性思维的脑机制研究取得了较大进展。创造性思维的脑机制研究主要包括顿悟的脑机制、发散性思维的脑机制、远距离联想的脑机制、言语创造性和图画创造性的对比的脑机制研究。研究结果显示创造性思维需要多个脑区的参与,因不同的认知任务其关键脑区而有所不同。对创造性思维的脑机制研究进行了总结,对这些研究可能存在创造性思维究竟应该定义为“领域一般的”还是“领域特殊的”的解释进行了讨论,并指出了研究中可能存在的基线任务设置问题和未来研究中需要在研究手段、研究设计、研究领域等方面加以改进的建议     

创伤后应激障碍的认知功能缺陷与执行控制 ——5·12震后创伤恢复的认知基础

创伤后应激障碍（Posttraumatic stress disorder,PTSD）患者通常伴随着明显的认知功能损伤。例如,存在注意保持缺陷,对与创伤相关的信息表现出更多的注意偏向和应激反应;并存在对创伤信息的记忆偏向,在陈述性记忆和自传体记忆中表现出一定的缺陷。近年的研究积累了更多类似的证据,表明PTSD的认知损伤可能与执行功能缺陷密切相关,但这一解释是否正确仍有待进一步的研究。本综述对5·12汶川大地震后长期的心理干预工作,尤其是认知功能损伤人群的筛选、恢复以及相关科学研究具有现实意义和理论启发作用     

年龄和性别对气味和词汇的语义识别的不同影响

本研究采用基于人口学特征的大规模取样, 通过线索气味识别测验和词汇测验考察了年龄和性别因素对嗅觉功能和语义知识的影响。1497位健康的成人(35岁~95岁)参与了气味识别和词汇熟练性测验。结果表明年龄对两项测验的成绩都有显著的负面影响, 尽管嗅觉测验的年龄效应更大。女性比男性识别出更多的气味且这种效应与年龄无关, 这进一步证实了先前的观察。本文详细讨论了这些发现的意义。