Alpha synchronization as a brain model for unconscious defense: An overview of the work of Howard Shevrin and his team

Howard Shevrin and his team have developed a stringent subliminal priming methodology, which experimentally approximates a situation of an internal, mental triggering of unconscious defense. Through a series of four studies they thus are able to bring evidence for this type of unconscious defense. With event‐related potentials, three clinical studies show how synchronization of a specific brain wave, the alpha wave, known for its inhibitory function, is also induced by subliminally presented conflictual subject‐specific stimuli. Therefore, alpha synchronization could serve as the brain mechanism of unconscious defense. The results only make sense if we suppose the existence of a dynamic unconscious, which has inherited childhood conflicts, and with privileged connections to neurotic symptom characteristics. Moreover, by showing that the unconscious conflict phrases, inferred by clinicians from clinical interviews, have a similar brain behavior, Shevrin and his team provide evidence that these inferences are not simply clinician‐dependent subjective interpretations but also imply some form of independent mental reality. Finally, interpretation of the results has led us to propose two distinct physiological mechanisms for defense: one, unconscious defense, by alpha synchronization in connection with the drive derivatives, and another, repression, based on the indications of reality in connection with the ego.     

Intelligence and neural efficiency: Measures of brain activation versus measures of functional connectivity in the brain

The neural efficiency hypothesis of intelligence suggests a more efficient use of the cortex (or even the brain) in brighter as compared to less intelligent individuals. This has been shown in a series of studies employing different neurophysiological measurement methods and a broad range of different cognitive task demands. However, most of the studies dealing with the brain–IQ relationship used parameters of absolute or relative brain activation such as the event-related (de-)synchronization of EEG alpha activity, allowing for interpretations in terms of more or less brain activation when individuals are confronted with cognitively demanding tasks. In order to investigate the neural efficiency hypothesis more thoroughly, we also used measures that inform us about functional connectivity between different brain areas (or functional coupling, respectively) when engaged in cognitive task performance. Analyses reveal evidence that higher intelligence is associated with a lower brain activation (or a lower ERD, respectively) and a stronger phase locking between short-distant regions of the frontal cortex.     

Evidence for a distributed hierarchy of action representation in the brain

Complex human behavior is organized around temporally distal outcomes. Behavioral studies based on tasks such as normal prehension, multi-step object use and imitation establish the existence of relative hierarchies of motor control. The retrieval errors in apraxia also support the notion of a hierarchical model for representing action in the brain. In this review, three functional brain imaging studies of action observation using the method of repetition suppression are used to identify a putative neural architecture that supports action understanding at the level of kinematics, object centered goals and ultimately, motor outcomes. These results, based on observation, may match a similar functional-anatomic hierarchy for action planning and execution. If this is true, then the findings support a functional-anatomic model that is distributed across a set of interconnected brain areas that are differentially recruited for different aspects of goal-oriented behavior, rather than a homogeneous mirror neuron system for organizing and understanding all behavior.     

Cognitive functions, bodily sensibility and the brain

Body representations traverse the whole of the brain. They provide vital sources of information for every facet of an animal’s behavior, and such direct neural connectivity of visceral input throughout the nervous system demonstrates just how strongly cognitive systems are linked to bodily representations. At each level of the neural axis there are visceral appraisal systems that are integral in the organization of action. Cognition is not one side of a divide and viscera the other, with action merely a reflexive outcome. There is no divide between cognition and bodily functions once the brain is involved. Cognitive mechanisms that permeate neural function are a cardinal piece of biological function and adaptation.     

人格特质及脑功能连接对社交网络的影响

采用网络分析的方法, 本研究从个体受欢迎程度和个体间亲密程度两方面探究了人格特质对社交网络的影响, 并在此基础上进一步探究了个体间大脑静息态功能连接相似性和社交网络的关系。结果发现：(1)高尽责性的个体在需要“值得信任”特质的社交网络中更受欢迎, 高宜人性的个体在需要“共享时光”的社交网络中更受欢迎; (2)在需要“相同兴趣”特质的社交网络中, 个体间人格相似性和社会距离呈显著负相关关系; (3)同样在需要“相同兴趣”特质的社交网络中, 个体间部分功能连接相似性与社会距离呈显著负相关关系, 这些功能连接主要集中在额顶控制网络以及背侧注意网络; 同时, 部分节点功能连接相似性与社会距离呈显著正相关关系, 这些功能连接主要集中在默认网络。研究结果揭示了人格特质对不同社交网络结构的影响, 以及个体间人格特质相似性和静息态脑网络相似性与社会距离的关系。本研究对理解社交网络的结构, 形成规律以及其中的信息传播规律有着重要启示意义。     

The role of the extrapersonal brain systems in religious activity

The neuropsychology of religious activity in normal and selected clinical populations is reviewed. Religious activity includes beliefs, experiences, and practice. Neuropsychological and functional imaging findings, many of which have derived from studies of experienced meditators, point to a ventral cortical axis for religious behavior, involving primarily the ventromedial temporal and frontal regions. Neuropharmacological studies generally point to dopaminergic activation as the leading neurochemical feature associated with religious activity. The ventral dopaminergic pathways involved in religious behavior most closely align with the action-extrapersonal system in the model of 3-D perceptual-motor interactions proposed by . These pathways are biased toward distant (especially upper) space and also mediate related extrapersonally dominated brain functions such as dreaming and hallucinations. Hyperreligiosity is a major feature of mania, obsessive-compulsive disorder, schizophrenia, temporal-lobe epilepsy and related disorders, in which the ventromedial dopaminergic systems are highly activated and exaggerated attentional or goal-directed behavior toward extrapersonal space occurs. The evolution of religion is linked to an expansion of dopaminergic systems in humans, brought about by changes in diet and other physiological influences.     

Neural coding of formant-exaggerated speech in the infant brain

Speech scientists have long proposed that formant exaggeration in infant-directed speech plays an important role in language acquisition. This event-related potential (ERP) study investigated neural coding of formant-exaggerated speech in 6-12-month-old infants. Two synthetic /i/ vowels were presented in alternating blocks to test the effects of formant exaggeration. ERP waveform analysis showed significantly enhanced N250 for formant exaggeration, which was more prominent in the right hemisphere than the left. Time-frequency analysis indicated increased neural synchronization for processing formant-exaggerated speech in the delta band at frontal-central-parietal electrode sites as well as in the theta band at frontal-central sites. Minimum norm estimates further revealed a bilateral temporal-parietal-frontal neural network in the infant brain sensitive to formant exaggeration. Collectively, these results provide the first evidence that formant expansion in infant-directed speech enhances neural activities for phonetic encoding and language learning.     

Survival with an asymmetrical brain: advantages and disadvantages of cerebral lateralization

Recent evidence in natural and semi-natural settings has revealed a variety of left-right perceptual asymmetries among vertebrates. These include preferential use of the left or right visual hemifield during activities such as searching for food, agonistic responses, or escape from predators in animals as different as fish, amphibians, reptiles, birds, and mammals. There are obvious disadvantages in showing such directional asymmetries because relevant stimuli may be located to the animal's left or right at random; there is no a priori association between the meaning of a stimulus (e.g., its being a predator or a food item) and its being located to the animal's left or right. Moreover, other organisms (e.g., predators) could exploit the predictability of behavior that arises from population-level lateral biases. It might be argued that lateralization of function enhances cognitive capacity and efficiency of the brain, thus counteracting the ecological disadvantages of lateral biases in behavior. However, such an increase in brain efficiency could be obtained by each individual being lateralized without any need to align the direction of the asymmetry in the majority of the individuals of the population. Here we argue that the alignment of the direction of behavioral asymmetries at the population level arises as an "evolutionarily stable strategy" under "social" pressures occurring when individually asymmetrical organisms must coordinate their behavior with the behavior of other asymmetrical organisms of the same or different species.     

The exploitation of regularities in the environment by the brain

Statistical regularities of the environment are important for learning, memory, intelligence, inductive inference, and in fact, for any area of cognitive science where an information-processing brain promotes survival by exploiting them. This has been recognised by many of those interested in cognitive function, starting with Helmholtz, Mach, and Pearson, and continuing through Craik, Tolman, Attneave, and Brunswik. In the current era, many of us have begun to show how neural mechanisms exploit the regular statistical properties of natural images. Shepard proposed that the apparent trajectory of an object when seen successively at two positions results from internalising the rules of kinematic geometry, and although kinematic geometry is not statistical in nature, this is clearly a related idea. Here it is argued that Shepard's term, "internalisation," is insufficient because it is also necessary to derive an advantage from the process. Having mechanisms selectively sensitive to the spatio-temporal patterns of excitation commonly experienced when viewing moving objects would facilitate the detection, interpolation, and extrapolation of such motions, and might explain the twisting motions that are experienced. Although Shepard's explanation in terms of Chasles' rule seems doubtful, his theory and experiments illustrate that local twisting motions are needed for the analysis of moving objects and provoke thoughts about how they might be detected.     

A mathematical model of the interaction between bottom-up and top-down attention controllers in response to a target and a distractor in human beings

Top-down and bottom-up attention are two systems that allocate our neuronal resources for processing different stimuli. To do the tasks efficiently, it is required to suppress irrelevant information. In the presence of both target and distractor, synchronization or desynchronization between the activities of neuronal responses has been observed in different regions of the brain. In the current study, we have proposed a mathematical model to show how the interaction between top-down and bottom-up attention, through synchronization and desynchronization, can lead to the suppression of distractor effects in human beings. The model structure was inspired by the results of neurological studies. The model consists of several oscillating units as a representation of top-down and bottom-up neuronal processing resources. These units communicate with each other through synchronization and desynchronization procedures.Results of simulations showed that how the mutual interaction between top-down and bottom-up units, which was done using synchronization and desynchronization procedures, led to the selective or divided attention between the target and distractor. It was shown that the activity of responsive units to the distractor could be suppressed by a desynchronous signal transmitted from the top-down attention unit. This model suggests a justification for brain waves synchronization or desynchronization during attentionally demand tasks. The proposed model also provides a tool to investigate the effect of some influencing factors such as the distractor intensity or similarity between the distractor and the target on the function of top-down and bottom-up systems.     

Categories in the pigeon brain: A reverse engineering approach

Pigeons are well known for their visual capabilities as well as their ability to categorize visual stimuli at both the basic and superordinate level. We adopt a reverse engineering approach to study categorization learning: Instead of training pigeons on predefined categories, we simply present stimuli and analyze neural output in search of categorical clustering on a solely neural level. We presented artificial stimuli, pictorial and grating stimuli, to pigeons without the need of any differential behavioral responding while recording from the nidopallium frontolaterale (NFL), a higher visual area in the avian brain. The pictorial stimuli differed in color and shape; the gratings differed in spatial frequency and amplitude. We computed representational dissimilarity matrices to reveal categorical clustering based on both neural data and pecking behavior. Based on neural output of the NFL, pictorial and grating stimuli were differentially represented in the brain. Pecking behavior showed a similar pattern, but to a lesser extent. A further subclustering within pictorial stimuli according to color and shape, and within gratings according to frequency and amplitude, was not present. Our study gives proof‐of‐concept that this reverse engineering approach—namely reading out categorical information from neural data—can be quite helpful in understanding the neural underpinnings of categorization learning.     

Personality and the neural efficiency theory

The neural efficiency theory was formulated in the field of intelligence research and it posits that better performers require less brain activity to successfully perform a task of a given difficulty level. Here we suggest that in the field of personality research, the neural efficiency concept could be reformulated so that habitual behavior requires less brain activity. To test this hypothesis, 46 participants were presented with a social interactions task, in which they had to choose one out of three ways of interaction with a virtual ‘person’: ‘attack’, ‘avoid’, or ‘make friends’, while EEG was recorded simultaneously. Personality was assessed using the Eysenck Personality Profiler. Extraverts made more friendly choices and these choices were accompanied by smaller event-related theta synchronization in the left prefrontal cortex. Neuroticism did not show significant behavioral effects, but in high neuroticism scorers, the choice of avoidance was accompanied by smaller theta synchronization in the right prefrontal cortex. Psychoticism was positively associated with the number of aggressive choices and in high psychoticism scorers, these choices were accompanied by smaller theta synchronization in the left precentral cortex. These results are consistent with the extension of the neural efficiency concept for personality.     

Dimensional emotions are represented by distinct topographical brain networks

The ability to recognize others’ facial emotions has become increasingly important after the COVID-19 pandemic, which causes stressful situations in emotion regulation. Considering the importance of emotion in maintaining a social life, emotion knowledge to perceive and label emotions of oneself and others requires an understanding of affective dimensions, such as emotional valence and emotional arousal. However, limited information is available about whether the behavioral representation of affective dimensions is similar to their neural representation. To explore the relationship between the brain and behavior in the representational geometries of affective dimensions, we constructed a behavioral paradigm in which emotional faces were categorized into geometric spaces along the valence, arousal, and valence and arousal dimensions. Moreover, we compared such representations to neural representations of the faces acquired by functional magnetic resonance imaging. We found that affective dimensions were similarly represented in the behavior and brain. Specifically, behavioral and neural representations of valence were less similar to those of arousal. We also found that valence was represented in the dorsolateral prefrontal cortex, frontal eye fields, precuneus, and early visual cortex, whereas arousal was represented in the cingulate gyrus, middle frontal gyrus, orbitofrontal cortex, fusiform gyrus, and early visual cortex. In conclusion, the current study suggests that dimensional emotions are similarly represented in the behavior and brain and are presented with differential topographical organizations in the brain.     

Search activity in the context of psychosomatic disturbances,of brain monoamines and REM sleep function

The author discusses a number of controversial aspects of the search activity concept. This concept, based on an analysis of data cited by other researchers and the results of the author’s own investigation, performed together with V. V. Arshavsky, postulates that search activity raises the body’s resistance to stress and experimentally induced pathology whereas renunciation of search forms a nonspecific predisposition to somatic disturbances (e.g., psychosomatic disease). REM sleep is regarded as a specific form of search activity aimed at compensating for the state of renunciation of search in walking. In this paper the author argues that 1) renunciation of search can be accompanied either by anxiety or by depression, 2) REM sleep deprivation on a “small platform” raises the requirement in REM sleep by producing renunciation of search, 3) during search activity brain catecholamine synthesis is stimulated by catabolism whereas a state of renunciation of search upsets this feedback system. The actuation of the brain mechanisms of search in REM sleep necessitates a certain brain catecholamine level. If the brain catecholamine level is very high during waking behavior due to intensive search activity, the REM sleep requirement is low, REM sleep becoming reduced. After a moderate drop in the brain catecholamine level at the initial stage of renunciation of search the requirement in REM sleep rises and this phase grows longer. But at the late stage of renunciation of search the brain catecholamine level drops extremely, REM sleep shrinking in spite of the great appropriate requirement, and 4) the functional insufficiency of REM sleep invites various forms of pathology.     

第二语言学习与脑可塑性

脑可塑性指人脑会因为环境刺激、认知需求和行为经验而产生功能或结构改变。近10年来的单双语者对比和语言训练研究结果表明, 不论儿童、青年或老年人, 第二语言学习和使用都能改变其脑运行模式并带来相应结构变化, 包括灰质(GM)体积和白质(WM)密度增加, 且长期持续的双语经验还能形成认知优势, 帮助抵制由老化导致的负面认知影响。基于脑可塑性概念及其研究证据, 从双语经验与语言训练两方面, 对比分析了长期和短期第二语言学习引起脑功能或结构变化及其内在机制, 并对未来相关研究进行了展望。     

认知年老化与执行衰退假说

在认知年老化领域,执行衰退假说是近年来新兴的一种理论。执行衰退假说在理论上具有很强的吸引力,但在实证研究中却存在很多困难,如执行功能的可分离性问题,执行功能测量的信度和效度问题,以及执行功能与加工速度的关系问题。目前,该领域研究的焦点是：在行为学水平上,控制一般性因素（加工速度）后,执行功能是否仍对认知年老化起重要的中介作用;在神经水平上,执行（额叶）功能随龄的变化情况,以及在认知年老化过程中,额叶在大脑功能重组中扮演的角色。最终实现对认知年老化的理解,需要将认知功能与大脑结构联系起来;既看到广泛存在的共同的基本机制,又不能忽略不同认知结构的选择性变化。     

A behavioral quantal theory of brain function: an alternative to Lashley's continuity theory of mass action

A behavioral quantal theory of brain function is formulated on the basis of a newly discovered step-wise relationship invariably present among the findings of three experiments by Tsai, et al. on the effects of (1) cerebral decortication, (2) cranial x-radiation, as well as (3) insulin, metrazol, and electroconvulsive shocks upon white rats' adaptive behavior during their learning of successive habit reversals and one-trial reversal problems. Confirmatory results from earlier investigators who studied effects of various current strengths of ECS upon learning and retention of various maze habits are also cited in support of the behavioral quantal theory of brain function which is proposed here as a close-up, more refined alternative to Lashley's continuity theory of mass action.     

MAOA基因与环境对反社会行为的交互作用及其可能的脑机制

反社会行为具有重要的遗传学基础。MAOA基因是反社会行为的重要候选基因,该基因与环境对反社会行为具有交互作用,然而其内在作用机制尚不清楚。与情绪管理相关的脑区和神经回路,以及与工作记忆能力相关的脑区和神经回路在其中起重要作用。未来研究可从多基因-环境交互作用、理论模型验证、脑结构与功能的中介作用等方面进一步深化MAOA基因与反社会行为的关系研究。     

Mental models in the brain: On context-dependent neural correlates of mental models

In this paper, the concept of context-dependent realisation of mental models is introduced and discussed. Literature from neuroscience is discussed showing that different types of mental models can use different types of brain areas. Moreover, it is discussed that the same occurs for the formation and adaptation of mental models and the control of these processes. This makes that it is hard to claim that all mental models use the same brain mechanisms and areas. Instead, the notion of context-dependent realisation is proposed here as a better manner to relate neural correlates to mental models. It is shown in some formal detail how this context-dependent realisation approach can be related to well-known perspectives based on bridge principle realisation and interpretation mapping realisation.