scholarly journals Computational dissociation of dopaminergic and cholinergic effects on action selection and inhibitory control

2019 ◽  
Author(s):  
Eduardo A. Aponte ◽  
Dario Schöbi ◽  
Klaas E. Stephan ◽  
Jakob Heinzle
Keyword(s):  
Inhibitory Control ◽  
Reaction Times ◽  
Action Selection ◽  
Error Rates ◽  
Antisaccade Task ◽  
Starting Point ◽  
Dose Dependent Fashion ◽  
The Cost ◽  
The Impact ◽  
Dose Dependent

AbstractBackgroundPatients with schizophrenia make more errors than healthy subjects on the antisaccade task. In this paradigm, participants are required to inhibit a reflexive saccade to a target and to select the correct action (a saccade in the opposite direction). While the precise origin of this deficit is not clear, it has been connected to aberrant dopaminergic and cholinergic neuromodulation.MethodsTo study the impact of dopamine and acetylcholine on inhibitory control and action selection, we administered two selective drugs (levodopa 200mg/galantamine 8mg) to healthy volunteers (N=100) performing the antisaccade task. A computational model (SERIA) was employed to separate the contribution of inhibitory control and action selection to empirical reaction times and error rates.ResultsModeling suggested that levodopa improved action selection (at the cost of increased reaction times) but did not have a significant effect on inhibitory control. By contrast, according to our model, galantamine affected inhibitory control in a dose dependent fashion, reducing inhibition failures at low doses and increasing them at higher levels. These effects were sufficiently specific that the computational analysis allowed for identifying the drug administered to an individual with 70% accuracy.ConclusionsOur results do not support the hypothesis that elevated tonic dopamine strongly impairs inhibitory control. Rather levodopa improved the ability to select correct actions. Instead, inhibitory control was modulated by cholinergic drugs. This approach may provide a starting point for future computational assays that differentiate neuromodulatory abnormalities in heterogeneous diseases like schizophrenia.

Cognitive inhibitory control in children following early childhood music education

2016 ◽  
Vol 21 (3) ◽  
pp. 303-315 ◽  
Author(s):  
Marie-Eve Joret ◽  
Filip Germeys ◽  
Yori Gidron
Keyword(s):  
Music Education ◽  
Executive Functions ◽  
Inhibitory Control ◽  
Simon Task ◽  
Musical Training ◽  
Economic Status ◽  
Reaction Times ◽  
Error Rates ◽  
Significant Group ◽  
Music Training

The relationship between music training and executive functions has remained inconsistent in previous studies, possibly due to methodological limitations. This study aims to investigate cognitive inhibitory control in children (9–12 years old) with and without musical training, while carefully considering confounding variables. To assess executive functions, the Simon task was used, measuring reaction times (RTs) and error rates on congruent and incongruent trials. Information on important variables such as bilingualism, socio-economic status (SES), music pedagogy and amount of musical training was collected through a parental questionnaire. Furthermore, verbal and non-verbal intelligence were assessed with validated tests to consider their effects as well. The results showed that the samples did not significantly differ in background variables. The analysis of the RT data on the Simon task revealed a significant group × congruency interaction, such that musically trained children showed a reduced magnitude of the congruency effect (RTs on incongruent trials – RTs on congruent trials) compared to non-musicians. To conclude, music training seems to be associated with enhanced cognitive inhibitory control in well-matched samples.

scholarly journals Reducing the Cost of Implementing Filters in LoRa Devices

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4037
Author(s):  
Shania Stewart ◽  
Ha H. Nguyen ◽  
Robert Barton ◽  
Jerome Henry
Keyword(s):  
Fourier Transform ◽  
Fast Fourier Transform ◽  
System Performance ◽  
Pulse Shaping ◽  
Error Rates ◽  
Lookup Table ◽  
Significant Performance ◽  
High Level ◽  
The Cost ◽  
The Impact

This paper presents two methods to optimize LoRa (Low-Power Long-Range) devices so that implementing multiplier-less pulse shaping filters is more economical. Basic chirp waveforms can be generated more efficiently using the method of chirp segmentation so that only a quarter of the samples needs to be stored in the ROM. Quantization can also be applied to the basic chirp samples in order to reduce the number of unique input values to the filter, which in turn reduces the size of the lookup table for multiplier-less filter implementation. Various tests were performed on a simulated LoRa system in order to evaluate the impact of the quantization error on the system performance. By examining the occupied bandwidth, fast Fourier transform used for symbol demodulation, and bit-error rates, it is shown that even performing a high level of quantization does not cause significant performance degradation. Therefore, the memory requirements of LoRa devices can be significantly reduced by using the methods of chirp segmentation and quantization so as to improve the feasibility of implementing multiplier-less filters in LoRa devices.

Activism in a time of pandemic: The impact of COVID-19 in Chilean citizen movement after the uprising of October 2019

2021 ◽  
Vol 16 (2) ◽  
pp. 201-211 ◽  
Author(s):  
Paulina Bronfman
Keyword(s):  
Secondary School ◽  
Ocular Trauma ◽  
The Other ◽  
Health Crisis ◽  
Social Nature ◽  
Starting Point ◽  
The Social ◽  
Entire World ◽  
The Cost ◽  
The Impact

Chile, unlike other countries in the region, is facing two major crises: one of a large social nature and the other in public health, which is in its form of the pandemic that is currently affecting the entire world. In October 2019, secondary-school and university students organized a massive evasion of the Santiago metro fare. The reason was to protest the 30 pesos increase in the cost of the ticket. This apparently small issue detonated the greatest protest movement of the last 30 years. By January 2019, the uprising had left 31 dead and 5,558 people who reported human rights violations, including 331 with ocular trauma or injury to their eyes and 21 suffered damage or loss of the eyeball. In March 2019, protests were eradicated from the streets and the development of the movement was slowed down by the powerful action of the Coronavirus. This article explores the impact that the COVID-19 crisis had on citizen movement, and the functionality of the health crisis to establish the de facto authoritarian hyper-controlled state in order to freeze the social crisis. Also, this work identifies the strategy that the Chilean citizen movement developed to survive during 2020, applying Pleyers’s (2020) model of analysis of activism under pandemic as a starting point.

A diminished serotonin level influences the performance in a modified AX-continuous performance task in adult ADHD

2011 ◽  
Vol 26 (S2) ◽  
pp. 430-430
Author(s):  
C. Mette ◽  
M. Grabemann ◽  
M. Zimmermann ◽  
M. Kraemer ◽  
F. Zepf ◽  
...  
Keyword(s):  
Performance Test ◽  
Reaction Times ◽  
Error Rates ◽  
Serotonergic System ◽  
Tryptophan Depletion ◽  
Serotonin Level ◽  
Adhd Group ◽  
Continuous Performance ◽  
Male Adult ◽  
The Impact

IntroductionAttention deficit disorder (ADHD) is a psychiatric disorder, which is characterized by deficits of executive functions (EF) and impulsivity. Whereas a variety of studies on the involvement of the dopaminergic system in ADHD exists, the impact of the serotonergic system to EF in ADHD in adults is underinvestigated.AimsTo ascertain the effects of rapid tryptophan depletion (RTD) and the resultant reduction of the central nervous levels of serotonin on the EF of male adult patients with ADHD.Methods20 ADHD patients and 20 healthy controls completed the RTD test on one day and a placebo on another day in a double-blind within subject crossover design.- In addition, the subtest alertness of the TAP and a modified Version of the Continuous performance test (AX-CPT) with three stimulus conditions (AX, AY, BX) were administered.ResultsStatistical analysis revealed significant shorter reaction times, more errors and more omission errors in the ADHD group in the AX-CPT. The omissions error rate increased in both groups in the RTD condition but not in the placebo condition. Statistical analyses did not yield any significant differences between groups in the subtest alertness and no significant interaction of group and effect of the RTD condition could be observed.ConclusionsIn addition to higher impulsivity of patients with ADHD as reflected by shorter reaction times and higher error rates, the results of the present study imply an involvement of the serotonergic system as reflected by RTD in sustained and selective attention.

scholarly journals Tissue inhibitor of metalloproteinase 1 expression and secretion are induced by β-adrenergic stimulation in 3T3-L1 adipocytes

2006 ◽  
Vol 189 (3) ◽  
pp. 665-670 ◽  
Author(s):  
S Kralisch ◽  
U Lossner ◽  
M Bluher ◽  
R Paschke ◽  
M Stumvoll ◽  
...  
Keyword(s):  
Tissue Inhibitor Of Metalloproteinase ◽  
Adrenergic Stimulation ◽  
Tissue Inhibitor ◽  
Dose Dependent Fashion ◽  
Adipose Tissue Development ◽  
Gs Protein ◽  
Β Adrenergic Receptors ◽  
The Impact ◽  
Camp Levels ◽  
Dose Dependent

Tissue inhibitor of metalloproteinase (TIMP)-1 is an adipocytokine upregulated in obesity which might promote adipose tissue development. In the current study, the impact of the β-adrenergic agonist isoproterenol on TIMP-1 gene expression and secretion was determined in 3T3-L1 adipocytes. Interestingly, isoproterenol increased TIMP-1 secretion 2.7-fold. Furthermore, isoproterenol induced TIMP-1 mRNA in a time- and dose-dependent fashion with significant effects observed as early as 1 h after effector addition and at concentrations as low as 1 μM isoproterenol. Significant isoproterenol-induced upregulation of TIMP-1 mRNA could also be found in immortalized brown adipocytes. Inhibitor experiments confirmed that the positive effect of isoproterenol on TIMP-1 is mediated via β-adrenergic receptors and protein kinase A. Moreover, increasing cAMP levels with forskolin or dibutyryl-cAMP was sufficient to stimulate TIMP-1 synthesis. Insulin induced basal TIMP-1 mRNA, but did not significantly influence forskolin-induced TIMP-1 expression. Taken together, we demonstrate that TIMP-1 expression and secretion are selectively upregulated in adipocytes by β-adrenergic agonists via a classic Gs-protein-coupled pathway.

scholarly journals Impact of Coexposure to Aluminum and Ethanol on Phosphoesterases and Transaminases of Rat Cerebrum

2011 ◽  
Vol 30 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Prasunpriya Nayak ◽  
Shiv Sharma ◽  
Nadella Chowdary
Keyword(s):  
Critical Level ◽  
Ethanol Exposure ◽  
Aluminum Exposure ◽  
Dose Dependent Fashion ◽  
Rat Cerebrum ◽  
Increasing Trends ◽  
The Impact ◽  
Dose Dependent ◽  
Ubiquitous Presence ◽  
Different Doses

Impact of Coexposure to Aluminum and Ethanol on Phosphoesterases and Transaminases of Rat CerebrumUbiquitous presence along with uncontrolled use of aluminum and increasing trends of ethanol consumption in India increased the chance of coexposure to aluminum and ethanol. Possibilities are there, that both of them follow common mechanisms to produce neurotoxicity. The phosphomonoesterases and glutamate transaminases are studied in rat brain cerebrum after combined exposure to aluminum and varied doses of ethanol for 4 weeks. Dose dependent decreases in growth have been observed. The impact of aluminum on cerebral acidic and alkaline phosphomonoesterases activities were shown to be altered in a dose dependent fashion by the coexposure to ethanol. Aspartate aminotransferase and alanine aminotransferase of the cerebrum were responding differentially to aluminum exposure in the presence of different doses of ethanol exposure. It has been suggested that the ethanol-induced augmentation of impacts of aluminum on the cerebrum is dose dependent and there might be a critical level of ethanol exposure for the observed effect on cerebrum.

scholarly journals GABAergic Modulation of Response Inhibition and Interference Control

2020 ◽  
Author(s):  
Kaja Faßbender ◽  
Katharina Bey ◽  
Julia V. Lippold ◽  
rene hurlemann ◽  
Ulrich Ettinger
Keyword(s):  
Inhibitory Control ◽  
Response Inhibition ◽  
Flanker Task ◽  
Reaction Times ◽  
Error Rates ◽  
Interference Control ◽  
Drug Induced ◽  
Double Blind ◽  
Delta Plots ◽  
Over Time

Background: Inhibitory control is a crucial executive function with high relevance to mental and physical wellbeing. However, there are still unanswered questions regarding its neural mechanisms, including the role of the major inhibitory neurotransmitter, γ-aminobutyric acid (GABA). Aims: This study examined the effects of lorazepam (0.5 mg and 1 mg), a positive allosteric modulator at the GABAA receptor, on response inhibition and interference control. We also explored the heterogeneity of inhibitory control and calculated delta plots to explore whether lorazepam affects the gradual build-up of inhibition and activation over time. Method: A sample of N=50 healthy participants performed antisaccade, Eriksen flanker and Simon tasks in a within-subjects, placebo-controlled, double-blind randomised design. Results: Lorazepam increased mean reaction times (MRT) and error rates dose-dependently in all tasks (p≤.005). In the antisaccade and Simon tasks, lorazepam increased congruency effects for error rate (p≤.029) but not for MRT (p≥.587). In the Eriksen flanker task, both congruency effects were increased by the drug (p≤.031). Delta plots did not reflect any drug-induced changes in inhibition and activation over time. Delta plots for MRT in the Simon task were negative-going, as expected, whereas those for the antisaccade and flanker tasks were positive-going. Conclusions: This study provides clear evidence for GABAergic involvement in inhibitory control. Furthermore, our findings highlight the diversity of inhibitory control while also pointing out similarities between different inhibitory control tasks. In contrast to MRTs and error rates, the cognitive processes provided by delta plots appear not to be sensitive to GABAergic modulation.Draft version, 02.04.2020. This paper has not been peer reviewed. Please do not copy or cite without author's permission.

scholarly journals A feed-centric hypoglycaemia pathway ensures appropriate care escalation in at-risk infants

2021 ◽  
Vol 10 (4) ◽  
pp. e001296
Author(s):  
Suresh Chandran ◽  
Jia Xuan Siew ◽  
Victor Samuel Rajadurai ◽  
Rachel Wei Shan Lim ◽  
Mei Chien Chua ◽  
...  
Keyword(s):  
At Risk ◽  
Total Duration ◽  
Cost Of Care ◽  
Intravenous Glucose ◽  
Starting Point ◽  
Before And After ◽  
The Cost ◽  
Glucose Management ◽  
Skin To Skin ◽  
The Impact

BackgroundThere is a lack of clarity of what constitutes the starting point of a clinical pathway for infants at-risk of hypoglycaemia. Glucose-centric pathways (GCP) identify low glucose in the first 2 hours of life that may not represent clinical hypoglycaemia and can lead to inappropriate glucose management with infusions and medications.ObjectiveTo study the impact of a feed-centric pathway (FCP) on the number of admissions for hypoglycaemia to level 2 special care nursery (SCN) and the need for parenteral glucose/medications, compared to GCP.MethodsThis project was conducted over 2 years, before and after switching from a GCP to FCP in our institution. FCP involves skin-to-skin care, early breast feeding, checking glucose at 2 hours and use of buccal glucose. The primary outcome was the number of SCN admissions for hypoglycaemia. Secondary outcomes include the number of infants needing intravenous glucose, medications and length of SCN stay.ResultsOf 23 786 live births, 4438 newborns were screened. We screened more infants at-risk for hypoglycaemia using the FCP (GCP:1462/11969, 12.2% vs FCP:2976/11817, 25.1%) but significantly reduced SCN admissions (GCP:246/1462, 16.8% vs FCP:102/2976, 3.4%; p<0.0001). Fewer but proportionally more FCP newborns required intravenous glucose (GCP: 136/246, 55% vs FCP: 88/102, 86%; p=0.000). Compared with GCP, FCP reduced the total duration of stay in SCN by 104 days per annum, reducing the cost of care. However, the mean length of SCN stay for FCP was higher (GCP:2.43 days vs FCP:3.49 days; p=0.001). There were no readmissions for neonatal hypoglycaemia to our institution.ConclusionThe use of FCP safely reduced SCN admissions, averted avoidable escalation of care and helped identify infants who genuinely required intravenous glucose and SCN care, allowing more efficient utilisation of healthcare resources.

The Perception of Involuntary Prosaccades in an Antisaccade Task

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 275-275
Author(s):  
A Mokler ◽  
B Fischer
Keyword(s):  
Error Rate ◽  
Reaction Times ◽  
Stimulus Onset ◽  
Error Rates ◽  
Data Sets ◽  
Antisaccade Task ◽  
Key Press ◽  
Extra Peak ◽  
The Mean ◽  
Strong Mode

In an antisaccade task subjects are required to generate a voluntary saccade to the side opposite to a small visual stimulus. With fixation-point offset preceding stimulus onset (gap) subjects produce some involuntary saccades to the stimulus and correct them by a second saccade. We wanted to know whether the subjects recognised their errors and whether a recognised sequence (error followed by correction) is different from an unrecognised sequence. To test the access to the correction mechanism, subjects were asked in subsequent experiments to produce the error-correction sequence voluntarily (voluntary sequence). We used the gap = 200 ms condition. A valid cue was presented 100 ms before stimulus onset. This manipulation increased the error rate (Fischer and Weber, 1996 Experimental Brain Research109 507 – 512). Subjects indicated errors by key-press. The rate of recognised and unrecognised errors, saccadic size, reaction times (SRT), and correction times (CRT) were determined. Altogether 93 data sets (400 trials each) from 38 subjects were analysed. The mean error rate was 20%, of which 62% went unrecognised. In sessions with high error rates the fraction of unrecognised errors was high. The SRT of the errors ranged from 80 to 170 ms with a strong mode of express saccades at 100 ms. Both types of errors had the same mean SRT of 117 – 119 ms. The unrecognised errors were 0.4 deg smaller. They were corrected after a mean CRT of 95 ms. The recognised errors were corrected after 127 ms; in the voluntary sequence the correction occurred after 217 ms. The CRT distributions differ from each other with the unrecognised errors having an extra peak around 45 ms, suggesting different modes of correction, to which perception has different access. These results raise the question why the large and long-lasting changes of the retinal image escape the conscious perception so often.

scholarly journals Exploring the impact of a brief mindfulness induction on motor inhibitory control

2020 ◽  
Vol 1 ◽  
Author(s):  
Satish Jaiswal ◽  
Shao-Yang Tsai ◽  
Chi-Hung Juan ◽  
Wei-Kuang Liang ◽  
Neil G. Muggleton
Keyword(s):  
Inhibitory Control ◽  
Reaction Times ◽  
Stop Signal ◽  
Mindfulness Training ◽  
Mindfulness Practice ◽  
Stop Signal Task ◽  
Motor Inhibition ◽  
Mindfulness Induction ◽  
Marginal Improvement ◽  
The Impact

AbstractInhibitory control can be divided into motor and cognitive inhibition. The current research is the first study exploring the impact of brief mindfulness training on motor inhibition, measured by a stop signal task in participants without any meditation experience. Motor inhibition performance was compared before and immediately after three different conditions; a brief mindfulness induction, a resting state and an active control session in which participants listened to their favorite music. Post-test learning effect on go-reaction times was seen for the resting and mindfulness conditions, but was absent in the music session, possibly due to emotional arousal might have led slower responses. Brief mindfulness training did not significantly alter inhibitory control, although marginal improvement in stop signal reaction time following the mindfulness induction was observed. Motor inhibition appears unresponsive to either short-term or long-term mindfulness practice. Future mindfulness studies should explore a broad spectrum of cognitive functions and populations.

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