Conditioned inhibition, inhibitory learning, response inhibition, and inhibitory control: Outlining a conceptual clarification.

Inhibition can be defined as a phenomenon in which an agent prevents or suppresses a behavioral state that would otherwise occur. Associative learning studies have extensively examined how experiences shape the acquisition of inhibitory behavioral tendencies across many species and situations. Associative inhibitory phenomena can be studied at various levels of analysis. One could focus on the trajectory of behavioral change involved in learning from negative statistical associations between discrete events (inhibitory learning). Alternatively, one could be interested in the effects of accumulated experience with those negative associations (conditioned inhibition). One could rather be interested in how organisms implement what they learn through experiences involving negative associations (response inhibition). Yet, one could inquire into how the capacity of learning negative associations and performing accordingly varies between individuals and along time for the same individual (inhibitory control). This article presents a tentative taxonomy addressing different levels of analysis of associative inhibitory phenomena by using different terms for each. In addition, recent evidence and certain unresolved issues at each level are thoroughly scrutinized and contrasted with prior findings. The empirical and theoretical advances made by modeling inhibition as an associative learning phenomenon have provided scaffolds for the current knowledge and emerging accounts of the topic. Some of those emerging accounts have the potential to bridge different levels of analysis and foster "cross-pollination" of ideas among broad fields beyond associative learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The nervous system as a solution for implementing closed negative feedback control loops.

Behavior can be regarded as the output of a system (action), as a function linking stimulus to response (reaction), or as an abstraction of the bidirectional relationship between the environment and the organism (interaction). When considering the latter possibility, a relevant question arises concerning how an organism can materially and continuously implement such a relationship during its lifetime in order to perpetuate itself. The feedback control approach has taken up the task of answering just that question. During the last several decades, said approach has been progressing and has started to be recognized as a paradigm shift, superseding certain canonical notions in mainstream behavior analysis, cognitive psychology, and even neuroscience. In this paper, we describe the main features of feedback control theory and its associated techniques, concentrating on its critiques of behavior analysis, as well as the commonalities they share. While some of feedback control theory's major critiques of behavior analysis arise from the fact that they focus on different levels of organization, we believe that some are legitimate and meaningful. Moreover, feedback control theory seems to blend with neurobiology more smoothly as compared to canonical behavior analysis, which only subsists in a scattered handful of fields. If this paradigm shift truly takes place, behavior analysts-whether they accept or reject this new currency-should be mindful of the basics of the feedback control approach.

Latin American surgical outcomes study: study protocol for a multicentre international observational cohort study of patient outcomes after surgery in Latin American countries.

Background: Reported data suggest that 4.2 million deaths will occur within 30 days of surgery worldwide each year, half of which are in low- and middle-income countries. Postoperative complications are a leading cause of long-term morbidity and mortality. Patients who survive and leave the hospital after surgical complications regularly experience reductions in long-term survival and functional independence, resulting in increased costs. With a high volume of surgery performed, there is a growing perception of the substantial impact of even minor enhancements in perioperative care. The Latin American Surgical Outcomes Study (LASOS) is an international, multicentre, prospective cohort study of adults submitted to in-patient surgery in Latin America aiming to provide detailed data describing postoperative complications and surgical mortality. Methods: LASOS is a 7 day cohort study of adults undergoing surgery in Latin America. Details of preoperative risk factors, intraoperative care, and postoperative outcomes will be collected. The primary outcome will be in-hospital postoperative complications of any cause. Secondary outcomes include in-hospital all-cause mortality, duration of hospital stay after surgery, and admission to a critical care unit within 30 days after surgery during the index hospitalisation. Results: The LASOS results will be published in peer-reviewed journals, reported and presented at international meetings, and widely disseminated to patients and public in participating countries via mainstream and social media. Conclusions: The LASOS may augment our understanding of postoperative complications and surgial mortality in Latin America. Clinical trial registration: NCT05169164.

The Role of the Lateral Habenula in Inhibitory Learning from Reward Omission.

The lateral habenula (LHb) is a phylogenetically primitive brain structure that plays a key role in learning to inhibit distinct responses to specific stimuli. This structure is activated by primary aversive stimuli, cues predicting an imminent aversive event, unexpected reward omissions, and cues associated with the omission of an expected reward. The most widely described physiological effect of LHb activation is acutely suppressing midbrain dopaminergic signaling. However, recent studies have identified multiple means by which the LHb promotes this effect as well as other mechanisms of action. These findings reveal the complex nature of LHb circuitry. The present paper reviews the role of this structure in learning from reward omission. We approach this topic from the perspective of computational models of behavioral change that account for inhibitory learning to frame key findings. Such findings are drawn from recent behavioral neuroscience studies that use novel brain imaging, stimulation, ablation, and reversible inactivation techniques. Further research and conceptual work are needed to clarify the nature of the mechanisms related to updating motivated behavior in which the LHb is involved. As yet, there is little understanding of whether such mechanisms are parallel or complementary to the well-known modulatory function of the more recently evolved prefrontal cortex.

Three Laboratory Procedures for Assessing Different Manifestations of Impulsivity in Rats.

The present article provides a guide for the conduction and analysis of three conditioning-based protocols to evaluate impulsivity in rats. Impulsivity is a meaningful concept because it is associated with psychiatric conditions in humans and with maladaptive behavior in non-human animals. It is believed that impulsivity is composed of separate factors. There are laboratory protocols devised to assess each of these factors using standardized automated equipment. Delay discounting is associated with the incapacity to be motivated by delayed outcomes. This factor is evaluated through intertemporal choice protocols, which consist of presenting the individual with a choice situation involving an immediate reward and a larger but delayed reward. Response inhibition deficit is associated with the incapacity to withhold prepotent responses. Differential reinforcement of low rates (DLR) and feature-negative discrimination protocols assess the response inhibition deficit factor of impulsivity. The former imposes a condition to a motivated individual in which most wait a minimum period of time for a response to be rewarded. The latter evaluates the capacity of individuals to refrain from food seeking responses when a signal of the absence of food is presented. The purpose of these protocols is to construct an objective quantitative measure of impulsivity, which serves to make cross-species comparisons, allowing the possibility of translational research. The advantages of these particular protocols include their easy set-up and application, which stems from the relatively small amount of equipment needed and the automated nature of these protocols.

Conditioned inhibition: Historical critiques and controversies in the light of recent advances.

Conditioned inhibition is a Pavlovian learning phenomenon in which a stimulus that predicts the absence of an otherwise expected outcome comes to control an organism's responding. Such responding usually manifests as a tendency that opposes that of a stimulus that predicts the outcome, also known as a conditioned excitor. Some learning theorists have expressed concerns about the validity and usefulness of conditioned inhibition as a concept; claims that may have negatively affected the reputation of this research area. This article offers a contemporary review of critiques of and controversies over conditioned inhibition and of arguments advanced in its defense. Some of these disputes have been reported in previous reviews, but here we have sought to compile the most representative among them. We also propose new arguments that answer some of those critiques. We then address the most prominent theoretical accounts of conditioned inhibition, identifying commonalities and differences among some of them. Finally, we review recent studies of conditioned inhibition. Some of the new findings contribute to rejecting early critiques of conditioned inhibition and others further elucidate the nature of this phenomenon. A new set of studies suggests that a deficit in conditioned inhibition characterizes some psychiatric conditions, illustrating its translational importance. We believe that new generations of researchers will benefit from being aware of past controversies and how they may have shaped the current conception of conditioned inhibition. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Toward a Unifying Account of Impulsivity and the Development of Self-Control.

Impulsivity has traditionally been thought to involve various behavioral traits that can be measured using different laboratory protocols. Whereas some authors regard different measures of impulsivity as reflecting fundamentally distinct and unrelated behavioral tendencies (fragmentation approach), others regard those different indexes as analogue forms of the same behavioral tendency, only superficially different (unification approach). Unifying accounts range from mere intuitions to more sophisticated theoretical systems. Some of the more complete attempts at unifying are intriguing but have validity weaknesses. We propose a new unifying attempt based on theoretical points posed by other authors and supplemented by theory and research on associative learning. We then apply these assumptions to characterize the paradigms used to study impulsivity in laboratory settings and evaluate their scope as an attempt at unification. We argue that our approach possesses a good balance of parsimony and empirical and theoretical grounding, as well as a more encompassing scope, and is more suitable for experimental testing than previous theoretical frameworks. In addition, the proposed approach is capable of generating a new definition of impulsivity and outlines a hypothesis of how self-control can be developed. Finally, we examine the fragmentation approach from a different perspective, emphasizing the importance of finding similarities among seemingly different phenomena.

Control del estímulo en programas fijos y variables definidos temporalmente / Stimulus control in fixed and variable temporally-defined schedules / Controle do estímulo em programas fixos e variáveis definidos temporalmente

Con el objetivo de evaluar el desarrollo del control del estímulo, seis ratas fueron expuestas a un programa de reforzamiento definido temporalmente (T = 60-s, = 0.5) en el que los subciclos tD y tΔ se correlacionaron con diferentes estímulos auditivos y probabilidades de reforzamiento de 1 y 0, respectivamente. Para tres ratas el subciclo tD siempre fue seguido del subciclo tΔ, mientras que para las ratas restantes ambos subciclos se presentaron de manera aleatoria (p = .5) dentro de la sesión. Al final del experimento, las frecuencias de respuesta de presión de la palanca fueron más altas durante tD y en presencia del estímulo que señaló dicho subciclo, que durante tΔ en todas las ratas. Los resultados indican que la disponibilidad limitada de reforzamiento de los programas definidos temporalmente no impide el control del estímulo, así como que dicho control se desarrolla sin patrones conductuales derivados de la regularidad secuencial entre los subciclos. Adicionalmente, los resultados cuestionan el posible desarrollo de una función de reforzador condicionado por parte del estímulo en el subciclo tΔ.

In order to evaluate the development of stimulus control, six rats were exposed to a temporally defined reinforcement schedule (T = 60-s, = 0.5) in which tD and tΔ were correlated with different auditory stimuli and with reinforcement probabilities of 1 and 0, respectively. For three rats, tD subcycle always was followed by tΔ subcycle, while for the remaining rats both subcycles were presented randomly (p = .5) within the session. At the end of the experiment, lever-pressing response frequencies were higher during tD and in the presence of the stimulus that signaled such subcycle than during tΔ subcycle for all rats. Results indicate that the limited-hold reinforcement in temporally defined schedules does not necessarily prevent stimulus control, and that such control develops without any behavioral pattern derived from sequential regularity between subcycles. Additionally, results call in to question the possible development of a conditioned reinforcement function by the stimulus in tΔ subcycle.

Com o objetivo de avaliar o desenvolvimento do controle do estímulo, seis ratos foram expostos a um programa de reforço definido temporalmente (T = 60-s, = 0.5) no qual os subciclos tD e tΔ se correlacionaram com diferentes estímulos auditivos e probabilidades de reforço de 1 e 0, respectivamente. Para três ratos, o subciclo tD sempre foi seguido do subciclo tΔ, enquanto, para os ratos restantes, ambos os subciclos foram apresentados de maneira aleatória (p = ,5) dentro da sessão. Ao final da experiência, as frequências de resposta de pressão da alavanca foram mais altas durante tD e em presença do estímulo que sinalizou esse subciclo do que durante tΔ em todos os ratos. Os resultados indicam que a disponibilidade limitada de reforço dos programas definidos temporalmente não impede o controle do estímulo, da mesma forma que esse controle se desenvolve sem padrões comportamentais derivados da regularidade sequencial entre os subciclos. Além disso, os resultados questionam o possível desenvolvimento de uma função de reforçador condicionado por parte do estímulo no subciclo tΔ.

Training a new response using conditioned reinforcement.

Some of the most frequently used methods in the study of conditioned reinforcement seem to be insufficient to demonstrate the effect. The clearest way to assess this phenomenon is the training of a new response. In the present study, rats were exposed to a situation in which a primary reinforcer and an arbitrary stimulus were paired and subsequently the effect of this arbitrary event was assessed by presenting it following a new response. Subjects under these conditions emitted more responses compared to their own responding before the pairing and to their responding on a similar operandum that was available concurrently that had no programmed consequences. Response rates also were higher compared to responding by subjects in similar conditions in which there was no contingency (a) between the arbitrary stimulus and the reinforcer, (b) between the response and the arbitrary stimulus or (c) both. Results are discussed in terms of necessary and sufficient conditions to study conditioned reinforcement.

Efecto de tres estrategias de suplementación con hierro y ácido fólico para el control y prevención de la anemia ferropriva en mujeres embarazadas

En todo el mundo, las embarazadas constituyen el grupo más vulnerable frente a la anemia ferropriva, debido a los aportes insuficientes de este nutriente en la dieta y a sus altos requerimientos metabólicos. No obstante, los esfuerzos encaminados al control y prevención de esta deficiencia, la prevalencia de la anemia no ha disminuido en los últimos años. La suplementación con hierro/ácido fólico constituye la principal estyrategia para el control de la anemia en el embarazo. Los mecanismos de aplicación efectiva de esta estrategia han sido revisados en los últimos años, a fin de lograr un impacto y control efectivo de la anemia de este grupo poblacional. Actualmente se propone la administración de una tableta de 200 mg/día de sulfato ferroso, lo que conlleva la presencia de efectos indeseables relacionados con dosis u frecuencia de administración del mismo. Estudios recientes ponen en evidencia que la adminsitración diaria de hierro reduce la capacidad de absorción intestinal por varios días, debido a un bloqueo mucoso por sobrecarga; mientras que la administración intermitente mejora la absorción de la dosis adminsitrada. Se realizó un estudio experimental en 90 mujeres embarazadas, sin patologías sobreañadidas, con una edad promedio de 25.8 +ó- 0.7 años, que acudieron a la consulta prenatal en el Hospital Gineco Obstétrico Isidro Ayora. Se asignaron aleatoriamente a uno de los tres esquemas de suplementación: 1) una tabla semanal; 2) dos tabletas semanales 3) una tableta diaria (UNICEF, 200 mg SO4 Fe+0.25 mg Ac. Fólico). En las madres gestantes se valoró; status de hierro al inicio y al parto; en los recíen nacidos; antropometría y status de hierro en la sangre de cordón (extremo placentario).