scholarly journals Shared responsibility decreases the sense of agency in the human brain

2021 ◽  
Author(s):  
Marwa El Zein ◽  
Raymond J Dolan ◽  
Bahador Bahrami
Keyword(s):  
Motor Preparation ◽  
Brain Regions ◽  
Stimulus Onset ◽  
Social Contexts ◽  
Reward Processing ◽  
Shared Responsibility ◽  
Positive Outcomes ◽  
Social Decisions ◽  
Sharing Responsibility ◽  
Increased Activity

Distributing responsibility across several individuals in social decisions helps minimize a burden of responsibility for consequences of decisions. Here we investigated the neural expression of this effect using magnetoencephalography (MEG). Participants performed a reward-based learning decision-making task in contexts where their sense of responsibility over outcomes decreased with group size. An MEG outcome processing effect was reduced as a function of decreasing responsibility at 200ms post outcome onset and centred over parietal and precentral brain regions. During social decisions, prior to outcome revelation, a motor preparation signature at 500ms after stimulus onset was attenuated. A boost in responsibility for positive outcomes in social contexts was associated with increased activity in regions related to social and reward processing. Together, these results show that sharing responsibility with others reduces agency through an influence on pre-outcome motor preparation and post-outcome processing, affording an opportunity for flexibility in credit for positive outcomes.

Reparation for Environmental Damage in Jus Post Bellum

2017 ◽  
Author(s):  
Ilias Plakokefalos
Keyword(s):  
Armed Conflict ◽  
Environmental Law ◽  
Shared Responsibility ◽  
Armed Conflicts ◽  
Environmental Harm ◽  
Environmental Damage ◽  
Jus Post Bellum ◽  
Typical Situation ◽  
Sharing Responsibility

This chapter explores the problems that environmental damage in armed conflict pose to the determination of shared responsibility, and especially the determination of reparations, in the context of the jus post bellum. When two actors are engaged in armed conflict, there arise no serious issues as to sharing responsibility for violations. But the fact that modern armed conflicts often involve more than two actors (e.g. Libya 2011) complicates the matters arising out of environmental harm, as there may be two or more actors contributing to the same harmful event. This is a typical situation of shared responsibility. Shared responsibility provides that the problem of reparations for environmental harm is to be examined in situations where there is a multiplicity of actors that contribute to a single harmful outcome. This definition covers the breach of obligations under jus ad bellum and jus in bello, as well as under international environmental law.

scholarly journals Neural substrates of propranolol-induced impairments in the reconsolidation of nicotine-associated memories in smokers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiao Lin ◽  
Jiahui Deng ◽  
Kai Yuan ◽  
Qiandong Wang ◽  
Lin Liu ◽  
...  
Keyword(s):  
Neural Activity ◽  
Neural Substrates ◽  
Brain Regions ◽  
Reward Processing ◽  
Memory Reconsolidation ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Postcentral Gyrus ◽  
Propranolol Group ◽  
Propranolol Administration

AbstractThe majority of smokers relapse even after successfully quitting because of the craving to smoking after unexpectedly re-exposed to smoking-related cues. This conditioned craving is mediated by reward memories that are frequently experienced and stubbornly resistant to treatment. Reconsolidation theory posits that well-consolidated memories are destabilized after retrieval, and this process renders memories labile and vulnerable to amnestic intervention. This study tests the retrieval reconsolidation procedure to decrease nicotine craving among people who smoke. In this study, 52 male smokers received a single dose of propranolol (n = 27) or placebo (n = 25) before the reactivation of nicotine-associated memories to impair the reconsolidation process. Craving for smoking and neural activity in response to smoking-related cues served as primary outcomes. Functional magnetic resonance imaging was performed during the memory reconsolidation process. The disruption of reconsolidation by propranolol decreased craving for smoking. Reactivity of the postcentral gyrus in response to smoking-related cues also decreased in the propranolol group after the reconsolidation manipulation. Functional connectivity between the hippocampus and striatum was higher during memory reconsolidation in the propranolol group. Furthermore, the increase in coupling between the hippocampus and striatum positively correlated with the decrease in craving after the reconsolidation manipulation in the propranolol group. Propranolol administration before memory reactivation disrupted the reconsolidation of smoking-related memories in smokers by mediating brain regions that are involved in memory and reward processing. These findings demonstrate the noradrenergic regulation of memory reconsolidation in humans and suggest that adjunct propranolol administration can facilitate the treatment of nicotine dependence. The present study was pre-registered at ClinicalTrials.gov (registration no. ChiCTR1900024412).

scholarly journals Cannabinoids, reward processing, and psychosis

2021 ◽  
Author(s):  
Brandon Gunasekera ◽  
Kelly Diederen ◽  
Sagnik Bhattacharyya
Keyword(s):  
Psychotic Disorders ◽  
Neural Substrates ◽  
Brain Regions ◽  
Reward Processing ◽  
Anterior Cingulate ◽  
Psychotic Symptoms ◽  
Dopamine Synthesis ◽  
Future Research ◽  
Drug Challenge ◽  
Psychotomimetic Effects

Abstract Background Evidence suggests that an overlap exists between the neurobiology of psychotic disorders and the effects of cannabinoids on neurocognitive and neurochemical substrates involved in reward processing. Aims We investigate whether the psychotomimetic effects of delta-9-tetrahydrocannabinol (THC) and the antipsychotic potential of cannabidiol (CBD) are underpinned by their effects on the reward system and dopamine. Methods This narrative review focuses on the overlap between altered dopamine signalling and reward processing induced by cannabinoids, pre-clinically and in humans. A systematic search was conducted of acute cannabinoid drug-challenge studies using neuroimaging in healthy subjects and those with psychosis Results There is evidence of increased striatal presynaptic dopamine synthesis and release in psychosis, as well as abnormal engagement of the striatum during reward processing. Although, acute THC challenges have elicited a modest effect on striatal dopamine, cannabis users generally indicate impaired presynaptic dopaminergic function. Functional MRI studies have identified that a single dose of THC may modulate regions involved in reward and salience processing such as the striatum, midbrain, insular, and anterior cingulate, with some effects correlating with the severity of THC-induced psychotic symptoms. CBD may modulate brain regions involved in reward/salience processing in an opposite direction to that of THC. Conclusions There is evidence to suggest modulation of reward processing and its neural substrates by THC and CBD. Whether such effects underlie the psychotomimetic/antipsychotic effects of these cannabinoids remains unclear. Future research should address these unanswered questions to understand the relationship between endocannabinoid dysfunction, reward processing abnormalities, and psychosis.

scholarly journals Transient neuronal suppression for exploitation of new sensory evidence

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Maxwell Shinn ◽  
Daeyeol Lee ◽  
John D. Murray ◽  
Hyojung Seo
Keyword(s):  
Decision Making ◽  
Neural Activity ◽  
Temporal Integration ◽  
Motor Preparation ◽  
Stimulus Onset ◽  
Frontal Eye Field ◽  
Perceptual Decision Making ◽  
Behavioral Studies ◽  
The Face ◽  
Sensory Evidence

AbstractIn noisy but stationary environments, decisions should be based on the temporal integration of sequentially sampled evidence. This strategy has been supported by many behavioral studies and is qualitatively consistent with neural activity in multiple brain areas. By contrast, decision-making in the face of non-stationary sensory evidence remains poorly understood. Here, we trained monkeys to identify and respond via saccade to the dominant color of a dynamically refreshed bicolor patch that becomes informative after a variable delay. Animals’ behavioral responses were briefly suppressed after evidence changes, and many neurons in the frontal eye field displayed a corresponding dip in activity at this time, similar to that frequently observed after stimulus onset but sensitive to stimulus strength. Generalized drift-diffusion models revealed consistency of behavior and neural activity with brief suppression of motor output, but not with pausing or resetting of evidence accumulation. These results suggest that momentary arrest of motor preparation is important for dynamic perceptual decision making.

scholarly journals Theory of Mind network activity is associated with metaethical judgment: An item analysis

2017 ◽  
Author(s):  
Jordan E. Theriault ◽  
Adam Waytz ◽  
Larisa Heiphetz ◽  
Liane Young
Keyword(s):  
Theory Of Mind ◽  
Item Analysis ◽  
Positive Association ◽  
Brain Regions ◽  
Social Contexts ◽  
Network Activity ◽  
Predictive Processing ◽  
Temporoparietal Junction ◽  
Social Tasks ◽  
Stimulus Features

The theory of mind network (ToMN) is a set of brain regions activated by a variety of social tasks. Recent work has proposed that these associations with ToMN activity may relate to a common underlying computation: processing prediction error in social contexts. The present work presents evidence consistent with this hypothesis, using a fine-grained item analysis to examine the relationship between ToMN activity and variance in stimulus features. We used an existing dataset (consisting of statements about morals, facts, and preferences) to explore variability in ToMN activity elicited by moral statements, using metaethical judgments (i.e. judgments of how fact-like/preference-like morals are) as a proxy for their predictability/support by social consensus. Study 1 validated expected patterns of behavioral judgments in our stimuli set, and Study 2 associated by-stimulus estimates of metaethical judgment with ToMN activity, showing that ToMN activity was negatively associated with objective morals and positively associated with subjective morals. Whole brain analyses indicated that these associations were strongest in bilateral temporoparietal junction (TPJ). We also observed additional by-stimulus associations with ToMN, including positive associations with the presence of a person (across morals, facts, and preferences), a negative association with agreement (among morals only), and a positive association with mental inference (in preferences only, across 3 independent measures and behavioral samples). We discuss these findings in the context of recent predictive processing models, and highlight how predictive models may facilitate new perspectives on metaethics, the centrality of morality to personal identity, and distinctions between social domains (e.g. morals vs. preferences).

scholarly journals Dissociable oscillatory networks support gain and loss processing in human orbitofrontal cortex

2021 ◽  
Author(s):  
Ignacio Saez ◽  
Jack Lin ◽  
Edward Chang ◽  
Josef Parvizi ◽  
Robert T. Knight ◽  
...  
Keyword(s):  
Neural Activity ◽  
Orbitofrontal Cortex ◽  
Low Frequency ◽  
Brain Regions ◽  
Reward Processing ◽  
Neural Oscillations ◽  
Beta Band ◽  
Neuronal Ensembles ◽  
Gain And Loss

AbstractHuman neuroimaging and animal studies have linked neural activity in orbitofrontal cortex (OFC) to valuation of positive and negative outcomes. Additional evidence shows that neural oscillations, representing the coordinated activity of neuronal ensembles, support information processing in both animal and human prefrontal regions. However, the role of OFC neural oscillations in reward-processing in humans remains unknown, partly due to the difficulty of recording oscillatory neural activity from deep brain regions. Here, we examined the role of OFC neural oscillations (<30Hz) in reward processing by combining intracranial OFC recordings with a gambling task in which patients made economic decisions under uncertainty. Our results show that power in different oscillatory bands are associated with distinct components of reward evaluation. Specifically, we observed a double dissociation, with a selective theta band oscillation increase in response to monetary gains and a beta band increase in response to losses. These effects were interleaved across OFC in overlapping networks and were accompanied by increases in oscillatory coherence between OFC electrode sites in theta and beta band during gain and loss processing, respectively. These results provide evidence that gain and loss processing in human OFC are supported by distinct low-frequency oscillations in networks, and provide evidence that participating neuronal ensembles are organized functionally through oscillatory coherence, rather than local anatomical segregation.

scholarly journals The effects of the form of sugar (solid vs. beverage) on body weight and fMRI activation: A randomized controlled pilot study

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251700
Author(s):  
John W. Apolzan ◽  
Owen T. Carmichael ◽  
Krystal M. Kirby ◽  
Sreekrishna R. Ramakrishnapillai ◽  
Robbie A. Beyl ◽  
...  
Keyword(s):  
Body Weight ◽  
Energy Homeostasis ◽  
Pilot Trial ◽  
Brain Regions ◽  
Reward Processing ◽  
Daily Consumption ◽  
Fed State ◽  
Randomized Controlled ◽  
The Right ◽  
The Brain

Objective To test if sugar sweetened beverages (SSBs) and sugar sweetened solids (SSSs) have differential effects on body weight and reward processing in the brain. Methods In a single blind randomized controlled pilot trial (RCT), twenty participants with BMI between 20 and 40 kg/m2 were randomized to consume a 20 fluid ounce soda (SSB, 248 kcal) or the equivalent in solid form (SSS; similar to thick gelatin or gummy candy) daily. At baseline and day 28, fasting body weight and fed-state BOLD fMRI of the brain were assessed. Differences in fMRI signals between views of low-fat (LF (<30%)) high sugar (HS (>30%)) food, and non-food images were calculated in brain regions implicated in energy homeostasis, taste, and reward. Results All participants in the SSB (6F 4M; 8 Caucasian; 36±14 y, 28.2±5.5 kg/m2; Mean±SD) and SSS (3F 7M; 6 Caucasian; 39±12; 26.3±4.4) groups completed the study. Weight change was 0.27±0.78 kg between SSB and SSS participants. Changes in the fMRI response to LF/HS foods in reward, homeostatic and taste regions tended to not be different between the groups over the four weeks. However, activation of the right substantia nigra increased following the SSB but decreased activation following the SSS in response to LF/HS foods over 28 days (-0.32±0.12). Ratings of wanting for LF/HS foods were correlated with activation in several brain regions, including the OFC. Conclusions Change in weight was modest between the groups in this study. Daily consumption of a SSB over 28 days led to mixed responses to LF/HS foods in areas of the brain associated with reward. Ratings of wanting are correlated with fMRI activation inside an MRI scanner.

Reward-Associated Gamma Oscillations in Ventral Striatum Are Regionally Differentiated and Modulate Local Firing Activity

2010 ◽  
Vol 103 (3) ◽  
pp. 1658-1672 ◽  
Author(s):  
Tobias Kalenscher ◽  
Carien S. Lansink ◽  
Jan V. Lankelma ◽  
Cyriel M. A. Pennartz
Keyword(s):  
Ventral Striatum ◽  
Phase Locking ◽  
Gamma Oscillations ◽  
Brain Regions ◽  
Reward Processing ◽  
Temporal Organization ◽  
Gamma Activity ◽  
Neural Ensembles ◽  
Gamma Range ◽  
Gamma Power

Oscillations of local field potentials (LFPs) in the gamma range are found in many brain regions and are supposed to support the temporal organization of cognitive, perceptual, and motor functions. Even though gamma oscillations have also been observed in ventral striatum, one of the brain's most important structures for motivated behavior and reward processing, their specific function during ongoing behavior is unknown. Using a movable tetrode array, we recorded LFPs and activity of neural ensembles in the ventral striatum of rats performing a reward-collection task. Rats were running along a triangle track and in each round collected one of three different types of rewards. The gamma power of LFPs on subsets of tetrodes was modulated by reward-site visits, discriminated between reward types, between baitedness of reward locations and was different before versus after arrival at a reward site. Many single units in ventral striatum phase-locked their discharge pattern to the gamma oscillations of the LFPs. Phase-locking occurred more often in reward-related than in reward-unrelated neurons and LFPs. A substantial number of simultaneously recorded LFPs correlated poorly with each other in terms of gamma rhythmicity, indicating that the expression of gamma activity was heterogeneous and regionally differentiated. The orchestration of LFPs and single-unit activity by way of gamma rhythmicity sheds light on the functional architecture of the ventral striatum and the temporal coordination of ventral striatal activity for modulating downstream areas and regulating synaptic plasticity.

scholarly journals Prestimulus feedback connectivity biases the content of visual experiences

2019 ◽  
Vol 116 (32) ◽  
pp. 16056-16061 ◽  
Author(s):  
Elie Rassi ◽  
Andreas Wutz ◽  
Nadia Müller-Voggel ◽  
Nathan Weisz
Keyword(s):  
Neural Activity ◽  
Activity Patterns ◽  
Low Frequency ◽  
Brain Regions ◽  
Stimulus Onset ◽  
Neural Excitability ◽  
Gamma Frequency ◽  
Face Area ◽  
Oscillatory Power ◽  
The Impact

Ongoing fluctuations in neural excitability and in networkwide activity patterns before stimulus onset have been proposed to underlie variability in near-threshold stimulus detection paradigms—that is, whether or not an object is perceived. Here, we investigated the impact of prestimulus neural fluctuations on the content of perception—that is, whether one or another object is perceived. We recorded neural activity with magnetoencephalography (MEG) before and while participants briefly viewed an ambiguous image, the Rubin face/vase illusion, and required them to report their perceived interpretation in each trial. Using multivariate pattern analysis, we showed robust decoding of the perceptual report during the poststimulus period. Applying source localization to the classifier weights suggested early recruitment of primary visual cortex (V1) and ∼160-ms recruitment of the category-sensitive fusiform face area (FFA). These poststimulus effects were accompanied by stronger oscillatory power in the gamma frequency band for face vs. vase reports. In prestimulus intervals, we found no differences in oscillatory power between face vs. vase reports in V1 or in FFA, indicating similar levels of neural excitability. Despite this, we found stronger connectivity between V1 and FFA before face reports for low-frequency oscillations. Specifically, the strength of prestimulus feedback connectivity (i.e., Granger causality) from FFA to V1 predicted not only the category of the upcoming percept but also the strength of poststimulus neural activity associated with the percept. Our work shows that prestimulus network states can help shape future processing in category-sensitive brain regions and in this way bias the content of visual experiences.

Disrupted prefrontal regulation of striatum-related craving in Internet gaming disorder revealed by dynamic causal modeling: results from a cue-reactivity task

2020 ◽  
pp. 1-13 ◽  
Author(s):  
Guang-Heng Dong ◽  
Min Wang ◽  
Hui Zheng ◽  
Ziliang Wang ◽  
Xiaoxia Du ◽  
...  
Keyword(s):  
Internet Gaming Disorder ◽  
Cingulate Cortex ◽  
Brain Regions ◽  
Reward Processing ◽  
Causal Modeling ◽  
Anterior Cingulate ◽  
Separate Analysis ◽  
Gaming Disorder ◽  
Lentiform Nucleus ◽  
Internet Gaming

Abstract Background Studies of Internet gaming disorder (IGD) suggest an imbalanced relationship between cognitive control and reward processing in people with IGD. However, it remains unclear how these two systems interact with each other, and whether they could serve as neurobiological markers for IGD. Methods Fifty IGD subjects and matched individuals with recreational game use (RGU) were selected and compared when they were performing a cue-craving task. Regions of interests [anterior cingulate cortex (ACC), lentiform nucleus] were selected based on the comparison between brain responses to gaming-related cues and neutral cues. Directional connectivities among these brain regions were determined using Bayesian estimation. We additionally examined the posterior cingulate cortex (PCC) in a separate analysis based on data implicating the PCC in craving in addiction. Results During fixed-connectivity analyses, IGD subjects showed blunted ACC-to-lentiform and lentiform-to-ACC connectivity relative to RGU subjects, especially in the left hemisphere. When facing gaming cues, IGD subjects trended toward lower left-hemispheric modulatory effects in ACC-to-lentiform connectivity than RGU subjects. Self-reported cue-related craving prior to scanning correlated inversely with left-hemispheric modulatory effects in ACC-to-lentiform connectivity. Conclusions The results suggesting that prefrontal-to-lentiform connectivity is impaired in IGD provides a possible neurobiological mechanism for difficulties in controlling gaming-cue-elicited cravings. Reduced connectivity ACC-lentiform connectivity may be a useful neurobiological marker for IGD.

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