Biogeographic and seasonal differences in consumer pressure underlie strong predation in the tropics.

Biotic interactions play a critical role in shaping patterns of global biodiversity. While several macroecological studies provide evidence for stronger predation in tropical regions compared with higher latitudes, results are variable even within the tropics, and the drivers of this variability are not well understood. We conducted two complementary standardized experiments on communities of sessile marine invertebrate prey and their associated predators to test for spatial and seasonal differences in predation across the tropical Atlantic and Pacific coastlines of Panama. We further tested the prediction that higher predator diversity contributes to stronger impacts of predation, using both direct observations of predators and data from extensive reef surveys. Our results revealed substantially higher predation rates and stronger effects of predators on prey in the Pacific than in the Atlantic, demonstrating striking variation within tropical regions. While regional predator diversity was high in the Atlantic, functional diversity at local scales was markedly low. Peak predation strength in the Pacific occurred during the wet, non-upwelling season when ocean temperatures were warmer and predator communities were more functionally diverse. Our results highlight the importance of regional biotic and abiotic drivers that shape interaction strength and the maintenance of tropical communities, which are experiencing rapid environmental change.

Formulation and optimization of pH-sensitive nanocrystals for improved oral delivery.

The challenge of low water solubility in pharmaceutical science profoundly impacts drug absorption and therapeutic effectiveness. Nanocrystals (NC), consisting of drug molecules and stabilizing agents, offer a promising solution to enhance solubility and control release rates. In the pharmaceutical industry, top-down techniques are favored for their flexibility and cost-effectiveness. However, increased solubility can lead to premature drug dissolution in the stomach, which is problematic due to the acidic pH or enzymes. Researchers are exploring encapsulating agents that facilitate drug release at customized pH levels as a valuable strategy to address this. This study employed wet milling and spray drying techniques to create encapsulated NC for delivering the drug to the intestinal tract using the model drug ivermectin (IVM). Nanosuspensions (NS) were efficiently produced within 2 h using NanoDisp®, with a particle size of 198.4 ± 0.6 nm and a low polydispersity index (PDI) of 0.184, ensuring uniformity. Stability tests over 100 days at 4 °C and 25 °C demonstrated practical viability, with no precipitation or significant changes observed. Cytotoxicity evaluations indicated less harm to Caco-2 cells compared to the pure drug. Furthermore, the solubility of the NC increased by 47-fold in water and 4.8-fold in simulated intestinal fluid compared to the pure active compound. Finally, dissolution tests showed less than 10% release in acidic conditions and significant improvement in simulated intestinal conditions, promising enhanced drug solubility and bioavailability. This addresses a long-standing pharmaceutical challenge in a cost-effective and scalable manner.

Controlling the input: How one-year-old infants sustain visual attention.

Traditionally, the exogenous control of gaze by external saliencies and the endogenous control of gaze by knowledge and context have been viewed as competing systems, with late infancy seen as a period of strengthening top-down control over the vagaries of the input. Here we found that one-year-old infants control sustained attention through head movements that increase the visibility of the attended object. Freely moving one-year-old infants (n = 45) wore head-mounted eye trackers and head motion sensors while exploring sets of toys of the same physical size. The visual size of the objects, a well-documented salience, varied naturally with the infant's moment-to-moment posture and head movements. Sustained attention to an object was characterized by the tight control of head movements that created and then stabilized a visual size advantage for the attended object for sustained attention. The findings show collaboration between exogenous and endogenous attentional systems and suggest new hypotheses about the development of sustained visual attention.

Review on Generation and Characterization of Copper Particles and Copper Composites Prepared by Mechanical Milling on a Lab-Scale.

This review aims to expose mechanical milling as an alternative method for generating copper-based particles (copper particles (CuP) and copper composites (CuC)); more specifically, via a top-down or bottom-up approach, on a lab-scale. This work will also highlight the different parameters that can affect the size distribution, the type, and the morphology of the obtained CuP or CuC, such as the type of mechanical mill, ball-to-powder ratios (BPR), the milling speed, milling time, and the milling environment, among others. This review analyzes various papers based on the Cu-based particle generation route, which begins with a pretreatment step, then mechanical milling, its approach (top-down or bottom-up), and the post-treatment. Finally, the characterization methods of the resulting CuP and CuC through mechanical milling are also discussed.

Top-down projections of the prefrontal cortex to the ventral tegmental area, laterodorsal tegmental nucleus, and median raphe nucleus.

Anatomical and functional evidence suggests that the PFC is fairly unique among all cortical regions, as it not only receives input from, but also robustly projects back to mesopontine monoaminergic and cholinergic cell groups. Thus, the PFC is in position to exert a powerful top-down control over several state-setting modulatory transmitter systems that are critically involved in the domains of arousal, motivation, reward/aversion, working memory, mood regulation, and stress processing. Regarding this scenario, the origin of cortical afferents to the ventral tegmental area (VTA), laterodorsal tegmental nucleus (LDTg), and median raphe nucleus (MnR) was here compared in rats, using the retrograde tracer cholera toxin subunit b (CTb). CTb injections into VTA, LDTg, or MnR produced retrograde labeling in the cortical mantle, which was mostly confined to frontal polar, medial, orbital, and lateral PFC subdivisions, along with anterior- and mid-cingulate areas. Remarkably, in all of the three groups, retrograde labeling was densest in layer V pyramidal neurons of the infralimbic, prelimbic, medial/ventral orbital and frontal polar cortex. Moreover, a lambda-shaped region around the apex of the rostral pole of the nucleus accumbens stood out as heavily labeled, mainly after injections into the lateral VTA and LDTg. In general, retrograde PFC labeling was strongest following injections into MnR and weakest following injections into VTA. Altogether, our findings reveal a fairly similar set of prefrontal afferents to VTA, LDTg, and MnR, further supporting an eminent functional role of the PFC as a controller of major state-setting mesopontine modulatory transmitter systems.

Synthesis, Purification, and Characterization of Carbon Dots from Non-Activated and Activated Pyrolytic Carbon Black.

In this work, carbon dots were created from activated and non-activated pyrolytic carbon black obtained from waste tires, which were then chemically oxidized with HNO3. The effects caused to the carbon dot properties were analyzed in detail through characterization techniques such as ion chromatography; UV-visible, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy; ζ potential; transmission electron microscopy (TEM); and spectrofluorometry. The presence of functional groups on the surface of all carbon dots was revealed by UV-visible, FTIR, XPS, and Raman spectra. The higher oxidation degrees of carbon dots from activated precursors compared to those from nonactivated precursors resulted in differences in photoluminescence (PL) properties such as bathochromic shift, lower intensity, and excitation-dependent behavior. The results demonstrate that the use of an activating agent in the recovery of pyrolytic carbon black resulted in carbon dots with different PL properties. In addition, a dialysis methodology is proposed to overcome purification obstacles, finding that 360 h were required to obtain pure carbon dots synthesized by a chemical oxidation method.

Medial prefrontal cortical control of reward- and aversion-based behavioral output: Bottom-up modulation.

How does the brain guide our actions? This is a complex issue, where the medial prefrontal cortex (mPFC) plays a crucial role. The mPFC is essential for cognitive flexibility and decision making. These functions are related to reward- and aversion-based learning, which ultimately drive behavior. Though, cortical projections and modulatory systems that may regulate those processes in the mPFC are less understood. How does the mPFC regulate approach-avoidance behavior in the case of conflicting aversive and appetitive stimuli? This is likely dependent on the bottom-up neuromodulation of the mPFC projection neurons. In this review, we integrate behavioral-, pharmacological-, and viral-based circuit manipulation data showing the involvement of mPFC dopaminergic, noradrenergic, cholinergic, and serotoninergic inputs in reward and aversion processing. Given that an incorrect balance of reward and aversion value could be a key problem in mental diseases such as substance use disorders, we discuss outstanding questions for future research on the role of mPFC modulation in reward and aversion.

Seasonal upwelling reduces herbivore control of tropical rocky intertidal algal communities.

Communities are shaped by a variety of ecological and environmental processes, each acting at different spatial scales. Seminal research on rocky shores highlighted the effects of consumers as local determinants of primary productivity and community assembly. However, it is now clear that the species interactions shaping communities at local scales are themselves regulated by large-scale oceanographic processes that generate regional variation in resource availability. Upwelling events deliver nutrient-rich water to coastal ecosystems, influencing primary productivity and algae-herbivore interactions. Despite the potential for upwelling to alter top-down control by herbivores, we know relatively little about the coupling between oceanographic processes and herbivory on tropical rocky shores, where herbivore effects on producers are considered to be strong and nutrient levels are considered to be limiting. By replicating seasonal molluscan herbivore exclusion experiments across three regions exposed to varying intensity of seasonal upwelling, separated by hundreds of kilometers along Panama's Pacific coast, we examine large-scale environmental determinants of consumer effects and community structure on tropical rocky shores. At sites experiencing seasonal upwelling, grazers strongly limited macroalgal cover when upwelling was absent, leading to dominance by crustose algae. As nutrients increased and surface water cooled during upwelling events, increases in primary productivity temporarily weakened herbivory, allowing foliose, turf and filamentous algae to replace crusts. Meanwhile, grazer effects were persistently strong at sites without seasonal upwelling. Our results confirm that herbivores are key determinants of tropical algal cover, and that the mollusk grazing guild can control initial stages of macroalgal succession. However, our focus on regional oceanographic conditions revealed that bottom-up processes regulate top-down control on tropical shorelines. This study expands on the extensive body of work highlighting the influence of upwelling on local ecological processes by demonstrating that nutrient subsidies delivered by upwelling events can weaken herbivory in tropical rocky shores.

Predictive processing: Is the future just a memory?

Predictive processing seems like a radical departure from traditional theories of information processing in the brain, but a broader view of predictions highlights many similarities with standard frameworks. Predictive processing is memory and competitive bias in a new outlook-and we should use this correspondence to advance research on both fronts.

Can small-bodied Daphnia control Raphidiopsis raciborskii in eutrophic tropical lakes? A mesocosm experiment.

Raphidiopsis raciborskii is being considered an expanding, invasive species all over the world. It is a potentially toxin producer cyanobacterium and form blooms specially in (sub)tropical lakes, causing concern to public health. Thus, controlling such phenomena are of vital importance. To test the hypothesis that a tropical clone of Daphnia laevis is able to reduce the biomass of R. raciborskii, we performed a mesocosm experiment simulating a bloom of this cyanobacterium in field conditions and exposing it to ecologically relevant densities of daphniids. In addition, we tested the hypothesis that omnivorous fish would be able to exert a top-down effect on Daphnia, decreasing the effectiveness of this control. We used treatments with (10 and 20 Daphnia L-1) or without Daphnia and fish (3 per mesocosm). Daphnia was able to significantly reduce the biomass of R. raciborskii only at the highest density tested. Fish had low effect on Daphnia biomass, but it is suggested that nutrient recycling by fish might have contributed to the higher R. raciborskii biomass in fish treatments. This is the first evidence of Daphnia control over saxitoxin-producing cyanobacteria in a tropical ecosystem.

Development of Polyelectrolyte Complex Nanoparticles-PECNs Loaded with Ampicillin by Means of Polyelectrolyte Complexation and Ultra-High Pressure Homogenization (UHPH).

This study was focused on synthesizing, characterizing and evaluating the biological potential of Polyelectrolyte Complex Nanoparticles (PECNs) loaded with the antibiotic ampicillin. For this, the PECNs were produced initially by polyelectrolytic complexation (bottom-up method) and subsequently subjected to ultra-high pressure homogenization-UHPH (top-down method). The synthetic polymeric materials corresponding to the sodium salt of poly(maleic acid-alt-octadecene) (PAM-18Na) and the chloride salt of Eudragit E-100 (EuCl) were used, where the order of polyelectrolyte complexation, the polyelectrolyte ratio and the UHPH conditions on the PECNs features were evaluated. Likewise, PECNs were physicochemically characterized through particle size, polydispersity index, zeta potential, pH and encapsulation efficiency, whereas the antimicrobial effect was evaluated by means of the broth microdilution method employing ampicillin sensitive and resistant S. aureus strains. The results showed that the classical method of polyelectrolyte complexation (bottom-up) led to obtain polymeric complexes with large particle size and high polydispersity, where the 1:1 ratio between the titrant and receptor polyelectrolyte was the most critical condition. In contrast, the UHPH technique (top-down method) proved high performance to produce uniform polymeric complexes on the nanometric scale (particle size < 200 nm and PDI < 0.3). Finally, it was found there was a moderate increase in antimicrobial activity when ampicillin was loaded into the PECNs.

Anthocyanins: New techniques and challenges in microencapsulation.

Anthocyanins are a bioactive compound belonging to the flavonoid classthatis present in human nutrition through plant-based foods. Due to their antioxidant properties, several health benefits related to their consumption are reported in the literature. The stability of the color and the properties of anthocyanins is strongly affected by pH, solvent, temperature, and other environmental conditions. In addition, the insufficient residence time of anthocyanins in the upper digestive tract causes apartialabsorption, which needs to be improved. These factshave led researchers to investigate new forms of processing that provide minimal degradation. Microencapsulation is a promising possibility to stabilize anthocyanin extracts and allow their addition to food products in a more stable form. The microcapsules can still provide a prolonged gastrointestinal retention time caused by the improvement of the bioadhesive properties in the mucus covering the intestinal epithelium. Although there are efficient and emerging techniques, anthocyanins microencapsulation is still a challenge for the food industry. The purpose of this work is to provide an overview of anthocyanins structure, absorptionand protection, and to show the main conventional and emerging microencapsulation methods and their pros and cons.

Biogeographic context dependence of trophic cascade strength in bromeliad food webs.

Ecosystem functions and the biomass of lower trophic levels are frequently controlled by predators. The strength of top-down control in these trophic cascades can be affected by the identity and diversity of predators, prey, and resources, as well as environmental conditions such as temperature, moisture, and nutrient loading, which can all impact interaction strength between trophic levels. Few studies have been able to replicate a complete community over a large geographic area to compare the full trophic cascade in a manipulative experiment. Here, we identify geographic dependency in trophic cascade strength, and the driving factors and specific mechanisms behind it, by combining geographically replicated experiments with a novel approach of community analogues of common garden and transplant experiments. We studied a predator-detritivore-detritus food web in bromeliads in Puerto Rico, Costa Rica, and Brazil. We found that interaction strengths between resources, consumers, and predators were strongly site-specific, but the exact mechanism differed between trophic levels. Large bodied predators created strong interaction strengths between predator and consumer trophic levels, reducing consumer abundance regardless of the geographic location, whereas small-bodied predators created weak interactions with no impact on consumer abundances in any site. In contrast, the interaction strength between consumers and resources varied among sites, depending on the dominant species of leaf detritus. More labile leaf species in Costa Rica created a strong consumer-resource interaction and therefore strong trophic cascade, whereas tougher leaf species in Brazil created a weak consumer-resource interaction, and an overall weaker trophic cascade. Our study highlights the importance of replicating experiments over geographic scales to understand general patterns of ecological processes.

Role of Late DMSA Renal Scan in Detecting High-Grade Vesicoureteral Reflux.

OBJECTIVE: To determine the performance of late dimercaptosuccinic acid (DMSA) renal scans in identifying high-grade (III-V) vesicoureteral reflux (VUR) in children aged over 3 y with a febrile urinary tract infection (fUTI) history that has not been timely investigated. METHODS: In this retrospective study of diagnostic accuracy, the clinical records of children aged between 3 and 18 y with fUTI history evaluated consecutively at Nephrology Unit of Hospital General de Niños Pedro de Elizalde, Argentina between 2006 and 2016 were reviewed. Patients with previously diagnosed renal or urinary tract abnormalities or who underwent previous postnatal genitourinary imaging were excluded. Only those assessed by renal and bladder ultrasound (RBUS), voiding cystourethrogram (VCUG) and late 6-mo DMSA scan were analyzed. The ability of the scintigraphy in identifying high-grade VUR was determined by comparing its findings with those of VCUG. RESULTS: In 122 children (median age 5.37 y, 88.5% girls) RBUS was abnormal in 53 (43.4%) and 58 (47.5%) had VUR (30 of high-grade). Abnormal DMSA scan findings (70 patients, 57.4%) were associated with all grade (p = 0.00001) and with high-grade VUR (p = 0.00001). Sensitivity, specificity, negative (NPV) and positive (PPV) predictive values of late DMSA scans for all grades VUR were 93.1%, 75%, 92.3% and 77.1%, respectively. Only 4 patients with low-grade VUR had normal scans. For high-grade VUR, sensitivity and NPV reached 100%. CONCLUSIONS: In older children, the normal late DMSA scan predicted the absence of high-grade VUR, obviating the need for a VCUG. This approach could be a possible strategy for children not studied at acute infection time.

Perceived Duration: The Interplay of Top-Down Attention and Task-Relevant Information.

Perception of time is susceptible to distortions; among other factors, it has been suggested that the perceived duration of a stimulus is affected by the observer's expectations. It has been hypothesized that the duration of an oddball stimulus is overestimated because it is unexpected, whereas repeated stimuli have a shorter perceived duration because they are expected. However, recent findings suggest instead that fulfilled expectations about a stimulus elicit an increase in perceived duration, and that the oddball effect occurs because the oddball is a target stimulus, not because it is unexpected. Therefore, it has been suggested that top-down attention is sometimes sufficient to explain this effect, and sometimes only necessary, with an additional contribution from saliency. However, how the expectedness of a target stimulus and its salient features affect its perceived duration is still an open question. In the present study, participants' expectations about and the saliency of target stimuli were orthogonally manipulated with stimuli presented on a short (Experiment 1) or long (Experiment 2) temporal scale. Four repetitive standard stimuli preceded each target stimulus in a task in which participants judged whether the target was longer or shorter in duration than the standards. Engagement of top-down attention to target stimuli increased their perceived duration to the same extent irrespective of their expectedness. A small but significant additional contribution to this effect from the saliency of target stimuli was dependent on the temporal scale of stimulus presentation. In Experiment 1, saliency only significantly increased perceived duration in the case of expected target stimuli. In contrast, in Experiment 2, saliency exerted a significant effect on the overestimation elicited by unexpected target stimuli, but the contribution of this variable was eliminated in the case of expected target stimuli. These findings point to top-down attention as the primary cognitive mechanism underlying the perceptual extraction and processing of task-relevant information, which may be strongly correlated with perceived duration. Furthermore, the scalar properties of timing were observed, favoring the pacemaker-accumulator model of timing as the underlying timing mechanism.

Consumptive effects and mismatch in predator-prey turnover rates cause inversion of biomass pyramids.

The mismatch between the turnover rates of predators and prey is one of the oldest explanations for the existence of inverted trophic pyramids. To date, the hypotheses regarding trophic pyramids have all been based on consumptive trophic links between predators and prey, and the relative contribution of non-consumptive effects is still unknown. In this study, we investigated if the inversion of pyramids in bromeliad ecosystems is driven by (i) a rapid colonization of organisms having short cohort interval production (CPI), and (ii) the prevalence of consumptive or non-consumptive effects of top predators. We used a manipulative experiment to investigate the patterns of prey colonization and to partition the net effects of the dominant predator (damselfly larvae) on biomass pyramids into consumptive (uncaged damselfly larvae) and non-consumptive effects (caged damselfly larvae). Consumptive effects of damselflies strengthened the inversion of trophic pyramids. Non-consumptive effects, however, did not affect the shape of biomass pyramids. Instead, the rapid colonization of organisms with predominantly short CPI sustained the large biomass of top predators found in natural bromeliad ecosystems. Prey colonized bromeliads rapidly, but this high production was never visible as standing stock because damselflies reduce prey densities by more than a magnitude through direct consumption. Our study adds to the growing evidence that there are a variety of possible ways that biomass can be trophically structured. Moreover, we suggest that the strength of biomass pyramids inversion may change with the time of ecological succession as prey communities become more equitable.

Production of Biocompatible Protein Functionalized Cellulose Membranes by a Top-Down Approach.

Protein functionalized cellulose fibrils were isolated from the tunic of Pyura chilensis and subsequently used to produce protein functionalized cellulose membranes. Bleached cellulose membranes were also obtained and used as reference material. FTIR and Raman spectroscopy demonstrated that the membranes are mostly constituted of cellulose along with the presence of residual proteins and pigments. Protein functionalized cellulose membranes were found to possess ∼3.1% of protein at their surface as measured by X-ray photoelectron spectroscopy. Powder X-ray diffraction, scanning electron microscopy, and thermogravimetric analysis were used to identify and semiquantify the amount of residual sand grains present within the structure of the membranes. The presence of residual proteins was found not to significantly affect the tensile mechanical properties of the membranes. Streaming ζ-potential was used to assess surface charges of the membranes. Below pH 4, nonbleached cellulose membranes possessed highly negative surfaces charges and also significantly less negative surface charges at physiological pH when compared to bleached cellulose membranes. No significant difference was found with respect to growth kinetics of myoblasts at the surface of the membranes for cell culturing times of 48 and 72 h. After 48 h of culture, protein functionalized cellulose-based membranes that possess ∼3.1% of proteins at their surface (H1) were, however, found to promote higher cell density, cell spreading, and more orientated shape cell morphology when compared to the other cellulose-based membranes (H3 and B) evaluated in the present study.

Top-down vs. Bottom-up: alterações no processamento de informações durante a indução de fadiga mental / Top-down vs. bottom-up: alterations in information processing during mental fatigue induction

A Fadiga Mental (FM) ocorre durante ou após um período prolongado de demanda cognitiva repetitiva somado a recompensas insatisfatórias. Este estudo pretende investigar alterações no processamento de informações top-down e bottom-up nocontrole inibitório durante a indução de FM através do protocolo de tarefa cognitiva por tempo prolongado. Participaram do experimento 19 sujeitos (9 homens) com idades entre 18 e 24 anos (M=21,21 DP=1,77), submetidos ao paradigma Go/NoGo contendo cinco blocos de 250 tentativas com intervalos de 30 segundos entre blocos, totalizando 50 minutos de atividade. A ANOVA para medidas repetidas sugere efeito significativo do tempo de realização da tarefa no aumento no tempo de reação do processamento top-down, F4,15 = 3,66, p<0,05, no número de erros por omissão, F4,15 = 4,75, p<0,05, e uma redução no tempo de resposta do processamento bottom-up, F4,15 = 5,39, p<0,05. Estes achados sugerem que a realização de uma tarefa cognitiva durante um período prolongado provoca prejuízo significativo no desempenho cognitivo, com ênfase no processamento de informações top-down, não impedindo a realização de um comportamento, mas prejudicando sua qualidade de execução.

Mental Fatigue (FM) occurs during or after a prolonged period of repetitivecognitive demand coupled with unsatisfactory rewards. This study intends toinvestigate changes in the processing of top-down and bottom-up information oninhibitory control during FM induction through the cognitive task protocol for aprolonged time. A total of 19 subjects (9 males) aged 18 to 24 years (M = 21.21 SD= 1.77) were submitted to the Go / NoGo paradigm containing five blocks of 250trials with 30-second intervals between blocks, totalizing 50 minutes of activity.The ANOVA for repeated measures suggests a significant effect of the time ofaccomplishment of the task in the increase in the time of reaction of the top-downprocessing, F4,15 = 3.66, p <0.05, in the number of errors by default, F4,15 = 4.75, p<0.05, and a reduction in response time of bottom-up processing, F4.15 = 5.39, p<0.05. These findings suggest that performing a cognitive task over a prolongedperiod causes significant impairment in cognitive performance, with an emphasison top-down information processing, not hindering the performance of a behaviorbut impairing its quality of execution.

Top-down vs. Bottom-up: alterações no processamento de informações durante a indução de fadiga mental / Top-down vs. bottom-up: alterations in information processing during mental fatigueinduction

A Fadiga Mental (FM) ocorre durante ou após um período prolongado de demandacognitiva repetitiva somado a recompensas insatisfatórias. Este estudo pretendeinvestigar alterações no processamento de informações top-down e bottom-up nocontrole inibitório durante a indução de FM através do protocolo de tarefacognitiva por tempo prolongado. Participaram do experimento 19 sujeitos (9homens) com idades entre 18 e 24 anos (M=21,21 DP=1,77), submetidos aoparadigma Go/NoGo contendo cinco blocos de 250 tentativas com intervalos de 30segundos entre blocos, totalizando 50 minutos de atividade. A ANOVA paramedidas repetidas sugere efeito significativo do tempo de realização da tarefa noaumento no tempo de reação do processamento top-down, F4,15 = 3,66, p<0,05, nonúmero de erros por omissão, F4,15 = 4,75, p<0,05, e uma redução no tempo deresposta do processamento bottom-up, F4,15 = 5,39, p<0,05. Estes achadossugerem que a realização de uma tarefa cognitiva durante um período prolongadoprovoca prejuízo significativo no desempenho cognitivo, com ênfase noprocessamento de informações top-down, não impedindo a realização de umcomportamento, mas prejudicando sua qualidade de execução.

Mental Fatigue (FM) occurs during or after a prolonged period of repetitivecognitive demand coupled with unsatisfactory rewards. This study intends toinvestigate changes in the processing of top-down and bottom-up information oninhibitory control during FM induction through the cognitive task protocol for aprolonged time. A total of 19 subjects (9 males) aged 18 to 24 years (M = 21.21 SD= 1.77) were submitted to the Go / NoGo paradigm containing five blocks of 250trials with 30-second intervals between blocks, totalizing 50 minutes of activity.The ANOVA for repeated measures suggests a significant effect of the time ofaccomplishment of the task in the increase in the time of reaction of the top-downprocessing, F4,15 = 3.66, p <0.05, in the number of errors by default, F4,15 = 4.75, p<0.05, and a reduction in response time of bottom-up processing, F4.15 = 5.39, p<0.05. These findings suggest that performing a cognitive task over a prolongedperiod causes significant impairment in cognitive performance, with an emphasison top-down information processing, not hindering the performance of a behaviorbut impairing its quality of execution.