scholarly journals Temporal cascade of frontal, motor and muscle processes underlying human action-stopping

2019 ◽  
Author(s):  
Sumitash Jana ◽  
Ricci Hannah ◽  
Vignesh Muralidharan ◽  
Adam R. Aron

AbstractAction-stopping is a canonical executive function thought to involve top-down control over the motor system. Here we aimed to validate this stopping system using high temporal resolution methods in humans. We show that, following the requirement to stop, there was an increase of right frontal beta (∼13 to 30 Hz) at ∼120 ms, likely a proxy of right inferior frontal gyrus; then, at 140 ms, there was a broad skeletomotor suppression, likely reflecting the impact of the subthalamic nucleus on basal ganglia output; then, at ∼160 ms, suppression was detected in the muscle, and, finally, the behavioral time of stopping was ∼220 ms. This temporal cascade confirms a detailed model of action-stopping, and partitions it into subprocesses that are isolable to different nodes and are more precise than the behavioral speed of stopping. Variation in these subprocesses, including at the single-trial level, could better explain individual differences in impulse control.

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Sumitash Jana ◽  
Ricci Hannah ◽  
Vignesh Muralidharan ◽  
Adam R Aron

Action-stopping is a canonical executive function thought to involve top-down control over the motor system. Here we aimed to validate this stopping system using high temporal resolution methods in humans. We show that, following the requirement to stop, there was an increase of right frontal beta (~13 to 30 Hz) at ~120 ms, likely a proxy of right inferior frontal gyrus; then, at 140 ms, there was a broad skeletomotor suppression, likely reflecting the impact of the subthalamic nucleus on basal ganglia output; then, at ~160 ms, suppression was detected in the muscle, and, finally, the behavioral time of stopping was ~220 ms. This temporal cascade supports a physiological model of action-stopping, and partitions it into subprocesses that are isolable to different nodes and are more precise than the behavioral latency of stopping. Variation in these subprocesses, including at the single-trial level, could better explain individual differences in impulse control.


2021 ◽  
pp. 1-8
Author(s):  
Thaísa Araújo ◽  
Helena Machado ◽  
Dimila Mothé ◽  
Leonardo dos Santos Avilla

Abstract Climatic and environmental changes, as well as human action, have been cited as potential causes for the extinction of megafauna in South America at the end of the Pleistocene. Among megamammals lineages with Holarctic origin, only horses and proboscideans went extinct in South America during this period. This study aims to understand how the spatial extent of habitats suitable for Equus neogeus and Notiomastodon platensis changed between the last glacial maximum (LGM) and the middle Holocene in order to determine the impact that climatic and environmental changes had on these taxa. We used species distribution modeling to estimate their potential extent on the continent and found that both species occupied arid and semiarid open lands during the LGM, mainly in the Pampean region of Argentina, southern and northeastern Brazil, and parts of the Andes. However, when climate conditions changed from dry and cold during the LGM to humid and warm during the middle Holocene, the areas suitable for these taxa were reduced dramatically. These results support the hypothesis that climatic changes were a driving cause of extinction of these megamammals in South America, although we cannot rule out the impact of human actions or other potential causes for their extinction.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bob Jacobs ◽  
Heather Rally ◽  
Catherine Doyle ◽  
Lester O’Brien ◽  
Mackenzie Tennison ◽  
...  

Abstract The present review assesses the potential neural impact of impoverished, captive environments on large-brained mammals, with a focus on elephants and cetaceans. These species share several characteristics, including being large, wide-ranging, long-lived, cognitively sophisticated, highly social, and large-brained mammals. Although the impact of the captive environment on physical and behavioral health has been well-documented, relatively little attention has been paid to the brain itself. Here, we explore the potential neural consequences of living in captive environments, with a focus on three levels: (1) The effects of environmental impoverishment/enrichment on the brain, emphasizing the negative neural consequences of the captive/impoverished environment; (2) the neural consequences of stress on the brain, with an emphasis on corticolimbic structures; and (3) the neural underpinnings of stereotypies, often observed in captive animals, underscoring dysregulation of the basal ganglia and associated circuitry. To this end, we provide a substantive hypothesis about the negative impact of captivity on the brains of large mammals (e.g., cetaceans and elephants) and how these neural consequences are related to documented evidence for compromised physical and psychological well-being.


2015 ◽  
Vol 10 (1-2) ◽  
pp. 157
Author(s):  
Fred Seddon

<p>This review comments upon the article entitled above. The article is well written and describes an interesting and original study. This review critiques the Method and Discussion sections of the article and offers suggestions for future research. Three specific points from the method are considered relating to: dual roles as researcher-musicians, the use of reflective diaries in research, and the impact on the research of the prior relationship between the authors. The unique role of &ldquo;written empathy&rdquo; is discussed within the context of empathic relationships. Also, this review considers how shifts from verbal to non-verbal communication may indicate movement from a &ldquo;top-down&rdquo; to &ldquo;bottom up&rdquo; response, and how this shift is related to &ldquo;empathetic attunement.&rdquo;</p>


2012 ◽  
Vol 36 (1) ◽  
pp. 9-15
Author(s):  
Sabrina Soares da Silva ◽  
Ricardo Pereira Reis ◽  
Patrícia Aparecida Ferreira

More attention has been paid to environmental matters in recent years, mainly due to the current scenario of accentuated environmental degradation. The economic valuation of nature goods can contribute to the decision-making process in environment management, generating a more comprehensive informational base. This paper aims to present, in a historic perspective, the different concepts attributed to nature goods and were related to the current predominant perspectives of nature analyses. For this purpose, this paper presents the different concepts attributed to value since the pre-classical period, when nature were viewed as inert and passive providers of goods and services, this view legitimized nature's exploration without concern over the preservation and conservation of nature. The capacity of nature to absorb the impact of human action appears to be reaching its limit, considering the irreversibility, the irreproducibility and the possibility of collapse. The appropriate method for valuing natural resources is not known, but more important than the method is to respect and incorporate the particular characteristics of the nature goods into this process. These characteristics must be valuated in order to arrive at a more consistence approach to nature value and promote sustainability.


2021 ◽  
Author(s):  
André Forster ◽  
Johannes Hewig ◽  
John JB Allen ◽  
Johannes Rodrigues ◽  
Philipp Ziebell ◽  
...  

Being able to control inner and environmental states is a basic need of living creatures. Control perception (CP) itself may be neurally computed as the subjective ratio of outcome probabilities given the presence and the absence of behavior. If behavior increases the perceived probability of a given outcome, action-outcome contingency is met, and CP may emerge. Nonetheless, in regard of this model, not much is known on how the brain processes CP from these information. This study uses low-intensity transcranial focused ultrasound neuromodulation in a randomized-controlled doubleblind cross-over design to investigate the impact of the right inferior frontal gyrus on this process. Fourty healthy participants visited the laboratory twice (once in a sham, once in a neuromodulation condition) and rated their control perception regarding a classical control illusion task. EEG alpha and theta power density were analyzed in a hierarchical single trial based mixed modeling approach. Results indicate that the right lateral PFC modulates action-outcome learning by providing stochastic information about the situation with increased alpha responses during low control situations (in which the ratio of probabilities is zero). Furthermore, this alpha response was found to modulate mid-frontal theta by altering its relationship with self-reported effort and worrying. These data provide evidencefor right lateral PFC mediated probabilistic stimulus processing during the emergence of CP.


2021 ◽  
Vol 5 (2) ◽  
pp. 405
Author(s):  
Lussi Agustin ◽  
Moh. Yusron Solikin ◽  
Zunairoh .

Penelitian ini bertujuan untuk menganalisis seberapa maksimal proses kebijakan retrukturisasi Kredit UMKM dalam Pemulihan Ekonomi di Masa Pandemi Covid-19. Kondisi perekonomian global sedang mengalami goncangan hebat akibat mewabahnya Covid-19. Dampak dari pandemic ini sangat mempengaruhi segala aspek terutama pada kondisi Kesehatan dan perekonomian suatu negara, tidak terkecuali Indonesia. Secara keseluruhan, hampir semua sektor industry mengalami goncangan dan tidak terkecuali sektor UMKM. Maka dari itu dikeluarkanlah kebijakan retrukturisasi Kredit UMKM guna mendorong optimalisasi fungsi intermediasi pada perbankan dan menjaga stabilitas sistem keuangan serta mendukung pertumbuhan perekonomian. Program restrukturisasi kredit menjadi program dari OJK yang dapat diterapkan oleh perbankan kepada UMKM. Metode yang digunakan dalam penelitian ini adalah metode kualitatif dengan menggunakan studi empiris dari penelitian terdahulu serta peraturan-peraturan terkait dengan restrukturisasi kredit yang dikeluarkan oleh Otoritas Jasa Keuangan. Hasil penelitian ini menunjukkan bahwa implementasi kebijakan restrukturisai kredit bagi UMKM sudah berjalan dan digunakan oleh para pelaku UMKM. Kemudian berdasarkan implementasinya kebijakan ini merupakan kebijakan top-down dimana memerlukan banyak Lembaga untuk bekerja sama dan keputusan berasal dari Peraturan pemerintah baru di teruskan ke Lembaga-lembaga lain di bawahnya hingga informasinya sampai dan bisa dirasakan oleh para UMKM.  This research aims to analyze the policy of restructuring SMEs Credit in Economic Recovery during the Covid-19 Pandemic. The global economy is experiencing severe shocks due to the outbreak of Covid-19. The impact of this pandemic greatly affects all aspects, especially on the health and economic condition of a country, not least Indonesia. Overall, almost all industry sectors are experiencing shocks and are no exception to the SMEs sector. Therefore, the policy of restructuring SMEs Credit was issued to encourage optimization of intermediation function in banking and maintain the financial system stability and support economic growth. Credit restructuring program becomes a program from OJK that can be applied by banks to SMEs. The method used in this research is a qualitative method using empirical studies from previous research as well as regulations related to credit restructuring issued by the Financial Services Authority. The results of this research show that the implementation of credit restructuring policy for SMEs is already running and used by SMEs. Then based on the difference in implementation of this policy is a top-down policy that requires many Institutions to cooperate and decisions derived from the new government regulations are forwarded to other institutions under it until the information reaches and can be felt by SMEs.


2011 ◽  
Vol 8 (5) ◽  
pp. 9847-9899 ◽  
Author(s):  
D.-G. Kim ◽  
R. Vargas ◽  
B. Bond-Lamberty ◽  
M. R. Turetsky

Abstract. The rewetting of dry soils and the thawing of frozen soils are short-term, transitional phenomena in terms of hydrology and the thermodynamics of soil systems. The impact of these short-term phenomena on larger scale ecosystem fluxes has only recently been fully appreciated, and a growing number of studies show that these events affect various biogeochemical processes including fluxes of soil gases such as carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ammonia (NH3) and nitric oxide (NO). Global climate models predict that future climatic change is likely to alter the frequency and intensity of drying-rewetting events and thawing of frozen soils, highlighting the importance of understanding how rewetting and thawing will influence soil gas fluxes. Here we summarize findings in a new database based on 338 studies conducted from 1956 to 2010, and highlight open research questions. The database revealed conflicting results following rewetting and thawing in various terrestrial ecosystems, ranging from large increases in gas fluxes to non-significant changes. An analysis of published field studies (n = 142) showed that after rewetting or thawing, CO2, CH4, N2O, NO and NH3 fluxes increase from pre-event fluxes following a power function, with no significant differenced among gases. We discuss possible mechanisms and controls that regulate flux responses, and note that a high temporal resolution of flux measurements is critical to capture rapid changes in gas fluxes after these soil perturbations. Finally, we propose that future studies should investigate the interactions between biological (i.e. microbial community and gas production) and physical (i.e. flux, diffusion, dissolution) changes in soil gas fluxes, and explore synergistic experimental and modelling approaches.


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