scholarly journals Spacetime in the brain: rapid brain network reorganization in visual processing and recovery

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zheng Wu ◽  
Bernhard A. Sabel
Keyword(s):  
Optic Nerve ◽  
Visual Processing ◽  
Stimulus Presentation ◽  
Fundamental Principle ◽  
Human Mind ◽  
Brain Network ◽  
Visual Performance ◽  
Physiological Basis ◽  
Brain Network Reorganization ◽  
Mental Acts

AbstractFunctional connectivity networks (FCN) are the physiological basis of brain synchronization to integrating neural activity. They are not rigid but can reorganize under pathological conditions or during mental or behavioral states. However, because mental acts can be very fast, like the blink of an eye, we now used the visual system as a model to explore rapid FCN reorganization and its functional impact in normal, abnormal and post treatment vision. EEG-recordings were time-locked to visual stimulus presentation; graph analysis of neurophysiological oscillations were used to characterize millisecond FCN dynamics in healthy subjects and in patients with optic nerve damage before and after neuromodulation with alternating currents stimulation and were correlated with visual performance. We showed that rapid and transient FCN synchronization patterns in humans can evolve and dissolve in millisecond speed during visual processing. This rapid FCN reorganization is functionally relevant because disruption and recovery after treatment in optic nerve patients correlated with impaired and recovered visual performance, respectively. Because FCN hub and node interactions can evolve and dissolve in millisecond speed to manage spatial and temporal neural synchronization during visual processing and recovery, we propose “Brain Spacetime” as a fundamental principle of the human mind not only in visual cognition but also in vision restoration.

scholarly journals Bad World: The Negativity Bias in International Politics

2019 ◽  
Vol 43 (3) ◽  
pp. 96-140 ◽  
Author(s):  
Dominic D.P. Johnson ◽  
Dominic Tierney
Keyword(s):  
International Relations ◽  
Fundamental Principle ◽  
Human Mind ◽  
Negative Information ◽  
Theory And Practice ◽  
Negativity Bias ◽  
Positive Information ◽  
Psychological Phenomena ◽  
Wide Range ◽  
New Research

A major puzzle in international relations is why states privilege negative over positive information. States tend to inflate threats, exhibit loss aversion, and learn more from failures than from successes. Rationalist accounts fail to explain this phenomenon, because systematically overweighting bad over good may in fact undermine state interests. New research in psychology, however, offers an explanation. The “negativity bias” has emerged as a fundamental principle of the human mind, in which people's response to positive and negative information is asymmetric. Negative factors have greater effects than positive factors across a wide range of psychological phenomena, including cognition, motivation, emotion, information processing, decision-making, learning, and memory. Put simply, bad is stronger than good. Scholars have long pointed to the role of positive biases, such as overconfidence, in causing war, but negative biases are actually more pervasive and may represent a core explanation for patterns of conflict. Positive and negative dispositions apply in different contexts. People privilege negative information about the external environment and other actors, but positive information about themselves. The coexistence of biases can increase the potential for conflict. Decisionmakers simultaneously exaggerate the severity of threats and exhibit overconfidence about their capacity to deal with them. Overall, the negativity bias is a potent force in human judgment and decisionmaking, with important implications for international relations theory and practice.

Functional brain network reorganization in HIV infection

2021 ◽  
Author(s):  
Silvia Minosse ◽  
Eliseo Picchi ◽  
Francesca Di Giuliano ◽  
Loredana Sarmati ◽  
Elisabetta Teti ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Brain Network ◽  
Functional Brain ◽  
Functional Brain Network ◽  
Brain Network Reorganization

scholarly journals Ecstasy from a physiological point of view

1982 ◽  
Vol 11 ◽  
pp. 74-86 ◽  
Author(s):  
Kaj Björkqvist
Keyword(s):  
Religious Tradition ◽  
Mental States ◽  
Human Mind ◽  
Point Of View ◽  
The Body ◽  
Biological Study ◽  
Physiological Basis ◽  
Slowing Down ◽  
Psychosomatic Diseases ◽  
The Brain

The biological study of man is one of today's most rapidly advancing sciences. There is no reason for not utilizing these methodologies of research and the knowledge already gained when studying ecstasy and other similar religious phenomena. Drugs have been used in all parts of the world as an ecstasy technique. Since mental states and physiological correlates always accompany each other, it is obvious that the human mind can be affected by external means, for instance by drugs. But the opposite is also true; mental changes affect the body, as they do in the case of psychosomatic diseases. Ecstasy is often described as an extremely joyful experience; this pleasure must necessarily also have a physiological basis. It is of course too early to say anything for certain, but the discovery of pleasure centres in the brain might offer an explanation. It is not far-fetched to suggest that when a person experiences euphoric ecstasy, it might, in some way or other, be connected with a cerebral pleasure center. Can it be, for example, that religious ecstasy is attained only by some mechanism triggering off changes in the balance of the transmitter substances? Or is it reached only via a change in the hormonal balance, or only by a slowing down of the brain waves, or is a pleasure centre activated? When a person is using an ecstasy technique, he usually does so within a religious tradition. When he reaches an experience, a traditional interpretation of it already exists.

scholarly journals The Myth of Objectivity: Implicit Racial Bias and the Law (Part 2)

2017 ◽  
Vol 20 ◽  
pp. 1
Author(s):  
Willem Hendrik Gravett
Keyword(s):  
South Africa ◽  
Racial Bias ◽  
Legal Theory ◽  
Fundamental Principle ◽  
Human Mind ◽  
Racial Prejudice ◽  
Theory And Practice ◽  
Differential Treatment ◽  
Implicit Racial Bias ◽  
The Law

The centrality of race to our history and the substantial racial inequalities that continue to pervade society ensure that "race" remains an extraordinarily salient and meaningful social category.  Explicit racial prejudice, however, is only part of the problem.  Equally important - and likely more pervasive - is the phenomenon of implicit racial prejudice: the cognitive processes whereby, despite even our best intentions, the human mind automatically classifies information in racial categories and against disfavoured social groups. Empirical research shows convincingly that these biases against socially disfavoured groups are (i) pervasive; (ii) often diverge from consciously reported attitudes and beliefs; and (iii) influence consequential behaviour towards the subjects of these biases. The existence of implicit racial prejudices poses a challenge to legal theory and practice. From the standpoint of a legal system that seeks to forbid differential treatment based upon race or other protected traits, if people are in fact treated differently, and worse, because of their race or other protected trait, then the fundamental principle of anti-discrimination has been violated. It hardly matters that the source of the differential treatment is implicit rather than conscious bias. This article investigates the relevance of this research to the law by means of an empirical account of how implicit racial bias could affect the criminal trial trajectory in the areas of policing, prosecutorial discretion and judicial decision-making.  It is the author's hypothesis that this mostly American research also applies to South Africa. The empirical evidence of implicit biases in every country tested shows that people are systematically implicitly biased in favour of socially privileged groups. Even after 1994 South Africa – similar to the US – continues to be characterised by a pronounced social hierarchy in which Whites overwhelmingly have the highest social status. The author argues that the law should normatively take cognizance of this issue.  After all, the mere fact that we may not be aware of, much less consciously intend, race-contingent behaviour does not magically erase the harm. The article concludes by addressing the question of the appropriate response of the law and legal role players to the problem of implicit racial bias.

scholarly journals Sensory-Motor Modulations of EEG Event-Related Potentials Reflect Walking-Related Macro-Affordances

2021 ◽  
Vol 11 (11) ◽  
pp. 1506
Author(s):  
Annalisa Tosoni ◽  
Emanuele Cosimo Altomare ◽  
Marcella Brunetti ◽  
Pierpaolo Croce ◽  
Filippo Zappasodi ◽  
...  
Keyword(s):  
Large Scale ◽  
Functional Organization ◽  
Sensory Information ◽  
Event Related Potentials ◽  
Stimulus Presentation ◽  
Fundamental Principle ◽  
Facilitation Effect ◽  
Extrapersonal Space ◽  
Sensory Motor ◽  
Related Potentials

One fundamental principle of the brain functional organization is the elaboration of sensory information for the specification of action plans that are most appropriate for interaction with the environment. Using an incidental go/no-go priming paradigm, we have previously shown a facilitation effect for the execution of a walking-related action in response to far vs. near objects/locations in the extrapersonal space, and this effect has been called “macro-affordance” to reflect the role of locomotion in the coverage of extrapersonal distance. Here, we investigated the neurophysiological underpinnings of such an effect by recording scalp electroencephalography (EEG) from 30 human participants during the same paradigm. The results of a whole-brain analysis indicated a significant modulation of the event-related potentials (ERPs) both during prime and target stimulus presentation. Specifically, consistent with a mechanism of action anticipation and automatic activation of affordances, a stronger ERP was observed in response to prime images framing the environment from a far vs. near distance, and this modulation was localized in dorso-medial motor regions. In addition, an inversion of polarity for far vs. near conditions was observed during the subsequent target period in dorso-medial parietal regions associated with spatially directed foot-related actions. These findings were interpreted within the framework of embodied models of brain functioning as arising from a mechanism of motor-anticipation and subsequent prediction error which was guided by the preferential affordance relationship between the distant large-scale environment and locomotion. More in general, our findings reveal a sensory-motor mechanism for the processing of walking-related environmental affordances.

scholarly journals Abnormal Functional and Structural networks in Rectal Cancer with Depressive symptoms: A Graph Theory Analysis

2019 ◽  
Author(s):  
Wenwen Zhang ◽  
Ying Zou ◽  
Yuan Li ◽  
Yu Fu ◽  
Jie Shi ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Emotional Disorders ◽  
Parietal Lobe ◽  
Diffusion Tensor ◽  
Brain Network ◽  
Imaging Data ◽  
Network Efficiency ◽  
Limbic Lobe ◽  
Random Node ◽  
Brain Network Reorganization

Abstract Background: Surgery and chemotherapy can cause emotional disorders in patients with rectal cancer (RC). However, few comprehensive studies are conducted on RC patients associated alterations in the topological organization of structural and functional networks. Methods: Resting-state functional MRI and Diffusion tensor imaging data were collected from 36 RC patients with surgery and chemotherapy and 32 healthy controls (HC). Functional network (FN) was constructed from extracting average time courses for 246 regions of interest (ROI) and structural network (SN) was established by deterministic tractography. Graph theoretical analysis was used to calculate small-worldness property, clustering coefficients, shortest path length and network efficiency. Additionally, we assess network resilient on FN and SN. Results: Abnormal small-worldness property of FN and SN were found in RC patients. The FN and SN exhibited increased local efficiency and global efficiency respectively in RC patients.The increased nodal efficiency in RC patients were mainly found in the frontal lobe, parietal lobe and limbic lobe for FN and SN, while the decreased nodal efficiency were distributed in subcortical nuclei, parietal lobe and limbic lobe only for SN. In network resilient analysis, the RC patients showed less resilient to targeted or random node deletion in both networks compared with HC. Moreover, FN is more robust than SN for all participants. Conclusions: This study revealed that topological organizations of the FN and SN may be disrupted in RC patients. Brain network reorganization is a compensation mechanism for brain impairment after surgery and chemotherapy.

scholarly journals Enhanced prefrontal functional–structural networks to support postural control deficits after traumatic brain injury in a pediatric population

2017 ◽  
Vol 1 (2) ◽  
pp. 116-142 ◽  
Author(s):  
Ibai Diez ◽  
David Drijkoningen ◽  
Sebastiano Stramaglia ◽  
Paolo Bonifazi ◽  
Daniele Marinazzo ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cognitive Control ◽  
Postural Control ◽  
Pediatric Population ◽  
Structural Connectivity ◽  
Brain Network ◽  
Body Sway ◽  
Brain Network Reorganization ◽  
Structural Networks

Traumatic brain injury (TBI) affects structural connectivity, triggering the reorganization of structural–functional circuits in a manner that remains poorly understood. We focus here on brain network reorganization in relation to postural control deficits after TBI. We enrolled young participants who had suffered moderate to severe TBI, comparing them to young, typically developing control participants. TBI patients (but not controls) recruited prefrontal regions to interact with two separated networks: (1) a subcortical network, including parts of the motor network, basal ganglia, cerebellum, hippocampus, amygdala, posterior cingulate gyrus, and precuneus; and (2) a task-positive network, involving regions of the dorsal attention system, together with dorsolateral and ventrolateral prefrontal regions. We also found that the increased prefrontal connectivity in TBI patients was correlated with some postural control indices, such as the amount of body sway, whereby patients with worse balance increased their connectivity in frontal regions more strongly. The increased prefrontal connectivity found in TBI patients may provide the structural scaffolding for stronger cognitive control of certain behavioral functions, consistent with the observations that various motor tasks are performed less automatically following TBI and that more cognitive control is associated with such actions.

scholarly journals Neural Correlates of Correct and Errant Attentional Selection Revealed Through N2pc and Frontal Eye Field Activity

2010 ◽  
Vol 104 (5) ◽  
pp. 2433-2441 ◽  
Author(s):  
Richard P. Heitz ◽  
Jeremiah Y. Cohen ◽  
Geoffrey F. Woodman ◽  
Jeffrey D. Schall
Keyword(s):  
Visual Search ◽  
Visual Processing ◽  
Neural Correlates ◽  
Event Related Potential ◽  
Covert Attention ◽  
Extrastriate Cortex ◽  
False Alarms ◽  
Frontal Eye Field ◽  
Physiological Basis ◽  
Eye Field

The goal of this study was to obtain a better understanding of the physiological basis of errors of visual search. Previous research has shown that search errors occur when visual neurons in the frontal eye field (FEF) treat distractors as if they were targets. We replicated this finding during an inefficient form search and extended it by measuring simultaneously a macaque homologue of an event-related potential indexing the allocation of covert attention known as the m-N2pc. Based on recent work, we expected errors of selection in FEF to propagate to areas of extrastriate cortex responsible for allocating attention and implicated in the generation of the m-N2pc. Consistent with this prediction, we discovered that when FEF neurons selected a distractor instead of the search target, the m-N2pc shifted in the same, incorrect direction prior to the erroneous saccade. This suggests that such errors are due to a systematic misorienting of attention from the initial stages of visual processing. Our analyses also revealed distinct neural correlates of false alarms and guesses. These results demonstrate that errant gaze shifts during visual search arise from errant attentional processing.

scholarly journals The representational dynamics of visual objects in rapid serial visual processing streams

2018 ◽  
Author(s):  
Tijl Grootswagers ◽  
Amanda K. Robinson ◽  
Thomas A. Carlson
Keyword(s):  
Visual Processing ◽  
Temporal Dynamics ◽  
Target Selection ◽  
Presentation Rate ◽  
Stimulus Presentation ◽  
Human Vision ◽  
Object Representations ◽  
Daily Lives ◽  
Multivariate Pattern ◽  
Rapid Serial Visual Processing

AbstractIn our daily lives, we are bombarded with a stream of rapidly changing visual input. Humans have the remarkable capacity to detect and identify objects in fast-changing scenes. Yet, when studying brain representations, stimuli are generally presented in isolation. Here, we studied the dynamics of human vision using a combination of fast stimulus presentation rates, electroencephalography and multivariate decoding analyses. Using a presentation rate of 5 images per second, we obtained the representational structure of a large number of stimuli, and showed the emerging abstract categorical organisation of this structure. Furthermore, we could separate the temporal dynamics of perceptual processing from higher-level target selection effects. In a second experiment, we used the same paradigm at 20Hz to show that shorter image presentation limits the categorical abstraction of object representations. Our results show that applying multivariate pattern analysis to every image in rapid serial visual processing streams has unprecedented potential for studying the temporal dynamics of the structure of representations in the human visual system.

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