Prior Learning of Relevant Nonaversive Information Is a Boundary Condition for Avoidance Memory Reconsolidation in the Rat Hippocampus.

PubMed

Radiske, Andressa; Gonzalez, Maria Carolina; Conde-Ocazionez, Sergio A; Feitosa, Anatildes; Köhler, Cristiano A; Bevilaqua, Lia R; Cammarota, Martín

2017-10-04

Reactivated memories can be modified during reconsolidation, making this process a potential therapeutic target for posttraumatic stress disorder (PTSD), a mental illness characterized by the recurring avoidance of situations that evoke trauma-related fears. However, avoidance memory reconsolidation depends on a set of still loosely defined boundary conditions, limiting the translational value of basic research. In particular, the involvement of the hippocampus in fear-motivated avoidance memory reconsolidation remains controversial. Combining behavioral and electrophysiological analyses in male Wistar rats, we found that previous learning of relevant nonaversive information is essential to elicit the participation of the hippocampus in avoidance memory reconsolidation, which is associated with an increase in theta- and gamma-oscillation power and cross-frequency coupling in dorsal CA1 during reactivation of the avoidance response. Our results indicate that the hippocampus is involved in memory reconsolidation only when reactivation results in contradictory representations regarding the consequences of avoidance and suggest that robust nesting of hippocampal theta-gamma rhythms at the time of retrieval is a specific reconsolidation marker. SIGNIFICANCE STATEMENT Posttraumatic stress disorder (PTSD) is characterized by maladaptive avoidance responses to stimuli or behaviors that represent or bear resemblance to some aspect of a traumatic experience. Disruption of reconsolidation, the process by which reactivated memories become susceptible to modifications, is a promising approach for treating PTSD patients. However, much of what is known about fear-motivated avoidance memory reconsolidation derives from studies based on fear conditioning instead of avoidance-learning paradigms. Using a step-down inhibitory avoidance task in rats, we found that the hippocampus is involved in memory reconsolidation only when the animals acquired the avoidance response in an environment that they had previously learned as safe and showed that increased theta- and gamma-oscillation coupling during reactivation is an electrophysiological signature of this process. Copyright © 2017 the authors 0270-6474/17/379675-11$15.00/0.

Chronic postnatal ornithine administration to rats provokes learning deficit in the open field task.

PubMed

Viegas, Carolina Maso; Busanello, Estela Natacha Brandt; Tonin, Anelise Miotti; Grings, Mateus; Moura, Alana Pimentel; Ritter, Luciana; Zanatta, Angela; Knebel, Lisiane Aurélio; Lobato, Vannessa Araujo; Pettenuzzo, Letícia Ferreira; Vargas, Carmen Regla; Leipnitz, Guilhian; Wajner, Moacir

2012-12-01

Hyperornithinemia is the biochemical hallmark of hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome, an inherited metabolic disease clinically characterized by mental retardation whose pathogenesis is still poorly known. In the present work, we produced a chemical animal model of hyperornithinemia induced by a subcutaneous injection of saline-buffered Orn (2-5 μmol/g body weight) to rats. High brain Orn concentrations were achieved, indicating that Orn is permeable to the blood brain barrier. We then investigated the effect of early chronic postnatal administration of Orn on physical development and on the performance of adult rats in the open field, the Morris water maze and in the step down inhibitory avoidance tasks. Chronic Orn treatment had no effect on the appearance of coat, eye opening or upper incisor eruption, nor on the free-fall righting reflex and on the adult rat performance in the Morris water maze and in the inhibitory avoidance tasks, suggesting that physical development, aversive and spatial localization were not changed by Orn. However, Orn-treated rats did not habituate to the open field apparatus, implying a deficit of learning/memory. Motor activity was the same for Orn- and saline- injected animals. We also verified that Orn subcutaneous injections provoked lipid peroxidation in the brain, as determined by a significant increase of thiobarbituric acid-reactive substances levels. Our results indicate that chronic early postnatal hyperornithinemia may impair the central nervous system, causing minor disabilities which result in specific learning deficiencies.

Effects of activation and blockade of dopamine receptors on the extinction of a passive avoidance reaction in mice with a depressive-like state.

PubMed

Dubrovina, N I; Zinov'eva, D V

2010-01-01

Learning and extinction of a conditioned passive avoidance reaction resulting from neuropharmacological actions on dopamine D(1) and D(2) receptors were demonstrated to be specific in intact mice and in mice with a depressive-like state. Learning was degraded only after administration of the D(2) receptor antagonist sulpiride and was independent of the initial functional state of the mice. In intact mice, activation of D(2) receptors with quinpirole led to a deficit of extinction, consisting of a reduction in the ability to acquire new inhibitory learning in conditions associated with the disappearance of the expected punishment. In mice with the "behavioral despair" reaction, characterized by delayed extinction, activation of D(1) receptors with SKF38393 normalized this process, while the D(2) agonist was ineffective. A positive effect consisting of accelerated extinction of the memory of fear of the dark ("dangerous") sector of the experimental chamber was also seen on blockade of both types of dopamine receptor.

Evidence for the involvement of extinction-associated inhibitory learning in the forced swimming test.

PubMed

Campus, P; Colelli, V; Orsini, C; Sarra, D; Cabib, S

2015-02-01

The forced swimming test (FST) remains one of the most used tools for screening antidepressants in rodent models. Nonetheless, the nature of immobility, its main behavioral measure, is still a matter of debate. The present study took advantage of our recent finding that mice of the inbred DBA/2J strain require a functioning left dorsolateral striatum (DLS) to consolidate long-term memory of FST to test whether immobility is the outcome of stress-related learning. Infusion of the GABA-A agonist muscimol in the left DLS immediately after a single experience of FST prevented and infusion in the left or the right amygdala impaired recall of the acquired levels of immobility in a probe test performed 24h later. Post-training left DLS infusion of muscimol, at a dose capable of preventing retention of FST-induced immobility, did not influence 24h retention of inhibitory avoidance training or of the escape response acquired in a water T-maze. However, this same treatment prevented 24h retention of the extinction training of the consolidated escape response. These results indicate that a left DLS-centered memory system selectively mediates memory consolidation of FST and of escape extinction and support the hypothesis that immobility is the result of extinction-like inhibitory learning involving all available escape responses due to the inescapable/unavoidable nature of FST experience. Copyright © 2014 Elsevier B.V. All rights reserved.

The inhibitory avoidance discrimination task to investigate accuracy of memory.

PubMed

Atucha, Erika; Roozendaal, Benno

2015-01-01

The present study was aimed at developing a new inhibitory avoidance task, based on training and/or testing rats in multiple contexts, to investigate accuracy of memory. In the first experiment, male Sprague-Dawley rats were given footshock in an inhibitory avoidance apparatus and, 48 h later, retention latencies of each rat were assessed in the training apparatus (Shock box) as well as in a novel, contextually modified, apparatus. Retention latencies in the Shock box were significantly longer than those in the Novel box, indicating accurate memory of the training context. When the noradrenergic stimulant yohimbine (0.3 mg/kg, sc) was administered after the training, 48-h retention latencies in the Shock box, but not Novel box, were increased, indicating that the noradrenergic activation enhanced memory of the training experience without reducing memory accuracy. In the second experiment, rats were trained on an inhibitory avoidance discrimination task: They were first trained in an inhibitory avoidance apparatus without footshock (Non-Shock box), followed 1 min later by footshock training in a contextually modified apparatus (Shock box). Forty-eight-hour retention latencies in the Shock and Non-Shock boxes did not differ from each other but were both significantly longer than those in a Novel box, indicating that rats remembered the two training contexts but did not have episodic-like memory of the association of footshock with the correct training context. When the interval between the two training episodes was increased to 2 min, rats showed accurate memory of the association of footshock with the training context. Yohimbine administered after the training also enhanced rats' ability to remember in which training context they had received actual footshock. These findings indicate that the inhibitory avoidance discrimination task is a novel variant of the well-established inhibitory avoidance task suitable to investigate accuracy of memory.

Ontogeny of passive avoidance learning in domestic chicks: punishment of key-peck and running responses.

PubMed

Mattingly, B A; Zolman, J F

1980-08-01

The effect of the number of prepunishment acquisition trials on the age dependency of passive avoidance (PA) learning of the Vantress X Arbor Acre chick was determined in both key-peck and runway tests. In nine experiments, 1- and 4-day-old chicks were first trained to respond for heat reward, and then, following a variable number of reinforced acquisition trials, the chicks' responses were punished with aversive wing shocks. The major finding of these experiments was that the age dependency of PA learning of the young chick is related specifically to the number of reinforced training trials given prior to PA testing. When a large number of prepunishment acquisition trials were given, 1-day-old chicks learned as quickly as 4-day-old chicks to withhold responding when punished. However, when only a few acquisition trials preceded PA testing, 1-day-old chicks showed significantly less response suppression than 4-day-old chicks. These acquisition effects indicate that the age-dependent changes in PA learning of the chick are not solely due to developmental changes in general inhibitory ability. Rather, these PA results suggest that the 1-day-old chick, compared with the 4-day-old chick, is deficient in learning, or detecting changes in, stimulus- and/or response-reinforcement contingencies.

Role of D2 dopamine receptors of the ventral pallidum in inhibitory avoidance learning.

PubMed

Lénárd, László; Ollmann, Tamás; László, Kristóf; Kovács, Anita; Gálosi, Rita; Kállai, Veronika; Attila, Tóth; Kertes, Erika; Zagoracz, Olga; Karádi, Zoltán; Péczely, László

2017-03-15

In our present experiments, the role of D2 dopamine (DA) receptors of the ventral pallidum (VP) was investigated in one trial step-through inhibitory avoidance paradigm. Animals were shocked 3 times in the conditioning trial, with 0.5mA current for 1s. Subsequently bilateral microinjection of the D2 DA receptor agonist quinpirole was administered into the VP in three doses (0.1μg, 1.0μg or 5.0μg in 0.4μl saline). We also applied the D2 DA receptor antagonist sulpiride (0.4μg in 0.4μl saline) alone or 15min prior to the agonist treatment to elucidate whether the agonist effect was specific for the D2 DA receptors. Control animals received saline. In a supplementary experiment, it was also investigated whether application of the same conditioning method leads to the formation of short-term memory in the experimental animals. In the experiment with the D2 DA receptor agonist, only the 0.1μg quinpirole increased significantly the step-through latency during the test trials: retention was significant compared to the controls even 2 weeks after conditioning. The D2 DA receptor antagonist sulpiride pretreatment proved that the effect was due to the agonist induced activation of the D2 DA receptors of the VP. The supplementary experiment demonstrated that short-term memory is formed after conditioning in the experimental animals, supporting that the agonist enhanced memory consolidation in the first two experiments. Our results show that the activation of the D2 DA receptors in the VP facilitates memory consolidation as well as memory-retention in inhibitory avoidance paradigm. Copyright © 2017 Elsevier B.V. All rights reserved.

Individual differences in heart rate variability are associated with the avoidance of negative emotional events.

PubMed

Katahira, Kentaro; Fujimura, Tomomi; Matsuda, Yoshi-Taka; Okanoya, Kazuo; Okada, Masato

2014-12-01

Although the emotional outcome of a choice generally affects subsequent decisions, humans can inhibit the influence of emotion. Heart rate variability (HRV) has emerged as an objective measure of individual differences in the capacity for inhibitory control. In the present study, we investigated how individual differences in HRV at rest are associated with the emotional effects of the outcome of a choice on subsequent decision making using a decision-making task in which emotional pictures appeared as decision outcomes. We used a reinforcement learning model to characterize the observed behaviors according to several parameters, namely, the learning rate and the motivational value of positive and negative pictures. Consequently, we found that individuals with a lower resting HRV exhibited a greater negative motivational value in response to negative pictures, suggesting that these individuals tend to avoid negative pictures compared with individuals with a higher resting HRV. Copyright © 2014 Elsevier B.V. All rights reserved.

Amnesia of Inhibitory Avoidance by Scopolamine Is Overcome by Previous Openfield Exposure

ERIC Educational Resources Information Center

Colettis, Natalia C.; Snitcofsky, Marina; Kornisiuk, Edgar E.; Gonzalez, Emilio N.; Quillfeldt, Jorge A.; Jerusalinsky, Diana A.

2014-01-01

The muscarinic cholinergic receptor (MAChR) blockade with scopolamine either extended or restricted to the hippocampus, before or after training in inhibitory avoidance (IA) caused anterograde or retrograde amnesia, respectively, in the rat, because there was no long-term memory (LTM) expression. Adult Wistar rats previously exposed to one or two…

Failure to Find Ethanol-Induced Conditioned Taste Aversion in Honey Bees (Apis mellifera L.).

PubMed

Varnon, Christopher A; Dinges, Christopher W; Black, Timothy E; Wells, Harrington; Abramson, Charles I

2018-04-24

Conditioned taste aversion (CTA) learning is a highly specialized form of conditioning found across taxa that leads to avoidance of an initially neutral stimulus, such as taste or odor, that is associated with, but is not the cause of, a detrimental health condition. This study examines if honey bees (Apis mellifera L.) develop ethanol (EtOH)-induced CTA. Restrained bees were first administered a sucrose solution that was cinnamon scented, lavender scented, or unscented, and contained either 0, 2.5, 5, 10, or 20% EtOH. Then, 30 minutes later, we used a proboscis extension response (PER) conditioning procedure where the bees were taught to associate either cinnamon odor, lavender odor, or an air-puff with repeated sucrose feedings. For some bees, the odor of the previously consumed EtOH solution was the same as the odor associated with sucrose in the conditioning procedure. If bees are able to learn EtOH-induced CTA, they should show an immediate low level of response to odors previously associated with EtOH. We found that bees did not develop CTA despite the substantial inhibitory and aversive effects EtOH has on behavior. Instead, bees receiving a conditioning odor that was previously associated with EtOH showed an immediate high level of response. While this demonstrates bees are capable of one-trial learning common to CTA experiments, this high level of response is the opposite of what would occur if the bees developed a CTA. Responding on subsequent trials also showed a general inhibitory effect of EtOH. Finally, we found that consumption of cinnamon extract reduced the effects of EtOH. The honey bees' lack of learned avoidance to EtOH mirrors that seen in human alcoholism. These findings demonstrate the usefulness of honey bees as an insect model for EtOH consumption. Copyright © 2018 by the Research Society on Alcoholism.

Beneficial effect of commercial Rhodiola extract in rats with scopolamine-induced memory impairment on active avoidance.

PubMed

Vasileva, Liliya V; Getova, Damianka P; Doncheva, Nina D; Marchev, Andrey S; Georgiev, Milen I

2016-12-04

Rhodiola rosea L., family Crassulaceae also known as Golden Root or Arctic root is one of the most widely used medicinal plants with effect on cognitive dysfunction, psychological stress and depression. The aim of the study was to examine the effect of a standardized commercial Rhodiola extract on learning and memory processes in naive rats as well as its effects in rats with scopolamine-induced memory impairment. Sixty male Wistar rats were used in the study. The experiment was conducted in two series - on naive rats and on rats with scopolamine-induced model of impaired memory. The active avoidance test was performed in an automatic conventional shuttle box set-up. The criteria used were the number of conditional stimuli (avoidances), the number of unconditioned stimuli (escapes) as well as the number of intertrial crossings. The chemical fingerprinting of the standardized commercial Rhodiola extract was performed by means of nuclear magnetic resonance (NMR). Naive rats treated with standardized Rhodiola extract increased the number of avoidances during the learning session and memory retention test compared to the controls. Rats with scopolamine-induced memory impairment treated with Rhodiola extract showed an increase in the number of avoidances during the learning session and on the memory tests compared to the scopolamine group. The other two parameters were not changed in rats treated with the extract of Rhodiola in the two series. It was found that the studied Rhodiola extract exerts a beneficial effect on learning and memory processes in naive rats and rats with scopolamine-induced memory impairment. The observed effect is probably due to multiple underlying mechanisms including its modulating effect on acetylcholine levels in the brain and MAO-inhibitory activity leading to stimulation of the monoamines' neurotransmission. In addition the pronounced stress-protective properties of Rhodiola rosea L. could also play a role in the improvement of cognitive functions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Contrasting effects of acute and chronic treatment with imipramine and fluoxetine on inhibitory avoidance and escape responses in mice exposed to the elevated T-maze.

PubMed

Gomes, Karina Santos; de Carvalho-Netto, Eduardo Ferreira; Monte, Kátia Cristina Da Silva; Acco, Bruno; Nogueira, Paulo José de Campos; Nunes-de-Souza, Ricardo Luiz

2009-03-30

The elevated T-maze (ETM) is an animal model of anxiety-like behavior that assesses two different defensive behavioral tasks in the same animal-acquisition of inhibitory avoidance and latency to escape from an open and elevated arm. In rats, cute and chronic treatments with anxiolytic-like drugs impair avoidance acquisition while only chronic administration of panicolytic-like drugs impairs open arm withdrawal. To date, only the acute effects of anxiolytic/anxiogenic or panicolytic/panicogenic drugs have been tested in the mouse ETM and the results have partially corroborated those found in the rat ETM. This study investigated the effects of acute (a single intraperitoneal injection 30 min before testing) and chronic (daily i.p. injections for 15 consecutive days) treatment with imipramine or fluoxetine, non-selective and selective serotonin reuptake inhibitors, respectively, on inhibitory avoidance and escape tasks in the mouse ETM. Neither acute nor chronic treatment with imipramine (0, 1, 5 or 10 mg/kg, i.p.) significantly changed the behavioral profile of mice in the two ETM tasks. Interestingly, while acute fluoxetine (0, 5, 10, 20 or 40 mg/kg, i.p.) facilitated inhibitory avoidance and impaired escape latency, chronic treatment (0, 5, 20 or 40 mg/kg, i.p.) with this selective serotonin reuptake inhibitor (SSRI) produced an opposite effect, i.e., it impaired inhibitory avoidance acquisition and facilitated open arm withdrawal. Importantly, acute or chronic treatment with imipramine (except at the highest dose that increased locomotion when given acutely) or fluoxetine failed to alter general locomotor activity in mice as assessed in an ETM in which all arms were enclosed by lateral walls (eETM). These results suggest that inhibitory avoidance acquisition is a useful task for the evaluation of acute and chronic effects of SSRI treatment on anxiety in mice. However, as open arm latency was actually increased and reduced by acute and chronic fluoxetine, respectively, this does not seem to be a useful measure of escape from a proximal threat in this species.

Belief-desire reasoning as a process of selection.

PubMed

Leslie, Alan M; German, Tim P; Polizzi, Pamela

2005-02-01

Human learning may depend upon domain specialized mechanisms. A plausible example is rapid, early learning about the thoughts and feelings of other people. A major achievement in this domain, at about age four in the typically developing child, is the ability to solve problems in which the child attributes false beliefs to other people and predicts their actions. The main focus of theorizing has been why 3-year-olds fail, and only recently have there been any models of how success is achieved in false-belief tasks. Leslie and Polizzi (Inhibitory processing in the false-belief task: Two conjectures. Developmental Science, 1, 247-254, 1998) proposed two competing models of success, which are the focus of the current paper. The models assume that belief-desire reasoning is a process which selects a content for an agent's belief and an action for the agent's desire. In false belief tasks, the theory of mind mechanism (ToMM) provides plausible candidate belief contents, among which will be a 'true-belief.' A second process reviews these candidates and by default will select the true-belief content for attribution. To succeed in a false-belief task, the default content must be inhibited so that attention shifts to another candidate belief. In traditional false-belief tasks, the protagonist's desire is to approach an object. Here we make use of tasks in which the protagonist has a desire to avoid an object, about which she has a false-belief. Children find such tasks much more difficult than traditional tasks. Our models explain the additional difficulty by assuming that predicting action from an avoidance desire also requires an inhibition. The two processing models differ in the way that belief and desire inhibitory processes combine to achieve successful action prediction. In six experiments we obtain evidence favoring one model, in which parallel inhibitory processes cancel out, over the other model, in which serial inhibitions force attention to a previously inhibited location. These results are discussed in terms of a set of simple proposals for the modus operandi of a domain specific learning mechanism. The learning mechanism is in part modular--the ToMM--and in part penetrable--the Selection Processor (SP). We show how ToMM-SP can account both for competence and for successful and unsuccessful performance on a wide range of belief-desire tasks across the preschool period. Together, ToMM and SP attend to and learn about mental states.

Computational Model of a Positive BDNF Feedback Loop in Hippocampal Neurons Following Inhibitory Avoidance Training

ERIC Educational Resources Information Center

Zhang, Yili; Smolen, Paul; Alberini, Cristina M.; Baxter, Douglas A.; Byrne, John H.

2016-01-01

Inhibitory avoidance (IA) training in rodents initiates a molecular cascade within hippocampal neurons. This cascade contributes to the transition of short- to long-term memory (i.e., consolidation). Here, a differential equation-based model was developed to describe a positive feedback loop within this molecular cascade. The feedback loop begins…

Alcohol and behavioral control: cognitive and neural mechanisms.

PubMed

Vogel-Sprott, M; Easdon, C; Fillmore, M; Finn, P; Justus, A

2001-01-01

This article represents the proceedings of a symposium at the 2000 RSA Meeting in Denver, Colorado. The organizer/chair was Muriel Vogel-Sprott. The presentations were (1) Alcohol-induced impairment of inhibitory control: Some commonalities with attention deficit hyperactivity disorder, by Mark Fillmore; (2) Neural interactions that underlie response inhibition under alcohol: A functional magnetic resonance imaging investigation, by Craig Easdon; (3) Intentional control of behavior under alcohol, by Muriel Vogel-Sprott; and (4) Working memory and the disinhibiting effects of alcohol on passive avoidance learning, by Alicia Justius and Peter Finn.

Hyperalgesia, low-anxiety, and impairment of avoidance learning in neonatal caffeine-treated rats.

PubMed

Pan, Hong-Zhen; Chen, Hwei-Hsien

2007-03-01

The nonselective adenosine receptor antagonist caffeine is used clinically to treat apnea in preterm infants. The brain developmental stage of preterm infants is usually at a period of rapid brain growth, referred as brain growth spurt, which occurs during early postnatal life in rats and is highly sensitive to central nervous system (CNS) acting drugs. The aim of this work was to study whether caffeine treatment during brain growth spurt produces long-term effects on the adenosine receptor-regulated behaviors including nociception, anxiety, learning, and memory. Neonatal male and female Sprague-Dawley rats were administered either deionized water or caffeine (15-20 mg kg(-1) day(-1)) through gavage (0.05 ml/10 g) over postnatal days (PN) 2-6. The hot-plate test, elevated plus-maze, dark-light transition test, and step-through inhibitory avoidance learning task were examined in juvenile rats. Furthermore, the responses to adenosine A(1) receptor agonist N(6)-cyclopentyladenosine (CPA)-induced hypothermia and A(2A) receptor agonist CGS21680-induced locomotor depression were also compared. Caffeine-treated rats showed hyperalgesia in hot-plate test, less anxiety than controls in the elevated plus-maze and dark-light transition, and impairment in step-through avoidance learning test. Moreover, the responses to CPA-induced hypothermia and CGS21680-induced locomotor depression were enhanced in caffeine-treated rats. These results indicate that caffeine exposure during brain growth spurt alters the adenosine receptor-regulated behaviors and the responsiveness to adenosine agonists, suggesting the risk of adenosine receptor-related behavioral dysfunction may exist in preterm newborns treated for apnea with caffeine.

Post-Training Reversible Disconnection of the Ventral Hippocampal-Basolateral Amygdaloid Circuits Impairs Consolidation of Inhibitory Avoidance Memory in Rats

ERIC Educational Resources Information Center

Wang, Gong-Wu; Liu, Jian; Wang, Xiao-Qin

2017-01-01

The ventral hippocampus (VH) and the basolateral amygdala (BLA) are both crucial in inhibitory avoidance (IA) memory. However, the exact role of the VH-BLA circuit in IA memory consolidation is unclear. This study investigated the effect of post-training reversible disconnection of the VH-BLA circuit in IA memory consolidation. Male Wistar rats…

Amygdala kindling-resistant (SLOW) or -prone (FAST) rat strains show differential fear responses.

PubMed

Mohapel, P; McIntyre, D C

1998-12-01

The authors compared two rat strains, selectively bred for their susceptibility to amygdala kindling, with respect to their performance on various behavioral and learning tasks that are associated with fear and anxiety. The two rat strains differed significantly in measurements of exploration of novel and familiar environments, as well as in reactivity to footshock and fear-based learning. The kindling-resistant (SLOW) strain exhibited a lower ratio of open- to closed-arm entries in the elevated plus-maze, less activity over days in the open field, greater behavioral suppression in the open-field if previously footshocked, greater freezing in the inhibitory avoidance task, and slower acquisition and poorer retention in the one-way avoidance task than did the kindling-prone (FAST) strain. These experiments suggest that the SLOW rats are more expressively fearful than the FAST rats, particularly with respect to environmentally triggered freezing or immobility. Further, these observations imply that the relatively constrained excitability of the amygdala network in the SLOW rats might mediate their relatively greater expression of fear and anxiety compared with the FAST rats.

Morvan's syndrome and the sustained absence of all sleep rhythms for months or years: An hypothesis.

PubMed

Touzet, Claude

2016-09-01

Despite the predation costs, sleep is ubiquitous in the animal realm. Humans spend a third of their life sleeping, and the quality of sleep has been related to co-morbidity, Alzheimer disease, etc. Excessive wakefulness induces rapid changes in cognitive performances, and it is claimed that one could die of sleep deprivation as quickly as by absence of water. In this context, the fact that a few people are able to go without sleep for months, even years, without displaying any cognitive troubles requires explanations. Theories ascribing sleep to memory consolidation are unable to explain such observations. It is not the case of the theory of sleep as the hebbian reinforcement of the inhibitory synapses (ToS-HRIS). Hebbian learning (Long Term Depression - LTD) guarantees that an efficient inhibitory synapse will lose its efficiency just because it is efficient at avoiding the activation of the post-synaptic neuron. This erosion of the inhibition is replenished by hebbian learning (Long Term Potentiation - LTP) when pre and post-synaptic neurons are active together - which is exactly what happens with the travelling depolarization waves of the slow-wave sleep (SWS). The best documented cases of months-long insomnia are reports of patients with Morvan's syndrome. This syndrome has an autoimmune cause that impedes - among many things - the potassium channels of the post-synaptic neurons, increasing LTP and decreasing LTD. We hypothesize that the absence of inhibitory efficiency erosion during wakefulness (thanks to a decrease of inhibitory LTD) is the cause for an absence of slow-wave sleep (SWS), which results also in the absence of REM sleep. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neuroprotective Activities of Saffron and Crocin.

PubMed

Soeda, Shinji; Aritake, Kosuke; Urade, Yoshihiro; Sato, Hiroshi; Shoyama, Yukihiro

2016-01-01

We first considered that saffron is really safety food because it has a long-use history. The neuroprotective activities of saffron and its major constituent, crocin, are separately discussed in vitro and in vivo. We reviewed the inhibitory activities of crocin against PC-12 cell apoptosis. The oxidative stress decreased the cellular levels of glutathione (GSH) which is an inhibitor of neutral sphingomyelinase (N-SMase). Therefore, the level of GSH was assayed by the addition of crocin resulted in the activation of glutathione reductase (GR). It became evident that crocin treatment prevents the N-SMase activation resulting in the decrease of ceramide release. From these evidences we summarized the role of crocin for neuronal cell death. We used the ethanol-blocking assay system for learning and memory activities. The effect of saffron and crocin on improving ethanol-induced impairment of learning behaviors of mice in passive avoidance tasks has been clear. Further, we did make clear that saffron and crocin prevent the inhibitory effect of ethanol on long-term potentiation (LTP) in the dentate gyrus. Finally we found that 100 mg/kg of crocin gave non-rapid eye movement sleep (non-REM sleep) although mice were started to be active during night time.

Altered behavior in experimental cortical dysplasia.

PubMed

Zhou, Fu-Wen; Rani, Asha; Martinez-Diaz, Hildabelis; Foster, Thomas C; Roper, Steven N

2011-12-01

Developmental delay and cognitive impairment are common comorbidities in people with epilepsy associated with malformations of cortical development (MCDs). We studied cognition and behavior in an animal model of diffuse cortical dysplasia (CD), in utero irradiation, using a battery of behavioral tests for neuromuscular and cognitive function. Fetal rats were exposed to 2.25 Gy external radiation on embryonic day 17 (E17). At 1 month of age they were tested using an open field task, a grip strength task, a grid walk task, inhibitory avoidance, an object recognition task, and the Morris water maze task. Rats with CD showed reduced nonlocomotor activity in the open field task and impaired motor coordination for grid walking but normal grip strength. They showed a reduced tendency to recognize novel objects and reduced retention in an inhibitory avoidance task. Water maze testing showed that learning and memory were impaired in irradiated rats for both cue discrimination and spatially oriented tasks. These results demonstrate significant deficits in cortex- and hippocampus-dependent cognitive functions associated with the diffuse abnormalities of cortical and hippocampal development that have been documented in this model. This study documents multimodal cognitive deficits associated with CD and can serve as the foundation for future investigations into the mechanisms of and possible therapeutic interventions for this problem. Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.

Prelimbic cortex extracellular signal-regulated kinase 1/2 activation is required for memory retrieval of long-term inhibitory avoidance.

PubMed

Luo, Fei; Zheng, Jian; Sun, Xuan; Deng, Wei-Ke; Li, Bao Ming; Liu, Fang

2017-04-15

Neural mechanism underlying memory retrieval has been extensively studied in the hippocampus and amygdala. However, little is known about the role of medial prefrontal cortex in long-term memory retrieval. We evaluate this issue in one-trial step-through inhibitory avoidance (IA) paradigm. Our results showed that, 1) inactivation of mPFC by local infusion of GABA A -receptor agonist muscimol caused severe deficits in retrieval of 1-day and 7-day but had no effects on 2-h inhibitory avoidance memory; 2) the protein level of phosphorylated-ERK1/2 in mPFC were significantly increased following retrieval of 1-day and 7-day IA memory, so did the numbers of phosphorylated-ERK (pERK) and phosphorylated-CREB (pCREB) labeled neurons; 3) intra-mPFC infusion of ERK kinase inhibitor PD98095 significantly reduced phosphorylated ERK1/2 levels and phosphorylated-ERK1/2 and phosphorylated-CREB labeled cells, and severely impaired retrieval of 7-day IA memory when the drugs were administrated 30min prior to test. The present study provides evidence that retrieval of long-lasting memory for inhibitory avoidance requires mPFC and involves the ERK-CREB signaling cascade. Copyright © 2017 Elsevier B.V. All rights reserved.

The Inhibitory Mechanism in Learning Ambiguous Words in a Second Language

PubMed Central

Lu, Yao; Wu, Junjie; Dunlap, Susan; Chen, Baoguo

2017-01-01

Ambiguous words are hard to learn, yet little is known about what causes this difficulty. The current study aimed to investigate the relationship between the representations of new and prior meanings of ambiguous words in second language (L2) learning, and to explore the function of inhibitory control on L2 ambiguous word learning at the initial stage of learning. During a 4-day learning phase, Chinese–English bilinguals learned 30 novel English words for 30 min per day using bilingual flashcards. Half of the words to be learned were unambiguous (had one meaning) and half were ambiguous (had two semantically unrelated meanings learned in sequence). Inhibitory control was introduced as a subject variable measured by a Stroop task. The semantic representations established for the studied items were probed using a cross-language semantic relatedness judgment task, in which the learned English words served as the prime, and the targets were either semantically related or unrelated to the prime. Results showed that response latencies for the second meaning of ambiguous words were slower than for the first meaning and for unambiguous words, and that performance on only the second meaning of ambiguous words was predicted by inhibitory control ability. These results suggest that, at the initial stage of L2 ambiguous word learning, the representation of the second meaning is weak, probably interfered with by the representation of the prior learned meaning. Moreover, inhibitory control may modulate learning of the new meanings, such that individuals with better inhibitory control may more effectively suppress interference from the first meaning, and thus learn the new meaning more quickly. PMID:28496423

The Inhibitory Mechanism in Learning Ambiguous Words in a Second Language.

PubMed

Lu, Yao; Wu, Junjie; Dunlap, Susan; Chen, Baoguo

2017-01-01

Ambiguous words are hard to learn, yet little is known about what causes this difficulty. The current study aimed to investigate the relationship between the representations of new and prior meanings of ambiguous words in second language (L2) learning, and to explore the function of inhibitory control on L2 ambiguous word learning at the initial stage of learning. During a 4-day learning phase, Chinese-English bilinguals learned 30 novel English words for 30 min per day using bilingual flashcards. Half of the words to be learned were unambiguous (had one meaning) and half were ambiguous (had two semantically unrelated meanings learned in sequence). Inhibitory control was introduced as a subject variable measured by a Stroop task. The semantic representations established for the studied items were probed using a cross-language semantic relatedness judgment task, in which the learned English words served as the prime, and the targets were either semantically related or unrelated to the prime. Results showed that response latencies for the second meaning of ambiguous words were slower than for the first meaning and for unambiguous words, and that performance on only the second meaning of ambiguous words was predicted by inhibitory control ability. These results suggest that, at the initial stage of L2 ambiguous word learning, the representation of the second meaning is weak, probably interfered with by the representation of the prior learned meaning. Moreover, inhibitory control may modulate learning of the new meanings, such that individuals with better inhibitory control may more effectively suppress interference from the first meaning, and thus learn the new meaning more quickly.

The consolidation of inhibitory avoidance memory in mice depends on the intensity of the aversive stimulus: The involvement of the amygdala, dorsal hippocampus and medial prefrontal cortex.

PubMed

Canto-de-Souza, L; Mattioli, R

2016-04-01

Several studies using inhibitory avoidance models have demonstrated the importance of limbic structures, such as the amygdala, dorsal hippocampus and medial prefrontal cortex, in the consolidation of emotional memory. However, we aimed to investigate the role of the amygdala (AMG), dorsal hippocampus (DH) and medial prefrontal cortex (mPFC) of mice in the consolidation of step-down inhibitory avoidance and whether this avoidance would be conditioned relative to the intensity of the aversive stimulus. To test this, we bilaterally infused anisomycin (ANI-40μg/μl, a protein synthesis inhibitor) into one of these three brain areas in mice. These mice were then exposed to one of two different intensities (moderate: 0.5mA or intense: 1.5mA) in a step-down inhibitory avoidance task. We found that consolidation of both of the aversive experiences was mPFC dependent, while the AMG and DH were only required for the consolidation of the intense experience. We suggest that in moderately aversive situations, which do not represent a severe physical risk to the individual, the consolidation of aversive experiences does not depend on protein synthesis in the AMG or the DH, but only the mPFC. However, for intense aversive stimuli all three of these limbic structures are essential for the consolidation of the experience. Copyright © 2016 Elsevier Inc. All rights reserved.

Intrahippocampal administration of an antibody against the HNK-1 carbohydrate impairs memory consolidation in an inhibitory learning task in mice.

PubMed

Strekalova, T; Wotjak, C T; Schachner, M

2001-06-01

Many cell adhesion molecules express the HNK-1 carbohydrate involved in formation and functioning of synapses. To assess its role in learning, we injected the monoclonal HNK-1 antibody or nonimmune IgG into the hippocampus of C57BL/6J mice 1 h after training in a step-down avoidance task. In animals treated with the HNK-1 antibody, latencies of step down in a recall session 48 h after injection did not change compared to training values and were significantly shorter versus IgG-treated controls, which acquired the task normally. Similar differences between the two treatments were also observed after a stronger training protocol in a step-down avoidance paradigm. The HNK-1 antibody was effective only when injected 1 h, but not 48 h after training, thus affecting memory consolidation but not memory recall itself. The HNK-1 antibody impaired memory also in tenascin-R knock-out mice, indicating that extracellular matrix molecule tenascin-R, one of the carriers of the HNK-1epitope in the hippocampus, does not mediate the function of the HNK-1 carbohydrate in this task. Our observations show that the HNK-1 carbohydrate is critically involved in memory consolidation in hippocampus-dependent learning in mammals. Copyright 2001 Academic Press.

Interactive contributions of self-regulation deficits and social motivation to psychopathology: Unraveling divergent pathways to aggressive behavior and depressive symptoms

PubMed Central

RUDOLPH, KAREN D.; TROOP-GORDON, WENDY; LLEWELLYN, NICOLE

2015-01-01

Poor self-regulation has been implicated as a significant risk factor for the development of multiple forms of psychopathology. This research examined the proposition that self-regulation deficits differentially predict aggressive behavior and depressive symptoms, depending on children’s social approach versus avoidance motivation. A prospective, multiple-informant approach was used to test this hypothesis in 419 children (M age = 8.92, SD = 0.36). Parents rated children’s inhibitory control. Children completed measures of social approach–avoidance motivation and depressive symptoms. Teachers rated children’s aggressive behavior. As anticipated, poor inhibitory control predicted aggressive behavior in boys with high but not low approach motivation and low but not high avoidance motivation, whereas poor inhibitory control predicted depressive symptoms in girls with high but not low avoidance motivation. This research supports several complementary theoretical models of psychopathology and provides insight into the differential contributions of poor self-regulation to maladaptive developmental outcomes. The findings suggest the need for targeted intervention programs that consider heterogeneity among children with self-regulatory deficits. PMID:23627953

CB1 receptors in the formation of the different phases of memory-related processes in the inhibitory avoidance test in mice.

PubMed

Kruk-Slomka, Marta; Biala, Grażyna

2016-03-15

The endocannabinoid system, through the cannabinoid type 1 (CB1) and 2 (CB2) receptors modulates many physiological functions, including different aspects of memory-related processes. The aim of the present experiments was to explore the role of the endocannabinoid system, through CB1 receptors in the different stages of short-term (acquisition, retention and retrieval) and long-term (acquisition, consolidation and retrieval) memory-related responses, using the inhibitory avoidance (IA) test in mice. Our results revealed that an acute injection of oleamide (10 and 20mg/kg), a CB1 receptor agonist, impairs the short-term or/and long-term acquisition, retention/consolidation, retrieval memory and learning processes in the IA test in mice. In turn, in this test an acute injection of AM 251 (1 and 3mg/kg), a CB1 receptor antagonist, improves the short-term or/and long-term memory stages, described above. Moreover, this memory impairment induced by effective dose of oleamide (20mg/kg) is reversed by non-effective dose of AM 251 (0.25mg/kg) in the IA task, which proves the selectivity of oleamide to CB1 receptors and confirms that the CB1 receptor-related mechanism is one of the possible mechanisms, responsible for memory and learning responses. Obtained results provide clear evidence that the endocannabinoid system, through CB1 receptors, participates in the different stages of short- and long-term memory-related behavior. This knowledge may open in the future new possibilities for the development of CB-based therapies, especially for memory impairment human disorders. Copyright © 2015 Elsevier B.V. All rights reserved.

Interactions of nitric oxide with α2 -adrenoceptors within the locus coeruleus underlie the facilitation of inhibitory avoidance memory by agmatine.

PubMed

Shelkar, Gajanan P; Gakare, Sukanya G; Chakraborty, Suwarna; Dravid, Shashank M; Ugale, Rajesh R

2016-09-01

Agmatine, a putative neurotransmitter, plays a vital role in learning and memory. Although it is considered an endogenous ligand of imidazoline receptors, agmatine exhibits high affinity for α-adrenoceptors, NOS and NMDA receptors. These substrates within the locus coeruleus (LC) are critically involved in learning and memory processes. The hippocampus and LC of male Wistar rat were stereotaxically cannulated for injection. Effects of agmatine, given i.p. or intra-LC, on acquisition, consolidation and retrieval of inhibitory avoidance (IA) memory were measured. The NO donor S-nitrosoglutathione, non-specific (L-NAME) and specific NOS inhibitors (L-NIL, 7-NI, L-NIO), the α2 -adrenoceptor antagonist (yohimbine) or the corresponding agonist (clonidine) were injected intra-LC before agmatine. Intra-hippocampal injections of the NMDA antagonist, MK-801 (dizocilpine), were used to modify the memory enhancing effects of agmatine, SNG and yohimbine. Expression of tyrosine hydroxylase (TH) and eNOS in the LC was assessed immunohistochemically. Agmatine (intra-LC or i.p.) facilitated memory retrieval in the IA test. S-nitrosoglutathione potentiated, while L-NAME and L-NIO decreased, these effects of agmatine. L-NIL and 7-NI did not alter the effects of agmatine. Yohimbine potentiated, whereas clonidine attenuated, effects of agmatine within the LC. The effects of agmatine, S-nitrosoglutathione and yohimbine were blocked by intra-hippocampal MK-801. Agmatine increased the population of TH- and eNOS-immunoreactive elements in the LC. The facilitation of memory retrieval in the IA test by agmatine is probably mediated by interactions between eNOS, NO and noradrenergic pathways in the LC. © 2016 The British Pharmacological Society.

Interactions of nitric oxide with α2‐adrenoceptors within the locus coeruleus underlie the facilitation of inhibitory avoidance memory by agmatine

PubMed Central

Shelkar, Gajanan P; Gakare, Sukanya G; Chakraborty, Suwarna; Dravid, Shashank M

2016-01-01

Background and Purpose Agmatine, a putative neurotransmitter, plays a vital role in learning and memory. Although it is considered an endogenous ligand of imidazoline receptors, agmatine exhibits high affinity for α‐adrenoceptors, NOS and NMDA receptors. These substrates within the locus coeruleus (LC) are critically involved in learning and memory processes. Experimental Approach The hippocampus and LC of male Wistar rat were stereotaxically cannulated for injection. Effects of agmatine, given i.p. or intra‐LC, on acquisition, consolidation and retrieval of inhibitory avoidance (IA) memory were measured. The NO donor S‐nitrosoglutathione, non‐specific (L‐NAME) and specific NOS inhibitors (L‐NIL, 7‐NI, L‐NIO), the α2‐adrenoceptor antagonist (yohimbine) or the corresponding agonist (clonidine) were injected intra‐LC before agmatine. Intra‐hippocampal injections of the NMDA antagonist, MK‐801 (dizocilpine), were used to modify the memory enhancing effects of agmatine, SNG and yohimbine. Expression of tyrosine hydroxylase (TH) and eNOS in the LC was assessed immunohistochemically. Key Results Agmatine (intra‐LC or i.p.) facilitated memory retrieval in the IA test. S‐nitrosoglutathione potentiated, while L‐NAME and L‐NIO decreased, these effects of agmatine. L‐NIL and 7‐NI did not alter the effects of agmatine. Yohimbine potentiated, whereas clonidine attenuated, effects of agmatine within the LC. The effects of agmatine, S‐nitrosoglutathione and yohimbine were blocked by intra‐hippocampal MK‐801. Agmatine increased the population of TH‐ and eNOS‐immunoreactive elements in the LC. Conclusions and Implications The facilitation of memory retrieval in the IA test by agmatine is probably mediated by interactions between eNOS, NO and noradrenergic pathways in the LC. PMID:27273730

Fear extinction can be made state-dependent on peripheral epinephrine: role of norepinephrine in the nucleus tractus solitarius.

PubMed

Rosa, Jessica; Myskiw, Jociane C; Furini, Cristiane R G; Sapiras, Gerson G; Izquierdo, Ivan

2014-09-01

We investigate whether the extinction of inhibitory avoidance (IA) learning can be subjected to endogenous state-dependence with systemic injections of epinephrine (E), and whether endogenous norepinephrine (NE) and the nucleus tractus solitarius (NTS)→locus coeruleus→hippocampus/amygdala (HIPP/BLA) pathway participate in this. Rats trained in IA were submitted to two sessions of extinction 24 h apart: In the first, the animals were submitted to a training session of extinction, and in the second they were tested for the retention of extinction. Saline or E were given i.p. immediately after the extinction training (post-extinction training injections) and/or 6 min before the extinction test (pre-extinction test). Post-extinction training E (50 or 100 μg/kg) induced a poor retrieval of extinction in the test session of this task unless an additional E injection (50 μg/kg) was given prior to the extinction test. This suggested state-dependence. Muscimol (0.01 μg/side) microinfused into the NTS prior to the extinction test session blocked E-induced state-dependence. Norepinephrine (NE, 1 μg/side) infused bilaterally into NTS restores the extinction impairment caused by post-extinction training i.p. E. In animals with bilateral NTS blockade induced by muscimol, NE (1 μg/side) given prior to the extinction test into the CA1 region of the dorsal hippocampus or into the basolateral amygdala restored the normal extinction levels that had been impaired by muscimol. These results suggest a role for the NTS→locus coeruleus→HIPP/BLA pathway in the retrieval of extinction, as it has been shown to have in the consolidation of inhibitory avoidance and of object recognition learning. Copyright © 2013 Elsevier Inc. All rights reserved.

Retrieval of Inhibitory Avoidance Memory Induces Differential Transcription of arc in Striatum, Hippocampus, and Amygdala.

PubMed

González-Salinas, Sofía; Medina, Andrea C; Alvarado-Ortiz, Eduardo; Antaramian, Anaid; Quirarte, Gina L; Prado-Alcalá, Roberto A

2018-07-01

Similar to the hippocampus and amygdala, the dorsal striatum is involved in memory retrieval of inhibitory avoidance, a task commonly used to study memory processes. It has been reported that memory retrieval of fear conditioning regulates gene expression of arc and zif268 in the amygdala and the hippocampus, and it is surprising that only limited effort has been made to study the molecular events caused by retrieval in the striatum. To further explore the involvement of immediate early genes in retrieval, we used real-time PCR to analyze arc and zif268 transcription in dorsal striatum, dorsal hippocampus, and amygdala at different time intervals after retrieval of step-through inhibitory avoidance memory. We found that arc expression in the striatum increased 30 min after retrieval while no changes were observed in zif268 in this region. Expression of arc and zif268 also increased in the dorsal hippocampus but the changes were attributed to context re-exposure. Control procedures indicated that in the amygdala, arc and zif268 expression was not dependent on retrieval. Our data indicate that memory retrieval of inhibitory avoidance induces arc gene expression in the dorsal striatum, caused, very likely, by the instrumental component of the task. Striatal arc expression after retrieval may induce structural and functional changes in the neurons involved in this process. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Modification of CO2 avoidance behaviour in Drosophila by inhibitory odorants.

PubMed

Turner, Stephanie Lynn; Ray, Anandasankar

2009-09-10

The fruitfly Drosophila melanogaster exhibits a robust and innate olfactory-based avoidance behaviour to CO(2), a component of odour emitted from stressed flies. Specialized neurons in the antenna and a dedicated neuronal circuit in the higher olfactory system mediate CO(2) detection and avoidance. However, fruitflies need to overcome this avoidance response in some environments that contain CO(2) such as ripening fruits and fermenting yeast, which are essential food sources. Very little is known about the molecular and neuronal basis of this unique, context-dependent modification of innate olfactory avoidance behaviour. Here we identify a new class of odorants present in food that directly inhibit CO(2)-sensitive neurons in the antenna. Using an in vivo expression system we establish that the odorants act on the Gr21a/Gr63a CO(2) receptor. The presence of these odorants significantly and specifically reduces CO(2)-mediated avoidance behaviour, as well as avoidance mediated by 'Drosophila stress odour'. We propose a model in which behavioural avoidance to CO(2) is directly influenced by inhibitory interactions of the novel odours with CO(2) receptors. Furthermore, we observe differences in the temporal dynamics of inhibition: the effect of one of these odorants lasts several minutes beyond the initial exposure. Notably, animals that have been briefly pre-exposed to this odorant do not respond to the CO(2) avoidance cue even after the odorant is no longer present. We also show that related odorants are effective inhibitors of the CO(2) response in Culex mosquitoes that transmit West Nile fever and filariasis. Our findings have broader implications in highlighting the important role of inhibitory odorants in olfactory coding, and in their potential to disrupt CO(2)-mediated host-seeking behaviour in disease-carrying insects like mosquitoes.

Opposite roles for neuropeptide S in the nucleus accumbens and bed nucleus of the stria terminalis in learned helplessness rats.

PubMed

Shirayama, Yukihiko; Ishima, Tamaki; Oda, Yasunori; Okamura, Naoe; Iyo, Masaomi; Hashimoto, Kenji

2015-09-15

The role of neuropeptide S (NPS) in depression remains unclear. We examined the antidepressant-like effects of NPS infusions into the shell or core regions of the nucleus accumbens (NAc) and into the bed nucleus of the stria terminalis (BNST) of learned helplessness (LH) rats (an animal model of depression). Infusions of NPS (10 pmol/side) into the NAc shell, but not the NAc core and BNST, exerted antidepressant-like effects in the LH paradigm. Implying that behavioral deficits could be improved in the conditioned avoidance test. Coinfusion of SHA68 (an NPS receptor antagonist, 100 pmol/side) with NPS into the NAc shell blocked these effects. In contrast, NPS receptor antagonism by SHA68 in the BNST induced antidepressant-like effects. Infusions of NPS into the NAc shell or SHA68 into the BNST did not produce memory deficits or locomotor activation in the passive avoidance and open field tests. These results suggest that excitatory and inhibitory actions by the NPS system are integral to the depression in LH animals. Copyright © 2015 Elsevier B.V. All rights reserved.

Enhancement of Inhibitory Avoidance and Conditioned Taste Aversion Memory With Insular Cortex Infusions of 8-Br-cAMP: Involvement of the Basolateral Amygdala

PubMed Central

Miranda, María I.; McGaugh, James L.

2004-01-01

There is considerable evidence that in rats, the insular cortex (IC) and amygdala are involved in the learning and memory of aversively motivated tasks. The present experiments examined the effects of 8-Br-cAMP, an analog of cAMP, and oxotremorine, a muscarinic agonist, infused into the IC after inhibitory avoidance (IA) training and during the acquisition/consolidation of conditioned taste aversion (CTA). Posttraining infusion into the IC of 0.3 μg oxotremorine and 1.25 μg 8-Br-cAMP enhanced IA retention. Infusions of 8-Br-cAMP, but not oxotremorine, into the IC enhanced taste aversion. The experiments also examined whether noradrenergic activity in the basolateral amygdala (BLA) is critical in enabling the enhancement of CTA and IA memory induced by drug infusions administered into the IC. For both CTA and IA, ipsilateral infusions of β-adrenergic antagonist propranolol administered into the BLA blocked the retention-enhancing effect of 8-Br-cAMP or oxotremorine infused into the IC. These results indicate that the IC is involved in the consolidation of memory for both IA and CTA, and this effect requires intact noradrenergic activity into the BLA. These findings provide additional evidence that the BLA interacts with other brain regions, including sensory cortex, in modulating memory consolidation. PMID:15169861

Learning to predict and control harmful events: chronic pain and conditioning.

PubMed

Vlaeyen, Johan W S

2015-04-01

Pain is a biologically relevant signal and response to bodily threat, associated with the urge to restore the integrity of the body. Immediate protective responses include increased arousal, selective attention, escape, and facial expressions, followed by recuperative avoidance and safety-seeking behaviors. To facilitate early and effective protection against future bodily threat or injury, learning takes place rapidly. Learning is the observable change in behavior due to events in the internal and external environmental and includes nonassociative (habituation and sensitization) and associative learning (Pavlovian and operant conditioning). Once acquired, these knowledge representations remain stored in memory and may generalize to perceptually or functionally similar events. Moreover, these processes are not just a consequence of pain; they may directly influence pain perception. In contrast to the rapid acquisition of learned responses, their extinction is slow, fragile, context dependent and only occurs through inhibitory processes. Here, we review features of associative forms of learning in humans that contribute to pain, pain-related distress, and disability and discuss promising future directions. Although conditioning has a long and honorable history, a conditioning perspective still might open new windows on novel treatment modalities that facilitate the well-being of individuals with chronic pain.

Neurocircuit function in eating disorders.

PubMed

Friederich, Hans-Christoph; Wu, Mudan; Simon, Joe J; Herzog, Wolfgang

2013-07-01

Eating disorders are serious psychosomatic disorders with high morbidity and lifetime mortality. Inadequate response to current therapeutic interventions constitutes a challenging clinical problem. A better understanding of the underlying neurobiological mechanisms could improve psychotherapeutic and drug treatment strategies. A review highlighting the current state of brain imaging in eating disorders related to the anxiety and pathological fear learning model of anorexia nervosa (AN) and the impulsivity model of binge eating in bulimia nervosa (BN). Available neuroimaging studies in patients with acute AN primarily suggest a hyper-responsive emotional and fear network to food, but not necessarily to eating disorder-unrelated, salient stimuli. Furthermore, patients with AN show decreased activation in the ventral fronto-striatal circuits during the performance of a cognitive flexibility task. Results in patients with BN primarily suggest a hypo-responsive reward system to food stimuli, especially to taste reward. Additionally, patients with BN exhibit impaired brain activation in the inhibitory control network during the performance of general response-inhibition tasks. Anxiety and pathological fear learning may lead to conditioned neural stimulus-response patterns to food stimuli and increased cognitive rigidity, which could account for the phobic avoidance of food intake in patients with acute AN. However, further neurobiological studies are required to investigate pathological fear learning in patients with AN. Patients with BN may binge eat to compensate for a hypo-responsive reward system. The impaired brain activation in the inhibitory control network may facilitate the loss of control over food intake in patients with BN. Copyright © 2013 Wiley Periodicals, Inc.

Facilitation of learning and modulation of frontal cortex acetylcholine by ventral pallidal injection of heparin glucosaminoglycan.

PubMed

De Souza Silva, M A; Jezek, K; Weth, K; Müller, H W; Huston, J P; Brandao, M L; Hasenöhrl, R U

2002-01-01

We examined the effects of heparin on learning and frontal cortex acetylcholine parameters following injection of the glucosaminoglycan into the ventral pallidum. In Experiment 1, possible mnemoactive effects of intrapallidal heparin injection were assessed. Rats with chronically implanted cannulae were administered heparin (0.1, 1.0, 10 ng) or vehicle (0.5 microl) and were tested on a one-trial step-through avoidance task. Two retention tests were carried out in each animal, one at 1.5 h after training to measure short-term memory and another at 24 h to measure long-term memory. Post-trial intrapallidal injection of 1.0 ng heparin improved both short- and long-term retention of the task, whereas the lower and the higher dose of the glucosaminoglycan had no effect. When the effective dose of heparin was injected 5 h, rather than immediately after training, it no longer facilitated long-term retention of the conditioned avoidance response. In Experiment 2, the effects of ventral pallidal heparin injection on frontal cortex acetylcholine and choline concentrations were investigated with in vivo microdialysis in anaesthetized rats. Heparin, administered in the dose of 1.0 ng, which was effective in facilitating avoidance performance, produced a delayed increase in cortical acetylcholine levels ipsi- and contralaterally to the side of intrabasalis injection, resembling the known neurochemical effects obtained for another glycosaminoglycan, chondroitin sulfate, which recently was shown to facilitate inhibitory avoidance learning and to increase frontal cortex acetylcholine. The present findings indicate that heparin, like other extracellular matrix proteoglycans, can exert beneficial effects on memory and strengthen the presumptive relationship between such promnestic effects of proteoglycans and basal forebrain cholinergic mechanisms. The data are discussed with respect to the presumed roles of matrix molecules in extrasynaptic volume transmission and in the 'cross-talk' between synapses.

Potential effects of reward and loss avoidance in overweight adolescents.

PubMed

Reyes, Sussanne; Peirano, Patricio; Luna, Beatriz; Lozoff, Betsy; Algarín, Cecilia

2015-08-01

Reward system and inhibitory control are brain functions that exert an influence on eating behavior regulation. We studied the differences in inhibitory control and sensitivity to reward and loss avoidance between overweight/obese and normal-weight adolescents. We assessed 51 overweight/obese and 52 normal-weight 15-y-old Chilean adolescents. The groups were similar regarding sex and intelligence quotient. Using Antisaccade and Incentive tasks, we evaluated inhibitory control and the effect of incentive trials (neutral, loss avoidance, and reward) on generating correct and incorrect responses (latency and error rate). Compared to normal-weight group participants, overweight/obese adolescents showed shorter latency for incorrect antisaccade responses (186.0 (95% CI: 176.8-195.2) vs. 201.3 ms (95% CI: 191.2-211.5), P < 0.05) and better performance reflected by lower error rate in incentive trials (43.6 (95% CI: 37.8-49.4) vs. 53.4% (95% CI: 46.8-60.0), P < 0.05). Overweight/obese adolescents were more accurate on loss avoidance (40.9 (95% CI: 33.5-47.7) vs. 49.8% (95% CI: 43.0-55.1), P < 0.05) and reward (41.0 (95% CI: 34.5-47.5) vs. 49.8% (95% CI: 43.0-55.1), P < 0.05) compared to neutral trials. Overweight/obese adolescents showed shorter latency for incorrect responses and greater accuracy in reward and loss avoidance trials. These findings could suggest that an imbalance of inhibition and reward systems influence their eating behavior.

On the Role of Cognitive Abilities in Second Language Vowel Learning.

PubMed

Ghaffarvand Mokari, Payam; Werner, Stefan

2018-03-01

This study investigated the role of different cognitive abilities-inhibitory control, attention control, phonological short-term memory (PSTM), and acoustic short-term memory (AM)-in second language (L2) vowel learning. The participants were 40 Azerbaijani learners of Standard Southern British English. Their perception of L2 vowels was tested through a perceptual discrimination task before and after five sessions of high-variability phonetic training. Inhibitory control was significantly correlated with gains from training in the discrimination of L2 vowel pairs. However, there were no significant correlations between attention control, AM, PSTM, and gains from training. These findings suggest the potential role of inhibitory control in L2 phonological learning. We suggest that inhibitory control facilitates the processing of L2 sounds by allowing learners to ignore the interfering information from L1 during training, leading to better L2 segmental learning.

Assessing Mongolian gerbil emotional behavior: effects of two shock intensities and response-independent shocks during an extended inhibitory-avoidance task.

PubMed

Hurtado-Parrado, Camilo; González-León, Camilo; Arias-Higuera, Mónica A; Cardona, Angelo; Medina, Lucia G; García-Muñoz, Laura; Sánchez, Christian; Cifuentes, Julián; Forigua, Juan Carlos; Ortiz, Andrea; Acevedo-Triana, Cesar A; Rico, Javier L

2017-01-01

Despite step-down inhibitory avoidance procedures that have been widely implemented in rats and mice to study learning and emotion phenomena, performance of other species in these tasks has received less attention. The case of the Mongolian gerbil is of relevance considering the discrepancies in the parameters of the step-down protocols implemented, especially the wide range of foot-shock intensities (i.e., 0.4-4.0 mA), and the lack of information on long-term performance, extinction effects, and behavioral patterning during these tasks. Experiment 1 aimed to (a) characterize gerbils' acquisition, extinction, and steady-state performance during a multisession (i.e., extended) step-down protocol adapted for implementation in a commercially-available behavioral package (Video Fear Conditioning System-MED Associates Fairfax, VT, USA), and (b) compare gerbils' performance in this task with two shock intensities - 0.5 vs. 1.0 mA-considered in the low-to-mid range. Results indicated that the 1.0 mA protocol produced more reliable and clear evidence of avoidance learning, extinction, and reacquisition in terms of increments in freezing and on-platform time as well as suppression of platform descent. Experiment 2 aimed to (a) assess whether an alternate protocol consisting of a random delivery of foot shocks could replicate the effects of Experiment 1 and (b) characterize gerbils' exploratory behavior during the step-down task (jumping, digging, rearing, and probing). Random shocks did not reproduce the effects observed with the first protocol. The data also indicated that a change from random to response-dependent shocks affects (a) the length of each visit to the platform, but not the frequency of platform descends or freezing time, and (b) the patterns of exploratory behavior, namely, suppression of digging and rearing, as well as increments in probing and jumping. Overall, the study demonstrated the feasibility of the extended step-down protocol for studying steady performance, extinction, and reacquisition of avoidance behavior in gerbils, which could be easily implemented in a commercially available system. The observation that 1.0 mA shocks produced a clear and consistent avoidance behavior suggests that implementation of higher intensities is unnecessary for reproducing aversive-conditioning effects in this species. The observed patterning of freezing, platform descents, and exploratory responses produced by the change from random to periodic shocks may relate to the active defensive system of the gerbil. Of special interest is the probing behavior, which could be interpreted as risk assessment and has not been reported in other rodent species exposed to step-down and similar tasks.

Assessing Mongolian gerbil emotional behavior: effects of two shock intensities and response-independent shocks during an extended inhibitory-avoidance task

PubMed Central

González-León, Camilo; Arias-Higuera, Mónica A.; Cardona, Angelo; Medina, Lucia G.; García-Muñoz, Laura; Sánchez, Christian; Cifuentes, Julián; Forigua, Juan Carlos; Ortiz, Andrea; Acevedo-Triana, Cesar A.; Rico, Javier L.

2017-01-01

Despite step-down inhibitory avoidance procedures that have been widely implemented in rats and mice to study learning and emotion phenomena, performance of other species in these tasks has received less attention. The case of the Mongolian gerbil is of relevance considering the discrepancies in the parameters of the step-down protocols implemented, especially the wide range of foot-shock intensities (i.e., 0.4–4.0 mA), and the lack of information on long-term performance, extinction effects, and behavioral patterning during these tasks. Experiment 1 aimed to (a) characterize gerbils’ acquisition, extinction, and steady-state performance during a multisession (i.e., extended) step-down protocol adapted for implementation in a commercially-available behavioral package (Video Fear Conditioning System—MED Associates Fairfax, VT, USA), and (b) compare gerbils’ performance in this task with two shock intensities – 0.5 vs. 1.0 mA—considered in the low-to-mid range. Results indicated that the 1.0 mA protocol produced more reliable and clear evidence of avoidance learning, extinction, and reacquisition in terms of increments in freezing and on-platform time as well as suppression of platform descent. Experiment 2 aimed to (a) assess whether an alternate protocol consisting of a random delivery of foot shocks could replicate the effects of Experiment 1 and (b) characterize gerbils’ exploratory behavior during the step-down task (jumping, digging, rearing, and probing). Random shocks did not reproduce the effects observed with the first protocol. The data also indicated that a change from random to response-dependent shocks affects (a) the length of each visit to the platform, but not the frequency of platform descends or freezing time, and (b) the patterns of exploratory behavior, namely, suppression of digging and rearing, as well as increments in probing and jumping. Overall, the study demonstrated the feasibility of the extended step-down protocol for studying steady performance, extinction, and reacquisition of avoidance behavior in gerbils, which could be easily implemented in a commercially available system. The observation that 1.0 mA shocks produced a clear and consistent avoidance behavior suggests that implementation of higher intensities is unnecessary for reproducing aversive-conditioning effects in this species. The observed patterning of freezing, platform descents, and exploratory responses produced by the change from random to periodic shocks may relate to the active defensive system of the gerbil. Of special interest is the probing behavior, which could be interpreted as risk assessment and has not been reported in other rodent species exposed to step-down and similar tasks. PMID:29152417

Effects of ethanolic extract and naphthoquinones obtained from the bulbs of Cipura paludosa on short-term and long-term memory: involvement of adenosine A₁ and A₂A receptors.

PubMed

Lucena, Greice M R S; Matheus, Filipe C; Ferreira, Vania M; Tessele, Priscila B; Azevedo, Mariangela S; Cechinel-Filho, Valdir; Prediger, Rui D

2013-04-01

Previous studies from our group have indicated important biological properties of the ethanolic extract and isolated compounds from the bulbs of Cipura paludosa (Iridaceae), a native plant widely distributed in northern Brazil, including antioxidant, neuroprotective and anti-nociceptive activities. In the present study, the effects of the ethanolic extract and its two naphthoquinones (eleutherine and isoeleutherine) on the short- and long-term memory of adult rodents were assessed in social recognition and inhibitory avoidance tasks. Acute pre-training oral administration of the ethanolic extract improved the short-term social memory in rats as well as facilitated the step-down inhibitory avoidance short- and long-term memory in mice. Moreover, the co-administration of 'non-effective' doses of the extract of Cipura paludosa and the adenosine receptor antagonists caffeine (non-selective), DPCPX (adenosine A1 receptor antagonist) and ZM241385 (adenosine A2A receptor antagonist) improved the social recognition memory of rats. In the inhibitory avoidance task, the co-administration of sub-effective doses of the extract with caffeine or ZM241385, but not with DPCPX, improved the short- and long-term memory of mice. Finally, the acute oral administration of eleutherine and isoeleutherine facilitated the inhibitory avoidance short- and long-term memory in mice. These results demonstrate for the first time the cognitive-enhancing properties of the extract and isolated compounds from the bulbs of Cipura paludosa in rodents and suggest a possible involvement of adenosine A1 and A2A receptors in these effects. © 2012 The Authors Basic & Clinical Pharmacology & Toxicology © 2012 Nordic Pharmacological Society.

Mechanisms of hippocampal long-term depression are required for memory enhancement by novelty exploration.

PubMed

Dong, Zhifang; Gong, Bo; Li, Hongjie; Bai, Yanrui; Wu, Xiaoyan; Huang, Yan; He, Wenting; Li, Tingyu; Wang, Yu Tian

2012-08-29

It is well known that novel environments can enhance learning and memory. However, the underlying mechanisms remain poorly understood. Here, we report that, in freely moving rats, novelty exploration facilitates the production of hippocampal CA1 long-term depression (LTD), a well characterized form of synaptic plasticity believed to be a cellular substrate of spatial learning, and thereby converts short-term memory (STM) into long-term memory (LTM) in an inhibitory avoidance learning procedure. Blocking the induction or the expression of CA1 LTD with two mechanistically and structurally distinct inhibitors prevents not only novelty acquisition but also the novelty exploration-promoted conversion of STM into LTM. Moreover, production of LTD with a strong electrical stimulation induction protocol or facilitation of hippocampal LTD by pharmacological inhibition of glutamate transporter activity mimics the behavioral effects of novelty exploration, sufficiently promoting the conversion of STM into LTM. Together, our findings suggest that induction of LTD may play an essential role not only in novelty acquisition but also in novelty-mediated memory enhancement.

Behavioral consequences of predator stress in the rat elevated T-maze.

PubMed

Bulos, Erika Mondin; Pobbe, Roger Luis Henschel; Zangrossi, Helio

2015-07-01

Analyses of the behavioral reactions of rodents to predators have greatly contributed to the understanding of defense-related human psychopathologies such as anxiety and panic.We here investigated the behavioral consequences of exposing male Wistar rats to a live cat using the elevated T-maze test of anxiety. This test allows the measurement of two defensive responses: inhibitory avoidance and escape, which in terms of pathology have been associated with generalized anxiety and panic disorders, respectively. For comparative reasons, the effects of exposure to the cat were also assessed in the elevated plus-maze. The results showed that a 5-min exposure to the cat selectively facilitated inhibitory avoidance acquisition, an anxiogenic effect, without affecting escape expression in the elevated T-maze. This was seen immediately but not 30 min after contact with the predator. This short-lived anxiogenic effect was also detected in the elevated plus-maze. Previous administration of the benzodiazepine anxiolytic diazepam (2 mg/kg) decreased the immediate avoidance response to the predator and the neophobic reaction to a dummy cat used as a control stimulus. The drug also impaired inhibitory avoidance acquisition in the elevated T-maze, indicating an anxiolytic effect, without affecting escape performance. The results indicate that the state of anxiety evoked during contact with the predator generalizes to both elevated plus- and T-mazes, impacting on defensive responses associated with generalized anxiety disorder.

Imidafenacin has no influence on learning in nucleus basalis of Meynert-lesioned rats.

PubMed

Yamazaki, Takanobu; Fukata, Ayako

2013-12-01

The prevalence of overactive bladder (OAB) and Alzheimer's disease (AD) increases with age, and much attention has been paid to the risk of cognitive impairment which may be induced by antimuscarinics used for OAB in patients with AD. Imidafenacin, an antimuscarinic agent for OAB treatment, has been reported not to affect learning in normal animals. However, under the condition in which sensitivity to learning impairment by antimuscarinics is increased, it remains unclear whether imidafenacin still does not impair the learning. Therefore, the influences of imidafenacin on passive avoidance response were investigated in sham-operated and nucleus basalis of Meynert (nbM)-lesioned rats and compared with oxybutynin hydrochloride and tolterodine tartrate. The learning-inhibitory doses of intravenous oxybutynin hydrochloride and tolterodine tartrate were 0.3 and 3 mg/kg in sham-operated rats and 0.1 and 1 mg/kg in nbM-lesioned rats, respectively. Thus, the learning impairments by those antimuscarinics were more sensitive in nbM-lesioned rats than in sham-operated rats. On the other hand, intravenous administration of imidafenacin had no influence on learning in either case of the rats. In normal rats, however, intracerebroventricular administration of imidafenacin impaired learning to the same degree as that of oxybutynin hydrochloride. Thus, the present study suggests that imidafenacin, unlike the other antimuscarinics used, has no significant risk of enhancing learning impairment even in models whose sensitivity to learning impairment by antimuscarinics is commonly increased, probably because of its low brain penetration.

Potential effects of reward and loss avoidance in overweight adolescents

PubMed Central

Reyes, Sussanne; Peirano, Patricio; Luna, Beatriz; Lozoff, Betsy; Algarín, Cecilia

2015-01-01

Background Reward system and inhibitory control are brain functions that exert an influence on eating behavior regulation. We studied the differences in inhibitory control and sensitivity to reward and loss avoidance between overweight/obese and normal-weight adolescents. Methods We assessed 51 overweight/obese and 52 normal-weight 15-y-old Chilean adolescents. The groups were similar regarding sex and intelligence quotient. Using Antisaccade and Incentive tasks, we evaluated inhibitory control and the effect of incentive trials (neutral, loss avoidance, and reward) on generating correct and incorrect responses (latency and error rate). Results Compared to normal-weight group participants, overweight/obese adolescents showed shorter latency for incorrect antisaccade responses (186.0 (95% CI: 176.8–195.2) vs. 201.3 ms (95% CI: 191.2–211.5), P < 0.05) and better performance reflected by lower error rate in incentive trials (43.6 (95% CI: 37.8–49.4) vs. 53.4% (95% CI: 46.8–60.0), P < 0.05). Overweight/obese adolescents were more accurate on loss avoidance (40.9 (95% CI: 33.5–47.7) vs. 49.8% (95% CI: 43.0–55.1), P < 0.05) and reward (41.0 (95% CI: 34.5–47.5) vs. 49.8% (95% CI: 43.0–55.1), P < 0.05) compared to neutral trials. Conclusion Overweight/obese adolescents showed shorter latency for incorrect responses and greater accuracy in reward and loss avoidance trials. These findings could suggest that an imbalance of inhibition and reward systems influence their eating behavior. PMID:25927543

Spike-timing dependent inhibitory plasticity to learn a selective gating of backpropagating action potentials.

PubMed

Wilmes, Katharina Anna; Schleimer, Jan-Hendrik; Schreiber, Susanne

2017-04-01

Inhibition is known to influence the forward-directed flow of information within neurons. However, also regulation of backward-directed signals, such as backpropagating action potentials (bAPs), can enrich the functional repertoire of local circuits. Inhibitory control of bAP spread, for example, can provide a switch for the plasticity of excitatory synapses. Although such a mechanism is possible, it requires a precise timing of inhibition to annihilate bAPs without impairment of forward-directed excitatory information flow. Here, we propose a specific learning rule for inhibitory synapses to automatically generate the correct timing to gate bAPs in pyramidal cells when embedded in a local circuit of feedforward inhibition. Based on computational modeling of multi-compartmental neurons with physiological properties, we demonstrate that a learning rule with anti-Hebbian shape can establish the required temporal precision. In contrast to classical spike-timing dependent plasticity of excitatory synapses, the proposed inhibitory learning mechanism does not necessarily require the definition of an upper bound of synaptic weights because of its tendency to self-terminate once annihilation of bAPs has been reached. Our study provides a functional context in which one of the many time-dependent learning rules that have been observed experimentally - specifically, a learning rule with anti-Hebbian shape - is assigned a relevant role for inhibitory synapses. Moreover, the described mechanism is compatible with an upregulation of excitatory plasticity by disinhibition. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

The effect of CA1 dopaminergic system on amnesia induced by harmane in mice.

PubMed

Nasehi, Mohammad; Hasanvand, Simin; Khakpai, Fatemeh; Zarrindast, Mohammad-Reza

2018-05-16

In the present study, the effects of bilateral injections of dopaminergic drugs into the hippocampal CA1 regions (intra-CA1) on harmane-induced amnesia were examined in mice. We used a single-trial step-down inhibitory avoidance task for the assessment of memory acquisition in adult male mice. Our data indicated that pre-training intra-peritoneal (i.p.) administration of harmane (12 mg/kg) impaired memory acquisition. Moreover, intra-CA1 administration of dopamine D1 receptor agonist, SKF38393 (0.25 µg/mouse), dopamine D1 receptor antagonist, SCH23390 (0.25 µg/mouse), dopamine D2 receptor agonist, quinpirole (0.125 and 0.25 µg/mouse) and dopamine D2 receptor antagonist, sulpiride (0.2 and 0.4 µg/mouse) decreased the learning of a single-trial inhibitory avoidance task. Furthermore, pre-training intra-CA1 injection of sub-threshold doses of SKF38393 (0.0625 µg/mouse) or sulpiride (0.1 µg/mouse) increased pre-training harmane (4 and 8 mg/kg, i.p.)-induced amnesia. On the other hand, pre-training intra-CA1 injection of a sub-threshold dose of SCH23390 (0.0625 µg/mouse) reversed amnesia induced by an effective dose of harmane (12 mg/kg; i.p.). In addition, Pre-training intra-CA1 injection of quinpirole (0.0625 µg/mouse) had no effect on memory impairment induced by harmane. These findings indicate the involvement of CA1 dopaminergic system on harmane-induced impairment of memory acquisition.

Linking Individual Learning Styles to Approach-Avoidance Motivational Traits and Computational Aspects of Reinforcement Learning

PubMed Central

Carl Aberg, Kristoffer; Doell, Kimberly C.; Schwartz, Sophie

2016-01-01

Learning how to gain rewards (approach learning) and avoid punishments (avoidance learning) is fundamental for everyday life. While individual differences in approach and avoidance learning styles have been related to genetics and aging, the contribution of personality factors, such as traits, remains undetermined. Moreover, little is known about the computational mechanisms mediating differences in learning styles. Here, we used a probabilistic selection task with positive and negative feedbacks, in combination with computational modelling, to show that individuals displaying better approach (vs. avoidance) learning scored higher on measures of approach (vs. avoidance) trait motivation, but, paradoxically, also displayed reduced learning speed following positive (vs. negative) outcomes. These data suggest that learning different types of information depend on associated reward values and internal motivational drives, possibly determined by personality traits. PMID:27851807

Memory Erasure Experiments Indicate a Critical Role of CaMKII in Memory Storage.

PubMed

Rossetti, Tom; Banerjee, Somdeb; Kim, Chris; Leubner, Megan; Lamar, Casey; Gupta, Pooja; Lee, Bomsol; Neve, Rachael; Lisman, John

2017-09-27

The abundant synaptic protein CaMKII is necessary for long-term potentiation (LTP) and memory. However, whether CaMKII is required only during initial processes or whether it also mediates memory storage remains unclear. The most direct test of a storage role is the erasure test. In this test, a putative memory molecule is inhibited after learning. The key prediction is that this should produce persistent memory erasure even after the inhibitory agent is removed. We conducted this test using transient viral (HSV) expression of dominant-negative CaMKII-alpha (K42M) in the hippocampus. This produced persistent erasure of conditioned place avoidance. As an additional test, we found that expression of activated CaMKII (T286D/T305A/T306A) impaired place avoidance, a result not expected if a process other than CaMKII stores memory. Our behavioral results, taken together with prior experiments on LTP, strongly support a critical role of CaMKII in LTP maintenance and memory storage. Copyright © 2017 Elsevier Inc. All rights reserved.

Selective deficiencies in descending inhibitory modulation in neuropathic rats: implications for enhancing noradrenergic tone.

PubMed

Patel, Ryan; Qu, Chaoling; Xie, Jennifer Y; Porreca, Frank; Dickenson, Anthony H

2018-06-22

Pontine noradrenergic neurones form part of a descending inhibitory system that influences spinal nociceptive processing. Weak or absent descending inhibition is a common feature of chronic pain patients. We examined the extent to which the descending noradrenergic system is tonically active, how control of spinal neuronal excitability is integrated into thalamic relays within sensory-discriminative projection pathways, and how this inhibitory control is altered after nerve injury. In vivo electrophysiology was performed in anaesthetised spinal nerve-ligated (SNL) and sham-operated rats to record from wide dynamic range neurones in the ventral posterolateral thalamus (VPL). In sham rats, spinal block of α2-adrenoceptors with atipamezole resulted in enhanced stimulus-evoked and spontaneous firing in the VPL, and produced conditioned place avoidance. However, in SNL rats, these conditioned avoidance behaviours were absent. Furthermore, inhibitory control of evoked neuronal responses was lost, but spinal atipamezole markedly increased spontaneous firing. Augmenting spinal noradrenergic tone in neuropathic rats with reboxetine, a selective noradrenergic reuptake inhibitor, modestly reinstated inhibitory control of evoked responses in the VPL but had no effect on spontaneous firing. By contrast, clonidine, an α2 agonist, inhibited both evoked and spontaneous firing, and exhibited increased potency in SNL rats compared with sham controls. These data suggest descending noradrenergic inhibitory pathways are tonically active in sham rats. Moreover, in neuropathic states, descending inhibitory control is diminished, but not completely absent, and distinguishes between spontaneous and evoked neuronal activity. These observations may have implications for how analgesics targeting the noradrenergic system provide relief.This is an open access article distributed under the Creative Commons Attribution License 4.0 (CCBY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

The ventral hippocampus, but not the dorsal hippocampus is critical for learned approach-avoidance decision making.

PubMed

Schumacher, Anett; Vlassov, Ekaterina; Ito, Rutsuko

2016-04-01

The resolution of an approach-avoidance conflict induced by ambivalent information involves the appraisal of the incentive value of the outcomes and associated stimuli to orchestrate an appropriate behavioral response. Much research has been directed at delineating the neural circuitry underlying approach motivation and avoidance motivation separately. Very little research, however, has examined the neural substrates engaged at the point of decision making when opposing incentive motivations are experienced simultaneously. We hereby examine the role of the dorsal and ventral hippocampus (HPC) in a novel approach-avoidance decision making paradigm, revisiting a once popular theory of HPC function, which posited the HPC to be the driving force of a behavioral inhibition system that is activated in situations of imminent threat. Rats received pre-training excitotoxic lesions of the dorsal or ventral HPC, and were trained to associate different non-spatial cues with appetitive, aversive and neutral outcomes in three separate arms of the radial maze. On the final day of testing, a state of approach-avoidance conflict was induced by simultaneously presenting two cues of opposite valences, and comparing the time the rats spent interacting with the superimposed 'conflict' cue, and the neutral cue. The ventral HPC-lesioned group showed significant preference for the conflict cue over the neutral cue, compared to the dorsal HPC-lesioned, and control groups. Thus, we provide evidence that the ventral, but not dorsal HPC, is a crucial component of the neural circuitry concerned with exerting inhibitory control over approach tendencies under circumstances in which motivational conflict is experienced. © 2015 Wiley Periodicals, Inc.

When Prior Knowledge Interferes, Inhibitory Control Matters for Learning: The Case of Numerical Magnitude Representations

ERIC Educational Resources Information Center

Laski, Elida V.; Dulaney, Alana

2015-01-01

The present study tested the "interference hypothesis"-that learning and using more advanced representations and strategies requires the inhibition of prior, less advanced ones. Specifically, it examined the relation between inhibitory control and number line estimation performance. Experiment 1 compared the accuracy of adults' (N = 53)…

Fear Conditioning Selectively Disrupts Noradrenergic Facilitation of GABAergic Inhibition in the Basolateral Amygdala

PubMed Central

Skelly, M. J.; Ariwodola, O. J.; Weiner, J. L.

2016-01-01

Inappropriate fear memory formation is symptomatic of many psychopathologies, and delineating the neurobiology of non-pathological fear learning may provide critical insight into treating these disorders. Fear memory formation is associated with decreased inhibitory signaling in the basolateral amygdala (BLA), and disrupted noradrenergic signaling may contribute to this decrease. BLA noradrenergic neurotransmission has been implicated in fear memory formation, and distinct adrenoreceptor (AR) subtypes modulate excitatory and inhibitory neurotransmission in this region. For example, α1-ARs promote GABA release from local inhibitory interneurons, while β3-ARs potentiate neurotransmission at lateral paracapsular (LPC) GABAergic synapses. Conversely, β1/2-ARs amplify excitatory signaling at glutamatergic synapses in the BLA. As increased BLA excitability promotes fear memory formation, we hypothesized that fear learning shifts the balanced regional effects of noradrenergic signaling toward excitation. To test this hypothesis, we used the fear-potentiated startle paradigm in combination with whole cell patch clamp electrophysiology to examine the effects of AR activation on BLA synaptic transmission following fear conditioning in male Long-Evans rats. We first demonstrated that inhibitory neurotransmission is decreased at both local and LPC synapses following fear conditioning. We next measured noradrenergic facilitation of BLA inhibitory signaling at local and LPC synapses using α1- and β3-AR agonists (1μM A61603 and 10μM BRL37344), and found that the ability of these agents to facilitate inhibitory neurotransmission is disrupted following fear conditioning. Conversely, we found that fear learning does not disrupt noradrenergic modulation of glutamatergic signaling via a β1/2-AR agonist (1μM isoproterenol). Taken together, these studies suggest that fear learning increases BLA excitability by selectively disrupting the inhibitory effects of noradrenaline. PMID:27720769

Fear conditioning selectively disrupts noradrenergic facilitation of GABAergic inhibition in the basolateral amygdala.

PubMed

Skelly, M J; Ariwodola, O J; Weiner, J L

2017-02-01

Inappropriate fear memory formation is symptomatic of many psychopathologies, and delineating the neurobiology of non-pathological fear learning may provide critical insight into treating these disorders. Fear memory formation is associated with decreased inhibitory signaling in the basolateral amygdala (BLA), and disrupted noradrenergic signaling may contribute to this decrease. BLA noradrenergic neurotransmission has been implicated in fear memory formation, and distinct adrenoreceptor (AR) subtypes modulate excitatory and inhibitory neurotransmission in this region. For example, α1-ARs promote GABA release from local inhibitory interneurons, while β3-ARs potentiate neurotransmission at lateral paracapsular (LPC) GABAergic synapses. Conversely, β1/2-ARs amplify excitatory signaling at glutamatergic synapses in the BLA. As increased BLA excitability promotes fear memory formation, we hypothesized that fear learning shifts the balanced regional effects of noradrenergic signaling toward excitation. To test this hypothesis, we used the fear-potentiated startle paradigm in combination with whole cell patch clamp electrophysiology to examine the effects of AR activation on BLA synaptic transmission following fear conditioning in male Long-Evans rats. We first demonstrated that inhibitory neurotransmission is decreased at both local and LPC synapses following fear conditioning. We next measured noradrenergic facilitation of BLA inhibitory signaling at local and LPC synapses using α1-and β3-AR agonists (1 μM A61603 and 10 μM BRL37344), and found that the ability of these agents to facilitate inhibitory neurotransmission is disrupted following fear conditioning. Conversely, we found that fear learning does not disrupt noradrenergic modulation of glutamatergic signaling via a β1/2-AR agonist (1 μM isoproterenol). Taken together, these studies suggest that fear learning increases BLA excitability by selectively disrupting the inhibitory effects of noradrenaline. Copyright © 2016 Elsevier Ltd. All rights reserved.

Medial prefrontal cortex dopamine controls the persistent storage of aversive memories

PubMed Central

Gonzalez, María C.; Kramar, Cecilia P.; Tomaiuolo, Micol; Katche, Cynthia; Weisstaub, Noelia; Cammarota, Martín; Medina, Jorge H.

2014-01-01

Medial prefrontal cortex (mPFC) is essential for initial memory processing and expression but its involvement in persistent memory storage has seldom been studied. Using the hippocampus dependent inhibitory avoidance learning task and the hippocampus-independent conditioned taste aversion paradigm together with specific dopamine receptor agonists and antagonists we found that persistence but not formation of long-term aversive memories requires dopamine D1/D5 receptors activation in mPFC immediately after training and, depending on the task, between 6 and 12 h later. Our results indicate that besides its well-known participation in retrieval and early consolidation, mPFC also modulates the endurance of long-lasting aversive memories regardless of whether formation of the aversive mnemonic trace requires the participation of the hippocampus. PMID:25506318

Constructive and Unproductive Processing of Traumatic Experiences in Trauma-Focused Cognitive-Behavioral Therapy for Youth.

PubMed

Hayes, Adele M; Yasinski, Carly; Grasso, Damion; Ready, C Beth; Alpert, Elizabeth; McCauley, Thomas; Webb, Charles; Deblinger, Esther

2017-03-01

Although there is substantial evidence to support the efficacy of cognitive-behavioral treatments (CBT) for posttraumatic stress disorder (PTSD), there is some debate about how these treatments have their effects. Modern learning theory and cognitive and emotional processing theories highlight the importance of reducing avoidance, facilitating the constructive processing of feared experiences, and strengthening new inhibitory learning. We examined variables thought to be associated with unproductive and constructive processing of traumatic experiences in a sample of 81 youth with elevated PTSD symptoms, who received Trauma-Focused Cognitive Behavioral Therapy (TF-CBT) for abuse or traumatic interpersonal loss. Sessions during the trauma narrative phase of TF-CBT were coded for indicators of unproductive processing (overgeneralization, rumination, avoidance) and constructive processing (decentering, accommodation of corrective information), as well as levels of negative emotion. In previous analyses of this trial (Ready et al., 2015), more overgeneralization during the narrative phase predicted less improvement in internalizing symptoms at posttreatment and a worsening of externalizing symptoms over the 12-month follow-up. In contrast, more accommodation predicted improvement in internalizing symptoms and also moderated the negative effects of overgeneralization on internalizing and externalizing symptoms. The current study examined correlates of overgeneralization and accommodation. Overgeneralization was associated with more rumination, less decentering, and more negative emotion, suggesting immersion in trauma-related material. Accommodation was associated with less avoidance and more decentering, suggesting a healthy distance from trauma-related material that might allow for processing and cognitive change. Decentering also predicted improvement in externalizing symptoms at posttreatment. Rumination and avoidance showed important associations with overgeneralization and accommodation, respectively, but did not predict treatment outcomes. This study identifies correlates of overgeneralization and accommodation that might shed light on how these variables relate to unproductive and constructive processing of traumatic experiences. Copyright © 2016. Published by Elsevier Ltd.

The role of outcome inhibition in interference between outcomes: a contingency-learning analogue of retrieval-induced forgetting.

PubMed

Vadillo, Miguel A; Orgaz, Cristina; Luque, David; Cobos, Pedro L; López, Francisco J; Matute, Helena

2013-05-01

Current associative theories of contingency learning assume that inhibitory learning plays a part in the interference between outcomes. However, it is unclear whether this inhibitory learning results in the inhibition of the outcome representation or whether it simply counteracts previous excitatory learning so that the outcome representation is neither activated nor inhibited. Additionally, these models tend to conceptualize inhibition as a relatively transient and cue-dependent state. However, research on retrieval-induced forgetting suggests that the inhibition of representations is a real process that can be relatively independent of the retrieval cue used to access the inhibited information. Consistent with this alternative view, we found that interference between outcomes reduces the retrievability of the target outcome even when the outcome is associated with a novel (non-inhibitory) cue. This result has important theoretical implications for associative models of interference and shows that the empirical facts and theories developed in studies of retrieval-induced forgetting might be relevant in contingency learning and vice versa. © 2012 The British Psychological Society.

Neurofeedback Training Effects on Inhibitory Brain Activation in ADHD: A Matter of Learning?

PubMed

Baumeister, Sarah; Wolf, Isabella; Holz, Nathalie; Boecker-Schlier, Regina; Adamo, Nicoletta; Holtmann, Martin; Ruf, Matthias; Banaschewski, Tobias; Hohmann, Sarah; Brandeis, Daniel

2018-05-15

Neurofeedback training (NF) is a promising non-pharmacological treatment for ADHD that has been associated with improvement of attention-deficit/hyperactivity disorder (ADHD)-related symptoms as well as changes in electrophysiological measures. However, the functional localization of neural changes following NF compared to an active control condition, and of successful learning during training (considered to be the critical mechanism for improvement), remains largely unstudied. Children with ADHD (N=16, mean age: 11.81, SD: 1.47) were randomly assigned to either slow cortical potential (SCP, n=8) based NF or biofeedback control training (electromyogram feedback, n=8) and performed a combined Flanker/NoGo task pre- and post-training. Effects of NF, compared to the active control, and of learning in transfer trials (approximating successful transfer to everyday life) were examined with respect to clinical outcome and functional magnetic resonance imaging (fMRI) changes during inhibitory control. After 20 sessions of training, children in the NF group presented reduced ADHD symptoms and increased activation in areas associated with inhibitory control compared to baseline. Subjects who were successful learners (n=9) also showed increased activation in an extensive inhibitory network irrespective of the type of training. Activation increased in an extensive inhibitory network following NF training, and following successful learning through NF and control biofeedback. Although this study was only powered to detect large effects and clearly requires replication in larger samples, the results suggest a crucial role for learning effects in biofeedback trainings. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Avoiding the Potential Pitfalls of Using Negative Priming Tasks in Developmental Studies: Assessing Inhibitory Control in Children, Adolescents, and Adults

ERIC Educational Resources Information Center

Pritchard, Verena E.; Neumann, Ewald

2009-01-01

Despite being ignored, visual distractors often produce traceable negative priming (NP) effects that can be used to investigate inhibitory processes. Robust NP effects are typically found with young adults, but not with children. Using 2 different NP tasks, the authors compared NP in 5 different age groups spanning 5 to 25 years of age. The 1st…

Hemispheric Asymmetries in Striatal Reward Responses Relate to Approach-Avoidance Learning and Encoding of Positive-Negative Prediction Errors in Dopaminergic Midbrain Regions.

PubMed

Aberg, Kristoffer Carl; Doell, Kimberly C; Schwartz, Sophie

2015-10-28

Some individuals are better at learning about rewarding situations, whereas others are inclined to avoid punishments (i.e., enhanced approach or avoidance learning, respectively). In reinforcement learning, action values are increased when outcomes are better than predicted (positive prediction errors [PEs]) and decreased for worse than predicted outcomes (negative PEs). Because actions with high and low values are approached and avoided, respectively, individual differences in the neural encoding of PEs may influence the balance between approach-avoidance learning. Recent correlational approaches also indicate that biases in approach-avoidance learning involve hemispheric asymmetries in dopamine function. However, the computational and neural mechanisms underpinning such learning biases remain unknown. Here we assessed hemispheric reward asymmetry in striatal activity in 34 human participants who performed a task involving rewards and punishments. We show that the relative difference in reward response between hemispheres relates to individual biases in approach-avoidance learning. Moreover, using a computational modeling approach, we demonstrate that better encoding of positive (vs negative) PEs in dopaminergic midbrain regions is associated with better approach (vs avoidance) learning, specifically in participants with larger reward responses in the left (vs right) ventral striatum. Thus, individual dispositions or traits may be determined by neural processes acting to constrain learning about specific aspects of the world. Copyright © 2015 the authors 0270-6474/15/3514491-10$15.00/0.

Sildenafil, a selective phosphodiesterase type 5 inhibitor, enhances memory reconsolidation of an inhibitory avoidance task in mice.

PubMed

Boccia, M M; Blake, M G; Krawczyk, M C; Baratti, C M

2011-07-07

Intracellular levels of the second messengers cAMP and cGMP are maintained through a balance between production, carried out by adenyl cyclase (AC) and guanylyl cyclase (GC), and degradation, carried out by phosphodiesterases (PDEs). Recently, PDEs have gained increased attention as potential new targets for cognition enhancement, with particular reference to phosphodiesterase type 5 (PDE5A). It is accepted that once consolidation is completed memory becomes permanent, but it has also been suggested that reactivation (memory retrieval) of the original memory makes it sensitive to the same treatments that affect memory consolidation when given after training. This new period of sensitivity coined the term reconsolidation. Sildenafil (1, 3, and 10mg/kg, ip), a cGMP-PDE5 inhibitor, facilitated retention performance of a one-trial step-through inhibitory avoidance task, when administered to CF-1 male mice immediately after retrieval. The effects of sildenafil (1mg/kg, ip) were time-dependent, long-lasting and inversely correlated with memory age. The administration of sildenafil (1mg/kg, ip) 30 min prior to the 2nd retention test did not affect retention of mice given post-retrieval injections of either vehicle or sildenafil (1mg/kg, ip). Finally, an enhancement of retention was also observed in CF-1 female mice receiving sildenafil (1mg/kg, ip) immediately, but not 180 min after retrieval. In the present paper we reported for the first time that systemic administration of sildenafil after memory reactivation enhances retention performance of the original learning. Our results indirectly point out cGMP, a component of the NO/cGMP/PKG pathway, as a necessary factor for memory reconsolidation. Copyright © 2011 Elsevier B.V. All rights reserved.

Treatment of avoidance behavior as an adjunct to exposure therapy: Insights from modern learning theory.

PubMed

Treanor, Michael; Barry, Tom J

2017-09-01

Pathological avoidance of benign stimuli is a hallmark of anxiety and related disorders, and exposure-based treatments have often encouraged the removal of avoidance, or safety behaviors, due to their negative effects on extinction learning. Unfortunately, empirical evidence suggests that avoidance behaviors can persist following treatment, and the mere availability of avoidance behavior can be sufficient to renew fear following successful extinction learning. The present paper critically examines the function of avoidance behavior through the lens of modern learning theory, and speculates on novel behavioral and pharmacological strategies for targeting avoidance as an adjunct to current evidence-based treatments. Copyright © 2017. Published by Elsevier Ltd.

Threat Interference Biases Predict Socially Anxious Behavior: The Role of Inhibitory Control and Minute of Stressor.

PubMed

Gorlin, Eugenia I; Teachman, Bethany A

2015-07-01

The current study brings together two typically distinct lines of research. First, social anxiety is inconsistently associated with behavioral deficits in social performance, and the factors accounting for these deficits remain poorly understood. Second, research on selective processing of threat cues, termed cognitive biases, suggests these biases typically predict negative outcomes, but may sometimes be adaptive, depending on the context. Integrating these research areas, the current study examined whether conscious and/or unconscious threat interference biases (indexed by the unmasked and masked emotional Stroop) can explain unique variance, beyond self-reported anxiety measures, in behavioral avoidance and observer-rated anxious behavior during a public speaking task. Minute of speech and general inhibitory control (indexed by the color-word Stroop) were examined as within-subject and between-subject moderators, respectively. Highly socially anxious participants (N=135) completed the emotional and color-word Stroop blocks prior to completing a 4-minute videotaped speech task, which was later coded for anxious behaviors (e.g., speech dysfluency). Mixed-effects regression analyses revealed that general inhibitory control moderated the relationship between both conscious and unconscious threat interference bias and anxious behavior (though not avoidance), such that lower threat interference predicted higher levels of anxious behavior, but only among those with relatively weaker (versus stronger) inhibitory control. Minute of speech further moderated this relationship for unconscious (but not conscious) social-threat interference, such that lower social-threat interference predicted a steeper increase in anxious behaviors over the course of the speech (but only among those with weaker inhibitory control). Thus, both trait and state differences in inhibitory control resources may influence the behavioral impact of threat biases in social anxiety. Copyright © 2015. Published by Elsevier Ltd.

Risky Decision Making Assessed With the Gambling Task in Adults with HIV

PubMed Central

Hardy, David J.; Hinkin, Charles H.; Castellon, Steven A.; Levine, Andrew J.; Lam, Mona N.

2010-01-01

Decision making was assessed using a laboratory gambling task in 67 adults with the Human Immunodeficiency Virus (HIV+) and in 19 HIV-seronegative (HIV−) control participants. Neurocognitive test performance across several domains was also analyzed to examine potential cognitive mechanisms of gambling task performance. As predicted, the HIV+ group performed worse on the gambling task, indicating greater risky decision making. Specifically, the HIV+ group selected more cards from the “risky” or disadvantageous deck that included relatively large payoffs but infrequent large penalties. The control group also selected such risky cards but quickly learned to avoid them. Exploratory analyses also indicated that in the HIV+ group, but not in the control group, gambling task performance was correlated with Stroop Interference performance and long delay free recall on the California Verbal Learning Test, suggesting the role of inhibitory processes and verbal memory in the poorer gambling task performance in HIV. These findings indicate the usefulness of the gambling task as a laboratory tool to examine risky decision making and cognition in the HIV population. PMID:16719628

Conditioned inhibition in the spatial domain.

PubMed

Sansa, J; Rodrigo, T; Santamaría, J J; Manteiga, R D; Chamizo, V D

2009-10-01

Using a variation on the standard procedure of conditioned inhibition (Trials A+ and AX-), rats (Rattus norvegicus) in a circular pool were trained to find a hidden platform that was located in a specific spatial position in relation to 2 individual landmarks (Trials A --> platform and B --> platform; Experiments 1a and 1b) and to 2 configurations of landmarks (Trials ABC --> platform and FGH --> platform; Experiment 2a). The rats also underwent inhibitory trials (Experiment 1: Trials AZ --> no platform; Experiment 2a: Trials CDE --> no platform) interspersed with these excitatory trials. In both experiments, subsequent test trials without the platform showed both a summation effect and retardation of excitatory conditioning, and in Experiment 2a rats learned to avoid the CDE quadrant over the course of the experiment. Two further experiments established that these results could not be attributed to any difference in salience between the conditioned inhibitors and the control stimuli. All these results contribute to the growing body of evidence consistent with the idea that there is a general mechanism of learning that is associative in nature. PsycINFO Database Record (c) 2009 APA, all rights reserved.

Aversive and non-aversive memory impairment in the mucopolysaccharidosis II mouse model.

PubMed

Azambuja, Amanda Stapenhorst; Correa, Lilian; Gabiatti, Bernardo Pappi; Martins, Giselle Renata; de Oliveira Franco, Álvaro; Ribeiro, Maria Flávia Marques; Baldo, Guilherme

2018-02-01

Hunter syndrome (MPS II, OMIM 309900) is a lysosomal storage disorder due to deficient iduronate sulphatase activity. Patients present multiple cognitive alterations, and the aim of this work was to verify if MPS II mice also present some progressive cognitive alterations. For that, MPS II mice from 2 to 6 months of age were submitted to repeated open field and inhibitory avoidance tests to evaluate memory parameters. MPS II mice presented impaired memory at 6 months evaluated by open field test. They also performed poorly in the inhibitory avoidance test from 4 months. We conclude that MPS II mice develop cognitive alterations as the disease progresses. These tests can be used in the future to study the efficacy of therapeutic approaches in the central nervous system.

Avoidance learning: a review of theoretical models and recent developments

PubMed Central

Krypotos, Angelos-Miltiadis; Effting, Marieke; Kindt, Merel; Beckers, Tom

2015-01-01

Avoidance is a key characteristic of adaptive and maladaptive fear. Here, we review past and contemporary theories of avoidance learning. Based on the theories, experimental findings and clinical observations reviewed, we distill key principles of how adaptive and maladaptive avoidance behavior is acquired and maintained. We highlight clinical implications of avoidance learning theories and describe intervention strategies that could reduce maladaptive avoidance and prevent its return. We end with a brief overview of recent developments and avenues for further research. PMID:26257618

Effects of histamine and some related compounds on conditioned avoidance response in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tasaka, K.; Kamei, C.; Akahori, H.

1985-11-25

When histamine (Hi) and other agonists were applied intraventricularly, Hi caused a dose-dependent inhibition of the avoidance response in rats; its ED50 was 3.60 ..mu..g. l-methylHi, l-methylimidazole acetic acid and imidazole acetic acid which are major metabolites of Hi produced no inhibitory effect even at 50 ..mu..g. H/sub 1/-agonists (2-methylHi and 2-thiazolylethylamine) also depressed the avoidance response; their dose-response lines run parallel to that of Hi. The depressant effects of H/sub 2/-agonists (4-methylHi and dimaprit) were relatively weak; their dose-response lines were not parallel to that of Hi. When antagonists were pretreated intravenously, Hi action was clearly antagonized by diphehydraminemore » and pyrilamine, but not by cimetidine or ranitidine. Intraventricular injection of Hi mixed with cimetidine or ranitidine did not change the effect induced by Hi alone. The avoidance response was not affected by noradrenaline, dopamine or 5-hydroxytryptamine. Although acetylcholine (ACh) suppressed the avoidance response dose-dependently, its effect was much weaker than that of Hi. Pretreatment with cholinergic blocking drugs (atropine and scopolamine) antagonized ACh action but not Hi action. From these results, it is assumed that the inhibitory effect of Hi on the avoidance response is preferentially linked to the H/sub 1/-receptor. After intraventricular application of /sup 3/H-Hi, the highest radioactivity was determined in the hypothalamus. 21 references, 4 figures, 4 tables.« less

Effects of the antidepressant drug moclobemide on learning and memory in rats.

PubMed

Getova, D; Dimitrova, D; Roukounakis, I

2003-12-01

Moclobemide is a well known drug with antidepressant action. The aim of this study was to investigate the effects of moclobemide on learning and memory processes in Sprague Dawley rats. Over a 5-day period, learning sessions with 30 trials per day and memory retention tests were performed. The conditioned responses (avoidances), the unconditioned responses (escapes) and the intertrial crossings were observed. An active avoidance test was carried out using a shuttle box. Two passive avoidance tests were used: step-through (using a light chamber) and step-down (using a platform). In the step-through passive avoidance test, the learning and retention sessions consisted of three trials each and the latency of reaction times (the rat remaining in the light chamber for more than 180 sec) was used as criterion. In the step-down passive avoidance test, learning and retention sessions consisted of two trials and the latency of reaction times (the rat remaining on the platform for 60 sec) was used as criterion. In the active avoidance tests, moclobemide dose-dependently increased the number of avoidances during learning sessions and maintained this number in memory retention tests. Moclobemide did not alter the number of escapes, but did increase motor activity. In the passive avoidance tests, moclobemide also increased the latency of reaction times in learning and short memory retrieval tests. These findings suggest that moclobemide improves learning and memory processes in active and passive avoidance tests and has a cognition-enhancing effect. (c) 2003 Prous Science

[Effect of 5-HT1A receptors in the hippocampal DG on active avoidance learning in rats].

PubMed

Jiang, Feng-ze; Lv, Jing; Wang, Dan; Jiang, Hai-ying; Li, Ying-shun; Jin, Qing-hua

2015-01-01

To investigate the effects of serotonin (5-HTIA) receptors in the hippocampal dentate gyrus (DG) on active avoidance learning in rats. Totally 36 SD rats were randomly divided into control group, antagonist group and agonist group(n = 12). Active avoidance learning ability of rats was assessed by the shuttle box. The extracellular concentrations of 5-HT in the DG during active avoidance conditioned reflex were measured by microdialysis and high performance liquid chromatography (HPLC) techniques. Then the antagonist (WAY-100635) or agonist (8-OH-DPAT) of the 5-HT1A receptors were microinjected into the DG region, and the active avoidance learning was measured. (1) During the active avoidance learning, the concentration of 5-HT in the hippocampal DG was significantly increased in the extinction but not establishment in the conditioned reflex, which reached 164.90% ± 26.07% (P <0.05) of basal level. (2) The microinjection of WAY-100635 (an antagonist of 5-HT1A receptor) into the DG did not significantly affect the active avoidance learning. (3) The microinjection of 8-OH-DPAT(an agonist of 5-HT1A receptor) into the DG significantly facilitated the establishment process and inhibited the extinction process during active avoidance conditioned reflex. The data suggest that activation of 5-HT1A receptors in hipocampal DG may facilitate active avoidance learning and memory in rats.

Successive and discrete spaced conditioning in active avoidance learning in young and aged zebrafish.

PubMed

Yang, Peng; Kajiwara, Riki; Tonoki, Ayako; Itoh, Motoyuki

2018-05-01

We designed an automated device to study active avoidance learning abilities of zebrafish. Open source tools were used for the device control, statistical computing, and graphic outputs of data. Using the system, we developed active avoidance tests to examine the effects of trial spacing and aging on learning. Seven-month-old fish showed stronger avoidance behavior as measured by color preference index with discrete spaced training as compared to successive spaced training. Fifteen-month-old fish showed a similar trend, but with reduced cognitive abilities compared with 7-month-old fish. Further, in 7-month-old fish, an increase in learning ability during trials was observed with discrete, but not successive, spaced training. In contrast, 15-month-old fish did not show increase in learning ability during trials. Therefore, these data suggest that discrete spacing is more effective for learning than successive spacing, with the zebrafish active avoidance paradigm, and that the time course analysis of active avoidance using discrete spaced training is useful to detect age-related learning impairment. Copyright © 2017 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Olfactory coding: giant inhibitory neuron governs sparse odor codes.

PubMed

Gupta, Nitin; Stopfer, Mark

2011-07-12

Electrophysiological investigations in locusts have revealed that the sparseness of odor representations, in the brain region expected to mediate olfactory learning, is shaped by a unique inhibitory neuron. Copyright © 2011 Elsevier Ltd. All rights reserved.

Learned parasite avoidance is driven by host personality and resistance to infection in a fish–trematode interaction

PubMed Central

Karvonen, Anssi

2016-01-01

Cognitive abilities related to the assessment of risk improve survival. While earlier studies have examined the ability of animals to learn to avoid predators, learned parasite avoidance has received little interest. In a series of behavioural trials with the trematode parasite Diplostomum pseudospathaceum, we asked whether sea trout (Salmo trutta trutta) hosts show associative learning in the context of parasitism and if so, whether learning capacity is related to the likelihood of infection mediated through host personality and resistance. We show that animals are capable of learning to avoid visual cues associated with the presence of parasites. However, avoidance behaviour ceased after the likely activation of host resistance following consecutive exposures during learning, suggesting that resistance to infection outweighs avoidance. Further, we found a positive relationship between learning ability and boldness, suggesting a compensation of risky lifestyles through increased investment in cognitive abilities. By contrast, an increased risk of infection due to low resistance was not balanced by learning ability. Instead, these traits were positively related, which may be explained by inherent physiological qualities controlling both traits. Overall, the results demonstrate that parasitism, in addition to other biological interactions such as predation, is an important selective factor in the evolution of animal cognition. PMID:27605504

The Relationship among Student Basic Need Satisfaction, Approaches to Learning, Reporting of Avoidance Strategies and Achievement

ERIC Educational Resources Information Center

Betoret, Fernando Domenech; Artiga, Amparo Gomez

2011-01-01

Introduction: This study examines the relationship between student basic need satisfaction (autonomy, competence, relatedness and belonging), their reporting of approaches to learning (deep and surface), their reporting of avoidance strategies (avoidance of effort and challenge, avoidance of help seeking and preference to avoid novelty) and…

The time course of location-avoidance learning in fear of spiders.

PubMed

Rinck, Mike; Koene, Marieke; Telli, Sibel; Moerman-van den Brink, Wiltine; Verhoeven, Barbara; Becker, Eni S

2016-01-01

Two experiments were designed to study the time course of avoidance learning in spider fearfuls (SFs) under controlled experimental conditions. To achieve this, we employed an immersive virtual environment (IVE): While walking freely through a virtual art museum to search for specific paintings, the participants were exposed to virtual spiders. Unbeknown to the participants, only two of four museum rooms contained spiders, allowing for avoidance learning. Indeed, the more SF the participants were, the faster they learned to avoid the rooms that contained spiders (Experiment. 1), and within the first six trials, high fearfuls already developed a preference for starting their search task in rooms without spiders (Experiment 2). These results illustrate the time course of avoidance learning in SFs, and they speak to the usefulness of IVEs in fundamental anxiety research.

Mixed Signal Learning by Spike Correlation Propagation in Feedback Inhibitory Circuits

PubMed Central

Hiratani, Naoki; Fukai, Tomoki

2015-01-01

The brain can learn and detect mixed input signals masked by various types of noise, and spike-timing-dependent plasticity (STDP) is the candidate synaptic level mechanism. Because sensory inputs typically have spike correlation, and local circuits have dense feedback connections, input spikes cause the propagation of spike correlation in lateral circuits; however, it is largely unknown how this secondary correlation generated by lateral circuits influences learning processes through STDP, or whether it is beneficial to achieve efficient spike-based learning from uncertain stimuli. To explore the answers to these questions, we construct models of feedforward networks with lateral inhibitory circuits and study how propagated correlation influences STDP learning, and what kind of learning algorithm such circuits achieve. We derive analytical conditions at which neurons detect minor signals with STDP, and show that depending on the origin of the noise, different correlation timescales are useful for learning. In particular, we show that non-precise spike correlation is beneficial for learning in the presence of cross-talk noise. We also show that by considering excitatory and inhibitory STDP at lateral connections, the circuit can acquire a lateral structure optimal for signal detection. In addition, we demonstrate that the model performs blind source separation in a manner similar to the sequential sampling approximation of the Bayesian independent component analysis algorithm. Our results provide a basic understanding of STDP learning in feedback circuits by integrating analyses from both dynamical systems and information theory. PMID:25910189

Ameliorating effects of aged garlic extracts against Aβ-induced neurotoxicity and cognitive impairment

PubMed Central

2013-01-01

Background In vitro antioxidant activities and neuron-like PC12 cell protective effects of solvent fractions from aged garlic extracts were investigated to evaluate their anti-amnesic functions. Ethyl acetate fractions of aged garlic had higher total phenolics than other fractions. Methods Antioxidant activities of ethyl acetate fractions from aged garlic were examined using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) and malondialdehyde (MDA) inhibitory effect using mouse whole brain homogenates. Levels of cellular oxidative stress as reactive oxygen species (ROS) accumulation were measured using 2',7'-dichlorofluorescein diacetate (DCF-DA). PC12 cell viability was investigated by 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and lactate dehydtrogenase (LDH) assay. The learning and memory impairment in institute of cancer research (ICR) mice was induced by neurotoxic amyloid beta protein (Aβ) to investigate in vivo anti-amnesic effects of aged garlic extracts by using Y-maze and passive avoidance tests. Results We discovered that ethyl acetate fractions showed the highest ABTS radical scavenging activity and MDA inhibitory effect. Intracellular ROS accumulation resulting from Aβ treatment in PC12 cells was significantly reduced when ethyl acetate fractions were presented in the medium compare to PC12 cells which was only treated with Aβ only. Ethyl acetate fractions from aged garlic extracts showed protection against Aβ-induced neurotoxicity. Pre-administration with aged garlic extracts attenuated Aβ-induced learning and memory deficits in both in vivo tests. Conclusions Our findings suggest that aged garlic extracts with antioxidant activities may improve cognitive impairment against Aβ-induced neuronal deficit, and possess a wide range of beneficial activities for neurodegenerative disorders, notably Alzheimer's disease (AD). PMID:24134394

The Homeostatic Interaction Between Anodal Transcranial Direct Current Stimulation and Motor Learning in Humans is Related to GABAA Activity.

PubMed

Amadi, Ugwechi; Allman, Claire; Johansen-Berg, Heidi; Stagg, Charlotte J

2015-01-01

The relative timing of plasticity-induction protocols is known to be crucial. For example, anodal transcranial direct current stimulation (tDCS), which increases cortical excitability and typically enhances plasticity, can impair performance if it is applied before a motor learning task. Such timing-dependent effects have been ascribed to homeostatic plasticity, but the specific synaptic site of this interaction remains unknown. We wished to investigate the synaptic substrate, and in particular the role of inhibitory signaling, underpinning the behavioral effects of anodal tDCS in homeostatic interactions between anodal tDCS and motor learning. We used transcranial magnetic stimulation (TMS) to investigate cortical excitability and inhibitory signaling following tDCS and motor learning. Each subject participated in four experimental sessions and data were analyzed using repeated measures ANOVAs and post-hoc t-tests as appropriate. As predicted, we found that anodal tDCS prior to the motor task decreased learning rates. This worsening of learning after tDCS was accompanied by a correlated increase in GABAA activity, as measured by TMS-assessed short interval intra-cortical inhibition (SICI). This provides the first direct demonstration in humans that inhibitory synapses are the likely site for the interaction between anodal tDCS and motor learning, and further, that homeostatic plasticity at GABAA synapses has behavioral relevance in humans. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Post-training reversible disconnection of the ventral hippocampal-basolateral amygdaloid circuits impairs consolidation of inhibitory avoidance memory in rats.

PubMed

Wang, Gong-Wu; Liu, Jian; Wang, Xiao-Qin

2017-11-01

The ventral hippocampus (VH) and the basolateral amygdala (BLA) are both crucial in inhibitory avoidance (IA) memory. However, the exact role of the VH-BLA circuit in IA memory consolidation is unclear. This study investigated the effect of post-training reversible disconnection of the VH-BLA circuit in IA memory consolidation. Male Wistar rats with implanted guide cannulae were trained with a one-trial IA task, then received immediate intracerebral injections of muscimol or saline, and were tested 24 h later. Muscimol injection into the bilateral BLA, or the unilateral VH and contralateral BLA, but not the unilateral VH and ipsilateral BLA, significantly decreased the retention latencies (versus saline treatment). The results suggest that the VH-BLA circuit could be an important circuit to modulate consolidation of IA memory in rats. © 2017 Wang et al.; Published by Cold Spring Harbor Laboratory Press.

Motivation, working memory, and decision making: a cognitive-motivational theory of personality vulnerability to alcoholism.

PubMed

Finn, Peter R

2002-09-01

This article presents a cognitive-motivational theory (CMT) of the mechanisms associated with three basic dimensions of personality vulnerability to alcoholism, impulsivity/novelty seeking, harm avoidance, and excitement seeking. CMT describes the interrelationships between activity in basic motivational systems and attentional, decision-making and working memory processes as the mechanisms associated with variation in each personality trait. Impulsivity/novelty seeking reflects activity in both appetitive and inhibitory motivational systems, greater attention to reward cues, and increased emotional reactivity to reward and frustration. Harm avoidance reflects individual differences in fearfulness and activity in specific inhibitory systems. Excitement seeking reflects the need to engage in appetitive behaviors in less predictable environments to experience positive affect. CMT also describes the impact of working memory and the specific motivational processes underlying each trait dimension on the dynamics of decision making from the perspective of decision field theory.

Myopic Regret Avoidance: Feedback Avoidance and Learning in Repeated Decision Making

ERIC Educational Resources Information Center

Reb, Jochen; Connolly, Terry

2009-01-01

Decision makers can become trapped by "myopic regret avoidance" in which rejecting feedback to avoid short-term "outcome regret" (regret associated with counterfactual outcome comparisons) leads to reduced learning and greater long-term regret over continuing poor decisions. In a series of laboratory experiments involving repeated choices among…

[Influence of activation and blockade of NMDA receptors on extinction of passive avoidance response in mice with different levels of anxiety].

PubMed

Tomilenko, R A; Dubrovina, N I

2006-03-01

Influence of agonist (D-cycloserine) and antagonist (dizocilpine) N-methyl-D-aspartate receptors on learning and extinction of passive avoidance response in medium-, high-, and low-anxious mice was studied. In medium-anxious mice, D-cycloserine (30 mg/kg) although not changing learning accelerated development of extinction, whereas dizocilpine (0.15 mg/kg), while impairing passive avoidance learning, detained the extinction. In high-anxious mice with good retrieval of memory trace and absence of extinction, D-cycloserine was ineffective, whereas dizocilpine reduced learning and promoted retention of memory trace retrieval at the generated level on extinction. In low-anxious mice, D-cycloserine impaired learning and accelerated extinction, whereas dizocilpine completely blocked learning and retention of passive avoidance response.

Disinhibition, an emerging pharmacology of learning and memory.

PubMed

Möhler, Hanns; Rudolph, Uwe

2017-01-01

Learning and memory are dependent on interactive excitatory and inhibitory mechanisms. In this review, we discuss a mechanism called disinhibition, which is the release of an inhibitory constraint that effectively results in an increased activity in the target neurons (for example, principal or projection neurons). We focus on discussing the role of disinhibition in learning and memory at a basic level and in disease models with cognitive deficits and highlight a strategy to reverse cognitive deficits caused by excess inhibition, through disinhibition of α5-containing GABA A receptors mediating tonic inhibition in the hippocampus, based on subtype-selective negative allosteric modulators as a novel class of drugs.

Local inhibition modulates learning-dependent song encoding in the songbird auditory cortex

PubMed Central

Thompson, Jason V.; Jeanne, James M.

2013-01-01

Changes in inhibition during development are well documented, but the role of inhibition in adult learning-related plasticity is not understood. In songbirds, vocal recognition learning alters the neural representation of songs across the auditory forebrain, including the caudomedial nidopallium (NCM), a region analogous to mammalian secondary auditory cortices. Here, we block local inhibition with the iontophoretic application of gabazine, while simultaneously measuring song-evoked spiking activity in NCM of European starlings trained to recognize sets of conspecific songs. We find that local inhibition differentially suppresses the responses to learned and unfamiliar songs and enhances spike-rate differences between learned categories of songs. These learning-dependent response patterns emerge, in part, through inhibitory modulation of selectivity for song components and the masking of responses to specific acoustic features without altering spectrotemporal tuning. The results describe a novel form of inhibitory modulation of the encoding of learned categories and demonstrate that inhibition plays a central role in shaping the responses of neurons to learned, natural signals. PMID:23155175

Proactive behavior, but not inhibitory control, predicts repeated innovation by spotted hyenas tested with a multi-access box.

PubMed

Johnson-Ulrich, Lily; Johnson-Ulrich, Zoe; Holekamp, Kay

2018-05-01

Innovation is widely linked to cognitive ability, brain size, and adaptation to novel conditions. However, successful innovation appears to be influenced by both cognitive factors, such as inhibitory control, and non-cognitive behavioral traits. We used a multi-access box (MAB) paradigm to measure repeated innovation, the number of unique innovations learned across trials, by 10 captive spotted hyenas (Crocuta crocuta). Spotted hyenas are highly innovative in captivity and also display striking variation in behavioral traits, making them good model organisms for examining the relationship between innovation and other behavioral traits. We measured persistence, motor diversity, motivation, activity, efficiency, inhibitory control, and neophobia demonstrated by hyenas while interacting with the MAB. We also independently assessed inhibitory control with a detour cylinder task. Most hyenas were able to solve the MAB at least once, but only four hyenas satisfied learning criteria for all four possible solutions. Interestingly, neither measure of inhibitory control predicted repeated innovation. Instead, repeated innovation was predicted by a proactive syndrome of behavioral traits that included high persistence, high motor diversity, high activity and low neophobia. Our results suggest that this proactive behavioral syndrome may be more important than inhibitory control for successful innovation with the MAB by members of this species.

The relationship of work avoidance and learning goals to perceived competence, externality and meaning.

PubMed

Seifert, T L; O'Keefe, B A

2001-03-01

Motivational researchers have suggested that work avoidance may be an academic goal in which students seek to minimise the amount of work they do in school. Additionally, research has also suggested that emotions may be catalysts for goals. This study examined the relationship between emotions and learning or work avoidance goals. Do emotions explain goals? The participants were 512 senior high school students in Eastern Canada. Students completed a survey assessing motivation related constructs. A structural equation model was postulated in which students' affect predicted learning goals and work avoidant goals. A cluster analysis of affect scores was performed followed by between-group and within-group contrasts of goal scores. The structural equation model suggested that a sense of competence and control were predictive of a learning goal while lack of meaning was related to work avoidance. The cluster analysis showed that confidence and control were associated with a learning goal but that a sense of inadequacy, lack of control or lack of meaning could give rise to work avoidance. Emotions seem to be directly linked to goals. Teachers who foster feelings of self-assuredness will be helping students develop learning goals. Students who feel less competent, bored or have little control will adopt work avoidant goals.

Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice

PubMed Central

Rubio, Julio; Qiong, Wang; Liu, Xinmin; Jiang, Zhen; Dang, Haixia; Chen, Shi-Lin; Gonzales, Gustavo F.

2011-01-01

The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized (OVX) mice and their relation with malonalehyde (MDA), acetylcholinesterase (Ache) and monoamine oxidase (MAO) brain levels. Female mice were divided into five groups: (i) naive (control), (ii) sham, (iii) OVX mice and OVX mice treated with (iv) 0.50 g kg−1 and (v) 2.00 g kg−1 black maca. Mice were orally treated with distilled water or black maca during 35 days starting 7 days after surgery. Memory and learning were assessed using the water Morris maze (from day 23–27) and the step-down avoidance test (days 34 and 35). At the end of each treatment, mice were sacrificed by decapitation and brains were dissected out for MDA, Ache and MAO determinations. Black maca (0.5 and 2.0 g/kg) increased step-down latency when compared to OVX control mice. Black maca decreased MDA and Ache levels in OVX mice; whereas, no differences were observed in MAO levels. Finally, black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and Ache inhibitory activities. PMID:18955369

Aqueous Extract of Black Maca (Lepidium meyenii) on Memory Impairment Induced by Ovariectomy in Mice.

PubMed

Rubio, Julio; Qiong, Wang; Liu, Xinmin; Jiang, Zhen; Dang, Haixia; Chen, Shi-Lin; Gonzales, Gustavo F

2011-01-01

The present study aims to test two different doses of aqueous extract of black maca on learning and memory in ovariectomized (OVX) mice and their relation with malonalehyde (MDA), acetylcholinesterase (Ache) and monoamine oxidase (MAO) brain levels. Female mice were divided into five groups: (i) naive (control), (ii) sham, (iii) OVX mice and OVX mice treated with (iv) 0.50 g kg(-1) and (v) 2.00 g kg(-1) black maca. Mice were orally treated with distilled water or black maca during 35 days starting 7 days after surgery. Memory and learning were assessed using the water Morris maze (from day 23-27) and the step-down avoidance test (days 34 and 35). At the end of each treatment, mice were sacrificed by decapitation and brains were dissected out for MDA, Ache and MAO determinations. Black maca (0.5 and 2.0 g/kg) increased step-down latency when compared to OVX control mice. Black maca decreased MDA and Ache levels in OVX mice; whereas, no differences were observed in MAO levels. Finally, black maca improved experimental memory impairment induced by ovariectomy, due in part, by its antioxidant and Ache inhibitory activities.

Unsupervised discrimination of patterns in spiking neural networks with excitatory and inhibitory synaptic plasticity

PubMed Central

Srinivasa, Narayan; Cho, Youngkwan

2014-01-01

A spiking neural network model is described for learning to discriminate among spatial patterns in an unsupervised manner. The network anatomy consists of source neurons that are activated by external inputs, a reservoir that resembles a generic cortical layer with an excitatory-inhibitory (EI) network and a sink layer of neurons for readout. Synaptic plasticity in the form of STDP is imposed on all the excitatory and inhibitory synapses at all times. While long-term excitatory STDP enables sparse and efficient learning of the salient features in inputs, inhibitory STDP enables this learning to be stable by establishing a balance between excitatory and inhibitory currents at each neuron in the network. The synaptic weights between source and reservoir neurons form a basis set for the input patterns. The neural trajectories generated in the reservoir due to input stimulation and lateral connections between reservoir neurons can be readout by the sink layer neurons. This activity is used for adaptation of synapses between reservoir and sink layer neurons. A new measure called the discriminability index (DI) is introduced to compute if the network can discriminate between old patterns already presented in an initial training session. The DI is also used to compute if the network adapts to new patterns without losing its ability to discriminate among old patterns. The final outcome is that the network is able to correctly discriminate between all patterns—both old and new. This result holds as long as inhibitory synapses employ STDP to continuously enable current balance in the network. The results suggest a possible direction for future investigation into how spiking neural networks could address the stability-plasticity question despite having continuous synaptic plasticity. PMID:25566045

Unsupervised discrimination of patterns in spiking neural networks with excitatory and inhibitory synaptic plasticity.

PubMed

Srinivasa, Narayan; Cho, Youngkwan

2014-01-01

A spiking neural network model is described for learning to discriminate among spatial patterns in an unsupervised manner. The network anatomy consists of source neurons that are activated by external inputs, a reservoir that resembles a generic cortical layer with an excitatory-inhibitory (EI) network and a sink layer of neurons for readout. Synaptic plasticity in the form of STDP is imposed on all the excitatory and inhibitory synapses at all times. While long-term excitatory STDP enables sparse and efficient learning of the salient features in inputs, inhibitory STDP enables this learning to be stable by establishing a balance between excitatory and inhibitory currents at each neuron in the network. The synaptic weights between source and reservoir neurons form a basis set for the input patterns. The neural trajectories generated in the reservoir due to input stimulation and lateral connections between reservoir neurons can be readout by the sink layer neurons. This activity is used for adaptation of synapses between reservoir and sink layer neurons. A new measure called the discriminability index (DI) is introduced to compute if the network can discriminate between old patterns already presented in an initial training session. The DI is also used to compute if the network adapts to new patterns without losing its ability to discriminate among old patterns. The final outcome is that the network is able to correctly discriminate between all patterns-both old and new. This result holds as long as inhibitory synapses employ STDP to continuously enable current balance in the network. The results suggest a possible direction for future investigation into how spiking neural networks could address the stability-plasticity question despite having continuous synaptic plasticity.

α1-Adrenoceptors in the hippocampal dentate gyrus involved in learning-dependent long-term potentiation during active-avoidance learning in rats.

PubMed

Lv, Jing; Zhan, Su-Yang; Li, Guang-Xie; Wang, Dan; Li, Ying-Shun; Jin, Qing-Hua

2016-11-09

The hippocampus is the key structure for learning and memory in mammals and long-term potentiation (LTP) is an important cellular mechanism responsible for learning and memory. The influences of norepinephrine (NE) on the modulation of learning and memory, as well as LTP, through β-adrenoceptors are well documented, whereas the role of α1-adrenoceptors in learning-dependent LTP is not yet clear. In the present study, we measured extracellular concentrations of NE in the hippocampal dentate gyrus (DG) region using an in-vivo brain microdialysis and high-performance liquid chromatography techniques during the acquisition and extinction of active-avoidance behavior in freely moving conscious rats. Next, the effects of prazosin (an antagonist of α1-adrenoceptor) and phenylephrine (an agonist of the α1-adrenoceptor) on amplitudes of field excitatory postsynaptic potential were measured in the DG region during the active-avoidance behavior. Our results showed that the extracellular concentration of NE in the DG was significantly increased during the acquisition of active-avoidance behavior and gradually returned to the baseline level following extinction training. A local microinjection of prazosin into the DG significantly accelerated the acquisition of the active-avoidance behavior, whereas a local microinjection of phenylephrine retarded the acquisition of the active-avoidance behavior. Furthermore, in all groups, the changes in field excitatory postsynaptic potential amplitude were accompanied by corresponding changes in active-avoidance behavior. Our results suggest that NE activation of α1-adrenoceptors in the hippocampal DG inhibits active-avoidance learning by modulation of synaptic efficiency in rats.

Do detour tasks provide accurate assays of inhibitory control?

PubMed Central

Whiteside, Mark A.; Laker, Philippa R.; Beardsworth, Christine E.

2018-01-01

Transparent Cylinder and Barrier tasks are used to purportedly assess inhibitory control in a variety of animals. However, we suspect that performances on these detour tasks are influenced by non-cognitive traits, which may result in inaccurate assays of inhibitory control. We therefore reared pheasants under standardized conditions and presented each bird with two sets of similar tasks commonly used to measure inhibitory control. We recorded the number of times subjects incorrectly attempted to access a reward through transparent barriers, and their latencies to solve each task. Such measures are commonly used to infer the differential expression of inhibitory control. We found little evidence that their performances were consistent across the two different Putative Inhibitory Control Tasks (PICTs). Improvements in performance across trials showed that pheasants learned the affordances of each specific task. Critically, prior experience of transparent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that they also learned the general properties of transparent obstacles. Individual measures of persistence, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks. Neophobia, Sex and Body Condition had no influence on individual performance. Contrary to previous studies of primates, pheasants with poor performance on PICTs had a wider dietary breadth assayed using a free-choice task. Our results demonstrate that in systems or taxa where prior experience and differences in development cannot be accounted for, individual differences in performance on commonly used detour-dependent PICTS may reveal more about an individual's prior experience of transparent objects, or their motivation to acquire food, than providing a reliable measure of their inhibitory control. PMID:29593115

Ameliorating effects of ethyl acetate fraction from onion (Allium cepa L.) flesh and peel in mice following trimethyltin-induced learning and memory impairment.

PubMed

Park, Seon Kyeong; Jin, Dong Eun; Park, Chang Hyeon; Seung, Tae Wan; Guo, Tian Jiao; Song, Jong Wook; Kim, Jong Hwan; Kim, Dae Ok; Heo, Ho Jin

2015-09-01

The anti-amnesic effects of onion (Allium cepa L.) flesh (OF) 1 and peel (OP) 2 on trimethyltin (TMT) 3 -induced learning and memory dysfunction were investigated to confirm learning and memory function. The inhibitory effect against cellular acetylcholinesterase (AChE) 4 showed that the EtOAc fraction of OP (EOP 5 , IC 50 value=37.11μg/mL) was higher than the EtOAc fraction of OF (EOF 6 , IC 50 value=433.34μg/mL). The cognitive effects in ICR mice were also evaluated using Y-maze, passive avoidance, and Morris water maze tests. After the behavioral tests, AChE activity (control=100%, TMT=128%, EOF 20=108%, EOP 10=104%, and EOP 20=98%), superoxide dismutase (SOD) 7 activity, oxidized glutathione (GSSG) 8 /total glutathione (GSH) 9 and malondialdehyde (MDA) 10 production were examined. These results indicate that both EOF and EOP improved learning and memory function. The main compounds of the EOF and EOP were analyzed by Q-TOF UPLC/MS, and the results were as follows: The EOF (quercetin and quercetin-4'-glucoside) and the EOP (quercetin-4'-glucoside and isorhamnetin-4'-glucoside). Consequently, our results suggest that both EOF and EOP could be efficacious in improving cognitive function through AChE inhibition and antioxidant activity in mice brains. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of oral supplementation of Glutamate and GABA on memory performance and neurochemical profile in hippocampus of rats.

PubMed

Tabassum, Saiqa; Ahmad, Saara; Madiha, Syeda; Khaliq, Saima; Shahzad, Sidrah; Batool, Zehra; Haider, Saida

2017-05-01

Glutamate (GLU) and gamma-amino butyric acid (GABA) are essential amino acids (AA) for brain function serving as excitatory and inhibitory neurotransmitter respectively. Their tablets are available in market for improving gut function and muscle performance. Despite of having a major role during memory formation and processing, effects of these tablets on brain functioning like learning and memory have not been investigated. Therefore, present study is aimed to investigate the effects of orally supplemented GLU and GABA on learning and memory performance and further to monitor related effects of these orally supplemented GLU and GABA on brain levels of these AA. Three groups of rats were supplemented orally with drinking water (control group) or suspension of tablets of GABA and Glutamate, respectively for four weeks. Cognitive performance was determined using behavioral tests (Novel object recognition test, Morris water maze, Passive avoidance test) measuring recognition, spatial reference and aversive memory. Levels of GLU, GABA and acetylcholine (ACh) were estimated in rat hippocampus. Results showed that chronic oral administration of GLU and GABA tablets has a significant impact on brain function and can alter GLU and GABA content in rat hippocampus. Compared to GABA, GLU supplementation specifically enhances memory performance via increasing ACh. Thus, GLU can be suggested as a useful supplement for improving learning and memory performance and neurochemical status of brain and in future could be effective in the treatment of neurological disorders affecting learning and memory performance.

Cognitive Deficits in Calsyntenin-2-deficient Mice Associated with Reduced GABAergic Transmission

PubMed Central

Lipina, Tatiana V; Prasad, Tuhina; Yokomaku, Daisaku; Luo, Lin; Connor, Steven A; Kawabe, Hiroshi; Wang, Yu Tian; Brose, Nils; Roder, John C; Craig, Ann Marie

2016-01-01

Calsyntenin-2 has an evolutionarily conserved role in cognition. In a human genome-wide screen, the CLSTN2 locus was associated with verbal episodic memory, and expression of human calsyntenin-2 rescues the associative learning defect in orthologous Caenorhabditis elegans mutants. Other calsyntenins promote synapse development, calsyntenin-1 selectively of excitatory synapses and calsyntenin-3 of excitatory and inhibitory synapses. We found that targeted deletion of calsyntenin-2 in mice results in a selective reduction in functional inhibitory synapses. Reduced inhibitory transmission was associated with a selective reduction of parvalbumin interneurons in hippocampus and cortex. Clstn2−/− mice showed normal behavior in elevated plus maze, forced swim test, and novel object recognition assays. However, Clstn2−/− mice were hyperactive in the open field and showed deficits in spatial learning and memory in the Morris water maze and Barnes maze. These results confirm a function for calsyntenin-2 in cognitive performance and indicate an underlying mechanism that involves parvalbumin interneurons and aberrant inhibitory transmission. PMID:26171716

Extinction learning in childhood anxiety disorders, obsessive compulsive disorder and posttraumatic stress disorder: implications for treatment

PubMed Central

McGuire, Joseph F.; Orr, Scott P.; Essoe, Joey K.-Y.; McCracken, James T.; Storch, Eric A.; Piacentini, John

2018-01-01

Introduction Threat conditioning and extinction play an important role in anxiety disorders, obsessive compulsive disorder (OCD), and posttraumatic stress disorder (PTSD). Although these conditions commonly affect children, threat conditioning and extinction have been primarily studied in adults. However, differences in phenomenology and neural architecture prohibit the generalization of adult findings to youth. Areas covered A comprehensive literature search using PubMed and PsycInfo was conducted to identify studies that have used differential conditioning tasks to examine threat acquisition and extinction in youth. The information obtained from this review helps to clarify the influence of these processes on the etiology and treatment of youth with OCD, PTSD and other anxiety disorders. Thirty studies of threat conditioning and extinction were identified. Expert Commentary Youth with anxiety disorders, OCD, and PTSD have largely comparable threat acquisition relative to unaffected controls, with some distinctions noted for youth with PTSD or youth who have suffered maltreatment. However, impaired extinction was consistently observed across youth with these disorders and appears to be consistent with deficiencies in inhibitory learning. Incorporating strategies to improve inhibitory learning may improve extinction learning within extinction-based treatments like cognitive behavioral therapy (CBT). Strategies to improve inhibitory learning in CBT are discussed. PMID:27275519

Rule-Based Category Learning in Children: The Role of Age and Executive Functioning

PubMed Central

Rabi, Rahel; Minda, John Paul

2014-01-01

Rule-based category learning was examined in 4–11 year-olds and adults. Participants were asked to learn a set of novel perceptual categories in a classification learning task. Categorization performance improved with age, with younger children showing the strongest rule-based deficit relative to older children and adults. Model-based analyses provided insight regarding the type of strategy being used to solve the categorization task, demonstrating that the use of the task appropriate strategy increased with age. When children and adults who identified the correct categorization rule were compared, the performance deficit was no longer evident. Executive functions were also measured. While both working memory and inhibitory control were related to rule-based categorization and improved with age, working memory specifically was found to marginally mediate the age-related improvements in categorization. When analyses focused only on the sample of children, results showed that working memory ability and inhibitory control were associated with categorization performance and strategy use. The current findings track changes in categorization performance across childhood, demonstrating at which points performance begins to mature and resemble that of adults. Additionally, findings highlight the potential role that working memory and inhibitory control may play in rule-based category learning. PMID:24489658

Extinction learning in childhood anxiety disorders, obsessive compulsive disorder and post-traumatic stress disorder: implications for treatment.

PubMed

McGuire, Joseph F; Orr, Scott P; Essoe, Joey K-Y; McCracken, James T; Storch, Eric A; Piacentini, John

2016-10-01

Threat conditioning and extinction play an important role in anxiety disorders, obsessive compulsive disorder (OCD), and post-traumatic stress disorder (PTSD). Although these conditions commonly affect children, threat conditioning and extinction have been primarily studied in adults. However, differences in phenomenology and neural architecture prohibit the generalization of adult findings to youth. A comprehensive literature search using PubMed and PsycInfo was conducted to identify studies that have used differential conditioning tasks to examine threat acquisition and extinction in youth. The information obtained from this review helps to clarify the influence of these processes on the etiology and treatment of youth with OCD, PTSD and other anxiety disorders. Thirty studies of threat conditioning and extinction were identified Expert commentary: Youth with anxiety disorders, OCD, and PTSD have largely comparable threat acquisition relative to unaffected controls, with some distinctions noted for youth with PTSD or youth who have suffered maltreatment. However, impaired extinction was consistently observed across youth with these disorders and appears to be consistent with deficiencies in inhibitory learning. Incorporating strategies to improve inhibitory learning may improve extinction learning within extinction-based treatments like cognitive behavioral therapy (CBT). Strategies to improve inhibitory learning in CBT are discussed.

Is all motivation good for learning? Dissociable influences of approach and avoidance motivation in declarative memory.

PubMed

Murty, Vishnu P; LaBar, Kevin S; Hamilton, Derek A; Adcock, R Alison

2011-01-01

The present study investigated the effects of approach versus avoidance motivation on declarative learning. Human participants navigated a virtual reality version of the Morris water task, a classic spatial memory paradigm, adapted to permit the experimental manipulation of motivation during learning. During this task, participants were instructed to navigate to correct platforms while avoiding incorrect platforms. To manipulate motivational states participants were either rewarded for navigating to correct locations (approach) or punished for navigating to incorrect platforms (avoidance). Participants' skin conductance levels (SCLs) were recorded during navigation to investigate the role of physiological arousal in motivated learning. Behavioral results revealed that, overall, approach motivation enhanced and avoidance motivation impaired memory performance compared to nonmotivated spatial learning. This advantage was evident across several performance indices, including accuracy, learning rate, path length, and proximity to platform locations during probe trials. SCL analysis revealed three key findings. First, within subjects, arousal interacted with approach motivation, such that high arousal on a given trial was associated with performance deficits. In addition, across subjects, high arousal negated or reversed the benefits of approach motivation. Finally, low-performing, highly aroused participants showed SCL responses similar to those of avoidance-motivation participants, suggesting that for these individuals, opportunities for reward may evoke states of learning similar to those typically evoked by threats of punishment. These results provide a novel characterization of how approach and avoidance motivation influence declarative memory and indicate a critical and selective role for arousal in determining how reinforcement influences goal-oriented learning.

Attenuating GABAA Receptor Signaling in Dopamine Neurons Selectively Enhances Reward Learning and Alters Risk Preference in Mice

PubMed Central

Parker, Jones G.; Wanat, Matthew J.; Soden, Marta E.; Ahmad, Kinza; Zweifel, Larry S.; Bamford, Nigel S.; Palmiter, Richard D.

2011-01-01

Phasic dopamine transmission encodes the value of reward-predictive stimuli and influences both learning and decision-making. Altered dopamine signaling is associated with psychiatric conditions characterized by risky choices such as pathological gambling. These observations highlight the importance of understanding how dopamine neuron activity is modulated. While excitatory drive onto dopamine neurons is critical for generating phasic dopamine responses, emerging evidence suggests that inhibitory signaling also modulates these responses. To address the functional importance of inhibitory signaling in dopamine neurons, we generated mice lacking the β3 subunit of the GABAA receptor specifically in dopamine neurons (β3-KO mice) and examined their behavior in tasks that assessed appetitive learning, aversive learning, and risk preference. Dopamine neurons in midbrain slices from β3-KO mice exhibited attenuated GABA-evoked inhibitory post-synaptic currents. Furthermore, electrical stimulation of excitatory afferents to dopamine neurons elicited more dopamine release in the nucleus accumbens of β3-KO mice as measured by fast-scan cyclic voltammetry. β3-KO mice were more active than controls when given morphine, which correlated with potential compensatory upregulation of GABAergic tone onto dopamine neurons. β3-KO mice learned faster in two food-reinforced learning paradigms, but extinguished their learned behavior normally. Enhanced learning was specific for appetitive tasks, as aversive learning was unaffected in β3-KO mice. Finally, we found that β3-KO mice had enhanced risk preference in a probabilistic selection task that required mice to choose between a small certain reward and a larger uncertain reward. Collectively, these findings identify a selective role for GABAA signaling in dopamine neurons in appetitive learning and decision-making. PMID:22114279

Sleep Supports Inhibitory Operant Conditioning Memory in "Aplysia"

ERIC Educational Resources Information Center

Vorster, Albrecht P. A.; Born, Jan

2017-01-01

Sleep supports memory consolidation as shown in mammals and invertebrates such as bees and "Drosophila." Here, we show that sleep's memory function is preserved in "Aplysia californica" with an even simpler nervous system. Animals performed on an inhibitory conditioning task ("learning that a food is inedible") three…

Socially acquired predator avoidance: is it just classical conditioning?

PubMed

Griffin, Andrea S

2008-06-15

Associative learning theories presume the existence of a general purpose learning process, the structure of which does not mirror the demands of any particular learning problem. In contrast, learning scientists working within an Evolutionary Biology tradition believe that learning processes have been shaped by ecological demands. One potential means of exploring how ecology may have modified properties of acquisition is to use associative learning theory as a framework within which to analyse a particular learning phenomenon. Recent work has used this approach to examine whether socially transmitted predator avoidance can be conceptualised as a classical conditioning process in which a novel predator stimulus acts as a conditioned stimulus (CS) and acquires control over an avoidance response after it has become associated with alarm signals of social companions, the unconditioned stimulus (US). I review here a series of studies examining the effect of CS/US presentation timing on the likelihood of acquisition. Results suggest that socially acquired predator avoidance may be less sensitive to forward relationships than traditional classical conditioning paradigms. I make the case that socially acquired predator avoidance is an exciting novel one-trial learning paradigm that could be studied along side fear conditioning. Comparisons between social and non-social learning of danger at both the behavioural and neural level may yield a better understanding of how ecology might shape properties and mechanisms of learning.

Cue avoidance training and inhibitory control training for the reduction of alcohol consumption: a comparison of effectiveness and investigation of their mechanisms of action.

PubMed

Di Lemma, Lisa C G; Field, Matt

2017-08-01

Both cue avoidance training (CAT) and inhibitory control training (ICT) reduce alcohol consumption in the laboratory. However, these interventions have never been directly compared and their mechanisms of action are poorly understood. We compared the effects of both types of training on alcohol consumption and investigated if they led to theoretically predicted changes in alcohol avoidance (CAT) or alcohol inhibition (ICT) associations and changes in evaluation of alcohol cues. Heavy drinking young adults (N = 120) were randomly assigned to one of four groups: (1) CAT (repeatedly pushing alcohol cues away with a joystick), (2) sham (control) CAT; (3) ICT (repeatedly inhibiting behaviour in response to alcohol cues); or (4) sham (control) ICT. Changes in reaction times and automatic evaluations of alcohol cues were assessed before and after training using assessment versions of tasks used in training and the implicit association test (IAT), respectively. Finally, participants completed a bogus taste test as a measure of ad libitum alcohol consumption. Compared to sham conditions, CAT and ICT both led to reduced alcohol consumption although there was no difference between the two. Neither intervention affected performance on the IAT, and changes in reaction time did not suggest the formation of robust alcohol avoidance (CAT) or alcohol inhibition (ICT) associations after training. CAT and ICT yielded equivalent reductions in alcohol consumption in the laboratory. However, these behavioural effects were not accompanied by devaluation of stimuli or the formation of alcohol avoidance or alcohol inhibition associations.

Learning multiple variable-speed sequences in striatum via cortical tutoring.

PubMed

Murray, James M; Escola, G Sean

2017-05-08

Sparse, sequential patterns of neural activity have been observed in numerous brain areas during timekeeping and motor sequence tasks. Inspired by such observations, we construct a model of the striatum, an all-inhibitory circuit where sequential activity patterns are prominent, addressing the following key challenges: (i) obtaining control over temporal rescaling of the sequence speed, with the ability to generalize to new speeds; (ii) facilitating flexible expression of distinct sequences via selective activation, concatenation, and recycling of specific subsequences; and (iii) enabling the biologically plausible learning of sequences, consistent with the decoupling of learning and execution suggested by lesion studies showing that cortical circuits are necessary for learning, but that subcortical circuits are sufficient to drive learned behaviors. The same mechanisms that we describe can also be applied to circuits with both excitatory and inhibitory populations, and hence may underlie general features of sequential neural activity pattern generation in the brain.

Learning and retrieval behavior in recurrent neural networks with pre-synaptic dependent homeostatic plasticity

NASA Astrophysics Data System (ADS)

Mizusaki, Beatriz E. P.; Agnes, Everton J.; Erichsen, Rubem; Brunnet, Leonardo G.

2017-08-01

The plastic character of brain synapses is considered to be one of the foundations for the formation of memories. There are numerous kinds of such phenomenon currently described in the literature, but their role in the development of information pathways in neural networks with recurrent architectures is still not completely clear. In this paper we study the role of an activity-based process, called pre-synaptic dependent homeostatic scaling, in the organization of networks that yield precise-timed spiking patterns. It encodes spatio-temporal information in the synaptic weights as it associates a learned input with a specific response. We introduce a correlation measure to evaluate the precision of the spiking patterns and explore the effects of different inhibitory interactions and learning parameters. We find that large learning periods are important in order to improve the network learning capacity and discuss this ability in the presence of distinct inhibitory currents.

Development Switch in Neural Circuitry Underlying Odor-Malaise Learning

ERIC Educational Resources Information Center

Lunday, Lauren; Miner, Cathrine; Roth, Tania L.; Sullivan, Regina M.; Shionoya, Kiseko; Moriceau, Stephanie

2006-01-01

Fetal and infant rats can learn to avoid odors paired with illness before development of brain areas supporting this learning in adults, suggesting an alternate learning circuit. Here we begin to document the transition from the infant to adult neural circuit underlying odor-malaise avoidance learning using LiCl (0.3 M; 1% of body weight, ip) and…

Avoidance of plants unsuitable for the symbiotic fungus in leaf-cutting ants: Learning can take place entirely at the colony dump.

PubMed

Arenas, Andrés; Roces, Flavio

2017-01-01

Plants initially accepted by foraging leaf-cutting ants are later avoided if they prove unsuitable for their symbiotic fungus. Plant avoidance is mediated by the waste produced in the fungus garden soon after the incorporation of the unsuitable leaves, as foragers can learn plant odors and cues from the damaged fungus that are both present in the recently produced waste particles. We asked whether avoidance learning of plants unsuitable for the symbiotic fungus can take place entirely at the colony dump. In order to investigate whether cues available in the waste chamber induce plant avoidance in naïve subcolonies, we exchanged the waste produced by subcolonies fed either fungicide-treated privet leaves or untreated leaves and measured the acceptance of untreated privet leaves before and after the exchange of waste. Second, we evaluated whether foragers could perceive the avoidance cues directly at the dump by quantifying the visits of labeled foragers to the waste chamber. Finally, we asked whether foragers learn to specifically avoid untreated leaves of a plant after a confinement over 3 hours in the dump of subcolonies that were previously fed fungicide-treated leaves of that species. After the exchange of the waste chambers, workers from subcolonies that had access to waste from fungicide-treated privet leaves learned to avoid that plant. One-third of the labeled foragers visited the dump. Furthermore, naïve foragers learned to avoid a specific, previously unsuitable plant if exposed solely to cues of the dump during confinement. We suggest that cues at the dump enable foragers to predict the unsuitable effects of plants even if they had never been experienced in the fungus garden.

Avoidance of plants unsuitable for the symbiotic fungus in leaf-cutting ants: Learning can take place entirely at the colony dump

PubMed Central

Roces, Flavio

2017-01-01

Plants initially accepted by foraging leaf-cutting ants are later avoided if they prove unsuitable for their symbiotic fungus. Plant avoidance is mediated by the waste produced in the fungus garden soon after the incorporation of the unsuitable leaves, as foragers can learn plant odors and cues from the damaged fungus that are both present in the recently produced waste particles. We asked whether avoidance learning of plants unsuitable for the symbiotic fungus can take place entirely at the colony dump. In order to investigate whether cues available in the waste chamber induce plant avoidance in naïve subcolonies, we exchanged the waste produced by subcolonies fed either fungicide-treated privet leaves or untreated leaves and measured the acceptance of untreated privet leaves before and after the exchange of waste. Second, we evaluated whether foragers could perceive the avoidance cues directly at the dump by quantifying the visits of labeled foragers to the waste chamber. Finally, we asked whether foragers learn to specifically avoid untreated leaves of a plant after a confinement over 3 hours in the dump of subcolonies that were previously fed fungicide-treated leaves of that species. After the exchange of the waste chambers, workers from subcolonies that had access to waste from fungicide-treated privet leaves learned to avoid that plant. One-third of the labeled foragers visited the dump. Furthermore, naïve foragers learned to avoid a specific, previously unsuitable plant if exposed solely to cues of the dump during confinement. We suggest that cues at the dump enable foragers to predict the unsuitable effects of plants even if they had never been experienced in the fungus garden. PMID:28273083

A spatial paradigm, the allothetic place avoidance alternation task, for testing visuospatial working memory and skill learning in rats.

PubMed

Dockery, Colleen A; Wesierska, Malgorzata J

2010-08-30

We present a paradigm for assessing visuospatial working memory and skill learning in a rodent model, based on the place avoidance test. In our allothetic place avoidance alternation task (APAAT) the paradigm is comprised of minimal training sessions, tests various aspects of learning and memory and provides a rich set of parameters. A single working memory session consists of four conditions: habituation (no shock), two place avoidance training intervals (shock activated) and a retrieval test (shock inactivated). The location of the shock sector is alternated for each training day which initially requires extinction of previous representations and further working memory to achieve effective place avoidance across sessions. Visuospatial skill memory was evaluated by the shock/entrance ratio by tracking locomotor activity which is essential to execute a place avoidance strategy. For each day rats learned to avoid a new place with shock, as shown by a decreased number of entrances, and an increased time to the first entrance and maximum avoidance time. Skill learning improved according to the decreased number of shocks per entrance across conditions. These results indicate that complex cognitive functions are captured by this behavioral method. This APAAT paradigm expands and complements existing tools for studying hippocampal-prefrontal dependent functions to support development of treatment interventions. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Electrical Stimulation of Lateral Habenula during Learning: Frequency-Dependent Effects on Acquisition but Not Retrieval of a Two-Way Active Avoidance Response

PubMed Central

Wetzel, Wolfram; Scheich, Henning; Ohl, Frank W.

2013-01-01

The lateral habenula (LHb) is an epithalamic structure involved in signaling reward omission and aversive stimuli, and it inhibits dopaminergic neurons during motivated behavior. Less is known about LHb involvement in the acquisition and retrieval of avoidance learning. Our previous studies indicated that brief electrical stimulation of the LHb, time-locked to the avoidance of aversive footshock (presumably during the positive affective “relief” state that occurs when an aversive outcome is averted), inhibited the acquisition of avoidance learning. In the present study, we used the same paradigm to investigate different frequencies of LHb stimulation. The effect of 20 Hz vs. 50 Hz vs. 100 Hz stimulation was investigated during two phases, either during acquisition or retrieval in Mongolian gerbils. The results indicated that 50 Hz, but not 20 Hz, was sufficient to produce a long-term impairment in avoidance learning, and was somewhat more effective than 100 Hz in this regard. None of the stimulation parameters led to any effects on retrieval of avoidance learning, nor did they affect general motor activity. This suggests that, at frequencies in excess of the observed tonic firing rates of LHb neurons (>1–20 Hz), LHb stimulation may serve to interrupt the consolidation of new avoidance memories. However, these stimulation parameters are not capable of modifying avoidance memories that have already undergone extensive consolidation. PMID:23840355

Individual differences in sensitivity to reward and punishment and neural activity during reward and avoidance learning

PubMed Central

Yoon, HeungSik; Kim, Hackjin; Hamann, Stephan

2015-01-01

In this functional neuroimaging study, we investigated neural activations during the process of learning to gain monetary rewards and to avoid monetary loss, and how these activations are modulated by individual differences in reward and punishment sensitivity. Healthy young volunteers performed a reinforcement learning task where they chose one of two fractal stimuli associated with monetary gain (reward trials) or avoidance of monetary loss (avoidance trials). Trait sensitivity to reward and punishment was assessed using the behavioral inhibition/activation scales (BIS/BAS). Functional neuroimaging results showed activation of the striatum during the anticipation and reception periods of reward trials. During avoidance trials, activation of the dorsal striatum and prefrontal regions was found. As expected, individual differences in reward sensitivity were positively associated with activation in the left and right ventral striatum during reward reception. Individual differences in sensitivity to punishment were negatively associated with activation in the left dorsal striatum during avoidance anticipation and also with activation in the right lateral orbitofrontal cortex during receiving monetary loss. These results suggest that learning to attain reward and learning to avoid loss are dependent on separable sets of neural regions whose activity is modulated by trait sensitivity to reward or punishment. PMID:25680989

Learning processes underlying avoidance of negative outcomes.

PubMed

Andreatta, Marta; Michelmann, Sebastian; Pauli, Paul; Hewig, Johannes

2017-04-01

Successful avoidance of a threatening event may negatively reinforce the behavior due to activation of brain structures involved in reward processing. Here, we further investigated the learning-related properties of avoidance using feedback-related negativity (FRN). The FRN is modulated by violations of an intended outcome (prediction error, PE), that is, the bigger the difference between intended and actual outcome, the larger the FRN amplitude is. Twenty-eight participants underwent an operant conditioning paradigm, in which a behavior (button press) allowed them to avoid a painful electric shock. During two learning blocks, participants could avoid an electric shock in 80% of the trials by pressing one button (avoidance button), or by not pressing another button (punishment button). After learning, participants underwent two test blocks, which were identical to the learning ones except that no shocks were delivered. Participants pressed the avoidance button more often than the punishment button. Importantly, response frequency increased throughout the learning blocks but it did not decrease during the test blocks, indicating impaired extinction and/or habit formation. In line with a PE account, FRN amplitude to negative feedback after correct responses (i.e., unexpected punishment) was significantly larger than to positive feedback (i.e., expected omission of punishment), and it increased throughout the blocks. Highly anxious individuals showed equal FRN amplitudes to negative and positive feedback, suggesting impaired discrimination. These results confirm the role of negative reinforcement in motivating behavior and learning, and reveal important differences between high and low anxious individuals in the processing of prediction errors. © 2017 Society for Psychophysiological Research.

Early Life Manipulations Alter Learning and Memory in Rats

PubMed Central

Kosten, Therese A; Kim, Jeansok J; Lee, Hongjoo J.

2012-01-01

Much research shows early life manipulations have enduring behavioral, neural, and hormonal effects. However, findings of learning and memory performance vary widely across studies. We reviewed studies in which pre-weaning rat pups were exposed to stressors and tested on learning and memory tasks in adulthood. Tasks were classified as aversive conditioning, inhibitory learning, or spatial/relational memory. Variables of duration, type, and timing of neonatal manipulation and sex and strain of animals were examined to determine if any predict enhanced or impaired performance. Brief separations enhanced and prolonged separations impaired performance on spatial/relational tasks. Performance was impaired in aversive conditioning and enhanced in inhibitory learning tasks regardless of manipulation duration. Opposing effects on performance for spatial/relational memory also depended upon timing of manipulation. Enhanced performance was likely if the manipulation occurred during postnatal week 3 but performance was impaired if it was confined to the first two postnatal weeks. Thus, the relationship between early life experiences and adulthood learning and memory performance is multifaceted and decidedly task-dependent. PMID:22819985

Scopolamine- and diazepam-induced amnesia are blocked by systemic and intraseptal administration of substance P and choline chloride.

PubMed

Costa, Joseane Carvalho; Costa, Kauê Machado; do Nascimento, José Luiz Martins

2010-09-01

Systemic (IP) and/or intraseptal (IS) administration of scopolamine (SCP) and diazepam (DZP) induce amnesia, whereas IP injection of the neuropeptide substance P (SP) and choline chloride (ChCl) produce memory facilitation. The septohippocampal cholinergic system has been pointed out as a possible site of SCP and DZP-induced amnesia as well as for the mnemonic effects induced by SP and ChCl. We performed a series of experiments in order to investigate the interactions between cholinergic and GABA/benzodiazepine (GABA/BZD) systems with the SPergic system on inhibitory avoidance retention. Male Wistar rats were trained and tested in a step-down inhibitory avoidance task (1.0 mA footshock). Animals received, pre-training, IP (1.0 mg/kg) or IS (1.0 nM/0.5 microl) injection of DZP, SCP (SCP; 1.0 mg/kg - IP or 0.5 microM/0.5 microl--IS) or vehicle (VEH). Immediately after training they received an IP or IS injections of SP 1-11 (50 microg/kg--IP or 1.0 nM/0.5 microl--IS), SP 1-7 (167 microg/kg--IP or 1.0 nM/0.5 microl--IS), ChCl (20 mg/kg--IP or 0.3 microM/0.5 microl--IS) or VEH. Rats pretreated with SCP and DZP showed amnesia. Post-trial treatments with SP 1-11, SP 1-7 or ChCl blocked the amnesic effects of SCP and DZP. These findings suggest an interaction between SPergic and cholinergic mechanisms with GABAergic systems in the modulation of inhibitory avoidance retention and that the effects of these treatments are mediated, at least in part, by interactions in the septohippocampal pathway. Copyright 2010 Elsevier Inc. All rights reserved.

Stimulation of postsynapse adrenergic α2A receptor improves attention/cognition performance in an animal model of attention deficit hyperactivity disorder.

PubMed

Kawaura, Kazuaki; Karasawa, Jun-ichi; Chaki, Shigeyuki; Hikichi, Hirohiko

2014-08-15

A 5-trial inhibitory avoidance test using spontaneously hypertensive rat (SHR) pups has been used as an animal model of attention deficit hyperactivity disorder (ADHD). However, the roles of noradrenergic systems, which are involved in the pathophysiology of ADHD, have not been investigated in this model. In the present study, the effects of adrenergic α2 receptor stimulation, which has been an effective treatment for ADHD, on attention/cognition performance were investigated in this model. Moreover, neuronal mechanisms mediated through adrenergic α2 receptors were investigated. We evaluated the effects of both clonidine, a non-selective adrenergic α2 receptor agonist, and guanfacine, a selective adrenergic α2A receptor agonist, using a 5-trial inhibitory avoidance test with SHR pups. Juvenile SHR exhibited a shorter transfer latency, compared with juvenile Wistar Kyoto (WKY) rats. Both clonidine and guanfacine significantly prolonged the transfer latency of juvenile SHR. The effects of clonidine and guanfacine were significantly blocked by pretreatment with an adrenergic α2A receptor antagonist. In contrast, the effect of clonidine was not attenuated by pretreatment with an adrenergic α2B receptor antagonist, or an adrenergic α2C receptor antagonist, while it was attenuated by a non-selective adrenergic α2 receptor antagonist. Furthermore, the effects of neither clonidine nor guanfacine were blocked by pretreatment with a selective noradrenergic neurotoxin. These results suggest that the stimulation of the adrenergic α2A receptor improves the attention/cognition performance of juvenile SHR in the 5-trial inhibitory avoidance test and that postsynaptic, rather than presynaptic, adrenergic α2A receptor is involved in this effect. Copyright © 2014 Elsevier B.V. All rights reserved.

High fat diet induced-obesity facilitates anxiety-like behaviors due to GABAergic impairment within the dorsomedial hypothalamus in rats.

PubMed

de Noronha, Sylvana Rendeiro; Campos, Glenda Viggiano; Abreu, Aline Rezende; de Souza, Aline Arlindo; Chianca, Deoclécio A; de Menezes, Rodrigo C

2017-01-01

Overweight and obesity are conditions associated with an overall range of clinical health consequences, and they could be involved with the development of neuropsychiatric diseases, such as generalized anxiety disorder (GAD) and panic disorder (PD). A crucial brain nuclei involved on the physiological functions and behavioral responses, especially fear, anxiety and panic, is the dorsomedial hypothalamus (DMH). However, the mechanisms underlying the process whereby the DMH is involved in behavioral changes in obese rats still remains unclear. The current study further investigates the relation between obesity and generalized anxiety, by investigating the GABA A sensitivity to pharmacological manipulation within the DMH in obese rats during anxiety conditions. Male Wistar rats were divided in two experimental groups: the first was fed a control diet (CD; 11% w/w) and second was fed a high fat diet (HFD; 45% w/w). Animals were randomly treated with muscimol, a GABA A agonist and bicuculline methiodide (BMI), a GABA A antagonist. Inhibitory avoidance and escape behaviors were investigated using the Elevated T-Maze (ETM) apparatus. Our results revealed that the obesity facilitated inhibitory avoidance acquisition, suggesting a positive relation between obesity and the development of an anxiety-like state. The injection of muscimol (an anxiolytic drug), within the DMH, increased the inhibitory avoidance latency in obese animals (featuring an anxiogenic state). Besides, muscimol prolonged the escape latency and controlling the possible panic-like behavior in these animals. Injection of BMI into the DMH was ineffective to produce an anxiety-like effect in obese animals opposing the results observed in lean animals. These findings support the hypotheses that obese animals are susceptible to develop anxiety-like behaviors, probably through changes in the GABAergic neurotransmission within the DMH. Copyright © 2016 Elsevier B.V. All rights reserved.

The Neural Foundations of Reaction and Action in Aversive Motivation.

PubMed

Campese, Vincent D; Sears, Robert M; Moscarello, Justin M; Diaz-Mataix, Lorenzo; Cain, Christopher K; LeDoux, Joseph E

2016-01-01

Much of the early research in aversive learning concerned motivation and reinforcement in avoidance conditioning and related paradigms. When the field transitioned toward the focus on Pavlovian threat conditioning in isolation, this paved the way for the clear understanding of the psychological principles and neural and molecular mechanisms responsible for this type of learning and memory that has unfolded over recent decades. Currently, avoidance conditioning is being revisited, and with what has been learned about associative aversive learning, rapid progress is being made. We review, below, the literature on the neural substrates critical for learning in instrumental active avoidance tasks and conditioned aversive motivation.

Defective GABAergic neurotransmision and pharmacological rescue of neuronal hyperexcitability in the amygdala in a mouse model of Fragile X Syndrome

PubMed Central

Olmos-Serrano, Jose Luis; Paluszkiewicz, Scott M.; Martin, Brandon S.; Kaufmann, Walter E.; Corbin, Joshua G.; Huntsman, Molly M.

2010-01-01

Fragile X Syndrome (FXS) is a neurodevelopmental disorder characterized by variable cognitive impairment and behavioural disturbances such as exaggerated fear, anxiety and gaze avoidance. Consistent with this, findings from human brain imaging studies suggest dysfunction of the amygdala. Underlying alterations in amygdala synaptic function in the Fmr1 knockout (KO) mouse model of FXS, however, remain largely unexplored. Utilizing a combination of approaches, we uncover profound alterations in inhibitory neurotransmission in the amygdala of Fmr1 KO mice. We demonstrate a dramatic reduction in the frequency and amplitude of phasic inhibitory postsynaptic currents (IPSCs), tonic inhibitory currents, as well as in the number of inhibitory synapses in Fmr1 KO mice. Furthermore, we observe significant alterations in GABA availability, both intracellularly and at the synaptic cleft. Together, these findings identify abnormalities in basal and action potential-dependent inhibitory neurotransmission. Additionally, we reveal a significant neuronal hyperexcitability in principal neurons of the amygdala in Fmr1 KO mice, which is strikingly rescued by pharmacological augmentation of tonic inhibitory tone using the GABA agonist, gaboxadol (THIP). Thus, our study reveals relevant inhibitory synaptic abnormalities in the amygdala in the Fmr1 KO brain and supports the notion that pharmacological approaches targeting the GABAergic system may be a viable therapeutic approach toward correcting amygdala-based symptoms in FXS. PMID:20660275

Extinction of avoidance behavior by safety learning depends on endocannabinoid signaling in the hippocampus.

PubMed

Micale, Vincenzo; Stepan, Jens; Jurik, Angela; Pamplona, Fabricio A; Marsch, Rudolph; Drago, Filippo; Eder, Matthias; Wotjak, Carsten T

2017-07-01

The development of exaggerated avoidance behavior is largely responsible for the decreased quality of life in patients suffering from anxiety disorders. Studies using animal models have contributed to the understanding of the neural mechanisms underlying the acquisition of avoidance responses. However, much less is known about its extinction. Here we provide evidence in mice that learning about the safety of an environment (i.e., safety learning) rather than repeated execution of the avoided response in absence of negative consequences (i.e., response extinction) allowed the animals to overcome their avoidance behavior in a step-down avoidance task. This process was context-dependent and could be blocked by pharmacological (3 mg/kg, s.c.; SR141716) or genetic (lack of cannabinoid CB1 receptors in neurons expressing dopamine D1 receptors) inactivation of CB1 receptors. In turn, the endocannabinoid reuptake inhibitor AM404 (3 mg/kg, i.p.) facilitated safety learning in a CB1-dependent manner and attenuated the relapse of avoidance behavior 28 days after conditioning. Safety learning crucially depended on endocannabinoid signaling at level of the hippocampus, since intrahippocampal SR141716 treatment impaired, whereas AM404 facilitated safety learning. Other than AM404, treatment with diazepam (1 mg/kg, i.p.) impaired safety learning. Drug effects on behavior were directly mirrored by drug effects on evoked activity propagation through the hippocampal trisynaptic circuit in brain slices: As revealed by voltage-sensitive dye imaging, diazepam impaired whereas AM404 facilitated activity propagation to CA1 in a CB1-dependent manner. In line with this, systemic AM404 enhanced safety learning-induced expression of Egr1 at level of CA1. Together, our data render it likely that AM404 promotes safety learning by enhancing information flow through the trisynaptic circuit to CA1. Copyright © 2017 Elsevier Ltd. All rights reserved.

Maximizing Exposure Therapy: An Inhibitory Learning Approach

PubMed Central

Craske, Michelle G.; Treanor, Michael; Conway, Chris; Zbozinek, Tomislav; Vervliet, Bram

2014-01-01

Exposure therapy is an effective approach for treating anxiety disorders, although a substantial number of individuals fail to benefit or experience a return of fear after treatment. Research suggests that anxious individuals show deficits in the mechanisms believed to underlie exposure therapy, such as inhibitory learning. Targeting these processes may help improve the efficacy of exposure-based procedures. Although evidence supports an inhibitory learning model of extinction, there has been little discussion of how to implement this model in clinical practice. The primary aim of this paper is to provide examples to clinicians for how to apply this model to optimize exposure therapy with anxious clients, in ways that distinguish it from a ‘fear habituation’ approach and ‘belief disconfirmation’ approach within standard cognitive-behavior therapy. Exposure optimization strategies include 1) expectancy violation, 2) deepened extinction, 3) occasional reinforced extinction, 4) removal of safety signals, 5) variability, 6) retrieval cues, 7) multiple contexts, and 8) affect labeling. Case studies illustrate methods of applying these techniques with a variety of anxiety disorders, including obsessive-compulsive disorder, posttraumatic stress disorder, social phobia, specific phobia, and panic disorder. PMID:24864005

Is all motivation good for learning? Dissociable influences of approach and avoidance motivation in declarative memory

PubMed Central

Murty, Vishnu P.; LaBar, Kevin S.; Hamilton, Derek A.; Adcock, R. Alison

2011-01-01

The present study investigated the effects of approach versus avoidance motivation on declarative learning. Human participants navigated a virtual reality version of the Morris water task, a classic spatial memory paradigm, adapted to permit the experimental manipulation of motivation during learning. During this task, participants were instructed to navigate to correct platforms while avoiding incorrect platforms. To manipulate motivational states participants were either rewarded for navigating to correct locations (approach) or punished for navigating to incorrect platforms (avoidance). Participants’ skin conductance levels (SCLs) were recorded during navigation to investigate the role of physiological arousal in motivated learning. Behavioral results revealed that, overall, approach motivation enhanced and avoidance motivation impaired memory performance compared to nonmotivated spatial learning. This advantage was evident across several performance indices, including accuracy, learning rate, path length, and proximity to platform locations during probe trials. SCL analysis revealed three key findings. First, within subjects, arousal interacted with approach motivation, such that high arousal on a given trial was associated with performance deficits. In addition, across subjects, high arousal negated or reversed the benefits of approach motivation. Finally, low-performing, highly aroused participants showed SCL responses similar to those of avoidance–motivation participants, suggesting that for these individuals, opportunities for reward may evoke states of learning similar to those typically evoked by threats of punishment. These results provide a novel characterization of how approach and avoidance motivation influence declarative memory and indicate a critical and selective role for arousal in determining how reinforcement influences goal-oriented learning. PMID:22021253

Neuroscientific Insights: Attention, Working Memory, and Inhibitory Control

ERIC Educational Resources Information Center

Raver, C. Cybele; Blair, Clancy

2016-01-01

In this article, Cybele Raver and Clancy Blair explore a group of cognitive processes called executive function (EF)--including the flexible control of attention, the ability to hold information through working memory, and the ability to maintain inhibitory control. EF processes are crucial for young children's learning. On the one hand, they can…

TGF-β Signaling in Dopaminergic Neurons Regulates Dendritic Growth, Excitatory-Inhibitory Synaptic Balance, and Reversal Learning.

PubMed

Luo, Sarah X; Timbang, Leah; Kim, Jae-Ick; Shang, Yulei; Sandoval, Kadellyn; Tang, Amy A; Whistler, Jennifer L; Ding, Jun B; Huang, Eric J

2016-12-20

Neural circuits involving midbrain dopaminergic (DA) neurons regulate reward and goal-directed behaviors. Although local GABAergic input is known to modulate DA circuits, the mechanism that controls excitatory/inhibitory synaptic balance in DA neurons remains unclear. Here, we show that DA neurons use autocrine transforming growth factor β (TGF-β) signaling to promote the growth of axons and dendrites. Surprisingly, removing TGF-β type II receptor in DA neurons also disrupts the balance in TGF-β1 expression in DA neurons and neighboring GABAergic neurons, which increases inhibitory input, reduces excitatory synaptic input, and alters phasic firing patterns in DA neurons. Mice lacking TGF-β signaling in DA neurons are hyperactive and exhibit inflexibility in relinquishing learned behaviors and re-establishing new stimulus-reward associations. These results support a role for TGF-β in regulating the delicate balance of excitatory/inhibitory synaptic input in local microcircuits involving DA and GABAergic neurons and its potential contributions to neuropsychiatric disorders. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Learning-Dependent Plasticity of the Barrel Cortex Is Impaired by Restricting GABA-Ergic Transmission.

PubMed

Posluszny, Anna; Liguz-Lecznar, Monika; Turzynska, Danuta; Zakrzewska, Renata; Bielecki, Maksymilian; Kossut, Malgorzata

2015-01-01

Experience-induced plastic changes in the cerebral cortex are accompanied by alterations in excitatory and inhibitory transmission. Increased excitatory drive, necessary for plasticity, precedes the occurrence of plastic change, while decreased inhibitory signaling often facilitates plasticity. However, an increase of inhibitory interactions was noted in some instances of experience-dependent changes. We previously reported an increase in the number of inhibitory markers in the barrel cortex of mice after fear conditioning engaging vibrissae, observed concurrently with enlargement of the cortical representational area of the row of vibrissae receiving conditioned stimulus (CS). We also observed that an increase of GABA level accompanied the conditioning. Here, to find whether unaltered GABAergic signaling is necessary for learning-dependent rewiring in the murine barrel cortex, we locally decreased GABA production in the barrel cortex or reduced transmission through GABAA receptors (GABAARs) at the time of the conditioning. Injections of 3-mercaptopropionic acid (3-MPA), an inhibitor of glutamic acid decarboxylase (GAD), into the barrel cortex prevented learning-induced enlargement of the conditioned vibrissae representation. A similar effect was observed after injection of gabazine, an antagonist of GABAARs. At the behavioral level, consistent conditioned response (cessation of head movements in response to CS) was impaired. These results show that appropriate functioning of the GABAergic system is required for both manifestation of functional cortical representation plasticity and for the development of a conditioned response.

A systematic review of the relationship between eating, weight and inhibitory control using the stop signal task.

PubMed

Bartholdy, Savani; Dalton, Bethan; O'Daly, Owen G; Campbell, Iain C; Schmidt, Ulrike

2016-05-01

Altered inhibitory control (response inhibition, reward-based inhibition, cognitive inhibition, reversal learning) has been implicated in eating disorders (EDs) and obesity. It is unclear, however, how different types of inhibitory control contribute to eating and weight-control behaviours. This review evaluates the relationship between one aspect of inhibitory control (a reactive component of motor response inhibition measured by the stop signal task) and eating/weight in clinical and non-clinical populations. Sixty-two studies from 58 journal articles were included. Restrained eaters had diminished reactive inhibitory control compared to unrestrained eaters, and showed greatest benefit to their eating behaviour from manipulations of inhibitory control. Obese individuals may show less reactive inhibitory control but only in the context of food-specific inhibition or after executive resources are depleted. Of the limited studies in EDs, the majority found no impairment in reactive inhibitory control, although findings are inconsistent. Thus, altered reactive inhibitory control is related to some maladaptive eating behaviours, and hence may provide a therapeutic target for behavioural manipulations and/or neuromodulation. However, other types of inhibitory control may also contribute. Methodological and theoretical considerations are discussed. Copyright © 2016. Published by Elsevier Ltd.

Potentiation of the early visual response to learned danger signals in adults and adolescents

PubMed Central

Howsley, Philippa; Jordan, Jeff; Johnston, Pat

2015-01-01

The reinforcing effects of aversive outcomes on avoidance behaviour are well established. However, their influence on perceptual processes is less well explored, especially during the transition from adolescence to adulthood. Using electroencephalography, we examined whether learning to actively or passively avoid harm can modulate early visual responses in adolescents and adults. The task included two avoidance conditions, active and passive, where two different warning stimuli predicted the imminent, but avoidable, presentation of an aversive tone. To avoid the aversive outcome, participants had to learn to emit an action (active avoidance) for one of the warning stimuli and omit an action for the other (passive avoidance). Both adults and adolescents performed the task with a high degree of accuracy. For both adolescents and adults, increased N170 event-related potential amplitudes were found for both the active and the passive warning stimuli compared with control conditions. Moreover, the potentiation of the N170 to the warning stimuli was stable and long lasting. Developmental differences were also observed; adolescents showed greater potentiation of the N170 component to danger signals. These findings demonstrate, for the first time, that learned danger signals in an instrumental avoidance task can influence early visual sensory processes in both adults and adolescents. PMID:24652856

Individual differences in sensitivity to reward and punishment and neural activity during reward and avoidance learning.

PubMed

Kim, Sang Hee; Yoon, HeungSik; Kim, Hackjin; Hamann, Stephan

2015-09-01

In this functional neuroimaging study, we investigated neural activations during the process of learning to gain monetary rewards and to avoid monetary loss, and how these activations are modulated by individual differences in reward and punishment sensitivity. Healthy young volunteers performed a reinforcement learning task where they chose one of two fractal stimuli associated with monetary gain (reward trials) or avoidance of monetary loss (avoidance trials). Trait sensitivity to reward and punishment was assessed using the behavioral inhibition/activation scales (BIS/BAS). Functional neuroimaging results showed activation of the striatum during the anticipation and reception periods of reward trials. During avoidance trials, activation of the dorsal striatum and prefrontal regions was found. As expected, individual differences in reward sensitivity were positively associated with activation in the left and right ventral striatum during reward reception. Individual differences in sensitivity to punishment were negatively associated with activation in the left dorsal striatum during avoidance anticipation and also with activation in the right lateral orbitofrontal cortex during receiving monetary loss. These results suggest that learning to attain reward and learning to avoid loss are dependent on separable sets of neural regions whose activity is modulated by trait sensitivity to reward or punishment. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Enhancement of fear memory by retrieval through reconsolidation

PubMed Central

Fukushima, Hotaka; Zhang, Yue; Archbold, Georgia; Ishikawa, Rie; Nader, Karim; Kida, Satoshi

2014-01-01

Memory retrieval is considered to have roles in memory enhancement. Recently, memory reconsolidation was suggested to reinforce or integrate new information into reactivated memory. Here, we show that reactivated inhibitory avoidance (IA) memory is enhanced through reconsolidation under conditions in which memory extinction is not induced. This memory enhancement is mediated by neurons in the amygdala, hippocampus, and medial prefrontal cortex (mPFC) through the simultaneous activation of calcineurin-induced proteasome-dependent protein degradation and cAMP responsive element binding protein-mediated gene expression. Interestingly, the amygdala is required for memory reconsolidation and enhancement, whereas the hippocampus and mPFC are required for only memory enhancement. Furthermore, memory enhancement triggered by retrieval utilizes distinct mechanisms to strengthen IA memory by additional learning that depends only on the amygdala. Our findings indicate that reconsolidation functions to strengthen the original memory and show the dynamic nature of reactivated memory through protein degradation and gene expression in multiple brain regions. DOI: http://dx.doi.org/10.7554/eLife.02736.001 PMID:24963141

Memory retrieval and the passage of time: from reconsolidation and strengthening to extinction

PubMed Central

Inda, Maria Carmen; Muravieva, Elizaveta V.; Alberini, Cristina M.

2011-01-01

An established memory can be made transiently labile if retrieved or reactivated. Over time, it becomes again resistant to disruption and this process that renders the memory stable is termed reconsolidation. The reasons why a memory becomes labile after retrieval and reconsolidates still remains debated. Here, using inhibitory avoidance (IA) learning in rats, we provide evidence that retrievals of a young memory, which are accompanied by its reconsolidation, result in memory strengthening and contribute to its overall consolidation. This function associated to reconsolidation is temporally limited. With the passage of time, the stored memory undergoes important changes, as revealed by the behavioral outcomes of its retrieval. Over time, without explicit retrievals, memory first strengthens and becomes refractory to both retrieval-dependent interference and strengthening. At later times, the same retrievals that lead to reconsolidation of a young memory extinguish an older memory. We conclude that the storage of information is very dynamic and that its temporal evolution regulates behavioral outcomes. These results are important for potential clinical applications. PMID:21289172

Bidirectional Regulation of Innate and Learned Behaviors That Rely on Frequency Discrimination by Cortical Inhibitory Neurons

PubMed Central

Aizenberg, Mark; Mwilambwe-Tshilobo, Laetitia; Briguglio, John J.; Natan, Ryan G.; Geffen, Maria N.

2015-01-01

The ability to discriminate tones of different frequencies is fundamentally important for everyday hearing. While neurons in the primary auditory cortex (AC) respond differentially to tones of different frequencies, whether and how AC regulates auditory behaviors that rely on frequency discrimination remains poorly understood. Here, we find that the level of activity of inhibitory neurons in AC controls frequency specificity in innate and learned auditory behaviors that rely on frequency discrimination. Photoactivation of parvalbumin-positive interneurons (PVs) improved the ability of the mouse to detect a shift in tone frequency, whereas photosuppression of PVs impaired the performance. Furthermore, photosuppression of PVs during discriminative auditory fear conditioning increased generalization of conditioned response across tone frequencies, whereas PV photoactivation preserved normal specificity of learning. The observed changes in behavioral performance were correlated with bidirectional changes in the magnitude of tone-evoked responses, consistent with predictions of a model of a coupled excitatory-inhibitory cortical network. Direct photoactivation of excitatory neurons, which did not change tone-evoked response magnitude, did not affect behavioral performance in either task. Our results identify a new function for inhibition in the auditory cortex, demonstrating that it can improve or impair acuity of innate and learned auditory behaviors that rely on frequency discrimination. PMID:26629746

Analysis of memory consolidation and evocation in rats by proton induced X-ray emission

NASA Astrophysics Data System (ADS)

Jobim, P. F. C.; dos Santos, C. E. I.; Maurmann, N.; Reolon, G. K.; Debastiani, R.; Pedroso, T. R.; Carvalho, L. M.; Dias, J. F.

2014-08-01

It is well known that trace elements such as Mg, Ca, Fe, Cu and Zn have a key role in synapse plasticity and learning. Learning process is conventionally divided in three distinct and complementary stages: memory acquisition, consolidation and evocation. Consolidation is the stabilization of the synaptic trace formed by acquisition, while evocation is the recall of this trace. Ion-based techniques capable of providing information concerning the elemental composition of organic tissues may be helpful to improve our understanding on memory consolidation and evocation processes. In particular, the Particle-Induced X-ray Emission (PIXE) technique can be used to analyze different biological tissues with good accuracy. In this work we explore the versatility of PIXE to measure the elemental concentrations in rat brain tissues in order to establish any possible correlation between them and the memory consolidation and evocation processes. To this end, six groups of middle-age male Wistar rats were trained and tested in a step-down Inhibitory Avoidance conditioning. After the behavior tests, the animals were decapitated in accordance with the legal procedures and their brains were removed and dissected for the PIXE analyses. The results demonstrated that there are differences in the elemental concentration among the groups and such variations may be associated with their availability to the learning processes (by memory consolidation and evocation). Moreover, the control groups circumvent the possibility that a non-specific event involved in learning tasks cause such variations. Our results suggest that PIXE may be a useful tool to investigate memory consolidation and evocation in animal models.

Somatostatin-Expressing Inhibitory Interneurons in Cortical Circuits

PubMed Central

Yavorska, Iryna; Wehr, Michael

2016-01-01

Cortical inhibitory neurons exhibit remarkable diversity in their morphology, connectivity, and synaptic properties. Here, we review the function of somatostatin-expressing (SOM) inhibitory interneurons, focusing largely on sensory cortex. SOM neurons also comprise a number of subpopulations that can be distinguished by their morphology, input and output connectivity, laminar location, firing properties, and expression of molecular markers. Several of these classes of SOM neurons show unique dynamics and characteristics, such as facilitating synapses, specific axonal projections, intralaminar input, and top-down modulation, which suggest possible computational roles. SOM cells can be differentially modulated by behavioral state depending on their class, sensory system, and behavioral paradigm. The functional effects of such modulation have been studied with optogenetic manipulation of SOM cells, which produces effects on learning and memory, task performance, and the integration of cortical activity. Different classes of SOM cells participate in distinct disinhibitory circuits with different inhibitory partners and in different cortical layers. Through these disinhibitory circuits, SOM cells help encode the behavioral relevance of sensory stimuli by regulating the activity of cortical neurons based on subcortical and intracortical modulatory input. Associative learning leads to long-term changes in the strength of connectivity of SOM cells with other neurons, often influencing the strength of inhibitory input they receive. Thus despite their heterogeneity and variability across cortical areas, current evidence shows that SOM neurons perform unique neural computations, forming not only distinct molecular but also functional subclasses of cortical inhibitory interneurons. PMID:27746722

Activation of β-adrenoceptor facilitates active avoidance learning through enhancement of glutamate levels in the hippocampal dentate gyrus.

PubMed

Lv, Jing; Feng, Hao; Chen, Ling; Wang, Wei-Yao; Yue, Xue-Ling; Jin, Qing-Hua

2017-10-18

Long-term potentiation (LTP) is widely accepted as the best studied model for neurophysiological mechanisms that could underlie learning and memory formation. Despite a number of studies indicating that β-adrenoceptors in the hippocampal dentate gyrus (DG) is involved in the modulation of learning and memory as well as LTP, few studies have used glutamate release as a visual indicator in awake animals to explore the role of β-adrenoceptors in learning-dependent LTP. Therefore, in the present study, the effects of propranolol (an antagonist of β-adrenoceptor) and isoproterenol (an agonist of β-adrenoceptor) on extracellular concentrations of glutamate and amplitudes of field excitatory postsynaptic potential were measured in the DG region during active avoidance learning in freely moving conscious rats. In the control group, the glutamate level in the DG was significantly increased during the acquisition of active avoidance behavior and returned to basal level following extinction training. In propranolol group, antagonism of β-adrenoceptors in the DG significantly reduced the change in glutamate level, and the acquisition of the active avoidance behavior was significantly inhibited. In contrast, the change in glutamate level was significantly enhanced by isoproterenol, and the acquisition of the active avoidance behavior was significantly accelerated. Furthermore, in all groups, the changes in glutamate level were accompanied by corresponding changes in field excitatory postsynaptic potential amplitude and active avoidance behavior. Our results suggest that activation of β-adrenoceptors in the hippocampal DG facilitates active avoidance learning by modulations of glutamate level and synaptic efficiency in rats.

Attenuated sensitivity to neuroactive steroids in γ-aminobutyrate type A receptor delta subunit knockout mice

PubMed Central

Mihalek, Robert M.; Banerjee, Pradeep K.; Korpi, Esa R.; Quinlan, Joseph J.; Firestone, Leonard L.; Mi, Zhi-Ping; Lagenaur, Carl; Tretter, Verena; Sieghart, Werner; Anagnostaras, Stephan G.; Sage, Jennifer R.; Fanselow, Michael S.; Guidotti, Alessandro; Spigelman, Igor; Li, Zhiwei; DeLorey, Timothy M.; Olsen, Richard W.; Homanics, Gregg E.

1999-01-01

γ-Aminobutyric acid (GABA) type A receptors mediate fast inhibitory synaptic transmission and have been implicated in responses to sedative/hypnotic agents (including neuroactive steroids), anxiety, and learning and memory. Using gene targeting technology, we generated a strain of mice deficient in the δ subunit of the GABA type A receptors. In vivo testing of various behavioral responses revealed a strikingly selective attenuation of responses to neuroactive steroids, but not to other modulatory drugs. Electrophysiological recordings from hippocampal slices revealed a significantly faster miniature inhibitory postsynaptic current decay time in null mice, with no change in miniature inhibitory postsynaptic current amplitude or frequency. Learning and memory assessed with fear conditioning were normal. These results begin to illuminate the novel contributions of the δ subunit to GABA pharmacology and sedative/hypnotic responses and behavior and provide insights into the physiology of neurosteroids. PMID:10536021

Value generalization in human avoidance learning

PubMed Central

Robbins, Trevor W; Seymour, Ben

2018-01-01

Generalization during aversive decision-making allows us to avoid a broad range of potential threats following experience with a limited set of exemplars. However, over-generalization, resulting in excessive and inappropriate avoidance, has been implicated in a variety of psychological disorders. Here, we use reinforcement learning modelling to dissect out different contributions to the generalization of instrumental avoidance in two groups of human volunteers (N = 26, N = 482). We found that generalization of avoidance could be parsed into perceptual and value-based processes, and further, that value-based generalization could be subdivided into that relating to aversive and neutral feedback − with corresponding circuits including primary sensory cortex, anterior insula, amygdala and ventromedial prefrontal cortex. Further, generalization from aversive, but not neutral, feedback was associated with self-reported anxiety and intrusive thoughts. These results reveal a set of distinct mechanisms that mediate generalization in avoidance learning, and show how specific individual differences within them can yield anxiety. PMID:29735014

Value generalization in human avoidance learning.

PubMed

Norbury, Agnes; Robbins, Trevor W; Seymour, Ben

2018-05-08

Generalization during aversive decision-making allows us to avoid a broad range of potential threats following experience with a limited set of exemplars. However, over-generalization, resulting in excessive and inappropriate avoidance, has been implicated in a variety of psychological disorders. Here, we use reinforcement learning modelling to dissect out different contributions to the generalization of instrumental avoidance in two groups of human volunteers ( N = 26, N = 482). We found that generalization of avoidance could be parsed into perceptual and value-based processes, and further, that value-based generalization could be subdivided into that relating to aversive and neutral feedback - with corresponding circuits including primary sensory cortex, anterior insula, amygdala and ventromedial prefrontal cortex. Further, generalization from aversive, but not neutral, feedback was associated with self-reported anxiety and intrusive thoughts. These results reveal a set of distinct mechanisms that mediate generalization in avoidance learning, and show how specific individual differences within them can yield anxiety. © 2018, Norbury et al.

The Plasticity of Extinction: Contribution of the Prefrontal Cortex in Treating Addiction through Inhibitory Learning

PubMed Central

Gass, J. T.; Chandler, L. J.

2013-01-01

Theories of drug addiction that incorporate various concepts from the fields of learning and memory have led to the idea that classical and operant conditioning principles underlie the compulsiveness of addictive behaviors. Relapse often results from exposure to drug-associated cues, and the ability to extinguish these conditioned behaviors through inhibitory learning could serve as a potential therapeutic approach for those who suffer from addiction. This review will examine the evidence that extinction learning alters neuronal plasticity in specific brain regions and pathways. In particular, subregions of the prefrontal cortex (PFC) and their projections to other brain regions have been shown to differentially modulate drug-seeking and extinction behavior. Additionally, there is a growing body of research demonstrating that manipulation of neuronal plasticity can alter extinction learning. Therefore, the ability to alter plasticity within areas of the PFC through pharmacological manipulation could facilitate the acquisition of extinction and provide a novel intervention to aid in the extinction of drug-related memories. PMID:23750137

Evidence for an expectancy-based theory of avoidance behaviour.

PubMed

Declercq, Mieke; De Houwer, Jan; Baeyens, Frank

2008-01-01

In most studies on avoidance learning, participants receive an aversive unconditioned stimulus after a warning signal is presented, unless the participant performs a particular response. Lovibond (2006) recently proposed a cognitive theory of avoidance learning, according to which avoidance behaviour is a function of both Pavlovian and instrumental conditioning. In line with this theory, we found that avoidance behaviour was based on an integration of acquired knowledge about, on the one hand, the relation between stimuli and, on the other hand, the relation between behaviour and stimuli.

Extinction and Renewal of Conditioned Sexual Responses

PubMed Central

Brom, Mirte; Laan, Ellen; Everaerd, Walter; Spinhoven, Philip; Both, Stephanie

2014-01-01

Introduction Extinction involves an inhibitory form of new learning that is highly dependent on the context for expression. This is supported by phenomena such as renewal and spontaneous recovery, which may help explain the persistence of appetitive behavior, and related problems such as addictions. Research on these phenomena in the sexual domain is lacking, where it may help to explain the persistence of learned sexual responses. Method Men (n = 40) and women (n = 62) participated in a differential conditioning paradigm, with genital vibrotactile stimulation as US and neutral pictures as conditional stimuli (CSs). Dependent variables were genital and subjective sexual arousal, affect, US expectancy, and approach and avoid tendencies towards the CSs. Extinction and renewal of conditioned sexual responses were studied by context manipulation (AAA vs. ABA condition). Results No renewal effect of genital conditioned responding could be detected, but an obvious recovery of US expectancy following a context change after extinction (ABA) was demonstrated. Additionally, women demonstrated recovery of subjective affect and subjective sexual arousal. Participants in the ABA demonstrated more approach biases towards stimuli. Conclusions The findings support the context dependency of extinction and renewal of conditioned sexual responses in humans. This knowledge may have implications for the treatment of disturbances in sexual appetitive responses such as hypo- and hypersexuality. PMID:25170909

Extinction and renewal of conditioned sexual responses.

PubMed

Brom, Mirte; Laan, Ellen; Everaerd, Walter; Spinhoven, Philip; Both, Stephanie

2014-01-01

Extinction involves an inhibitory form of new learning that is highly dependent on the context for expression. This is supported by phenomena such as renewal and spontaneous recovery, which may help explain the persistence of appetitive behavior, and related problems such as addictions. Research on these phenomena in the sexual domain is lacking, where it may help to explain the persistence of learned sexual responses. Men (n = 40) and women (n = 62) participated in a differential conditioning paradigm, with genital vibrotactile stimulation as US and neutral pictures as conditional stimuli (CSs). Dependent variables were genital and subjective sexual arousal, affect, US expectancy, and approach and avoid tendencies towards the CSs. Extinction and renewal of conditioned sexual responses were studied by context manipulation (AAA vs. ABA condition). No renewal effect of genital conditioned responding could be detected, but an obvious recovery of US expectancy following a context change after extinction (ABA) was demonstrated. Additionally, women demonstrated recovery of subjective affect and subjective sexual arousal. Participants in the ABA demonstrated more approach biases towards stimuli. The findings support the context dependency of extinction and renewal of conditioned sexual responses in humans. This knowledge may have implications for the treatment of disturbances in sexual appetitive responses such as hypo- and hypersexuality.

Behaviourally-inhibited temperament and female sex, two vulnerability factors for anxiety disorders, facilitate conditioned avoidance (also) in humans

PubMed Central

Sheynin, Jony; Beck, Kevin D.; Pang, Kevin C.H.; Servatius, Richard J.; Shikari, Saima; Ostovich, Jacqueline; Myers, Catherine E.

2014-01-01

Acquisition and maintenance of avoidance behaviour is a key feature of all human anxiety disorders. Animal models have been useful in understanding how anxiety vulnerability could translate into avoidance learning. For example, behaviourally-inhibited temperament and female sex, two vulnerability factors for clinical anxiety, are associated with faster acquisition of avoidance responses in rodents. However, to date, the translation of such empirical data to human populations has been limited since many features of animal avoidance paradigms are not typically captured in human research. Here, using a computer-based task that captures many features of rodent escape-avoidance learning paradigms, we investigated whether avoidance learning would be faster in humans with inhibited temperament and/or female sex and, if so, whether this facilitation would take the same form. Results showed that, as in rats, both vulnerability factors were associated with facilitated acquisition of avoidance behaviour in humans. Specifically, inhibited temperament was specifically associated with higher rate of avoidance responding, while female sex was associated with longer avoidance duration. These findings strengthen the direct link between animal avoidance work and human anxiety vulnerability, further motivating the study of animal models while also providing a simple testbed for a direct human testing. PMID:24412263

Executive Functions and Inhibitory Control in Multilingual Children: Evidence from Second-Language Learners, Bilinguals, and Trilinguals

ERIC Educational Resources Information Center

Poarch, Gregory J.; van Hell, Janet G.

2012-01-01

In two experiments, we examined inhibitory control processes in three groups of bilinguals and trilinguals that differed in nonnative language proficiency and language learning background. German 5- to 8-year-old second-language learners of English, German-English bilinguals, German-English-Language X trilinguals, and 6- to 8-year-old German…

Nogo-A regulates spatial learning as well as memory formation and modulates structural plasticity in the adult mouse hippocampus.

PubMed

Zagrebelsky, Marta; Lonnemann, Niklas; Fricke, Steffen; Kellner, Yves; Preuß, Eike; Michaelsen-Preusse, Kristin; Korte, Martin

2017-02-01

Behavioral learning has been shown to involve changes in the function and structure of synaptic connections of the central nervous system (CNS). On the other hand, the neuronal circuitry in the mature brain is characterized by a high degree of stability possibly providing a correlate for long-term storage of information. This observation indicates the requirement for a set of molecules inhibiting plasticity and promoting stability thereby providing temporal and spatial specificity to plastic processes. Indeed, signaling of Nogo-A via its receptors has been shown to play a crucial role in restricting activity-dependent functional and structural plasticity in the adult CNS. However, whether Nogo-A controls learning and memory formation and what are the cellular and molecular mechanisms underlying this function is still unclear. Here we show that Nogo-A signaling controls spatial learning and reference memory formation upon training in the Morris water maze and negatively modulates structural changes at spines in the mouse hippocampus. Learning processes and the correlated structural plasticity have been shown to involve changes in excitatory as well as in inhibitory neuronal connections. We show here that Nogo-A is highly expressed not only in excitatory, but also in inhibitory, Parvalbumin positive neurons in the adult hippocampus. By this means our current and previous data indicate that Nogo-A loss-of-function positively influences spatial learning by priming the neuronal structure to a higher plasticity level. Taken together our results link the role of Nogo-A in negatively regulating plastic processes to a physiological function in controlling learning and memory processes in the mature hippocampus and open the interesting possibility that it might mainly act by controlling the function of the hippocampal inhibitory circuitry. Copyright © 2016 Elsevier Inc. All rights reserved.

Learning to integrate versus inhibiting information is modulated by age.

PubMed

Cappelletti, Marinella; Pikkat, Helen; Upstill, Emily; Speekenbrink, Maarten; Walsh, Vincent

2015-02-04

Cognitive training aiming at improving learning is often successful, but what exactly underlies the observed improvements and how these differ across the age spectrum are currently unknown. Here we asked whether learning in young and older people may reflect enhanced ability to integrate information required to perform a cognitive task or whether it may instead reflect the ability to inhibit task-irrelevant information for successful task performance. We trained 30 young and 30 aging human participants on a numerosity discrimination task known to engage the parietal cortex and in which cue-integration and inhibitory abilities can be distinguished. We coupled training with parietal, motor, or sham transcranial random noise stimulation, known for modulating neural activity. Numerosity discrimination improved after training and was maintained long term, especially in the training + parietal stimulation group, regardless of age. Despite the quantitatively similar improvement in the two age groups, the content of learning differed remarkably: aging participants improved more in inhibitory abilities, whereas younger subjects improved in cue-integration abilities. Moreover, differences in the content of learning were reflected in different transfer effects to untrained but related abilities: in the younger group, improvements in cue integration paralleled improvements in continuous quantity (time and space), whereas in the elderly group, improvements in numerosity-based inhibitory abilities generalized to other measures of inhibition and corresponded to a decline in space discrimination, possibly because conflicting learning resources are used in numerosity and continuous quantity processing. These results indicate that training can enhance different, age-dependent cognitive processes and highlight the importance of identifying the exact processes underlying learning for effective training programs. Copyright © 2015 the authors 0270-6474/15/352213-13$15.00/0.

Retrieval Does Not Induce Reconsolidation of Inhibitory Avoidance Memory

ERIC Educational Resources Information Center

Medina, Jorge H.; Izquierdo, Ivan; Cammarota, Martin; Bevilaqua, Lia R. M.

2004-01-01

It has been suggested that retrieval during a nonreinforced test induces reconsolidation instead of extinction of the mnemonic trace. Reconsolidation would preserve the original memory from the labilization induced by its nonreinforced recall through a hitherto uncharacterized mechanism requiring protein synthesis. Given the importance that such a…

Intrahippocampal Muscimol Shifts Learning Strategy in Gonadally Intact Young Adult Female Rats

ERIC Educational Resources Information Center

McElroy, Molly W.; Korol, Donna L.

2005-01-01

Learning strategy preferences depend upon circulating estrogen levels, with enhanced hippocampus-sensitive place learning coinciding with elevated estrogen levels. The effects of estrogen on strategy may be mediated by fluctuations in GABAergic function, given that inhibitory tone in the hippocampus is low when estrogen is high. We investigated…

Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants

PubMed Central

Falibene, Agustina; Roces, Flavio; Rössler, Wolfgang

2015-01-01

Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to control for possible neuronal changes related to age and body size, we quantified synaptic complexes (microglomeruli, MG) in olfactory regions of the mushroom bodies (MBs) at different times after learning. Long-term avoidance memory formation was associated with a transient change in MG densities. Two days after learning, MG density was higher than before learning. At days 4 and 15 after learning—when ants still showed plant avoidance—MG densities had decreased to the initial state. The structural reorganization of MG triggered by long-term avoidance memory formation clearly differed from changes promoted by pure exposure to and collection of novel plants with distinct odors. Sensory exposure by the simultaneous collection of several, instead of one, non-harmful plant species resulted in a decrease in MG densities in the olfactory lip. We hypothesize that while sensory exposure leads to MG pruning in the MB olfactory lip, the formation of long-term avoidance memory involves an initial growth of new MG followed by subsequent pruning. PMID:25904854

Modeling Avoidance in Mood and Anxiety Disorders Using Reinforcement Learning.

PubMed

Mkrtchian, Anahit; Aylward, Jessica; Dayan, Peter; Roiser, Jonathan P; Robinson, Oliver J

2017-10-01

Serious and debilitating symptoms of anxiety are the most common mental health problem worldwide, accounting for around 5% of all adult years lived with disability in the developed world. Avoidance behavior-avoiding social situations for fear of embarrassment, for instance-is a core feature of such anxiety. However, as for many other psychiatric symptoms the biological mechanisms underlying avoidance remain unclear. Reinforcement learning models provide formal and testable characterizations of the mechanisms of decision making; here, we examine avoidance in these terms. A total of 101 healthy participants and individuals with mood and anxiety disorders completed an approach-avoidance go/no-go task under stress induced by threat of unpredictable shock. We show an increased reliance in the mood and anxiety group on a parameter of our reinforcement learning model that characterizes a prepotent (pavlovian) bias to withhold responding in the face of negative outcomes. This was particularly the case when the mood and anxiety group was under stress. This formal description of avoidance within the reinforcement learning framework provides a new means of linking clinical symptoms with biophysically plausible models of neural circuitry and, as such, takes us closer to a mechanistic understanding of mood and anxiety disorders. Copyright © 2017 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Is All Motivation Good for Learning? Dissociable Influences of Approach and Avoidance Motivation in Declarative Memory

ERIC Educational Resources Information Center

Murty, Vishnu P.; LaBar, Kevin S.; Hamilton, Derek A.; Adcock, R. Alison

2011-01-01

The present study investigated the effects of approach versus avoidance motivation on declarative learning. Human participants navigated a virtual reality version of the Morris water task, a classic spatial memory paradigm, adapted to permit the experimental manipulation of motivation during learning. During this task, participants were instructed…

Affective Factors Which Influence Learning about Sexually Transmitted Diseases.

ERIC Educational Resources Information Center

Schmidt, Mary F.; McKirnan, David

This study investigated the role that emotional factors play in learning about sexual health and in adopting sexually healthy behaviors. Learning about health and adopting healthy behaviors hinges on two variables: the desire to avoid illness and a belief that one can avoid threats to health through personal action. This paper reports on…

Hispanics' SAT Scores: The Influences of Level of Parental Education, Performance-Avoidance Goals, and Knowledge about Learning

ERIC Educational Resources Information Center

Hannon, Brenda

2015-01-01

This study uncovers which learning (epistemic belief of learning), socioeconomic background (level of parental education, family income) or social-personality factors (performance-avoidance goals, test anxiety) mitigate the ethnic gap in SAT (Scholastic Assessment Test) scores. Measures assessing achievement motivation, test anxiety, socioeconomic…

Defective GABAergic neurotransmission and pharmacological rescue of neuronal hyperexcitability in the amygdala in a mouse model of fragile X syndrome.

PubMed

Olmos-Serrano, Jose Luis; Paluszkiewicz, Scott M; Martin, Brandon S; Kaufmann, Walter E; Corbin, Joshua G; Huntsman, Molly M

2010-07-21

Fragile X syndrome (FXS) is a neurodevelopmental disorder characterized by variable cognitive impairment and behavioral disturbances such as exaggerated fear, anxiety and gaze avoidance. Consistent with this, findings from human brain imaging studies suggest dysfunction of the amygdala. Underlying alterations in amygdala synaptic function in the Fmr1 knock-out (KO) mouse model of FXS, however, remain largely unexplored. Utilizing a combination of approaches, we uncover profound alterations in inhibitory neurotransmission in the amygdala of Fmr1 KO mice. We demonstrate a dramatic reduction in the frequency and amplitude of phasic IPSCs, tonic inhibitory currents, as well as in the number of inhibitory synapses in Fmr1 KO mice. Furthermore, we observe significant alterations in GABA availability, both intracellularly and at the synaptic cleft. Together, these findings identify abnormalities in basal and action potential-dependent inhibitory neurotransmission. Additionally, we reveal a significant neuronal hyperexcitability in principal neurons of the amygdala in Fmr1 KO mice, which is strikingly rescued by pharmacological augmentation of tonic inhibitory tone using the GABA agonist gaboxadol (THIP). Thus, our study reveals relevant inhibitory synaptic abnormalities in the amygdala in the Fmr1 KO brain and supports the notion that pharmacological approaches targeting the GABAergic system may be a viable therapeutic approach toward correcting amygdala-based symptoms in FXS.

Requirement of Dopamine Signaling in the Amygdala and Striatum for Learning and Maintenance of a Conditioned Avoidance Response

ERIC Educational Resources Information Center

Darvas, Martin; Fadok, Jonathan P.; Palmiter, Richard D.

2011-01-01

Two-way active avoidance (2WAA) involves learning Pavlovian (association of a sound cue with a foot shock) and instrumental (shock avoidance) contingencies. To identify regions where dopamine (DA) is involved in mediating 2WAA, we restored DA signaling in specific brain areas of dopamine-deficient (DD) mice by local reactivation of conditionally…

Edible bioactive fatty acid-cellulosic derivative composites used in food-packaging applications.

PubMed

Sebti, Issam; Ham-Pichavant, Frédérique; Coma, Véronique

2002-07-17

To develop biodegradable packaging that both acts as a moisture barrier and as antimicrobial activity, nisin and stearic acid were incorporated into a hydroxy propyl methyl cellulose (HPMC) based film. Fifteen percent (w/w HPMC) of stearic acid improved film moisture barrier. However, film mechanical resistance and film antimicrobial activity on Listeria monocytogenes and Staphylococcus aureus pathogenic strains were both reduced. This lower film inhibitory activity was due to interactions between nisin and stearic acid. The molecular interaction was modeled, and an equation was developed to calculate the nisin concentration needed to be incorporated into the film matrix to obtain a desired residual antimicrobial activity. Because the molecular interactions were pH dependent, the impact of the pH of the film-forming solution on film inhibitory activity was investigated. Adjusting the pH to 3 totally avoided stearic acid and nisin interaction, inducing a high film inhibitory activity.

Processing demands in belief-desire reasoning: inhibition or general difficulty?

PubMed

Friedman, Ori; Leslie, Alan M

2005-05-01

Most 4-year-olds can predict the behavior of a person who wants an object but is mistaken about its location. More difficult is predicting behavior when the person is mistaken about location and wants to avoid the object. We tested between two explanations for children's difficulties with avoidance false belief: the Selection Processing model of inhibitory processing and a General Difficulty account. Children were presented with a false belief task and a control task, in which belief attribution was as difficult as in the false belief task. Predicting behavior in light of the character's desire to avoid the object added more difficulty in the false belief task. This finding is consistent with the Selection Processing model, but not with the General Difficulty account.

The dense core vesicle protein IA-2, but not IA-2β, is required for active avoidance learning.

PubMed

Carmona, G N; Nishimura, T; Schindler, C W; Panlilio, L V; Notkins, A L

2014-06-06

The islet-antigens IA-2 and IA-2β are major autoantigens in type-1 diabetes and transmembrane proteins in dense core vesicles (DCV). Recently we showed that deletion of both IA-2 and IA-2β alters the secretion of hormones and neurotransmitters and impairs behavior and learning. The present study was designed to evaluate the contribution to learning of each of these genes by using single knockout (SKO) and double knockout (DKO) mice in an active avoidance test. After 5 days of training, wild-type (WT) mice showed 60-70% active avoidance responses, whereas the DKO mice showed only 10-15% active avoidance responses. The degree of active avoidance responses in the IA-2 SKO mice was similar to that of the DKO mice, but in contrast, the IA-2β SKO mice behaved like WT mice showing 60-70% active avoidance responses. Molecular studies revealed a marked decrease in the phosphorylation of the cAMP response element-binding protein (CREB) and Ca(2+)/calmodulin-dependent protein kinase II (CAMKII) in the striatum and hippocampus of the IA-2 SKO and DKO mice, but not in the IA-2β SKO mice. To evaluate the role of CREB and CAMKII in the SKO and DKO mice, GBR-12909, which selectively blocks the dopamine uptake transporter and increases CREB and CAMKII phosphorylation, was administered. GBR-12909 restored the phosphorylation of CREB and CAMKII and increased active avoidance learning in the DKO and IA-2 SKO to near the normal levels found in the WT and IA-2β SKO mice. We conclude that in the absence of the DCV protein IA-2, active avoidance learning is impaired. Published by Elsevier Ltd.

Language learning without control: the role of the PFC.

PubMed

Friederici, Angela D; Mueller, Jutta L; Sehm, Bernhard; Ragert, Patrick

2013-05-01

Learning takes place throughout lifetime but differs in infants and adults because of the development of the PFC, a brain region responsible for cognitive control. To test this hypothesis, adults were investigated in a language learning paradigm under inhibitory, cathodal transcranial direct current stimulation over PFC. The experiment included a learning session interspersed with test phases and a test-only session. The stimulus material required the learning of grammatical dependencies between two elements in a novel language. In a parallel design, cathodal transcranial direct current stimulation over the left PFC, right PFC, or sham stimulation was applied during the learning session but not during the test-only session. Event-related brain potentials (ERPs) were recorded during both sessions. Whereas no ERP learning effects were observed during the learning session, different ERP learning effects as a function of prior stimulation type were found during the test-only session, although behavioral learning success was equal across conditions. With sham stimulation, the ERP learning effect was reflected in a centro-parietal N400-like negativity indicating lexical processes. Inhibitory stimulation over the left PFC, but not over the right PFC, led to a late positivity similar to that previously observed in prelinguistic infants indicating associative learning. The present data demonstrate that adults can learn with and without cognitive control using different learning mechanisms. In the presence of cognitive control, adult language learning is lexically guided, whereas it appears to be associative in nature when PFC control is downregulated.

Histone Modifications around Individual BDNF Gene Promoters in Prefrontal Cortex Are Associated with Extinction of Conditioned Fear

ERIC Educational Resources Information Center

Bredy, Timothy W.; Wu, Hao; Crego, Cortney; Zellhoefer, Jessica; Sun, Yi E.; Barad, Mark

2007-01-01

Extinction of conditioned fear is an important model both of inhibitory learning and of behavior therapy for human anxiety disorders. Like other forms of learning, extinction learning is long-lasting and depends on regulated gene expression. Epigenetic mechanisms make an important contribution to persistent changes in gene expression; therefore,…

Let's Burn Them All: Reflections on the Learning-Inhibitory Nature of Introduction to Management and Introduction to Organizational Behavior Textbooks

ERIC Educational Resources Information Center

Snyder, Robert A.

2014-01-01

This essay provides evidence from the neurosciences that standard Introduction to Management and "Introduction to Organizational Behavior" textbooks may inhibit, rather than facilitate, learning of the basic concepts and the rudimentary knowledge-basis that underlie the complex skills business students should learn in subsequent…

The Effect of Disgust and Fear Modeling on Children’s Disgust and Fear for Animals

PubMed Central

2014-01-01

Disgust is a protective emotion associated with certain types of animal fears. Given that a primary function of disgust is to protect against harm, increasing children’s disgust-related beliefs for animals may affect how threatening they think animals are and their avoidance of them. One way that children’s disgust beliefs for animals might change is via vicarious learning: by observing others responding to the animal with disgust. In Experiment 1, children (ages 7–10 years) were presented with images of novel animals together with adult faces expressing disgust. Children’s fear beliefs and avoidance preferences increased for these disgust-paired animals compared with unpaired control animals. Experiment 2 used the same procedure and compared disgust vicarious learning with vicarious learning with fear faces. Children’s fear beliefs and avoidance preferences for animals again increased as a result of disgust vicarious learning, and animals seen with disgust or fear faces were also rated more disgusting than control animals. The relationship between increased fear beliefs and avoidance preferences for animals was mediated by disgust for the animals. The experiments demonstrate that children can learn to believe that animals are disgusting and threatening after observing an adult responding with disgust toward them. The findings also suggest a bidirectional relationship between fear and disgust with fear-related vicarious learning leading to increased disgust for animals and disgust-related vicarious learning leading to increased fear and avoidance. PMID:24955571

Neurobehavioral impairments produced by developmental lead exposure persisted for generations in zebrafish (Danio rerio).

PubMed

Xu, Xiaojuan; Weber, Daniel; Burge, Rebekah; VanAmberg, Kelsey

2016-01-01

The zebrafish has become a useful animal model for studying the effects of environmental contaminants on neurobehavioral development due to its ease of breeding, high number of eggs per female, short generation times, and a well-established avoidance conditioning paradigm. Using avoidance conditioning as the behavioral paradigm, the present study investigated the effects of embryonic exposure to lead (Pb) on learning in adult zebrafish and the third (F3) generation of those fish. In Experiment 1, adult zebrafish that were developmentally exposed to 0.0, 0.1, 1.0 or 10.0μM Pb (2-24h post fertilization) as embryos were trained and tested for avoidance responses. The results showed that adult zebrafish hatched from embryos exposed to 0.0 or 0.1μM Pb learned avoidance responses during training and displayed significantly increased avoidance responses during testing, while those hatched from embryos exposed to 1.0 or 10.0μM Pb displayed no significant increases in avoidance responses from training to testing. In Experiment 2, the F3 generation of zebrafish that were developmentally exposed to an identical exposure regimen as in Experiment 1 were trained and tested for avoidance responses. The results showed that the F3 generation of zebrafish developmentally exposed as embryos to 0.0 or 0.1μM Pb learned avoidance responses during training and displayed significantly increased avoidance responses during testing, while the F3 generation of zebrafish developmentally exposed as embryos to 1.0 or 10.0μM Pb displayed no significant changes in avoidance responses from training to testing. Thus, developmental Pb exposure produced learning impairments that persisted for at least three generations, demonstrating trans-generational effects of embryonic exposure to Pb. Copyright © 2015. Published by Elsevier B.V.

Inhibitory Control as a Moderator of Threat-related Interference Biases in Social Anxiety

PubMed Central

Gorlin, Eugenia I.; Teachman, Bethany A.

2014-01-01

Prior findings are mixed regarding the presence and direction of threat-related interference biases in social anxiety. The current study examined general inhibitory control (IC), measured by the classic color-word Stroop, as a moderator of the relationship between both threat interference biases (indexed by the emotional Stroop) and several social anxiety indicators. High socially anxious undergraduate students (N=159) completed the emotional and color-word Stroop tasks, followed by an anxiety-inducing speech task. Participants completed measures of trait social anxiety, state anxiety before and during the speech, negative task-interfering cognitions during the speech, and overall self-evaluation of speech performance. Speech duration was used to measure behavioral avoidance. In line with hypotheses, IC moderated the relationship between emotional Stroop bias and every anxiety indicator (with the exception of behavioral avoidance), such that greater social-threat interference was associated with higher anxiety among those with weak IC, whereas lesser social-threat interference was associated with higher anxiety among those with strong IC. Implications for the theory and treatment of threat interference biases in socially anxious individuals are discussed. PMID:24967719

Without the Light of Evolution: A Case Study of Resistance and Avoidance in Learning to Teach High School Biology

ERIC Educational Resources Information Center

Larkin, Douglas B.; Perry-Ryder, Gail M.

2015-01-01

We present the case of Michael, a prospective high school biology teacher, to explore the implications of teacher resistance and avoidance to the topic of evolution. This case is drawn from a year-long qualitative research study that examined Michael's process of learning to teach high school biology and describes how his avoidance of evolution in…

Too (mentally) busy to chill: Cognitive load and inhibitory cues interact to moderate triggered displaced aggression.

PubMed

Vasquez, Eduardo A; Howard-Field, Joanna

2016-11-01

Inhibitory information can be expected to reduce triggered displaced aggression by signaling the potential for negative consequences as a result of acting aggressively. We examined how cognitive load might interfere with these aggression-reducing effects of inhibitory cues. Participants (N = 80) were randomly assigned to a condition in a 2 (cognitive load: high/low) × 2 (inhibiting cues: yes/no) between-subjects design. Following procedures in the TDA paradigm, participants received an initial provocation from the experimenter and a subsequent triggering annoyance from another individual. In the inhibitory cue condition, participants were told, before they had the opportunity to aggress, that others would learn of their aggressive responses. In the high cognitive load condition, participants rehearsed a 10-digit number while aggressing. Those in the low cognitive load condition rehearsed a three digit number. We found significant main effects of cognitive load and inhibitory cue, which were qualified by the expected load × inhibitory cue interaction. Thus, inhibitory cues reduced displaced aggression under low-cognitive load. However, when participants in the inhibitory cue condition were under cognitive load, aggression increased, suggesting that mental busyness interfered with the full use of inhibitory information. Aggr. Behav. 42:598-604, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Variable learning performance: the levels of behaviour organization.

PubMed

Csányi, V; Altbäcker, V

1990-01-01

Our experiments were focused on some special aspects of learning in the paradise fish. Passive avoidance conditioning method was used with different success depending on the complexity of the learning tasks. In the case of simple behavioural elements various "constrains" on avoidance learning were found. In a small, covered place the fish were ready to perform freezing reaction and mild punishment increased the frequency and duration of the freezing bouts very substantially. However, it was very difficult to enhance the frequency of freezing by punishment in a tank with transparent walls, where the main response to punishment was escape. The most easily learned tasks were the complex ones which had several different solutions. The fish learned to avoid either side of an aquarium very easily because they could use various behavioural elements to solve the problem. These findings could be interpreted within the framework of different organizational levels of behaviour.

Contextual modulation of value signals in reward and punishment learning

PubMed Central

Palminteri, Stefano; Khamassi, Mehdi; Joffily, Mateus; Coricelli, Giorgio

2015-01-01

Compared with reward seeking, punishment avoidance learning is less clearly understood at both the computational and neurobiological levels. Here we demonstrate, using computational modelling and fMRI in humans, that learning option values in a relative—context-dependent—scale offers a simple computational solution for avoidance learning. The context (or state) value sets the reference point to which an outcome should be compared before updating the option value. Consequently, in contexts with an overall negative expected value, successful punishment avoidance acquires a positive value, thus reinforcing the response. As revealed by post-learning assessment of options values, contextual influences are enhanced when subjects are informed about the result of the forgone alternative (counterfactual information). This is mirrored at the neural level by a shift in negative outcome encoding from the anterior insula to the ventral striatum, suggesting that value contextualization also limits the need to mobilize an opponent punishment learning system. PMID:26302782

[Stimulation of D1-receptors improves passive avoidance learning of female rats during ovary cycle].

PubMed

Fedotova, Iu O; Sapronov, N S

2012-01-01

The involvement of D1-receptors in learning/memory processes during ovary cycle was assessed in the adult female rats. SKF-38393 (0,1 mg/kg, i.p.), D1-receptor agonist and SCH-23390 (0,1 mg/kg, i.p.), D1-receptor antagonist were injected chronically to adult female rats. Learning of these animals was assessed in different models: passive avoidance performance and Morris water maze. Chronic SKF-3839 administration to females resulted in the appearance of the passive avoidance performance in proestrous and estrous, as distinct from the control animals, but failed to change the dynamics of spatial learning in Morris water maze. Chronic SCH-23390 administration similarly impaired non-spatial and spatial learning in females during all phases of ovary cycle. The results of the study suggest modulating role of D1-receptors in learning/memory processes during ovary cycle in the adult female rats.

[Stimulation of D2-receptors improves passive avoidance learning in female rats].

PubMed

Fedotova, Iu O

2012-01-01

The involvement of D2-receptors in learning/memory processes during ovary cycle was assessed in the adult female rats. Quinperole (0,1 mg/kg, i.p.), D2-receptor agonist and sulpiride (10,0 mg/kg, i.p.), D2-receptor antagonist were injected chronically to adult female rats. Learning of these animals was assessed in different models: passive avoidance performance and Morris water maze. Chronic quinperole administration to females resulted in the appearance of the passive avoidance performance in proestrous and estrous, as distinct from the control animals. Also, quinperole improved spatial learning in proestrous and stimulated it in estrous in Morris water maze. Chronic sulpiride administration similarly impaired non-spatial and spatial learning in females during all phases of ovary cycle. The results of the study suggest modulating role of D2-receptors in learning/memory processes during ovary cycle in the adult female rats.

Effects of activation and blockade of NMDA receptors on the extinction of a conditioned passive avoidance response in mice with different levels of anxiety.

PubMed

Tomilenko, R A; Dubrovina, N I

2007-06-01

The effects of an agonist (D-cycloserine) and an antagonist (dizocilpine) of N-methyl-D-aspartate (NMDA) receptors on the learning and extinction of a conditioned passive avoidance response were studied in mice with low, intermediate, and high levels of anxiety. In intermediate-anxiety mice, D-cycloserine (30 mg/kg) had no effect on learning but accelerated extinction, while dizocilpine (0.15 mg/kg) degraded acquisition of the reflex but delayed extinction. In high-anxiety mice, with good learning and no extinction, D-cycloserine had no effect, while dizocilpine decreased learning and facilitated retention of performance of the memory trace at the ongoing level in conditions promoting extinction. In low-anxiety mice, D-cycloserine degraded learning and accelerated extinction, while dizocilpine completely blocked learning and the retention of the passive avoidance response.

Contextual modulation of value signals in reward and punishment learning.

PubMed

Palminteri, Stefano; Khamassi, Mehdi; Joffily, Mateus; Coricelli, Giorgio

2015-08-25

Compared with reward seeking, punishment avoidance learning is less clearly understood at both the computational and neurobiological levels. Here we demonstrate, using computational modelling and fMRI in humans, that learning option values in a relative--context-dependent--scale offers a simple computational solution for avoidance learning. The context (or state) value sets the reference point to which an outcome should be compared before updating the option value. Consequently, in contexts with an overall negative expected value, successful punishment avoidance acquires a positive value, thus reinforcing the response. As revealed by post-learning assessment of options values, contextual influences are enhanced when subjects are informed about the result of the forgone alternative (counterfactual information). This is mirrored at the neural level by a shift in negative outcome encoding from the anterior insula to the ventral striatum, suggesting that value contextualization also limits the need to mobilize an opponent punishment learning system.

Inhibitory control and counterintuitive science and maths reasoning in adolescence.

PubMed

Brookman-Byrne, Annie; Mareschal, Denis; Tolmie, Andrew K; Dumontheil, Iroise

2018-01-01

Existing concepts can be a major barrier to learning new counterintuitive concepts that contradict pre-existing experience-based beliefs or misleading perceptual cues. When reasoning about counterintuitive concepts, inhibitory control is thought to enable the suppression of incorrect concepts. This study investigated the association between inhibitory control and counterintuitive science and maths reasoning in adolescents (N = 90, 11-15 years). Both response and semantic inhibition were associated with counterintuitive science and maths reasoning, when controlling for age, general cognitive ability, and performance in control science and maths trials. Better response inhibition was associated with longer reaction times in counterintuitive trials, while better semantic inhibition was associated with higher accuracy in counterintuitive trials. This novel finding suggests that different aspects of inhibitory control may offer unique contributions to counterintuitive reasoning during adolescence and provides further support for the hypothesis that inhibitory control plays a role in science and maths reasoning.

Negative symptoms in schizophrenia result from a failure to represent the expected value of rewards: Behavioral and computational modeling evidence

PubMed Central

Gold, James M.; Waltz, James A.; Matveeva, Tatyana M.; Kasanova, Zuzana; Strauss, Gregory P.; Herbener, Ellen S.; Collins, Anne G.E.; Frank, Michael J.

2015-01-01

Context Negative symptoms are a core feature of schizophrenia, but their pathophysiology remains unclear. Objective Negative symptoms are defined by the absence of normal function. However, there must be a productive mechanism that leads to this absence. Here, we test a reinforcement learning account suggesting that negative symptoms result from a failure to represent the expected value of rewards coupled with preserved loss avoidance learning. Design Subjects performed a probabilistic reinforcement learning paradigm involving stimulus pairs in which choices resulted in either reward or avoidance of loss. Following training, subjects indicated their valuation of the stimuli in a transfer task. Computational modeling was used to distinguish between alternative accounts of the data. Setting A tertiary care research outpatient clinic. Patients A total of 47 clinically stable patients with a diagnosis of schizophrenia or schizoaffective disorder and 28 healthy volunteers participated. Patients were divided into high and low negative symptom groups. Main Outcome measures 1) The number of choices leading to reward or loss avoidance and 2) performance in the transfer phase. Quantitative fits from three different models were examined. Results High negative symptom patients demonstrated impaired learning from rewards but intact loss avoidance learning, and failed to distinguish rewarding stimuli from loss-avoiding stimuli in the transfer phase. Model fits revealed that high negative symptom patients were better characterized by an “actor-critic” model, learning stimulus-response associations, whereas controls and low negative symptom patients incorporated expected value of their actions (“Q-learning”) into the selection process. Conclusions Negative symptoms are associated with a specific reinforcement learning abnormality: High negative symptoms patients do not represent the expected value of rewards when making decisions but learn to avoid punishments through the use of prediction errors. This computational framework offers the potential to understand negative symptoms at a mechanistic level. PMID:22310503

Brain Mechanisms Underlying Individual Differences in Reaction to Stress: An Animal Model

DTIC Science & Technology

1988-10-29

Schooler, et al., 1976; Gershon & Buchsbaum, 1977; Buchsbaum, et al., 1977), personality scales of extraversion- introversion (Haier, 1984) and sensation...exploratory and learned to bar press more quickly and efficiently. Reducers with a lower inhibitory threshold learned the differential reinforcement of

Focal Uncaging of GABA Reveals a Temporally Defined Role for GABAergic Inhibition during Appetitive Associative Olfactory Conditioning in Honeybees

ERIC Educational Resources Information Center

Raccuglia, Davide; Mueller, Uli

2013-01-01

Throughout the animal kingdom, the inhibitory neurotransmitter ?-aminobutyric acid (GABA) is a key modulator of physiological processes including learning. With respect to associative learning, the exact time in which GABA interferes with the molecular events of learning has not yet been clearly defined. To address this issue, we used two…

Rats with ventral hippocampal damage are impaired at various forms of learning including conditioned inhibition, spatial navigation, and discriminative fear conditioning to similar contexts.

PubMed

McDonald, Robert J; Balog, R J; Lee, Justin Q; Stuart, Emily E; Carrels, Brianna B; Hong, Nancy S

2018-10-01

The ventral hippocampus (vHPC) has been implicated in learning and memory functions that seem to differ from its dorsal counterpart. The goal of this series of experiments was to provide further insight into the functional contributions of the vHPC. Our previous work implicated the vHPC in spatial learning, inhibitory learning, and fear conditioning to context. However, the specific role of vHPC on these different forms of learning are not clear. Accordingly, we assessed the effects of neurotoxic lesions of the ventral hippocampus on retention of a conditioned inhibitory association, early versus late spatial navigation in the water task, and discriminative fear conditioning to context under high ambiguity conditions. The results showed that the vHPC was necessary for the expression of conditioned inhibition, early spatial learning, and discriminative fear conditioning to context when the paired and unpaired contexts have high cue overlap. We argue that this pattern of effects, combined with previous work, suggests a key role for vHPC in the utilization of broad contextual representations for inhibition and discriminative memory in high ambiguity conditions. Copyright © 2018 Elsevier B.V. All rights reserved.

Implicit chaining in cotton-top tamarins (Saguinus oedipus) with elements equated for probability of reinforcement

PubMed Central

Dillon, Laura; Collins, Meaghan; Conway, Maura; Cunningham, Kate

2013-01-01

Three experiments examined the implicit learning of sequences under conditions in which the elements comprising a sequence were equated in terms of reinforcement probability. In Experiment 1 cotton-top tamarins (Saguinus oedipus) experienced a five-element sequence displayed serially on a touch screen in which reinforcement probability was equated across elements at .16 per element. Tamarins demonstrated learning of this sequence with higher latencies during a random test as compared to baseline sequence training. In Experiments 2 and 3, manipulations of the procedure used in the first experiment were undertaken to rule out a confound owing to the fact that the elements in Experiment 1 bore different temporal relations to the intertrial interval (ITI), an inhibitory period. The results of Experiments 2 and 3 indicated that the implicit learning observed in Experiment 1 was not due to temporal proximity between some elements and the inhibitory ITI. The results taken together support two conclusion: First that tamarins engaged in sequence learning whether or not there was contingent reinforcement for learning the sequence, and second that this learning was not due to subtle differences in associative strength between the elements of the sequence. PMID:23344718

Inhibition of long-term memory formation by anti-ependymin antisera after active shock-avoidance learning in goldfish.

PubMed

Piront, M L; Schmidt, R

1988-02-23

Ependymins are acidic glycoprotein constituents of goldfish brain cytoplasm and extracellular fluid which are known to participate in biochemical reactions of long-term memory formation. In earlier experiments, anti-ependymin antisera were found to cause amnesia when injected into goldfish brain ventricles after the acquisition of a vestibulomotoric training task. To investigate whether they also inhibit memory consolidation after other learning events the anti-ependymin antisera were injected after an active shock-avoidance learning paradigm, as follows: goldfish were trained in a shuttle-box to cross a barrier in order to avoid electric shocks (unconditioned stimulus) applied shortly after a light signal (conditioned stimulus). Anti-ependymin antisera blocked retention of the learned avoidance when injected 0.5, 4.5 or 24 h after acquisition of the new behavior. They had no effect, however, when injected 72 h after learning. Apparently, long-term memory was already consolidated at this point. Antisera injected 0.5 or 72 h prior to training, also did not influence learning or memory. Thirteen percent of the goldfish fled the light stimulus spontaneously. These fish therefore did not experience the unconditioned stimulus and thus were unable to learn the task. When they were treated with the anti-ependymin antisera and tested 3 days later, the spontaneous escape reaction was not affected (active control group). The ability of anti-ependymin antisera to inhibit memory consolidation and their efficacy after administration at specific time intervals are very similar for the active shock-avoidance learning and for the vestibulomotoric training. We conclude that ependymins are not task-specific, but serve a general function in biochemical reactions essential for long-term memory formation.

Nitric oxide facilitates active avoidance learning via enhancement of glutamate levels in the hippocampal dentate gyrus.

PubMed

Wang, Shi; Pan, De-Xi; Wang, Dan; Wan, Peng; Qiu, De-Lai; Jin, Qing-Hua

2014-09-01

The hippocampus is a key structure for learning and memory in mammals, and long-term potentiation (LTP) is an important cellular mechanism responsible for learning and memory. Despite a number of studies indicating that nitric oxide (NO) is involved in the formation and maintenance of LTP as a retrograde messenger, few studies have used neurotransmitter release as a visual indicator in awake animals to explore the role of NO in learning-dependent long-term enhancement of synaptic efficiency. Therefore, in the present study, the effects of l-NMMA (a NO synthase inhibitor) and SNP (a NO donor) on extracellular glutamate (Glu) concentrations and amplitudes of field excitatory postsynaptic potential (fEPSP) were measured in the hippocampal dentate gyrus (DG) region during the acquisition and extinction of active-avoidance behavior in freely-moving conscious rats. In the control group, the extracellular concentration of Glu in the DG was significantly increased during the acquisition of active-avoidance behavior and gradually returned to baseline levels following extinction training. In the experimental group, the change in Glu concentration was significantly reduced by local microinjection of l-NMMA, as was the acquisition of the active-avoidance behavior. In contrast, the change in Glu concentration was significantly enhanced by SNP, and the acquisition of the active-avoidance behavior was significantly accelerated. Furthermore, in all groups, the changes in extracellular Glu were accompanied by corresponding changes in fEPSP amplitude and active-avoidance behavior. Our results suggest that NO in the hippocampal DG facilitates active avoidance learning via enhancements of glutamate levels and synaptic efficiency in rats. Copyright © 2014 Elsevier B.V. All rights reserved.

MDMA modifies active avoidance learning and recall in mice.

PubMed

Trigo, José Manuel; Cabrero-Castel, Araceli; Berrendero, Fernando; Maldonado, Rafael; Robledo, Patricia

2008-04-01

Several studies have suggested the existence of cognitive deficits after repeated or high doses of 3,4-methylenedioxymethamphetamine (MDMA) in humans and experimental animals. However, the extent of the impairments observed in learning or memory tasks remains unclear. The objective of this study was to evaluate the effects of different dosing regimens of MDMA on the ability of mice to learn and recall an active avoidance task. Animals were treated with MDMA (0, 1, 3, 10 and 30 mg/kg) under four different experimental conditions, and active avoidance acquisition and recall were evaluated. In experiments 1 and 2, MDMA was administered 1 h before different active avoidance training sessions. In experiments 3 and 4, mice received a repeated treatment with MDMA before or after active avoidance training, respectively. Changes in presynaptic striatal dopamine transporter (DAT) binding sites were evaluated at two different time points in animals receiving a high dose of MDMA (30 mg/kg) or saline twice a day over 4 days. MDMA administered before the active avoidance sessions interfered with the acquisition and the execution of a previously learned task. A repeated treatment with high doses of MDMA administered before training reduced acquisition of active avoidance in mice, while pre-treatment with both high and low doses of MDMA impaired recall of this task. A reduction in DAT binding was observed 4 days but not 23 days after the last MDMA administration. Acute MDMA modifies the acquisition and execution of active avoidance in mice, while repeated pre-treatment with MDMA impairs acquisition and recall of this task.

Development switch in neural circuitry underlying odor-malaise learning.

PubMed

Shionoya, Kiseko; Moriceau, Stephanie; Lunday, Lauren; Miner, Cathrine; Roth, Tania L; Sullivan, Regina M

2006-01-01

Fetal and infant rats can learn to avoid odors paired with illness before development of brain areas supporting this learning in adults, suggesting an alternate learning circuit. Here we begin to document the transition from the infant to adult neural circuit underlying odor-malaise avoidance learning using LiCl (0.3 M; 1% of body weight, ip) and a 30-min peppermint-odor exposure. Conditioning groups included: Paired odor-LiCl, Paired odor-LiCl-Nursing, LiCl, and odor-saline. Results showed that Paired LiCl-odor conditioning induced a learned odor aversion in postnatal day (PN) 7, 12, and 23 pups. Odor-LiCl Paired Nursing induced a learned odor preference in PN7 and PN12 pups but blocked learning in PN23 pups. 14C 2-deoxyglucose (2-DG) autoradiography indicated enhanced olfactory bulb activity in PN7 and PN12 pups with odor preference and avoidance learning. The odor aversion in weanling aged (PN23) pups resulted in enhanced amygdala activity in Paired odor-LiCl pups, but not if they were nursing. Thus, the neural circuit supporting malaise-induced aversions changes over development, indicating that similar infant and adult-learned behaviors may have distinct neural circuits.

A novel single neuron perceptron with universal approximation and XOR computation properties.

PubMed

Lotfi, Ehsan; Akbarzadeh-T, M-R

2014-01-01

We propose a biologically motivated brain-inspired single neuron perceptron (SNP) with universal approximation and XOR computation properties. This computational model extends the input pattern and is based on the excitatory and inhibitory learning rules inspired from neural connections in the human brain's nervous system. The resulting architecture of SNP can be trained by supervised excitatory and inhibitory online learning rules. The main features of proposed single layer perceptron are universal approximation property and low computational complexity. The method is tested on 6 UCI (University of California, Irvine) pattern recognition and classification datasets. Various comparisons with multilayer perceptron (MLP) with gradient decent backpropagation (GDBP) learning algorithm indicate the superiority of the approach in terms of higher accuracy, lower time, and spatial complexity, as well as faster training. Hence, we believe the proposed approach can be generally applicable to various problems such as in pattern recognition and classification.

Aversive learning shapes neuronal orientation tuning in human visual cortex.

PubMed

McTeague, Lisa M; Gruss, L Forest; Keil, Andreas

2015-07-28

The responses of sensory cortical neurons are shaped by experience. As a result perceptual biases evolve, selectively facilitating the detection and identification of sensory events that are relevant for adaptive behaviour. Here we examine the involvement of human visual cortex in the formation of learned perceptual biases. We use classical aversive conditioning to associate one out of a series of oriented gratings with a noxious sound stimulus. After as few as two grating-sound pairings, visual cortical responses to the sound-paired grating show selective amplification. Furthermore, as learning progresses, responses to the orientations with greatest similarity to the sound-paired grating are increasingly suppressed, suggesting inhibitory interactions between orientation-selective neuronal populations. Changes in cortical connectivity between occipital and fronto-temporal regions mirror the changes in visuo-cortical response amplitudes. These findings suggest that short-term behaviourally driven retuning of human visual cortical neurons involves distal top-down projections as well as local inhibitory interactions.

Intra-Amygdala Injections of CREB Antisense Impair Inhibitory Avoidance Memory: Role of Norepinephrine and Acetylcholine

ERIC Educational Resources Information Center

Canal, Clinton E.; Chang, Qing; Gold, Paul E.

2008-01-01

Infusions of CREB antisense into the amygdala prior to training impair memory for aversive tasks, suggesting that the antisense may interfere with CRE-mediated gene transcription and protein synthesis important for the formation of new memories within the amygdala. However, the amygdala also appears to modulate memory formation in distributed…

Is previous experience important for inhibitory control? A comparison between shelter and pet dogs in A-not-B and cylinder tasks.

PubMed

Fagnani, J; Barrera, G; Carballo, F; Bentosela, M

2016-11-01

This study compares the performance of two groups of dogs with different levels of social interaction with humans, shelter and pet dogs, in two inhibitory control tasks. (1) In the A-not-B task, dogs were required to resist searching for food in a previously rewarded location, and (2) in the cylinder task, dogs were required to resist approaching visible food directly in favor of a detour reaching response. Our first aim was to evaluate the importance of learning and ontogeny in performing inhibitory tasks. Also, we assessed whether there is a correlation between the two tasks by comparing performance in the same subjects. Results showed significant differences between shelter and pet dogs in the A-not-B task, with poorer performance in shelter dogs. However, no differences were found in the cylinder task. The poorer performance of shelter dogs might be related to their infrequent interaction with humans, which reduces the chances to learn to inhibit certain behaviors. This result would highlight the importance of ontogeny in developing that ability. On the other hand, no correlations were found between the two tasks, which contributes information to the debate about the context specificity of inhibitory control in dogs.

Active Avoidance: Neural Mechanisms and Attenuation of Pavlovian Conditioned Responding.

PubMed

Boeke, Emily A; Moscarello, Justin M; LeDoux, Joseph E; Phelps, Elizabeth A; Hartley, Catherine A

2017-05-03

Patients with anxiety disorders often experience a relapse in symptoms after exposure therapy. Similarly, threat responses acquired during Pavlovian threat conditioning often return after extinction learning. Accordingly, there is a need for alternative methods to persistently reduce threat responding. Studies in rodents have suggested that exercising behavioral control over an aversive stimulus can persistently diminish threat responses, and that these effects are mediated by the amygdala, ventromedial prefrontal cortex, and striatum. In this fMRI study, we attempted to translate these findings to humans. Subjects first underwent threat conditioning. We then contrasted two forms of safety learning: active avoidance, in which participants could prevent the shock through an action, and yoked extinction, with shock presentation matched to the active condition, but without instrumental control. The following day, we assessed subjects' threat responses (measured by skin conductance) to the conditioned stimuli without shock. Subjects next underwent threat conditioning with novel stimuli. Yoked extinction subjects showed an increase in conditioned response to stimuli from the previous day, but the active avoidance group did not. Additionally, active avoidance subjects showed reduced conditioned responding during novel threat conditioning, but the extinction group did not. We observed between-group differences in striatal BOLD responses to shock omission in Avoidance/Extinction. These findings suggest a differential role for the striatum in human active avoidance versus extinction learning, and indicate that active avoidance may be more effective than extinction in persistently diminishing threat responses. SIGNIFICANCE STATEMENT Extinguished threat responses often reemerge with time, highlighting the importance of identifying more enduring means of attenuation. We compared the effects of active avoidance learning and yoked extinction on threat responses in humans and contrasted the neural circuitry engaged by these two processes. Subjects who learned to prevent a shock through an action maintained low threat responses after safety learning and showed attenuated threat conditioning with novel stimuli, in contrast to those who underwent yoked extinction. The results suggest that experiences of active control over threat engage the striatum and promote a shift from expression of innate defensive responses toward more adaptive behavioral responses to threatening stimuli. Copyright © 2017 the authors 0270-6474/17/374808-11$15.00/0.

Active Avoidance: Neural Mechanisms and Attenuation of Pavlovian Conditioned Responding

PubMed Central

Boeke, Emily A.; Moscarello, Justin M.; Phelps, Elizabeth A.

2017-01-01

Patients with anxiety disorders often experience a relapse in symptoms after exposure therapy. Similarly, threat responses acquired during Pavlovian threat conditioning often return after extinction learning. Accordingly, there is a need for alternative methods to persistently reduce threat responding. Studies in rodents have suggested that exercising behavioral control over an aversive stimulus can persistently diminish threat responses, and that these effects are mediated by the amygdala, ventromedial prefrontal cortex, and striatum. In this fMRI study, we attempted to translate these findings to humans. Subjects first underwent threat conditioning. We then contrasted two forms of safety learning: active avoidance, in which participants could prevent the shock through an action, and yoked extinction, with shock presentation matched to the active condition, but without instrumental control. The following day, we assessed subjects' threat responses (measured by skin conductance) to the conditioned stimuli without shock. Subjects next underwent threat conditioning with novel stimuli. Yoked extinction subjects showed an increase in conditioned response to stimuli from the previous day, but the active avoidance group did not. Additionally, active avoidance subjects showed reduced conditioned responding during novel threat conditioning, but the extinction group did not. We observed between-group differences in striatal BOLD responses to shock omission in Avoidance/Extinction. These findings suggest a differential role for the striatum in human active avoidance versus extinction learning, and indicate that active avoidance may be more effective than extinction in persistently diminishing threat responses. SIGNIFICANCE STATEMENT Extinguished threat responses often reemerge with time, highlighting the importance of identifying more enduring means of attenuation. We compared the effects of active avoidance learning and yoked extinction on threat responses in humans and contrasted the neural circuitry engaged by these two processes. Subjects who learned to prevent a shock through an action maintained low threat responses after safety learning and showed attenuated threat conditioning with novel stimuli, in contrast to those who underwent yoked extinction. The results suggest that experiences of active control over threat engage the striatum and promote a shift from expression of innate defensive responses toward more adaptive behavioral responses to threatening stimuli. PMID:28408411

Cognitive and Emotional Factors in Children with Mathematical Learning Disabilities

ERIC Educational Resources Information Center

Passolunghi, Maria Chiara

2011-01-01

Emotional and cognitive factors were examined in 18 children with mathematical learning disabilities (MLD), compared with 18 normally achieving children, matched for chronological age, school level, gender and verbal IQ. Working memory, short-term memory, inhibitory processes, speed of processing and level of anxiety in mathematics were assessed…

The Metamorphosis of the Statistical Segmentation Output: Lexicalization during Artificial Language Learning

ERIC Educational Resources Information Center

Fernandes, Tania; Kolinsky, Regine; Ventura, Paulo

2009-01-01

This study combined artificial language learning (ALL) with conventional experimental techniques to test whether statistical speech segmentation outputs are integrated into adult listeners' mental lexicon. Lexicalization was assessed through inhibitory effects of novel neighbors (created by the parsing process) on auditory lexical decisions to…

Endocannabinoids and stress.

PubMed

Riebe, Caitlin J; Wotjak, Carsten T

2011-07-01

Endogenous cannabinoids play an important role in the physiology and behavioral expression of stress responses. Activation of the hypothalamic-pituitary-adrenal (HPA) axis, including the release of glucocorticoids, is the fundamental hormonal response to stress. Endocannabinoid (eCB) signaling serves to maintain HPA-axis homeostasis, by buffering basal activity as well as by mediating glucocorticoid fast feedback mechanisms. Following chronic stressor exposure, eCBs are also involved in physiological and behavioral habituation processes. Behavioral consequences of stress include fear and stress-induced anxiety as well as memory formation in the context of stress, involving contextual fear conditioning and inhibitory avoidance learning. Chronic stress can also lead to depression-like symptoms. Prominent in these behavioral stress responses is the interaction between eCBs and the HPA-axis. Future directions may differentiate among eCB signaling within various brain structures/neuronal subpopulations as well as between the distinct roles of the endogenous cannabinoid ligands. Investigation into the role of the eCB system in allostatic states and recovery processes may give insight into possible therapeutic manipulations of the system in treating chronic stress-related conditions in humans.

Zinc supplementation in rats impairs hippocampal-dependent memory consolidation and dampens post-traumatic recollection of stressful event.

PubMed

Contestabile, Antonio; Peña-Altamira, Emiliano; Virgili, Marco; Monti, Barbara

2016-06-01

Zinc is a trace element important for synaptic plasticity, learning and memory. Zinc deficiency, both during pregnancy and after birth, impairs cognitive performance and, in addition to memory deficits, also results in alterations of attention, activity, neuropsychological behavior and motor development. The effects of zinc supplementation on cognition, particularly in the adult, are less clear. We demonstrate here in adult rats, that 4 week-long zinc supplementation given by drinking water, and approximately doubling normal daily intake, strongly impairs consolidation of hippocampal-dependent memory, tested through contextual fear conditioning and inhibitory avoidance. Furthermore, the same treatment started after memory consolidation of training for the same behavioral tests, substantially dampens the recall of the stressful event occurred 4 weeks before. A molecular correlate of the amnesic effect of zinc supplementation is represented by a dysregulated function of GSK-3ß in the hippocampus, a kinase that participates in memory processes. The possible relevance of these data for humans, in particular regarding post-traumatic stress disorders, is discussed in view of future investigation. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

A Positive Autoregulatory BDNF Feedback Loop via C/EBPβ Mediates Hippocampal Memory Consolidation

PubMed Central

Bambah-Mukku, Dhananjay; Travaglia, Alessio; Chen, Dillon Y.; Pollonini, Gabriella

2014-01-01

Little is known about the temporal progression and regulation of the mechanisms underlying memory consolidation. Brain-derived-neurotrophic-factor (BDNF) has been shown to mediate the maintenance of memory consolidation, but the mechanisms of this regulation remain unclear. Using inhibitory avoidance (IA) in rats, here we show that a hippocampal BDNF-positive autoregulatory feedback loop via CCAAT-enhancer binding protein β (C/EBPβ) is necessary to mediate memory consolidation. At training, a very rapid, learning-induced requirement of BDNF accompanied by rapid de novo translation controls the induction of a persistent activation of cAMP-response element binding-protein (CREB) and C/EBPβ expression. The latter, in turn, controls an increase in expression of bdnf exon IV transcripts and BDNF protein, both of which are necessary and, together with the initial BDNF requirement, mediate memory consolidation. The autoregulatory loop terminates by 48 h after training with decreased C/EBPβ and pCREB and increased methyl-CpG binding protein-2, histone-deacetylase-2, and switch-independent-3a binding at the bdnf exon IV promoter. PMID:25209292

Improvements of the Penalty Avoiding Rational Policy Making Algorithm and an Application to the Othello Game

NASA Astrophysics Data System (ADS)

Miyazaki, Kazuteru; Tsuboi, Sougo; Kobayashi, Shigenobu

The purpose of reinforcement learning is to learn an optimal policy in general. However, in 2-players games such as the othello game, it is important to acquire a penalty avoiding policy. In this paper, we focus on formation of a penalty avoiding policy based on the Penalty Avoiding Rational Policy Making algorithm [Miyazaki 01]. In applying it to large-scale problems, we are confronted with the curse of dimensionality. We introduce several ideas and heuristics to overcome the combinational explosion in large-scale problems. First, we propose an algorithm to save the memory by calculation of state transition. Second, we describe how to restrict exploration by two type knowledge; KIFU database and evaluation funcion. We show that our learning player can always defeat against the well-known othello game program KITTY.

Lesions of the rat nucleus basalis magnocellularis disrupt appetitive-to-aversive transfer learning.

PubMed

Butt, A E; Schultz, J A; Arnold, L L; Garman, E E; George, C L; Garraghty, P E

2003-01-01

Rats with selective lesions of the nucleus basalis magnocellularis (NBM) and sham-lesion control animals were tested in an operant appetitive-to-aversive transfer task. We hypothesized that NBM lesions would not affect performance in the appetitive phase, but that performance would be impaired during subsequent transfer to the aversive phase of the task. Additional groups of NBM lesion and control rats were tested in the avoidance condition only, where we hypothesized that NBM lesions would not disrupt performance. These hypotheses were based on the argument that the NBM is not necessary for simple association learning that does not tax attention. Both the appetitive phase of the transfer task and the avoidance only task depend only on simple associative learning and are argued not to tax attention. Consequently, performance in these tasks was predicted to be spared following NBM lesions. Complex, attention-demanding associative learning, however, is argued to depend on the NBM. Performance in the aversive phase of the transfer task is both attentionally demanding and associatively more complex than in either the appetitive or aversive tasks alone; thus, avoidance performance in the NBM lesion group was predicted to be impaired following transfer from prior appetitive conditioning. Results supported our hypotheses, with the NBM lesion group acquiring the appetitive response normally, but showing impaired performance following transfer to the aversive conditioning phase of the transfer task. Impairments were not attributable to disrupted avoidance learning per se, as avoidance behavior was normal in the NBM lesion group tested in the avoidance condition only.

A study of students' learning styles and mathematics anxiety amongst form four students in Kerian Perak

NASA Astrophysics Data System (ADS)

Esa, Suraya; Mohamed, Nurul Akmal

2017-05-01

This study aims to identify the relationship between students' learning styles and mathematics anxiety amongst Form Four students in Kerian, Perak. The study involves 175 Form Four students as respondents. The instrument which is used to assess the students' learning styles and mathematic anxiety is adapted from the Grasha's Learning Styles Inventory and the Mathematics Anxiety Scale (MAS) respectively. The types of learning styles used are independent, avoidant, collaborative, dependent, competitive and participant. The collected data is processed by SPSS (Statistical Packages for Social Sciences 16.0). The data is analysed by using descriptive statistics and inferential statistics that include t-test and Pearson correlation. The results show that majority of the students adopt collaborative learning style and the students have moderate level of mathematics anxiety. Moreover, it is found that there is significant difference between learning style avoidant, collaborative, dependent and participant based on gender. Amongst all students' learning style, there exists a weak but significant correlation between avoidant, independent and participant learning style and mathematics anxiety. It is very important for the teachers need to be concerned about the effects of learning styles on mathematics anxiety. Therefore, the teachers should understand mathematics anxiety and implement suitable learning strategies in order for the students to overcome their mathematics anxiety.

Reversal learning as a measure of impulsive and compulsive behavior in addictions.

PubMed

Izquierdo, Alicia; Jentsch, J David

2012-01-01

Our ability to measure the cognitive components of complex decision-making across species has greatly facilitated our understanding of its neurobiological mechanisms. One task in particular, reversal learning, has proven valuable in assessing the inhibitory processes that are central to executive control. Reversal learning measures the ability to actively suppress reward-related responding and to disengage from ongoing behavior, phenomena that are biologically and descriptively related to impulsivity and compulsivity. Consequently, reversal learning could index vulnerability for disorders characterized by impulsivity such as proclivity for initial substance abuse as well as the compulsive aspects of dependence. Though we describe common variants and similar tasks, we pay particular attention to discrimination reversal learning, its supporting neural circuitry, neuropharmacology and genetic determinants. We also review the utility of this task in measuring impulsivity and compulsivity in addictions. We restrict our review to instrumental, reward-related reversal learning studies as they are most germane to addiction. The research reviewed here suggests that discrimination reversal learning may be used as a diagnostic tool for investigating the neural mechanisms that mediate impulsive and compulsive aspects of pathological reward-seeking and -taking behaviors. Two interrelated mechanisms are posited for the neuroadaptations in addiction that often translate to poor reversal learning: frontocorticostriatal circuitry dysregulation and poor dopamine (D2 receptor) modulation of this circuitry. These data suggest new approaches to targeting inhibitory control mechanisms in addictions.

Trichotomous goals of elementary school students learning English as a foreign language: a structural equation model.

PubMed

He, Tung-Hsien; Chang, Shan-Mao; Chen, Shu-Hui Eileen; Gou, Wen Johnny

2012-02-01

This study applied structural equation modeling (SEM) techniques to define the relations among trichotomous goals (mastery goals, performance-approach goals, and performance-avoidance goals), self-efficacy, use of metacognitive self-regulation strategies, positive belief in seeking help, and help-avoidance behavior. Elementary school students (N = 105), who were learning English as a foreign language, were surveyed using five self-report scales. The structural equation model showed that self-efficacy led to the adoption of mastery goals but discouraged the adoption of performance-approach goals and performance-avoidance goals. Furthermore, mastery goals increased the use of metacognitive self-regulation strategies, whereas performance-approach goals and performance-avoidance goals reduced their use. Mastery goals encouraged positive belief in help-seeking, but performance-avoidance goals decreased such belief. Finally, performance-avoidance goals directly led to help-avoidance behavior, whereas positive belief assumed a critical role in reducing help-avoidance. The established structural equation model illuminated the potential causal relations among these variables for the young learners in this study.

[Beta]-Adrenergic Receptors in the Insular Cortex are Differentially Involved in Aversive vs. Incidental Context Memory Formation

ERIC Educational Resources Information Center

Miranda, Maria Isabel; Sabath, Elizabeth; Nunez-Jaramillo, Luis; Puron-Sierra, Liliana

2011-01-01

The goal of this research was to determine the effects of [beta]-adrenergic antagonism in the IC before or after inhibitory avoidance (IA) training or context pre-exposure in a latent inhibition protocol. Pretraining intra-IC infusion of the [beta]-adrenergic antagonist propranolol disrupted subsequent IA retention and impaired latent inhibition…

Catching Fish and Avoiding Sharks: Investigating Factors That Influence Developmentally Appropriate Measurement of Preschoolers' Inhibitory Control

ERIC Educational Resources Information Center

Howard, Steven J.; Okely, Anthony D.

2015-01-01

Although researchers agree that the first 5 years of life are critical for children's developing executive functions (EFs), further advances are hindered by a lack of consensus on the design and selection of developmentally appropriate EF tasks for young children. Given this debate, well-established adult measures of EF routinely have been adapted…

Neural and behavioral mechanisms of proactive and reactive inhibition

PubMed Central

Meyer, Heidi C.

2016-01-01

Response inhibition is an important component of adaptive behavior. Substantial prior research has focused on reactive inhibition, which refers to the cessation of a motor response that is already in progress. More recently, a growing number of studies have begun to examine mechanisms underlying proactive inhibition, whereby preparatory processes result in a response being withheld before it is initiated. It has become apparent that proactive inhibition is an essential component of the overall ability to regulate behavior and has implications for the success of reactive inhibition. Moreover, successful inhibition relies on learning the meaning of specific environmental cues that signal when a behavioral response should be withheld. Proactive inhibitory control is mediated by stopping goals, which reflect the desired outcome of inhibition and include information about how and when inhibition should be implemented. However, little is known about the circuits and cellular processes that encode and represent features in the environment that indicate the necessity for proactive inhibition or how these representations are implemented in response inhibition. In this article, we will review the brain circuits and systems involved in implementing inhibitory control through both reactive and proactive mechanisms. We also comment on possible cellular mechanisms that may contribute to inhibitory control processes, noting that substantial further research is necessary in this regard. Furthermore, we will outline a number of ways in which the temporal dynamics underlying the generation of the proactive inhibitory signal may be particularly important for parsing out the neurobiological correlates that contribute to the learning processes underlying various aspects of inhibitory control. PMID:27634142

Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc protein in the hippocampus.

PubMed

McIntyre, Christa K; Miyashita, Teiko; Setlow, Barry; Marjon, Kristopher D; Steward, Oswald; Guzowski, John F; McGaugh, James L

2005-07-26

Activation of beta-adrenoceptors in the basolateral complex of the amygdala (BLA) modulates memory storage processes and long-term potentiation in downstream targets of BLA efferents, including the hippocampus. Here, we show that this activation also increases hippocampal levels of activity-regulated cytoskeletal protein (Arc), an immediate-early gene (also termed Arg 3.1) implicated in hippocampal synaptic plasticity and memory consolidation processes. Infusions of the beta-adrenoreceptor agonist, clenbuterol, into the BLA immediately after training on an inhibitory avoidance task enhanced memory tested 48 h later. The same dose of clenbuterol significantly increased Arc protein levels in the dorsal hippocampus. Additionally, posttraining intra-BLA infusions of a memory-impairing dose of lidocaine significantly reduced Arc protein levels in the dorsal hippocampus. Increases in Arc protein levels were not accompanied by increases in Arc mRNA, suggesting that amygdala modulation of Arc protein and synaptic plasticity in efferent brain regions occurs at a posttranscriptional level. Finally, infusions of Arc antisense oligodeoxynucleotides into the dorsal hippocampus impaired performance of an inhibitory avoidance task, indicating that the changes in Arc protein expression are related to the observed changes in memory performance.

Memory-influencing intra-basolateral amygdala drug infusions modulate expression of Arc protein in the hippocampus

PubMed Central

McIntyre, Christa K.; Miyashita, Teiko; Setlow, Barry; Marjon, Kristopher D.; Steward, Oswald; Guzowski, John F.; McGaugh, James L.

2005-01-01

Activation of β-adrenoceptors in the basolateral complex of the amygdala (BLA) modulates memory storage processes and long-term potentiation in downstream targets of BLA efferents, including the hippocampus. Here, we show that this activation also increases hippocampal levels of activity-regulated cytoskeletal protein (Arc), an immediate-early gene (also termed Arg 3.1) implicated in hippocampal synaptic plasticity and memory consolidation processes. Infusions of the β-adrenoreceptor agonist, clenbuterol, into the BLA immediately after training on an inhibitory avoidance task enhanced memory tested 48 h later. The same dose of clenbuterol significantly increased Arc protein levels in the dorsal hippocampus. Additionally, posttraining intra-BLA infusions of a memory-impairing dose of lidocaine significantly reduced Arc protein levels in the dorsal hippocampus. Increases in Arc protein levels were not accompanied by increases in Arc mRNA, suggesting that amygdala modulation of Arc protein and synaptic plasticity in efferent brain regions occurs at a posttranscriptional level. Finally, infusions of Arc antisense oligodeoxynucleotides into the dorsal hippocampus impaired performance of an inhibitory avoidance task, indicating that the changes in Arc protein expression are related to the observed changes in memory performance. PMID:16020527

The birth, death and resurrection of avoidance: a reconceptualization of a troubled paradigm.

PubMed

LeDoux, J E; Moscarello, J; Sears, R; Campese, V

2017-01-01

Research on avoidance conditioning began in the late 1930s as a way to use laboratory experiments to better understand uncontrollable fear and anxiety. Avoidance was initially conceived of as a two-factor learning process in which fear is first acquired through Pavlovian aversive conditioning (so-called fear conditioning), and then behaviors that reduce the fear aroused by the Pavlovian conditioned stimulus are reinforced through instrumental conditioning. Over the years, criticisms of both the avoidance paradigm and the two-factor fear theory arose. By the mid-1980s, avoidance had fallen out of favor as an experimental model relevant to fear and anxiety. However, recent progress in understanding the neural basis of Pavlovian conditioning has stimulated a new wave of research on avoidance. This new work has fostered new insights into contributions of not only Pavlovian and instrumental learning but also habit learning, to avoidance, and has suggested that the reinforcing event underlying the instrumental phase should be conceived in terms of cellular and molecular events in specific circuits rather than in terms of vague notions of fear reduction. In our approach, defensive reactions (freezing), actions (avoidance) and habits (habitual avoidance) are viewed as being controlled by unique circuits that operate nonconsciously in the control of behavior, and that are distinct from the circuits that give rise to conscious feelings of fear and anxiety. These refinements, we suggest, overcome older criticisms, justifying the value of the new wave of research on avoidance, and offering a fresh perspective on the clinical implications of this work.

The birth, death and resurrection of avoidance: a reconceptualization of a troubled paradigm

PubMed Central

LeDoux, J E; Moscarello, J; Sears, R; Campese, V

2017-01-01

Research on avoidance conditioning began in the late 1930s as a way to use laboratory experiments to better understand uncontrollable fear and anxiety. Avoidance was initially conceived of as a two-factor learning process in which fear is first acquired through Pavlovian aversive conditioning (so-called fear conditioning), and then behaviors that reduce the fear aroused by the Pavlovian conditioned stimulus are reinforced through instrumental conditioning. Over the years, criticisms of both the avoidance paradigm and the two-factor fear theory arose. By the mid-1980s, avoidance had fallen out of favor as an experimental model relevant to fear and anxiety. However, recent progress in understanding the neural basis of Pavlovian conditioning has stimulated a new wave of research on avoidance. This new work has fostered new insights into contributions of not only Pavlovian and instrumental learning but also habit learning, to avoidance, and has suggested that the reinforcing event underlying the instrumental phase should be conceived in terms of cellular and molecular events in specific circuits rather than in terms of vague notions of fear reduction. In our approach, defensive reactions (freezing), actions (avoidance) and habits (habitual avoidance) are viewed as being controlled by unique circuits that operate nonconsciously in the control of behavior, and that are distinct from the circuits that give rise to conscious feelings of fear and anxiety. These refinements, we suggest, overcome older criticisms, justifying the value of the new wave of research on avoidance, and offering a fresh perspective on the clinical implications of this work. PMID:27752080

Psychological and Neural Mechanisms of Experimental Extinction: A Selective Review

PubMed Central

Delamater, Andrew R.; Westbrook, R. Frederick

2013-01-01

The present review examines key psychological concepts in the study of experimental extinction and implications these have for an understanding of the underlying neurobiology of extinction learning. We suggest that many of the signature characteristics of extinction learning (spontaneous recovery, renewal, reinstatement, rapid reacquisition) can be accommodated by the standard associative learning theory assumption that extinction results in partial erasure of the original learning together with new inhibitory learning. Moreover, we consider recent behavioral and neural evidence that supports the partial erasure view of extinction, but also note shortcomings in our understanding of extinction circuits as these relate to the negative prediction error concept. Recent work suggests that common prediction error and stimulus-specific prediction error terms both may be required to explain neural plasticity both in acquisition and extinction learning. In addition, we suggest that many issues in the content of extinction learning have not been fully addressed in current research, but that neurobiological approaches should be especially helpful in addressing such issues. These include questions about the nature of extinction learning (excitatory CS-No US, inhibitory CS-US learning, occasion setting processes), especially as this relates to studies of the micro-circuitry of extinction, as well as its representational content (sensory, motivational, response). An additional understudied problem in extinction research is the role played by attention processes and their underlying neural networks, although some research and theory converge on the idea that extinction is accompanied by attention decrements (i.e., habituation-like processes). PMID:24104049

Psychological and neural mechanisms of experimental extinction: a selective review.

PubMed

Delamater, Andrew R; Westbrook, R Frederick

2014-02-01

The present review examines key psychological concepts in the study of experimental extinction and implications these have for an understanding of the underlying neurobiology of extinction learning. We suggest that many of the signature characteristics of extinction learning (spontaneous recovery, renewal, reinstatement, rapid reacquisition) can be accommodated by the standard associative learning theory assumption that extinction results in partial erasure of the original learning together with new inhibitory learning. Moreover, we consider recent behavioral and neural evidence that supports the partial erasure view of extinction, but also note shortcomings in our understanding of extinction circuits as these relate to the negative prediction error concept. Recent work suggests that common prediction error and stimulus-specific prediction error terms both may be required to explain neural plasticity both in acquisition and extinction learning. In addition, we suggest that many issues in the content of extinction learning have not been fully addressed in current research, but that neurobiological approaches should be especially helpful in addressing such issues. These include questions about the nature of extinction learning (excitatory CS-No US, inhibitory CS-US learning, occasion setting processes), especially as this relates to studies of the micro-circuitry of extinction, as well as its representational content (sensory, motivational, response). An additional understudied problem in extinction research is the role played by attention processes and their underlying neural networks, although some research and theory converge on the idea that extinction is accompanied by attention decrements (i.e., habituation-like processes). Copyright © 2013 Elsevier Inc. All rights reserved.

Design, synthesis and structure-activity relationships of dual inhibitors of acetylcholinesterase and serotonin transporter as potential agents for Alzheimer's disease.

PubMed

Toda, Narihiro; Tago, Keiko; Marumoto, Shinji; Takami, Kazuko; Ori, Mayuko; Yamada, Naho; Koyama, Kazuo; Naruto, Shunji; Abe, Kazumi; Yamazaki, Reina; Hara, Takao; Aoyagi, Atsushi; Abe, Yasuyuki; Kaneko, Tsugio; Kogen, Hiroshi

2003-05-01

We have designed and synthesized a dual inhibitor of acetylcholinesterase (AChE) and serotonin transporter (SERT) as a novel class of treatment drugs for Alzheimer's disease on the basis of a hypothetical model of the AChE active site. Dual inhibitions of AChE and SERT would bring about greater therapeutic effects than AChE inhibition alone and avoid adverse peripheral effects caused by excessive AChE inhibition. Compound (S)-6j exhibited potent inhibitory activities against AChE (IC(50)=101 nM) and SERT (IC(50)=42 nM). Furthermore, (S)-6j showed inhibitory activities of both AChE and SERT in mice brain following oral administration.

A subliminal inhibitory mechanism for the negative compatibility effect: a continuous versus threshold mechanism.

PubMed

Liu, Peng; Chen, Xuhai; Dai, Dongyang; Wang, Yongchun; Wang, Yonghui

2014-07-01

The current study investigated the mechanism underlying subliminal inhibition using the negative compatibility effect (NCE) paradigm. We hypothesized that a decrease in prime activation affects the subsequent inhibitory process, delaying onset of inhibition and reducing its strength. Two experiments tested this hypothesis using arrow stimuli as primes and targets. Two different irrelevant masks (i.e., a mask sharing no prime features) were presented in succession in each trial to not only ensure that primes were processed subliminally, but also avoid feature updating between primes and masks. Prime/target compatibility and prime background density were manipulated in Experiment 1. Results showed that under subliminal inhibitory condition, the NCE disappears when the density increases (i.e., pixel density in the prime's background of 25 %) in Experiment 1. However, when we fixed the prime's background at the density of 25 % and manipulated prime/target compatibility as well as inter-stimuli-interval (ISI) between mask and target in Experiment 2, behavioral results showed marginally significant NCEs in the 150-ms ISI condition. Electrophysiological evidence showed the lateralized readiness potential for compatible trials was significantly more positive than that for incompatible trials during the two consecutive time windows (i.e., 400-450 and 450-500 ms) in the 150-ms ISI condition. In addition, the NCE size was significant smaller in Experiment 2 than in Experiment 1. All of the results support predictions of the continuous subliminal inhibitory mechanism hypothesis which posits that decreases in prime activation strength lead to delay in inhibitory onset and decline in inhibitory strength.

Criterion learning in rule-based categorization: Simulation of neural mechanism and new data

PubMed Central

Helie, Sebastien; Ell, Shawn W.; Filoteo, J. Vincent; Maddox, W. Todd

2015-01-01

In perceptual categorization, rule selection consists of selecting one or several stimulus-dimensions to be used to categorize the stimuli (e.g, categorize lines according to their length). Once a rule has been selected, criterion learning consists of defining how stimuli will be grouped using the selected dimension(s) (e.g., if the selected rule is line length, define ‘long’ and ‘short’). Very little is known about the neuroscience of criterion learning, and most existing computational models do not provide a biological mechanism for this process. In this article, we introduce a new model of rule learning called Heterosynaptic Inhibitory Criterion Learning (HICL). HICL includes a biologically-based explanation of criterion learning, and we use new category-learning data to test key aspects of the model. In HICL, rule selective cells in prefrontal cortex modulate stimulus-response associations using pre-synaptic inhibition. Criterion learning is implemented by a new type of heterosynaptic error-driven Hebbian learning at inhibitory synapses that uses feedback to drive cell activation above/below thresholds representing ionic gating mechanisms. The model is used to account for new human categorization data from two experiments showing that: (1) changing rule criterion on a given dimension is easier if irrelevant dimensions are also changing (Experiment 1), and (2) showing that changing the relevant rule dimension and learning a new criterion is more difficult, but also facilitated by a change in the irrelevant dimension (Experiment 2). We conclude with a discussion of some of HICL’s implications for future research on rule learning. PMID:25682349

Criterion learning in rule-based categorization: simulation of neural mechanism and new data.

PubMed

Helie, Sebastien; Ell, Shawn W; Filoteo, J Vincent; Maddox, W Todd

2015-04-01

In perceptual categorization, rule selection consists of selecting one or several stimulus-dimensions to be used to categorize the stimuli (e.g., categorize lines according to their length). Once a rule has been selected, criterion learning consists of defining how stimuli will be grouped using the selected dimension(s) (e.g., if the selected rule is line length, define 'long' and 'short'). Very little is known about the neuroscience of criterion learning, and most existing computational models do not provide a biological mechanism for this process. In this article, we introduce a new model of rule learning called Heterosynaptic Inhibitory Criterion Learning (HICL). HICL includes a biologically-based explanation of criterion learning, and we use new category-learning data to test key aspects of the model. In HICL, rule selective cells in prefrontal cortex modulate stimulus-response associations using pre-synaptic inhibition. Criterion learning is implemented by a new type of heterosynaptic error-driven Hebbian learning at inhibitory synapses that uses feedback to drive cell activation above/below thresholds representing ionic gating mechanisms. The model is used to account for new human categorization data from two experiments showing that: (1) changing rule criterion on a given dimension is easier if irrelevant dimensions are also changing (Experiment 1), and (2) showing that changing the relevant rule dimension and learning a new criterion is more difficult, but also facilitated by a change in the irrelevant dimension (Experiment 2). We conclude with a discussion of some of HICL's implications for future research on rule learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Evolutionary Responses to Invasion: Cane Toad Sympatric Fish Show Enhanced Avoidance Learning

PubMed Central

Caller, Georgina; Brown, Culum

2013-01-01

The introduced cane toad (Bufo marinus) poses a major threat to biodiversity due to its lifelong toxicity. Several terrestrial native Australian vertebrates are adapting to the cane toad’s presence and lab trials have demonstrated that repeated exposure to B. marinus can result in learnt avoidance behaviour. Here we investigated whether aversion learning is occurring in aquatic ecosystems by comparing cane toad naïve and sympatric populations of crimson spotted rainbow fish (Melanotaenia duboulayi). The first experiment indicated that fish from the sympatric population had pre-existing aversion to attacking cane toad tadpoles but also showed reduced attacks on native tadpoles. The second experiment revealed that fish from both naïve and sympatric populations learned to avoid cane toad tadpoles following repeated, direct exposure. Allopatric fish also developed a general aversion to tadpoles. The aversion learning abilities of both groups was examined using an experiment involving novel distasteful prey items. While both populations developed a general avoidance of edible pellets in the presence of distasteful pellets, only the sympatric population significantly reduced the number of attacks on the novel distasteful prey item. These results indicate that experience with toxic prey items over multiple generations can enhance avoidance leaning capabilities via natural selection. PMID:23372788

Dopamine and Octopamine Influence Avoidance Learning of Honey Bees in a Place Preference Assay

PubMed Central

Agarwal, Maitreyi; Giannoni Guzmán, Manuel; Morales-Matos, Carla; Del Valle Díaz, Rafael Alejandro; Abramson, Charles I.; Giray, Tugrul

2011-01-01

Biogenic amines are widely characterized in pathways evaluating reward and punishment, resulting in appropriate aversive or appetitive responses of vertebrates and invertebrates. We utilized the honey bee model and a newly developed spatial avoidance conditioning assay to probe effects of biogenic amines octopamine (OA) and dopamine (DA) on avoidance learning. In this new protocol non-harnessed bees associate a spatial color cue with mild electric shock punishment. After a number of experiences with color and shock the bees no longer enter the compartment associated with punishment. Intrinsic aspects of avoidance conditioning are associated with natural behavior of bees such as punishment (lack of food, explosive pollination mechanisms, danger of predation, heat, etc.) and their association to floral traits or other spatial cues during foraging. The results show that DA reduces the punishment received whereas octopamine OA increases the punishment received. These effects are dose-dependent and specific to the acquisition phase of training. The effects during acquisition are specific as shown in experiments using the antagonists Pimozide and Mianserin for DA and OA receptors, respectively. This study demonstrates the integrative role of biogenic amines in aversive learning in the honey bee as modeled in a novel non-appetitive avoidance learning assay. PMID:21980435

Learn to Avoid or Overcome Leadership Obstacles

ERIC Educational Resources Information Center

D'Auria, John

2015-01-01

Leadership is increasingly recognized as an important factor in moving schools forward, yet we have been relatively random in how we prepare and support them. Four obstacles often block or diminish their effectiveness. Avoiding or overcoming each of these requires an underlying set of skills and knowledge that we believe can be learned and…

Leaders Behaving Badly: Using Power to Generate Undiscussables in Action Learning Sets

ERIC Educational Resources Information Center

Donovan, Paul Jeffrey

2014-01-01

"Undiscussables" are topics associated with threat or embarrassment that are avoided by groups, where that avoidance is also not discussed. Their deleterious effect on executive groups has been a point of discussion for several decades. More recently critical action learning (AL) has brought a welcome focus to power relations within AL…

Behavioral semantics of learning and crossmodal processing in auditory cortex: the semantic processor concept.

PubMed

Scheich, Henning; Brechmann, André; Brosch, Michael; Budinger, Eike; Ohl, Frank W; Selezneva, Elena; Stark, Holger; Tischmeyer, Wolfgang; Wetzel, Wolfram

2011-01-01

Two phenomena of auditory cortex activity have recently attracted attention, namely that the primary field can show different types of learning-related changes of sound representation and that during learning even this early auditory cortex is under strong multimodal influence. Based on neuronal recordings in animal auditory cortex during instrumental tasks, in this review we put forward the hypothesis that these two phenomena serve to derive the task-specific meaning of sounds by associative learning. To understand the implications of this tenet, it is helpful to realize how a behavioral meaning is usually derived for novel environmental sounds. For this purpose, associations with other sensory, e.g. visual, information are mandatory to develop a connection between a sound and its behaviorally relevant cause and/or the context of sound occurrence. This makes it plausible that in instrumental tasks various non-auditory sensory and procedural contingencies of sound generation become co-represented by neuronal firing in auditory cortex. Information related to reward or to avoidance of discomfort during task learning, that is essentially non-auditory, is also co-represented. The reinforcement influence points to the dopaminergic internal reward system, the local role of which for memory consolidation in auditory cortex is well-established. Thus, during a trial of task performance, the neuronal responses to the sounds are embedded in a sequence of representations of such non-auditory information. The embedded auditory responses show task-related modulations of auditory responses falling into types that correspond to three basic logical classifications that may be performed with a perceptual item, i.e. from simple detection to discrimination, and categorization. This hierarchy of classifications determine the semantic "same-different" relationships among sounds. Different cognitive classifications appear to be a consequence of learning task and lead to a recruitment of different excitatory and inhibitory mechanisms and to distinct spatiotemporal metrics of map activation to represent a sound. The described non-auditory firing and modulations of auditory responses suggest that auditory cortex, by collecting all necessary information, functions as a "semantic processor" deducing the task-specific meaning of sounds by learning. © 2010. Published by Elsevier B.V.

A bio-inspired kinematic controller for obstacle avoidance during reaching tasks with real robots.

PubMed

Srinivasa, Narayan; Bhattacharyya, Rajan; Sundareswara, Rashmi; Lee, Craig; Grossberg, Stephen

2012-11-01

This paper describes a redundant robot arm that is capable of learning to reach for targets in space in a self-organized fashion while avoiding obstacles. Self-generated movement commands that activate correlated visual, spatial and motor information are used to learn forward and inverse kinematic control models while moving in obstacle-free space using the Direction-to-Rotation Transform (DIRECT). Unlike prior DIRECT models, the learning process in this work was realized using an online Fuzzy ARTMAP learning algorithm. The DIRECT-based kinematic controller is fault tolerant and can handle a wide range of perturbations such as joint locking and the use of tools despite not having experienced them during learning. The DIRECT model was extended based on a novel reactive obstacle avoidance direction (DIRECT-ROAD) model to enable redundant robots to avoid obstacles in environments with simple obstacle configurations. However, certain configurations of obstacles in the environment prevented the robot from reaching the target with purely reactive obstacle avoidance. To address this complexity, a self-organized process of mental rehearsals of movements was modeled, inspired by human and animal experiments on reaching, to generate plans for movement execution using DIRECT-ROAD in complex environments. These mental rehearsals or plans are self-generated by using the Fuzzy ARTMAP algorithm to retrieve multiple solutions for reaching each target while accounting for all the obstacles in its environment. The key aspects of the proposed novel controller were illustrated first using simple examples. Experiments were then performed on real robot platforms to demonstrate successful obstacle avoidance during reaching tasks in real-world environments. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Classroom Environment and Students' Reports of Avoidance Strategies in Mathematics: A Multimethod Study.

ERIC Educational Resources Information Center

Turner, Julianne C.; Midgley, Carol; Meyer, Debra K.; Gheen, Margaret; Anderman, Eric M.; Kang, Yongjin; Patrick, Helen

2002-01-01

The relation between learning environment (perceptions of classroom goal structure and teachers' instructional discourse) and students' reported use of avoidance strategies (self-handicapping, avoidance of help seeking) and preference to avoid novelty in mathematics was examined. High incidence of motivational support was uniquely characteristic…

The intrauterine environment affects learning ability of Tokai high avoider rat offspring derived using cryopreservation and embryo transfer-mediated reproduction.

PubMed

Endo, Hitoshi; Eto, Tomoo; Yoshii, Fumihito; Owada, Satoshi; Watanabe, Tetsu; Tatemichi, Masayuki; Kimura, Minoru

2017-07-22

Embryo transfer (ET) to recipient female animals is a useful technique in biological and experimental animal studies. While cryopreservation of two-cell stage rat embryos and ET to recipient rats are currently well-defined, it is unknown whether these artificial reproductive techniques and maternal factors affect offspring phenotype, particularly higher brain functions. Therefore, we assessed the effects of cryopreservation, ET, and maternal care on learning behaviour of the offspring, using Tokai high avoider (THA) rats that have a high learning ability phenotype. We found that the high learning ability of THA rat offspring was not replicated following ET to surrogate Wistar rats with a low-avoidance phenotype. Additionally, the characteristic phenotype of offspring obtained through mating of ET-derived rats was similar to that of THA rats. A postnatal cross-fostering investigation with the offspring of Wistar and THA rats showed that maternal behaviour, including postnatal care and lactation traits, did not differ between the dams of low-avoidance Wistar rats and THA rats; therefore, learning behaviour was retained in both Wistar and THA rat offspring. We conclude that the offspring phenotype, although unchanged, has an imperceptible effect on the learning ability of ET-derived THA rats through the intrauterine environment of the recipient. Copyright © 2017 Elsevier Inc. All rights reserved.

Food Avoidance Learning in Squirrel Monkeys and Common Marmosets

PubMed Central

Laska, Matthias; Metzker, Karin

1998-01-01

Using a conditioned food avoidance learning paradigm, six squirrel monkeys (Saimiri sciureus) and six common marmosets (Callithrix jacchus) were tested for their ability to (1) reliably form associations between visual or olfactory cues of a potential food and its palatability and (2) remember such associations over prolonged periods of time. We found (1) that at the group level both species showed one-trial learning with the visual cues color and shape, whereas only the marmosets were able to do so with the olfactory cue, (2) that all individuals from both species learned to reliably avoid the unpalatable food items within 10 trials, (3) a tendency in both species for quicker acquisition of the association with the visual cues compared with the olfactory cue, (4) a tendency for quicker acquisition and higher reliability of the aversion by the marmosets compared with the squirrel monkeys, and (5) that all individuals from both species were able to reliably remember the significance of the visual cues, color and shape, even after 4 months, whereas only the marmosets showed retention of the significance of the olfactory cues for up to 4 weeks. Furthermore, the results suggest that in both species tested, illness is not a necessary prerequisite for food avoidance learning but that the presumably innate rejection responses toward highly concentrated but nontoxic bitter and sour tastants are sufficient to induce robust learning and retention. PMID:10454364

Learning by stimulation avoidance: A principle to control spiking neural networks dynamics.

PubMed

Sinapayen, Lana; Masumori, Atsushi; Ikegami, Takashi

2017-01-01

Learning based on networks of real neurons, and learning based on biologically inspired models of neural networks, have yet to find general learning rules leading to widespread applications. In this paper, we argue for the existence of a principle allowing to steer the dynamics of a biologically inspired neural network. Using carefully timed external stimulation, the network can be driven towards a desired dynamical state. We term this principle "Learning by Stimulation Avoidance" (LSA). We demonstrate through simulation that the minimal sufficient conditions leading to LSA in artificial networks are also sufficient to reproduce learning results similar to those obtained in biological neurons by Shahaf and Marom, and in addition explains synaptic pruning. We examined the underlying mechanism by simulating a small network of 3 neurons, then scaled it up to a hundred neurons. We show that LSA has a higher explanatory power than existing hypotheses about the response of biological neural networks to external simulation, and can be used as a learning rule for an embodied application: learning of wall avoidance by a simulated robot. In other works, reinforcement learning with spiking networks can be obtained through global reward signals akin simulating the dopamine system; we believe that this is the first project demonstrating sensory-motor learning with random spiking networks through Hebbian learning relying on environmental conditions without a separate reward system.

Different types of avoidance behavior in rats produce dissociable post-training changes in sleep.

PubMed

Fogel, Stuart M; Smith, Carlyle T; Higginson, Caitlin D; Beninger, Richard J

2011-02-01

Avoidance learning affects post-training sleep, and post-training sleep deprivation impairs performance. However, not all rats learn to make avoidance responses, and some rats fail to escape; a definitive behavior of learned helplessness, a model of depression. This study investigated the changes in sleep associated with different behaviors adopted following avoidance training. Rats (n=53) were trained for 100 trials over 2 days (50 trials/day), followed by 23-24 h of post-training polysomnography, then re-tested (25 trials). At re-test, rats were categorized into: 1) Active Avoiders (AA; n=22), 2), Non-learning (NL; n=21), or 3) Escape Failures (EF; n=10). AA rats increased avoidances over days, whereas the NL and EF groups did not. EF rats increased escape failures over days, whereas the NL and AA rats did not. EF rats had increased rapid eye movement (REM) sleep in the first 4h on training day 1. They also had increased non-REM sleep in the first 4h and last 4h on both training days. AA rats had increased REM sleep 13-20 h post-training. The type of behavioral strategy adopted throughout training is associated with a unique pattern of changes in post-training sleep. Training-dependent changes in post-acquisition sleep may reflect distinct processes involved in the consolidation of these different memory traces. Copyright © 2010 Elsevier Inc. All rights reserved.

Examining the Role of the Human Hippocampus in Approach-Avoidance Decision Making Using a Novel Conflict Paradigm and Multivariate Functional Magnetic Resonance Imaging.

PubMed

O'Neil, Edward B; Newsome, Rachel N; Li, Iris H N; Thavabalasingam, Sathesan; Ito, Rutsuko; Lee, Andy C H

2015-11-11

Rodent models of anxiety have implicated the ventral hippocampus in approach-avoidance conflict processing. Few studies have, however, examined whether the human hippocampus plays a similar role. We developed a novel decision-making paradigm to examine neural activity when participants made approach/avoidance decisions under conditions of high or absent approach-avoidance conflict. Critically, our task required participants to learn the associated reward/punishment values of previously neutral stimuli and controlled for mnemonic and spatial processing demands, both important issues given approach-avoidance behavior in humans is less tied to predation and foraging compared to rodents. Participants played a points-based game where they first attempted to maximize their score by determining which of a series of previously neutral image pairs should be approached or avoided. During functional magnetic resonance imaging, participants were then presented with novel pairings of these images. These pairings consisted of images of congruent or opposing learned valences, the latter creating conditions of high approach-avoidance conflict. A data-driven partial least squares multivariate analysis revealed two reliable patterns of activity, each revealing differential activity in the anterior hippocampus, the homolog of the rodent ventral hippocampus. The first was associated with greater hippocampal involvement during trials with high as opposed to no approach-avoidance conflict, regardless of approach or avoidance behavior. The second pattern encompassed greater hippocampal activity in a more anterior aspect during approach compared to avoid responses, for conflict and no-conflict conditions. Multivoxel pattern classification analyses yielded converging findings, underlining a role of the anterior hippocampus in approach-avoidance conflict decision making. Approach-avoidance conflict has been linked to anxiety and occurs when a stimulus or situation is associated with reward and punishment. Although rodent work has implicated the hippocampus in approach-avoidance conflict processing, there is limited data on whether this role applies to learned, as opposed to innate, incentive values, and whether the human hippocampus plays a similar role. Using functional neuroimaging with a novel decision-making task that controlled for perceptual and mnemonic processing, we found that the human hippocampus was significantly active when approach-avoidance conflict was present for stimuli with learned incentive values. These findings demonstrate a role for the human hippocampus in approach-avoidance decision making that cannot be explained easily by hippocampal-dependent long-term memory or spatial cognition. Copyright © 2015 the authors 0270-6474/15/3515040-11$15.00/0.

Neural Mechanisms for Adaptive Learned Avoidance of Mental Effort.

PubMed

Mitsuto Nagase, Asako; Onoda, Keiichi; Clifford Foo, Jerome; Haji, Tomoki; Akaishi, Rei; Yamaguchi, Shuhei; Sakai, Katsuyuki; Morita, Kenji

2018-02-05

Humans tend to avoid mental effort. Previous studies have demonstrated this tendency using various demand-selection tasks; participants generally avoid options associated with higher cognitive demand. However, it remains unclear whether humans avoid mental effort adaptively in uncertain and non-stationary environments, and if so, what neural mechanisms underlie this learned avoidance and whether they remain the same irrespective of cognitive-demand types. We addressed these issues by developing novel demand-selection tasks where associations between choice options and cognitive-demand levels change over time, with two variations using mental arithmetic and spatial reasoning problems (29:4 and 18:2 males:females). Most participants showed avoidance, and their choices depended on the demand experienced on multiple preceding trials. We assumed that participants updated the expected cost of mental effort through experience, and fitted their choices by reinforcement learning models, comparing several possibilities. Model-based fMRI analyses revealed that activity in the dorsomedial and lateral frontal cortices was positively correlated with the trial-by-trial expected cost for the chosen option commonly across the different types of cognitive demand, and also revealed a trend of negative correlation in the ventromedial prefrontal cortex. We further identified correlates of cost-prediction-error at time of problem-presentation or answering the problem, the latter of which partially overlapped with or were proximal to the correlates of expected cost at time of choice-cue in the dorsomedial frontal cortex. These results suggest that humans adaptively learn to avoid mental effort, having neural mechanisms to represent expected cost and cost-prediction-error, and the same mechanisms operate for various types of cognitive demand. SIGNIFICANCE STATEMENT In daily life, humans encounter various cognitive demands, and tend to avoid high-demand options. However, it remains unclear whether humans avoid mental effort adaptively under dynamically changing environments, and if so, what are the underlying neural mechanisms and whether they operate irrespective of cognitive-demand types. To address these issues, we developed novel tasks, where participants could learn to avoid high-demand options under uncertain and non-stationary environments. Through model-based fMRI analyses, we found regions whose activity was correlated with the expected mental effort cost, or cost-prediction-error, regardless of demand-type, with overlap or adjacence in the dorsomedial frontal cortex. This finding contributes to clarifying the mechanisms for cognitive-demand avoidance, and provides empirical building blocks for the emerging computational theory of mental effort. Copyright © 2018 the authors.

Dizocilpine (MK-801) impairs learning in the active place avoidance task but has no effect on the performance during task/context alternation.

PubMed

Vojtechova, Iveta; Petrasek, Tomas; Hatalova, Hana; Pistikova, Adela; Vales, Karel; Stuchlik, Ales

2016-05-15

The prevention of engram interference, pattern separation, flexibility, cognitive coordination and spatial navigation are usually studied separately at the behavioral level. Impairment in executive functions is often observed in patients suffering from schizophrenia. We have designed a protocol for assessing these functions all together as behavioral separation. This protocol is based on alternated or sequential training in two tasks testing different hippocampal functions (the Morris water maze and active place avoidance), and alternated or sequential training in two similar environments of the active place avoidance task. In Experiment 1, we tested, in adult rats, whether the performance in two different spatial tasks was affected by their order in sequential learning, or by their day-to-day alternation. In Experiment 2, rats learned to solve the active place avoidance task in two environments either alternately or sequentially. We found that rats are able to acquire both tasks and to discriminate both similar contexts without obvious problems regardless of the order or the alternation. We used two groups of rats, controls and a rat model of psychosis induced by a subchronic intraperitoneal application of 0.08mg/kg of dizocilpine (MK-801), a non-competitive antagonist of NMDA receptors. Dizocilpine had no selective effect on parallel/sequential learning of tasks/contexts. However, it caused hyperlocomotion and a significant deficit in learning in the active place avoidance task regardless of the task alternation. Cognitive coordination tested by this task is probably more sensitive to dizocilpine than spatial orientation because no hyperactivity or learning impairment was observed in the Morris water maze. Copyright © 2016 Elsevier B.V. All rights reserved.

Docosahexaenoic acid provides protection from impairment of learning ability in Alzheimer's disease model rats.

PubMed

Hashimoto, Michio; Hossain, Shahdat; Shimada, Toshio; Sugioka, Kozo; Yamasaki, Hiroshi; Fujii, Yoshimi; Ishibashi, Yutaka; Oka, Jun-Ichiro; Shido, Osamu

2002-06-01

Docosahexaenoic acid (C22:6, n-3), a major n-3 fatty acid of the brain, has been implicated in restoration and enhancement of memory-related functions. Because Alzheimer's disease impairs memory, and infusion of amyloid-beta (Abeta) peptide (1-40) into the rat cerebral ventricle reduces learning ability, we investigated the effect of dietary pre-administration of docosahexaenoic acid on avoidance learning ability in Abeta peptide-produced Alzheimer's disease model rats. After a mini-osmotic pump filled with Abeta peptide or vehicle was implanted in docosahexaenoic acid-fed and control rats, they were subjected to an active avoidance task in a shuttle avoidance system apparatus. Pre-administration of docosahexaenoic acid had a profoundly beneficial effect on the decline in avoidance learning ability in the Alzheimer's disease model rats, associated with an increase in the cortico-hippocampal docosahexaenoic acid/arachidonic acid molar ratio, and a decrease in neuronal apoptotic products. Docosahexaenoic acid pre-administration furthermore increased cortico-hippocampal reduced glutathione levels and glutathione reductase activity, and suppressed the increase in lipid peroxide and reactive oxygen species levels in the cerebral cortex and hippocampus of the Alzheimer's disease model rats, suggesting an increase in antioxidative defence. Docosahexaenoic acid is thus a possible prophylactic means for preventing the learning deficiencies of Alzheimer's disease.

Learning by heart-the relationship between resting vagal tone and metacognitive judgments: a pilot study.

PubMed

Meessen, Judith; Sütterlin, Stefan; Gauggel, Siegfried; Forkmann, Thomas

2018-05-23

Metacognitive awareness and resting vagally mediated heart rate variability (HRV) as a physiological trait marker of cognitive inhibitory control capacities are both associated with better well-being and seem to share a common neural basis. Executive functioning which is considered a prerequisite for delivering prospective metacognitive judgments has been found to be correlated with HRV. This pilot study addresses the question, whether metacognitive awareness and resting vagally mediated HRV are positively associated. A sample of 20 healthy participants was analyzed that completed a typical Judgment of Learning task after an electrocardiogram had been recorded. The root-mean-squares of successive differences were used to calculate vagally mediated HRV. Metacognitive awareness was measured by comparing the judgments of learning with the actual memory performance, yielding a deviation score. HRV was found to be positively correlated with metacognitive awareness. Results suggest that metacognitive abilities might relate to physiological trait markers of cognitive inhibitory control capacities. Further experimental studies are needed to investigate causal relations.

Test anxiety and performance-avoidance goals explain gender differences in SAT-V, SAT-M, and overall SAT scores.

PubMed

Hannon, Brenda

2012-11-01

This study uses analysis of co-variance in order to determine which cognitive/learning (working memory, knowledge integration, epistemic belief of learning) or social/personality factors (test anxiety, performance-avoidance goals) might account for gender differences in SAT-V, SAT-M, and overall SAT scores. The results revealed that none of the cognitive/learning factors accounted for gender differences in SAT performance. However, the social/personality factors of test anxiety and performance-avoidance goals each separately accounted for all of the significant gender differences in SAT-V, SAT-M, and overall SAT performance. Furthermore, when the influences of both of these factors were statistically removed simultaneously, all non-significant gender differences reduced further to become trivial by Cohen's (1988) standards. Taken as a whole, these results suggest that gender differences in SAT-V, SAT-M, and overall SAT performance are a consequence of social/learning factors.

Individual Differences in the Severely Retarded Child in Acquisition, Stimulus Generalization, and Extinction in Go-No-Go Discrimination Learning

ERIC Educational Resources Information Center

Evans, P. L. C.; Hogg, J. H.

1975-01-01

This study relates excitatory and inhibitory personality variables of a heterogeneous group of severely retarded children to performance on a discrete trial, successive go-no-go intradimensional discrimination learning problem, which was followed by stimulus generalization tests on a color hue continuum and extinction trials. (GO)

The Contribution of Primary Motor Cortex Is Essential for Probabilistic Implicit Sequence Learning: Evidence from Theta Burst Magnetic Stimulation

ERIC Educational Resources Information Center

Wilkinson, Leonora; Teo, James T.; Obeso, Ignacio; Rothwell, John C.; Jahanshahi, Marjan

2010-01-01

Theta burst transcranial magnetic stimulation (TBS) is considered to produce plastic changes in human motor cortex. Here, we examined the inhibitory and excitatory effects of TBS on implicit sequence learning using a probabilistic serial reaction time paradigm. We investigated the involvement of several cortical regions associated with implicit…

Dealing with Racist Incidents: What Do Beginning Teachers Learn from Schools?

ERIC Educational Resources Information Center

Pearce, Sarah

2014-01-01

This article focuses on how schools respond to racist incidents, and what new teachers learn from their involvement in those processes. It analyses four incidents involving the pupils of four beginning teachers. The article suggests that in each case, schools either partly or wholly avoided addressing the incident, and that this avoidance can be…

Don't look now! Oculomotor avoidance as a conditioned disgust response.

PubMed

Armstrong, Thomas; McClenahan, Laura; Kittle, Jody; Olatunji, Bunmi O

2014-02-01

Pavlovian conditioning paradigms have revealed fear learning tendencies that may be implicated in the etiology and maintenance of anxiety disorders. Given the prominence of disgust in certain anxiety disorders, it may be fruitful to study disgust learning in addition to fear learning. The present study utilized eye tracking to examine the effects of disgust conditioning on attentional bias, a phenomenon that characterizes anxiety disorders. Participants completed either a disgust condition, in which a face (conditioned stimulus; CS+) was paired with videos of individuals vomiting (unconditioned stimulus; US), or a negative condition in which a face was paired with videos of individuals being harmed in motor-vehicle accidents. Eye movements were used to measure attentional biases related to the USs and the CSs. In line with prior research, attentional avoidance was observed for the disgust CS+. However, this effect did not reach significance until after extinction and was linked to self-reported disgust postacquisition, yet decoupled from self-reported disgust postextinction. Attentional avoidance of the CS+ was not found in the negative condition, and postextinction differences in attentional bias for the CS+ between conditions were found to be mediated by differences in attentional bias for the US, as only the disgust US elicited attentional avoidance. Also, individual differences in disgust sensitivity were found to be associated with attentional avoidance of the disgust US, and this effect was mediated by self-reported disgust in response to the US. Further, disgust sensitivity was associated with attentional avoidance of the disgust CS+, and this effect was mediated by attentional avoidance of the disgust US. These findings provide new insight into a complex pattern of relations between disgust, evaluative learning, and attention that may have implications for the etiology and maintenance of certain anxiety disorders. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Anisomycin Infused into the Hippocampus Fails to Block "Reconsolidation" but Impairs Extinction: The Role of Re-Exposure Duration

ERIC Educational Resources Information Center

McGaugh, James L.; Steward, Oswald; Power, Ann E.; Berlau, Daniel J.

2006-01-01

Recent studies have reported new evidence consistent with the hypothesis that reactivating a memory by re-exposure to a training context destabilizes the memory and induces "reconsolidation." In the present experiments, rats' memory for inhibitory avoidance (IA) training was tested 6 h (Test 1), 2 d (Test 2), and 6 d (Test 3) after training. On…

Effect of noopept and afobazole on the development of neurosis of learned helplessness in rats.

PubMed

Uyanaev, A A; Fisenko, V P; Khitrov, N K

2003-08-01

We studied the effects of new psychotropic preparations noopept and afobazole on acquisition of the conditioned active avoidance response and development of neurosis of learned helplessness in rats. Noopept in doses of 0.05-0.10 mg/kg accelerated acquisition of conditioned active avoidance response and reduced the incidence of learned helplessness in rats. Afobazole in a dose of 5 mg/kg produced an opposite effect, which is probably related to high selective anxiolytic activity of this preparation.

Context specificity of inhibitory control in dogs

PubMed Central

MacLean, Evan L.; Hare, Brian A.

2014-01-01

Across three experiments, we explored whether a dog's capacity for inhibitory control is stable or variable across decision-making contexts. In the social task, dogs were first exposed to the reputations of a stingy experimenter that never shared food and a generous experimenter who always shared food. In subsequent test trials, dogs were required to avoid approaching the stingy experimenter when this individual offered (but withheld) a higher-value reward than the generous experimenter did. In the A-not-B task, dogs were required to inhibit searching for food in a previously rewarded location after witnessing the food being moved from this location to a novel hiding place. In the cylinder task, dogs were required to resist approaching visible food directly (because it was behind a transparent barrier), in favor of a detour reaching response. Overall, dogs exhibited inhibitory control in all three tasks. However, individual scores were not correlated between tasks, suggesting that context has a large effect on dogs' behavior. This result mirrors studies of humans, which have highlighted intra-individual variation in inhibitory control as a function of the decision-making context. Lastly, we observed a correlation between a subject's age and performance on the cylinder task, corroborating previous observations of age-related decline in dogs' executive function. PMID:23584618

Effects of various treatments on the chemokinetic behavior of third-stage larvae of Strongyloides ratti on a sodium chloride gradient.

PubMed

Tobata-Kudo, H; Higo, H; Koga, M; Tada, I

2000-11-01

In observations of the movements of the infective third-stage larvae of a rodent parasitic nematode, Strongyloides ratti, on a sodium chloride gradient set up on agarose plates, two types of chemokinetic behavior were seen: a unidirectional avoidance movement on initial placement of the larvae in unfavorable environmental conditions and a random dispersal movement on their placement within an area of favorable conditions. Track patterns were straight in the avoidance movement but included multiple changes of direction and loops in the dispersal movement. In the present study we examined the interventional activity of treatment with various enzymes, lectins, and chemicals by analyzing the unidirectional avoidance movements of the larvae. We observed that beta-glucosidase, hyaluronidase, beta-galactosidase, trypsin, protease, lipase, phospholipase C, soybean agglutinin, wheat germ agglutinin, and spermidine exerted inhibitory actions on those movements, which may be guided by the chemosensory function of this nematode.

Bitter-sweet processing in larval Drosophila.

PubMed

König, Christian; Schleyer, Michael; Leibiger, Judith; El-Keredy, Amira; Gerber, Bertram

2014-07-01

"Sweet-" and "bitter-" tasting substances distinctively support attractive and aversive choice behavior, respectively, and therefore are thought to be processed by distinct pathways. Interestingly, electrophysiological recordings in adult Drosophila suggest that bitter and salty tastants, in addition to activating bitter, salt, or bitter/salt sensory neurons, can also inhibit sweet-sensory neurons. However, the behavioral significance of such a potential for combinatorial coding is little understood. Using larval Drosophila as a study case, we find that the preference towards fructose is inhibited when assayed in the background of the bitter tastant quinine. When testing the influence of quinine on the preference to other, equally preferred sweet tastants, we find that these sweet tastants differ in their susceptibility to be inhibited by quinine. Such stimulus specificity argues that the inhibitory effect of quinine is not due to general effects on locomotion or nausea. In turn, not all bitter tastants have the same potency to inhibit sweet preference; notably, their inhibitory potency is not determined by the strength of the avoidance of them. Likewise, equally avoided concentrations of sodium chloride differ in their potency to inhibit sugar preference. Furthermore, Gr33a-Gal4-positive neurons, while being necessary for bitter avoidance, are dispensable for inhibition of the sweet pathway. Thus, interactions across taste modalities are behaviorally significant and, as we discuss, arguably diverse in mechanism. These results suggest that the coding of tastants and the organization of gustatory behavior may be more combinatorial than is generally acknowledged. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Dyslexia, authorial identity, and approaches to learning and writing: a mixed methods study.

PubMed

Kinder, Julianne; Elander, James

2012-06-01

Dyslexia may lead to difficulties with academic writing as well as reading. The authorial identity approach aims to help students improve their academic writing and avoid unintentional plagiarism, and could help to understand dyslexic students' approaches to writing. (1) To compare dyslexic and non-dyslexic students' authorial identity and approaches to learning and writing; (2) to compare correlations between approaches to writing and approaches to learning among dyslexic and non-dyslexic students; (3) to explore dyslexic students' understandings of authorship and beliefs about dyslexia, writing and plagiarism. Dyslexic (n= 31) and non-dyslexic (n= 31) university students. Questionnaire measures of self-rated confidence in writing, understanding of authorship, knowledge to avoid plagiarism, and top-down, bottom-up and pragmatic approaches to writing (Student Authorship Questionnaire; SAQ), and deep, surface and strategic approaches to learning (Approaches and Study Skills Inventory for Students; ASSIST), plus qualitative interviews with dyslexic students with high and low SAQ scores. Dyslexic students scored lower for confidence in writing, understanding authorship, and strategic approaches to learning, and higher for surface approaches to learning. Correlations among SAQ and ASSIST scores were larger and more frequently significant among non-dyslexic students. Self-rated knowledge to avoid plagiarism was associated with a top-down approach to writing among dyslexic students and with a bottom-up approach to writing among non-dyslexic students. All the dyslexic students interviewed described how dyslexia made writing more difficult and reduced their confidence in academic writing, but they had varying views about whether dyslexia increased the risk of plagiarism. Dyslexic students have less strong authorial identities, and less congruent approaches to learning and writing. Knowledge to avoid plagiarism may be more salient for dyslexic students, who may benefit from specific interventions to increase confidence in writing and understanding of authorship. Further research could investigate how dyslexic students develop approaches to academic writing, and how that could be affected by perceived knowledge to avoid plagiarism. ©2011 The British Psychological Society.

Distinct sets of FGF receptors sculpt excitatory and inhibitory synaptogenesis.

PubMed

Dabrowski, Ania; Terauchi, Akiko; Strong, Cameron; Umemori, Hisashi

2015-05-15

Neurons in the brain must establish a balanced network of excitatory and inhibitory synapses during development for the brain to function properly. An imbalance between these synapses underlies various neurological and psychiatric disorders. The formation of excitatory and inhibitory synapses requires precise molecular control. In the hippocampus, the structure crucial for learning and memory, fibroblast growth factor 22 (FGF22) and FGF7 specifically promote excitatory or inhibitory synapse formation, respectively. Knockout of either Fgf gene leads to excitatory-inhibitory imbalance in the mouse hippocampus and manifests in an altered susceptibility to epileptic seizures, underscoring the importance of FGF-dependent synapse formation. However, the receptors and signaling mechanisms by which FGF22 and FGF7 induce excitatory and inhibitory synapse differentiation are unknown. Here, we show that distinct sets of overlapping FGF receptors (FGFRs), FGFR2b and FGFR1b, mediate excitatory or inhibitory presynaptic differentiation in response to FGF22 and FGF7. Excitatory presynaptic differentiation is impaired in Fgfr2b and Fgfr1b mutant mice; however, inhibitory presynaptic defects are only found in Fgfr2b mutants. FGFR2b and FGFR1b are required for an excitatory presynaptic response to FGF22, whereas only FGFR2b is required for an inhibitory presynaptic response to FGF7. We further find that FGFRs are required in the presynaptic neuron to respond to FGF22, and that FRS2 and PI3K, but not PLCγ, mediate FGF22-dependent presynaptic differentiation. Our results reveal the specific receptors and signaling pathways that mediate FGF-dependent presynaptic differentiation, and thereby provide a mechanistic understanding of precise excitatory and inhibitory synapse formation in the mammalian brain. © 2015. Published by The Company of Biologists Ltd.

Inhibitory ryanodine prevents ryanodine receptor-mediated Ca²⁺ release without affecting endoplasmic reticulum Ca²⁺ content in primary hippocampal neurons.

PubMed

Adasme, Tatiana; Paula-Lima, Andrea; Hidalgo, Cecilia

2015-02-27

Ryanodine is a cell permeant plant alkaloid that binds selectively and with high affinity to ryanodine receptor (RyR) Ca(2+) release channels. Sub-micromolar ryanodine concentrations activate RyR channels while micromolar concentrations are inhibitory. Several reports indicate that neuronal synaptic plasticity, learning and memory require RyR-mediated Ca(2+)-release, which is essential for muscle contraction. The use of micromolar (inhibitory) ryanodine represents a common strategy to suppress RyR activity in neuronal cells: however, micromolar ryanodine promotes RyR-mediated Ca(2+) release and endoplasmic reticulum Ca(2+) depletion in muscle cells. Information is lacking in this regard in neuronal cells; hence, we examined here if addition of inhibitory ryanodine elicited Ca(2+) release in primary hippocampal neurons, and if prolonged incubation of primary hippocampal cultures with inhibitory ryanodine affected neuronal ER calcium content. Our results indicate that inhibitory ryanodine does not cause Ca(2+) release from the ER in primary hippocampal neurons, even though ryanodine diffusion should produce initially low intracellular concentrations, within the RyR activation range. Moreover, neurons treated for 1 h with inhibitory ryanodine had comparable Ca(2+) levels as control neurons. These combined findings imply that prolonged incubation with inhibitory ryanodine, which effectively abolishes RyR-mediated Ca(2+) release, preserves ER Ca(2+) levels and thus constitutes a sound strategy to suppress neuronal RyR function. Copyright © 2015 Elsevier Inc. All rights reserved.

Requirement of NF-kappa B Activation in Different Mice Brain Areas during Long-Term Memory Consolidation in Two Contextual One-Trial Tasks with Opposing Valences

PubMed Central

Salles, Angeles; Krawczyk, Maria del C.; Blake, Mariano; Romano, Arturo; Boccia, Mariano M.; Freudenthal, Ramiro

2017-01-01

NF-kappa B is a transcription factor whose activation has been shown to be necessary for long-term memory consolidation in several species. NF-kappa B is activated and translocates to the nucleus of cells in a specific temporal window during consolidation. Our work focuses on a one trial learning tasks associated to the inhibitory avoidance (IA) setting. Mice were trained either receiving or not a footshock when entering a dark compartment (aversive vs. appetitive learning). Regardless of training condition (appetitive or aversive), latencies to step-through during testing were significantly different to those measured during training. Additionally, these testing latencies were also different from those of a control group that only received a shock unrelated to context. Moreover, nuclear NF-kappa B DNA-binding activity was augmented in the aversive and the appetitive tasks when compared with control and naïve animals. NF-kappa B inhibition by Sulfasalazine injected either in the Hippocampus, Amygdala or Nucleus accumbens immediately after training was able to impair retention in both training versions. Our results suggest that NF-kappa B is a critical molecular step, in different brain areas on memory consolidation. This was the case for both the IA task and also the modified version of the same task where the footshock was omitted during training. This work aims to further investigate how appetitive and aversive memories are consolidated. PMID:28439227

AX+, BX- Discrimination Learning in the Fear-Potentiated Startle Paradigm: Possible Relevance to Inhibitory Fear Learning in Extinction

ERIC Educational Resources Information Center

Myers, Karyn M.; Davis, Michael

2004-01-01

The neural mechanisms of fear suppression most commonly are studied through the use of extinction, a behavioral procedure in which a feared stimulus (i.e., one previously paired with shock) is nonreinforced repeatedly, leading to a reduction or elimination of the fear response. Although extinction is perhaps the most convenient index of fear…

Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink conditioning.

PubMed

Nokia, Miriam S; Wikgren, Jan

2010-04-01

The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative responding due to sustained responding to the conditioned stimulus not paired with an unconditioned stimulus. The results indicate that the neural state reflected by the hippocampal theta ratio is specifically linked to forming associations between stimuli rather than to the learning of inhibitory associations needed for successful discrimination. This is in line with the view that the hippocampus is responsible for contingency detection in the early phase of learning in eyeblink conditioning. (c) 2009 Wiley-Liss, Inc.

[Influence of stress on learning and memory].

PubMed

Ukai, M

2000-08-01

This paper describes the influence of stress on learning and memory. The mice receiving inescapable electroshock fail to perform the active conditioned avoidance response of lever-pressing. This is called learned helplessness, which is ameliorated by treatment with antidepressants including one of the selective serotonin reuptake inhibitors (SSRIs). It is of particular interest that posttraumatic stress disease (PTSD) accompanied by memory impairment could be improved by treatment with SSRIs. The different kinds of stress including ischemia, footshock, psychological stress, and forced swimming influence learning and memory as indexed by spontaneous alternation performance as well as passive avoidance learning. In addition, a variety of stresses influence the activity of hormones and neurotransmitters like monoamines, neuropeptides, and excitatory amino acids resulting in changes in learning and memory. Finally, the accumulation of data is necessary to clarify the exact mechanism of stress on learning and memory.

Inhibitory Network Interactions Shape the Auditory Processing of Natural Communication Signals in the Songbird Auditory Forebrain

PubMed Central

Pinaud, Raphael; Terleph, Thomas A.; Tremere, Liisa A.; Phan, Mimi L.; Dagostin, André A.; Leão, Ricardo M.; Mello, Claudio V.; Vicario, David S.

2008-01-01

The role of GABA in the central processing of complex auditory signals is not fully understood. We have studied the involvement of GABAA-mediated inhibition in the processing of birdsong, a learned vocal communication signal requiring intact hearing for its development and maintenance. We focused on caudomedial nidopallium (NCM), an area analogous to parts of the mammalian auditory cortex with selective responses to birdsong. We present evidence that GABAA-mediated inhibition plays a pronounced role in NCM's auditory processing of birdsong. Using immunocytochemistry, we show that approximately half of NCM's neurons are GABAergic. Whole cell patch-clamp recordings in a slice preparation demonstrate that, at rest, spontaneously active GABAergic synapses inhibit excitatory inputs onto NCM neurons via GABAA receptors. Multi-electrode electrophysiological recordings in awake birds show that local blockade of GABAA-mediated inhibition in NCM markedly affects the temporal pattern of song-evoked responses in NCM without modifications in frequency tuning. Surprisingly, this blockade increases the phasic and largely suppresses the tonic response component, reflecting dynamic relationships of inhibitory networks that could include disinhibition. Thus processing of learned natural communication sounds in songbirds, and possibly other vocal learners, may depend on complex interactions of inhibitory networks. PMID:18480371

NCAM deficiency in the mouse forebrain impairs innate and learned avoidance behaviours.

PubMed

Brandewiede, J; Stork, O; Schachner, M

2014-06-01

The neural cell adhesion molecule (NCAM) has been implicated in the development and plasticity of neural circuits and the control of hippocampus- and amygdala-dependent learning and behaviour. Previous studies in constitutive NCAM null mutants identified emotional behaviour deficits related to disturbances of hippocampal and amygdala functions. Here, we studied these behaviours in mice conditionally deficient in NCAM in the postmigratory forebrain neurons. We report deficits in both innate and learned avoidance behaviours, as observed in elevated plus maze and passive avoidance tasks. In contrast, general locomotor activity, trait anxiety or neophobia were unaffected by the mutation. Altered avoidance behaviour of the conditional NCAM mutants was associated with a deficit in serotonergic signalling, as indicated by their reduced responsiveness to (±)-8-hydroxy-2-(dipropylamino)-tetralin-induced hypothermia. Another serotonin-dependent behaviour, namely intermale aggression that is massively increased in constitutively NCAM-deficient mice, was not affected in the forebrain-specific mutants. Our data suggest that genetically or environmentally induced changes of NCAM expression in the late postnatal and mature forebrain determine avoidance behaviour and serotonin (5-HT)1A receptor signalling. © 2014 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Effect of harmane, an endogenous β-carboline, on learning and memory in rats.

PubMed

Celikyurt, Ipek Komsuoglu; Utkan, Tijen; Gocmez, Semil Selcen; Hudson, Alan; Aricioglu, Feyza

2013-01-01

Our aim was to investigate the effects of acute harmane administration upon learning and memory performance of rats using the three-panel runway paradigm and passive avoidance test. Male rats received harmane (2.5, 5, and 7.5mg/kg, i.p.) or saline 30 min. before each session of experiments. In the three panel runway paradigm, harmane did not affect the number of errors and latency in reference memory. The effect of harmane on the errors of working memory was significantly higher following the doses of 5mg/kg and 7.5mg/kg. The latency was changed significantly at only 7.5mg/kg in comparison to control group. Animals were given pre-training injection of harmane in the passive avoidance test in order to determine the learning function. Harmane treatment decreased the retention latency significantly and dose dependently, which indicates an impairment in learning. In this study, harmane impaired working memory in three panel runway test and learning in passive avoidance test. As an endogenous bioactive molecule, harmane might have a critical role in the modulation of learning and memory functions. Copyright © 2012 Elsevier Inc. All rights reserved.

Soft Graphene Nanofibers Designed for the Acceleration of Nerve Growth and Development.

PubMed

Feng, Zhang-Qi; Wang, Ting; Zhao, Bin; Li, Jiacheng; Jin, Lin

2015-11-04

Soft graphene nanofibers with recoverable electrical conductivity and excellent physicochemical stability are prepared by a controlled assembly technique. By using the soft graphene nanofibers for cellular electrical stimulation, the common inhibitory effect of long-term electrical stimulation on nerve growth and development is avoided, which usually happens with traditional 2D conductive materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effects of the beta-blocker propranolol on cued and contextual fear conditioning in humans.

PubMed

Grillon, Christian; Cordova, Jeremy; Morgan, Charles Andrew; Charney, Dennis S; Davis, Michael

2004-09-01

Beta-adrenergic receptors are involved in the consolidation of emotional memories. Yet, a number of studies using Pavlovian cued fear conditioning have been unable to demonstrate an effect of beta-adrenergic blockade on acquisition or retention of fear conditioning. Evidence for the involvement of beta-adrenergic receptors in emotional memories comes mostly from studies using fear inhibitory avoidance in rodents. It is possible that fear inhibitory avoidance is more akin to contextual conditioning than to cued fear conditioning, suggesting that context conditioning may be disrupted by beta-adrenergic blockade. This study investigated the effects of the beta-adrenergic blocker propranolol on cued and contextual fear conditioning in humans. Subjects were given either placebo (n=15) or 40 mg propranolol (n=15) prior to differential cued conditioning. A week later, they were tested for retention of context and cued fear conditioning using physiological (startle reflex and electrodermal activity) and subjective measures of emotional arousal. The results were consistent with the hypothesis. The skin conductance level (SCL) and the subjective measure of arousal suggested reduced emotional arousal upon returning to the conditioning context in the propranolol group, compared to the placebo group. The acquisition and retention of cued fear conditioning were not affected by propranolol. These results suggest that beta-adrenergic receptors are involved in contextual fear conditioning.

Neurobehavioral and Antioxidant Effects of Ethanolic Extract of Yellow Propolis

PubMed Central

da Silveira, Cinthia Cristina Sousa de Menezes; Fernandes, Luanna Melo Pereira; Silva, Mallone Lopes; Luz, Diandra Araújo; Gomes, Antônio Rafael Quadros; Machado, Christiane Schineider; de Lira, Tatiana Onofre; Ferreira, Antonio Gilberto

2016-01-01

Propolis is a resin produced by bees from raw material collected from plants, salivary secretions, and beeswax. New therapeutic properties for the Central Nervous System have emerged. We explored the neurobehavioral and antioxidant effects of an ethanolic extract of yellow propolis (EEYP) rich in triterpenoids, primarily lupeol and β-amyrin. Male Wistar rats, 3 months old, were intraperitoneally treated with Tween 5% (control), EEYP (1, 3, 10, and 30 mg/kg), or diazepam, fluoxetine, and caffeine (positive controls) 30 min before the assays. Animals were submitted to open field, elevated plus maze, forced swimming, and inhibitory avoidance tests. After behavioral tasks, blood samples were collected through intracardiac pathway, to evaluate the oxidative balance. The results obtained in the open field and in the elevated plus maze assay showed spontaneous locomotion preserved and anxiolytic-like activity. In the forced swimming test, EEYP demonstrated antidepressant-like activity. In the inhibitory avoidance test, EEYP showed mnemonic activity at 30 mg/kg. In the evaluation of oxidative biochemistry, the extract reduced the production of nitric oxide and malondialdehyde without changing level of total antioxidant, catalase, and superoxide dismutase, induced by behavioral stress. Our results highlight that EEYP emerges as a promising anxiolytic, antidepressant, mnemonic, and antioxidant natural product. PMID:27822336

Enhancing inhibitory learning to reduce overeating: Design and rationale of a cue exposure therapy trial in overweight and obese women.

PubMed

van den Akker, Karolien; Schyns, Ghislaine; Jansen, Anita

2016-07-01

The prevalence of overweight and obesity has increased substantially over the last decades. Weight loss attempts in overweight individuals are common, though they seldom result in successful long-term weight loss. One very promising treatment is food cue exposure therapy, during which overweight individuals are repeatedly exposed to food-associated cues (e.g., the sight, smell and taste of high-calorie foods, overeating environments) without eating in order to extinguish cue-elicited appetitive responses to food cues. However, only few studies have tested the effectiveness of cue exposure, especially with regards to weight loss. For exposure treatment of anxiety disorders, it has been proposed that inhibitory learning is critical for exposure to be effective. In this RCT, we translated techniques proposed by Craske et al. (2014) to the appetitive domain and developed a novel cue exposure therapy for overeating aimed at maximizing inhibitory learning. The current RCT tested the effectiveness of this 8-session cue exposure intervention relative to a control intervention in 45 overweight adult (aged 18-60) females at post-treatment and 3-month follow-up, of which 39 participants completed the study. Weight loss, eating psychopathology, food cue reactivity, and snacking behaviour were studied as main treatment outcomes, and mediators and moderators of treatment effects were studied. The presented study design represents an innovative effort to provide valuable clinical recommendations for the treatment of overeating and obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

Perinatal exposure to genistein, a soy phytoestrogen, improves spatial learning and memory but impairs passive avoidance learning and memory in offspring.

PubMed

Kohara, Yumi; Kuwahara, Rika; Kawaguchi, Shinichiro; Jojima, Takeshi; Yamashita, Kimihiro

2014-05-10

This study investigated the effects of perinatal genistein (GEN) exposure on the central nervous system of rat offspring. Pregnant dams orally received GEN (1 or 10 mg/kg/day) or vehicle (1 ml/kg/day) from gestation day 10 to postnatal day 14. In order to assess the effects of GEN on rat offspring, we used a battery of behavioral tests, including the open-field, elevated plus-maze, MAZE and step-through passive avoidance tests. MAZE test is an appetite-motivation test, and we used this mainly for assessing spatial learning and memory. In the MAZE test, GEN groups exhibited shorter latency from start to goal than the vehicle-treated group in both sexes. On the other hand, performances in the step-through passive avoidance test were non-monotonically inhibited by GEN in both sexes, and a significant difference was observed in low dose of the GEN-treated group compared to the vehicle-treated group in female rats. Furthermore, we found that perinatal exposure to GEN did not significantly alter locomotor activity or emotionality as assessed by the open-field and elevated-plus maze tests. These results suggest that perinatal exposure to GEN improved spatial learning and memory of rat offspring, but impaired their passive avoidance learning and memory. Copyright © 2014 Elsevier Inc. All rights reserved.

The effect of Vitamin E on learning and memory deficits in intrahippocampal kainate-induced temporal lobe epilepsy in rats.

PubMed

Kiasalari, Zahra; Khalili, Mohsen; Shafiee, Samaneh; Roghani, Mehrdad

2016-01-01

Since temporal lobe epilepsy (TLE) is associated with learning and memory impairment, we investigated the beneficial effect of Vitamin E on the impaired learning and memory in the intrahippocampal kainate model of TLE in rats. Rats were divided into sham, Vitamin E-treated sham, kainate, and Vitamin E-treated kainate. Intrahippocampal kainate was used for induction of epilepsy. Vitamin E was injected intraperitoneal (i.p.) at a dose of 200 mg/kg/day started 1 week before surgery until 1 h presurgery. Initial and step-through latencies in the passive avoidance test and alternation behavior percentage in Y-maze were finally determined in addition to measurement of some oxidative stress markers. Kainate injection caused a higher severity and rate of seizures and deteriorated learning and memory performance in passive avoidance paradigm and spontaneous alternation as an index of spatial recognition memory in Y-maze task. Intrahippocampal kainate also led to the elevation of malondialdehyde (MDA) and nitrite and reduced activity of superoxide dismutase (SOD). Vitamin E pretreatment significantly attenuated severity and incidence rate of seizures, significantly improved retrieval and recall in passive avoidance, did not ameliorate spatial memory deficit in Y-maze, and lowered MDA and enhanced SOD activity. Vitamin E improves passive avoidance learning and memory and part of its beneficial effect is due to its potential to mitigate hippocampal oxidative stress.

Intra-Amygdala ZIP Injections Impair the Memory of Learned Active Avoidance Responses and Attenuate Conditioned Taste-Aversion Acquisition in Rats

ERIC Educational Resources Information Center

Gamiz, Fernando; Gallo, Milagros

2011-01-01

We have investigated the effect of protein kinase Mzeta (PKM[zeta]) inhibition in the basolateral amygdala (BLA) upon the retention of a nonspatial learned active avoidance response and conditioned taste-aversion (CTA) acquisition in rats. ZIP (10 nmol/[mu]L) injected into the BLA 24 h after training impaired retention of a learned…

Complex-learning Induced Modifications in Synaptic Inhibition: Mechanisms and Functional Significance.

PubMed

Reuveni, Iris; Lin, Longnian; Barkai, Edi

2018-06-15

Following training in a difficult olfactory-discrimination (OD) task rats acquire the capability to perform the task easily, with little effort. This new acquired skill, of 'learning how to learn' is termed 'rule learning'. At the single-cell level, rule learning is manifested in long-term enhancement of intrinsic neuronal excitability of piriform cortex (PC) pyramidal neurons, and in excitatory synaptic connections between these neurons to maintain cortical stability, such long-lasting increase in excitability must be accompanied by paralleled increase in inhibitory processes that would prevent hyper-excitable activation. In this review we describe the cellular and molecular mechanisms underlying complex-learning-induced long-lasting modifications in GABA A -receptors and GABA B -receptor-mediated synaptic inhibition. Subsequently we discuss how such modifications support the induction and preservation of long-term memories in the in the mammalian brain. Based on experimental results, computational analysis and modeling, we propose that rule learning is maintained by doubling the strength of synaptic inputs, excitatory as well as inhibitory, in a sub-group of neurons. This enhanced synaptic transmission, which occurs in all (or almost all) synaptic inputs onto these neurons, activates specific stored memories. At the molecular level, such rule-learning-relevant synaptic strengthening is mediated by doubling the conductance of synaptic channels, but not their numbers. This post synaptic process is controlled by a whole-cell mechanism via particular second messenger systems. This whole-cell mechanism enables memory amplification when required and memory extinction when not relevant. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Absence of “Warm-Up” during Active Avoidance Learning in a Rat Model of Anxiety Vulnerability: Insights from Computational Modeling

PubMed Central

Myers, Catherine E.; Smith, Ian M.; Servatius, Richard J.; Beck, Kevin D.

2014-01-01

Avoidance behaviors, in which a learned response causes omission of an upcoming punisher, are a core feature of many psychiatric disorders. While reinforcement learning (RL) models have been widely used to study the development of appetitive behaviors, less attention has been paid to avoidance. Here, we present a RL model of lever-press avoidance learning in Sprague-Dawley (SD) rats and in the inbred Wistar Kyoto (WKY) rat, which has been proposed as a model of anxiety vulnerability. We focus on “warm-up,” transiently decreased avoidance responding at the start of a testing session, which is shown by SD but not WKY rats. We first show that a RL model can correctly simulate key aspects of acquisition, extinction, and warm-up in SD rats; we then show that WKY behavior can be simulated by altering three model parameters, which respectively govern the tendency to explore new behaviors vs. exploit previously reinforced ones, the tendency to repeat previous behaviors regardless of reinforcement, and the learning rate for predicting future outcomes. This suggests that several, dissociable mechanisms may contribute independently to strain differences in behavior. The model predicts that, if the “standard” inter-session interval is shortened from 48 to 24 h, SD rats (but not WKY) will continue to show warm-up; we confirm this prediction in an empirical study with SD and WKY rats. The model further predicts that SD rats will continue to show warm-up with inter-session intervals as short as a few minutes, while WKY rats will not show warm-up, even with inter-session intervals as long as a month. Together, the modeling and empirical data indicate that strain differences in warm-up are qualitative rather than just the result of differential sensitivity to task variables. Understanding the mechanisms that govern expression of warm-up behavior in avoidance may lead to better understanding of pathological avoidance, and potential pathways to modify these processes. PMID:25183956

Paraventricular Thalamus Balances Danger and Reward.

PubMed

Choi, Eun A; McNally, Gavan P

2017-03-15

Foraging animals balance the need to seek food and energy against the accompanying dangers of injury and predation. To do so, they rely on learning systems encoding reward and danger. Whereas much is known about these separate learning systems, little is known about how they interact to shape and guide behavior. Here we show a key role for the rat paraventricular nucleus of the thalamus (PVT), a nucleus of the dorsal midline thalamus, in this interaction. First, we show behavioral competition between reward and danger: the opportunity to seek food reward negatively modulates expression of species-typical defensive behavior. Then, using a chemogenetic approach expressing the inhibitory hM4Di designer receptor exclusively activated by a designer drug in PVT neurons, we show that the PVT is central to this behavioral competition. Chemogenetic PVT silencing biases behavior toward either defense or reward depending on the experimental conditions, but does not consistently favor expression of one over the other. This bias could not be attributed to changes in fear memory retrieval, learned safety, or memory interference. Rather, our results demonstrate that the PVT is essential for balancing conflicting behavioral tendencies toward danger and reward, enabling adaptive responding under this basic selection pressure. SIGNIFICANCE STATEMENT Among the most basic survival problems faced by animals is balancing the need to seek food and energy against the accompanying dangers of injury and predation. Although much is known about the brain mechanisms that underpin learning about reward and danger, little is known about how these interact to solve basic survival problems. Here we show competition between defensive (to avoid predatory detection) and approach (to obtain food) behavior. We show that the paraventricular thalamus, a nucleus of the dorsal midline thalamus, is integral to this behavioral competition. The paraventricular thalamus balances the competing behavioral demands of danger and reward, enabling adaptive responding under this selection pressure. Copyright © 2017 the authors 0270-6474/17/373018-12$15.00/0.

Antiamnesic Effect of Actinidia arguta Extract Intake in a Mouse Model of TMT-Induced Learning and Memory Dysfunction

PubMed Central

Ha, Jeong Su; Jin, Dong Eun; Park, Seon Kyeong; Park, Chang Hyeon; Seung, Tae Wan; Bae, Dong-Won; Kim, Dae-Ok; Heo, Ho Jin

2015-01-01

The antiamnesic effects of ethyl acetate fraction from Actinidia arguta (EFAA) on trimethyltin- (TMT-) induced memory impairment were investigated to find the possibility of functional food substances. EFAA showed a potent AChE inhibitory effect (IC50 = 53 μg/mL) and efficient neuroprotection against H2O2-induced oxidative stress. The administration of EFAA significantly decreased TMT-induced cognitive deficit in Y-maze, passive avoidance, and Morris water maze (MWM) tests. After the behavioral tests, the antioxidant activities were confirmed using mice brain tissues. EFAA not only showed the inhibition of AChE activity and the decline of malondialdehyde (MDA) level as a sign of lipid peroxidation but also presented the increase of the superoxide dismutase (SOD) level and the decrease of the oxidized glutathione (GSSG)/total glutathione (GSH + GSSG) ratio. Finally, the phenolics in EFAA were identified using liquid chromatography coupled with hybrid triple quadrupole-linear ion trap mass spectrometry, and four main phenolics, such as quinic acid, chlorogenic acid, caffeoyl hexose, and quercetin-3-glucoside, were identified. These results suggest that EFAA containing physiological phenolics might enhance drug-induced amnesia through AChE inhibition and neuroprotection. PMID:26576196

Antiamnesic Effect of Actinidia arguta Extract Intake in a Mouse Model of TMT-Induced Learning and Memory Dysfunction.

PubMed

Ha, Jeong Su; Jin, Dong Eun; Park, Seon Kyeong; Park, Chang Hyeon; Seung, Tae Wan; Bae, Dong-Won; Kim, Dae-Ok; Heo, Ho Jin

2015-01-01

The antiamnesic effects of ethyl acetate fraction from Actinidia arguta (EFAA) on trimethyltin- (TMT-) induced memory impairment were investigated to find the possibility of functional food substances. EFAA showed a potent AChE inhibitory effect (IC50 = 53 μg/mL) and efficient neuroprotection against H2O2-induced oxidative stress. The administration of EFAA significantly decreased TMT-induced cognitive deficit in Y-maze, passive avoidance, and Morris water maze (MWM) tests. After the behavioral tests, the antioxidant activities were confirmed using mice brain tissues. EFAA not only showed the inhibition of AChE activity and the decline of malondialdehyde (MDA) level as a sign of lipid peroxidation but also presented the increase of the superoxide dismutase (SOD) level and the decrease of the oxidized glutathione (GSSG)/total glutathione (GSH + GSSG) ratio. Finally, the phenolics in EFAA were identified using liquid chromatography coupled with hybrid triple quadrupole-linear ion trap mass spectrometry, and four main phenolics, such as quinic acid, chlorogenic acid, caffeoyl hexose, and quercetin-3-glucoside, were identified. These results suggest that EFAA containing physiological phenolics might enhance drug-induced amnesia through AChE inhibition and neuroprotection.

Negative reinforcement learning is affected in substance dependence.

PubMed

Thompson, Laetitia L; Claus, Eric D; Mikulich-Gilbertson, Susan K; Banich, Marie T; Crowley, Thomas; Krmpotich, Theodore; Miller, David; Tanabe, Jody

2012-06-01

Negative reinforcement results in behavior to escape or avoid an aversive outcome. Withdrawal symptoms are purported to be negative reinforcers in perpetuating substance dependence, but little is known about negative reinforcement learning in this population. The purpose of this study was to examine reinforcement learning in substance dependent individuals (SDI), with an emphasis on assessing negative reinforcement learning. We modified the Iowa Gambling Task to separately assess positive and negative reinforcement. We hypothesized that SDI would show differences in negative reinforcement learning compared to controls and we investigated whether learning differed as a function of the relative magnitude or frequency of the reinforcer. Thirty subjects dependent on psychostimulants were compared with 28 community controls on a decision making task that manipulated outcome frequencies and magnitudes and required an action to avoid a negative outcome. SDI did not learn to avoid negative outcomes to the same degree as controls. This difference was driven by the magnitude, not the frequency, of negative feedback. In contrast, approach behaviors in response to positive reinforcement were similar in both groups. Our findings are consistent with a specific deficit in negative reinforcement learning in SDI. SDI were relatively insensitive to the magnitude, not frequency, of loss. If this generalizes to drug-related stimuli, it suggests that repeated episodes of withdrawal may drive relapse more than the severity of a single episode. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Associative learning for danger avoidance nullifies innate positive chemotaxis to host olfactory stimuli in a parasitic wasp

NASA Astrophysics Data System (ADS)

Benelli, Giovanni; Stefanini, Cesare; Giunti, Giulia; Geri, Serena; Messing, Russell H.; Canale, Angelo

2014-09-01

Animals rely on associative learning for a wide range of purposes, including danger avoidance. This has been demonstrated for several insects, including cockroaches, mosquitoes, drosophilid flies, paper wasps, stingless bees, bumblebees and honeybees, but less is known for parasitic wasps. We tested the ability of Psyttalia concolor (Hymenoptera: Braconidae) females to associate different dosages of two innately attractive host-induced plant volatiles (HIPVs), ethyl octanoate and decanal, with danger (electric shocks). We conducted an associative treatment involving odours and shocks and two non-associative controls involving shocks but not odours and odours but not shocks. In shock-only and odour-only trained wasps, females preferred on HIPV-treated than on blank discs. In associative-trained wasps, however, P. concolor's innate positive chemotaxis for HIPVs was nullified (lowest HIPV dosage tested) or reversed (highest HIPV dosage tested). This is the first report of associative learning of olfactory cues for danger avoidance in parasitic wasps, showing that the effects of learning can override innate positive chemotaxes.

Investigation of neuropsychopharmacological effects of a polyherbal formulation on the learning and memory process in rats.

PubMed

Shah, Js; Goyal, Rk

2011-04-01

To investigate the neuropsychopharmacological effect of a polyherbal formulation (PHF) on the learning and memory processes in rats. PHF contains Withania somnifera (Ashwagandha), Nardostachys jatamansi (Jatamansi), Rauwolfia serpentina (Sarpagandha), Evolvulus alsinoides (Shankhpushpi), Asparagus racemosus (Shatavari), Emblica officinalis (Amalki), Mucuna pruriens (Kauch bij extract), Hyoscyamus niger (Khurasani Ajmo), Mineral resin (Shilajit), Pearl (Mukta Shukhti Pishti), and coral calcium (Praval pishti). Its effect (500 mg / kg, p.o.) on the learning and memory processes was tested. The activity of PHF on memory acquisition and retention was studied using passive avoidance learning and elevated plus maze model (EPM) in rats. The animals treated with PHF showed a significant decrease in transfer latency as compared to the control group in EPM. PHF also produced significant improvement in passive avoidance acquisition and memory retrieval, as compared to the controls and reduced the latency to reach the shock free zone (SFZ) after 24 hours. The PHF produces significant improvement in passive avoidance acquisition and memory retrieval in rats, which needs further investigation.

A rapid throughput approach identifies cognitive deficits in adult zebrafish from developmental exposure to polybrominated flame retardants.

PubMed

Truong, Lisa; Mandrell, David; Mandrell, Rick; Simonich, Michael; Tanguay, Robert L

2014-07-01

A substantial body of evidence has correlated the human body burdens of some polybrominated diphenyl ether (PBDE) flame retardants with cognitive and other behavioral deficits. Adult zebrafish exhibit testable learning and memory, making them an increasingly attractive model for neurotoxicology. Our goal was to develop a rapid throughput means of identifying the cognitive impact of developmental exposure to flame retardants in the zebrafish model. We exposed embryos from 6h post fertilization to 5 days post fertilization to either PBDE 47 (0.1μM), PBDE 99 (0.1μM) or PBDE 153 (0.1μM), vehicle (0.1% DMSO), or embryo medium (EM). The larvae were grown to adulthood and evaluated for the rate at which they learned an active-avoidance response in an automated shuttle box array. Zebrafish developmentally exposed to PBDE 47 learned the active avoidance paradigm significantly faster than the 0.1% DMSO control fish (P<0.0001), but exhibited significantly poorer performance when retested suggestive of impaired memory retention or altered neuromotor activity. Learning in the PBDE 153 group was not significantly different from the DMSO group. Developmental exposure to 0.1% DMSO impaired adult active avoidance learning relative to the sham group (n=39; P<0.0001). PBDE 99 prevented the DMSO effect, yielding a learning rate not significantly different from the sham group (n=36; P>0.9). Our results underscore the importance of vehicle choice in accurately assessing chemical effects on behavior. Active avoidance response in zebrafish is an effective model of learning that, combined with automated shuttle box testing, will provide a highly efficient platform for evaluating persistent neurotoxic hazard from many chemicals. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of vitamin E on lead exposure-induced learning and memory impairment in rats.

PubMed

Khodamoradi, Nasrin; Komaki, Alireza; Salehi, Iraj; Shahidi, Siamak; Sarihi, Abdolrahman

2015-05-15

Chronic lead (Pb(2+)) exposure has been associated with learning and memory impairments, whereas vitamin E improves cognitive deficits. In this study, using a passive avoidance learning model in rats, we investigated the effects of vitamin E on Pb(2+) exposure-induced learning and memory impairments in rats. In the present study, 56 Wistar male rats (weighting 230-250g) were divided into eight groups (n=7). The Pb(2+) exposure involved gavages of lead acetate solution using three different doses (0.05%, 0.1%, and 0.2%) and the vitamin E consisted of three different doses (10, 25, 50μg/rat) for 30days. After the 30-day period, the rats were tested using a passive avoidance task (acquisition test). In a retrieval test conducted 48h after the training, step through latency (STL) and time in the dark compartment (TDC) were recorded. The statistical analysis of data was performed using ANOVA followed by Tukey's post hoc analysis. In all cases, differences were considered significant if p<0.05. The results of the present study showed that chronic exposure to high doses of Pb(2+) significantly increased both the number of trails required for learning and the TDC, whereas it decreased the STL in the passive avoidance test. Administration of vitamin E ameliorated the effects of Pb(2+) on animal behavior in the passive avoidance learning and memory task. Our results indicate that impairments of learning and memory in Pb(2+)-exposed rats are dose dependent and can be inhibited by antioxidants such as vitamin E. Copyright © 2015 Elsevier Inc. All rights reserved.

Racial bias shapes social reinforcement learning.

PubMed

Lindström, Björn; Selbing, Ida; Molapour, Tanaz; Olsson, Andreas

2014-03-01

Both emotional facial expressions and markers of racial-group belonging are ubiquitous signals in social interaction, but little is known about how these signals together affect future behavior through learning. To address this issue, we investigated how emotional (threatening or friendly) in-group and out-group faces reinforced behavior in a reinforcement-learning task. We asked whether reinforcement learning would be modulated by intergroup attitudes (i.e., racial bias). The results showed that individual differences in racial bias critically modulated reinforcement learning. As predicted, racial bias was associated with more efficiently learned avoidance of threatening out-group individuals. We used computational modeling analysis to quantitatively delimit the underlying processes affected by social reinforcement. These analyses showed that racial bias modulates the rate at which exposure to threatening out-group individuals is transformed into future avoidance behavior. In concert, these results shed new light on the learning processes underlying social interaction with racial-in-group and out-group individuals.

Effects of the novel compound aniracetam (Ro 13-5057) upon impaired learning and memory in rodents.

PubMed

Cumin, R; Bandle, E F; Gamzu, E; Haefely, W E

1982-01-01

The effect of aniracetam (Ro 13-5057, 1-anisoyl-2-pyrrolidinone) was studied on various forms of experimentally impaired cognitive functions (learning and memory) in rodents and produced the following effects: (1) almost complete prevention of the incapacity to learn a discrete escape response in rats exposed to sublethal hypercapnia immediately before the acquisition session; (2) partial (rats) or complete (mice) prevention of the scopolamine-induced short-term amnesia for a passive avoidance task; (3) complete protection against amnesia for a passive avoidance task in rats submitted to electroconvulsive shock immediately after avoidance acquisition; (4) prevention of the long-term retention- or retrieval-deficit for a passive avoidance task induced in rats and mice by chloramphenicol or cycloheximide administered immediately after acquisition; (5) reversal, when administered as late as 1 h before the retention test, of the deficit in retention or retrieval of a passive avoidance task induced by cycloheximide injected 2 days previously; (6) prevention of the deficit in the retrieval of an active avoidance task induced in mice by subconvulsant electroshock or hypercapnia applied immediately before retrieval testing (24 h after acquisition). These improvements or normalizations of impaired cognitive functions were seen at oral aniracetam doses of 10-100 mg/kg. Generally, the dose-response curves were bell-shaped. The mechanisms underlying the activity of aniracetam and its 'therapeutic window' are unknown. Piracetam, another pyrrolidinone derivative was used for comparison. It was active only in six of nine tests and had about one-tenth the potency of aniracetam. The results indicate that aniracetam improves cognitive functions which are impaired by different procedure and in different phases of the learning and memory process.

Conditioned flavor aversion and location avoidance in hamsters from toxic extract of tall larkspur (Delphinium barbeyi)

USDA-ARS?s Scientific Manuscript database

Studies were conducted to address conditioned flavour aversion (CFA) and place avoidance learning in hamsters given injections of alkaloid extracts from tall larkspur (Delphinium barbeyi), to determine if larkspur had reinforcing or negative properties sufficient to cause place avoidance or preferen...

"Learning-in-Action" and "Learning Inaction": Advancing the Theory and Practice of Critical Action Learning

ERIC Educational Resources Information Center

Vince, Russ

2008-01-01

This paper seeks to improve our understanding of the emotional and political dynamics that are generated (and too often avoided) in action learning. The idea at the centre of the paper is a distinction between "learning-in-action" and "learning inaction". The phrase "learning-in-action" represents the value of action…

Learning to Obtain Reward, but Not Avoid Punishment, Is Affected by Presence of PTSD Symptoms in Male Veterans: Empirical Data and Computational Model

PubMed Central

Myers, Catherine E.; Moustafa, Ahmed A.; Sheynin, Jony; VanMeenen, Kirsten M.; Gilbertson, Mark W.; Orr, Scott P.; Beck, Kevin D.; Pang, Kevin C. H.; Servatius, Richard J.

2013-01-01

Post-traumatic stress disorder (PTSD) symptoms include behavioral avoidance which is acquired and tends to increase with time. This avoidance may represent a general learning bias; indeed, individuals with PTSD are often faster than controls on acquiring conditioned responses based on physiologically-aversive feedback. However, it is not clear whether this learning bias extends to cognitive feedback, or to learning from both reward and punishment. Here, male veterans with self-reported current, severe PTSD symptoms (PTSS group) or with few or no PTSD symptoms (control group) completed a probabilistic classification task that included both reward-based and punishment-based trials, where feedback could take the form of reward, punishment, or an ambiguous “no-feedback” outcome that could signal either successful avoidance of punishment or failure to obtain reward. The PTSS group outperformed the control group in total points obtained; the PTSS group specifically performed better than the control group on reward-based trials, with no difference on punishment-based trials. To better understand possible mechanisms underlying observed performance, we used a reinforcement learning model of the task, and applied maximum likelihood estimation techniques to derive estimated parameters describing individual participants’ behavior. Estimations of the reinforcement value of the no-feedback outcome were significantly greater in the control group than the PTSS group, suggesting that the control group was more likely to value this outcome as positively reinforcing (i.e., signaling successful avoidance of punishment). This is consistent with the control group’s generally poorer performance on reward trials, where reward feedback was to be obtained in preference to the no-feedback outcome. Differences in the interpretation of ambiguous feedback may contribute to the facilitated reinforcement learning often observed in PTSD patients, and may in turn provide new insight into how pathological behaviors are acquired and maintained in PTSD. PMID:24015254

Social Phobia

MedlinePlus

... also unintentionally set an example by avoiding certain social interactions. A shy child who watches this learns that socializing is uncomfortable, distressing, and something to avoid. ... anxiety. People who constantly receive critical or disapproving ...

Research report: variations on the theme of avoidance as compensations during unsuccessful reading performance.

PubMed

Damico, Jack S; Abendroth, Kathleen J; Nelson, Ryan L; Lynch, Karen E; Damico, Holly L

2011-08-01

This research report provides additional data, manifestations and discussion about avoidance strategies employed by a language-learning disabled student during reading activities. Rather than seeing avoidance as due to random distractions or oppositional behaviours, these data provide a rationale for viewing many types of avoidance as systematic and compensatory efforts to sustain interactional success in the emergence of linguistic difficulty.

RGD and polyhistidine tumor homing peptides potentiates the action of human Maspin as an antineoplastic candidate.

PubMed

Yin, Runting; Guo, Le; Zhang, Jie; Liu, Guangzhao; Yao, Wenjuan; Zhu, Hongyan; Xu, Xiaole; Zhang, Wei

2016-07-01

Maspin, a non-inhibitory member of serine protease family, acts as an effective tumor suppressor by inhibiting cell inhesion and mobility. We found that exogenous wild-type rMaspin had a low effect on tumor growth in vivo. However, when the peptide Arg-Gly-Asp-hexahistidine (RGD-6His) was introduced into rMaspin, the modified rMaspin showed significant inhibitory activity in angiogenic assays and tumor-bearing animal models. Overall, our data suggested that both the RGD and hexahistidine fragments contributed to improve the fusion protein activity and polyhistidine peptide could be considered as flexible linker to separate RGD and Maspin moieties to avoid function interference. Besides, it is an efficient tag to achieve purified recombinant proteins. Furthermore, rMaspin fusing with RGD and hexahistidine could be a viable anticancer candidate.

Heart failure - discharge

MedlinePlus

... Avoid fatty foods. Stay away from fast-food restaurants. Avoid some prepared and frozen foods. Learn fast ... A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among ...

Role of Dopamine Receptors Subtypes, D1-Like and D2-Like, within the Nucleus Accumbens Subregions, Core and Shell, on Memory Consolidation in the One-Trial Inhibitory Avoidance Task

ERIC Educational Resources Information Center

Manago, Francesca; Castellano, Claudio; Oliverio, Alberto; Mele, Andrea; De Leonibus, Elvira

2009-01-01

Recent evidence demonstrated that dopamine within the nucleus accumbens mediates consolidation of both associative and nonassociative memories. However, the specific contribution of the nucleus accumbens subregions, core and shell, and of D1 and D2 receptors subtypes has not been yet clarified. The aim of this study was, therefore, to directly…

Post-Retrieval Effects of ICV Infusions of Hemicholinium in Mice Are Dependent on the Age of the Original Memory

ERIC Educational Resources Information Center

Boccia, Mariano M.; Blake, Mariano G.; Acosta, Gabriela B.; Baratti, Carlos M.

2006-01-01

CF-1 male mice were trained in an inhibitory avoidance task using a high footshock (1,2 mA, 50 Hz, 1 sec) in order to reduce the influence of extinction on retention performance. At 2, 7, 14, or 30 d after training, the first retention test was performed and hemicholinium (HC-3, 1.0 microgram/mice), a specific inhibitor of high-affinity choline…

Unsupervised learning of contextual constraints in neural networks for simultaneous visual processing of multiple objects

NASA Astrophysics Data System (ADS)

Marshall, Jonathan A.

1992-12-01

A simple self-organizing neural network model, called an EXIN network, that learns to process sensory information in a context-sensitive manner, is described. EXIN networks develop efficient representation structures for higher-level visual tasks such as segmentation, grouping, transparency, depth perception, and size perception. Exposure to a perceptual environment during a developmental period serves to configure the network to perform appropriate organization of sensory data. A new anti-Hebbian inhibitory learning rule permits superposition of multiple simultaneous neural activations (multiple winners), while maintaining contextual consistency constraints, instead of forcing winner-take-all pattern classifications. The activations can represent multiple patterns simultaneously and can represent uncertainty. The network performs parallel parsing, credit attribution, and simultaneous constraint satisfaction. EXIN networks can learn to represent multiple oriented edges even where they intersect and can learn to represent multiple transparently overlaid surfaces defined by stereo or motion cues. In the case of stereo transparency, the inhibitory learning implements both a uniqueness constraint and permits coactivation of cells representing multiple disparities at the same image location. Thus two or more disparities can be active simultaneously without interference. This behavior is analogous to that of Prazdny's stereo vision algorithm, with the bonus that each binocular point is assigned a unique disparity. In a large implementation, such a NN would also be able to represent effectively the disparities of a cloud of points at random depths, like human observers, and unlike Prazdny's method

Network congestion control algorithm based on Actor-Critic reinforcement learning model

NASA Astrophysics Data System (ADS)

Xu, Tao; Gong, Lina; Zhang, Wei; Li, Xuhong; Wang, Xia; Pan, Wenwen

2018-04-01

Aiming at the network congestion control problem, a congestion control algorithm based on Actor-Critic reinforcement learning model is designed. Through the genetic algorithm in the congestion control strategy, the network congestion problems can be better found and prevented. According to Actor-Critic reinforcement learning, the simulation experiment of network congestion control algorithm is designed. The simulation experiments verify that the AQM controller can predict the dynamic characteristics of the network system. Moreover, the learning strategy is adopted to optimize the network performance, and the dropping probability of packets is adaptively adjusted so as to improve the network performance and avoid congestion. Based on the above finding, it is concluded that the network congestion control algorithm based on Actor-Critic reinforcement learning model can effectively avoid the occurrence of TCP network congestion.

Visual learning in drosophila: application on a roving robot and comparisons

NASA Astrophysics Data System (ADS)

Arena, P.; De Fiore, S.; Patané, L.; Termini, P. S.; Strauss, R.

2011-05-01

Visual learning is an important aspect of fly life. Flies are able to extract visual cues from objects, like colors, vertical and horizontal distributedness, and others, that can be used for learning to associate a meaning to specific features (i.e. a reward or a punishment). Interesting biological experiments show trained stationary flying flies avoiding flying towards specific visual objects, appearing on the surrounding environment. Wild-type flies effectively learn to avoid those objects but this is not the case for the learning mutant rutabaga defective in the cyclic AMP dependent pathway for plasticity. A bio-inspired architecture has been proposed to model the fly behavior and experiments on roving robots were performed. Statistical comparisons have been considered and mutant-like effect on the model has been also investigated.

Studies of learned helplessness in honey bees (Apis mellifera ligustica).

PubMed

Dinges, Christopher W; Varnon, Christopher A; Cota, Lisa D; Slykerman, Stephen; Abramson, Charles I

2017-04-01

The current study reports 2 experiments investigating learned helplessness in the honey bee (Apis mellifera ligustica). In Experiment 1, we used a traditional escape method but found the bees' activity levels too high to observe changes due to treatment conditions. The bees were not able to learn in this traditional escape procedure; thus, such procedures may be inappropriate to study learned helplessness in honey bees. In Experiment 2, we used an alternative punishment, or passive avoidance, method to investigate learned helplessness. Using a master and yoked design where bees were trained as either master or yoked and tested as either master or yoked, we found that prior training with unavoidable and inescapable shock in the yoked condition interfered with avoidance and escape behavior in the later master condition. Unlike control bees, learned helplessness bees failed to restrict their movement to the safe compartment following inescapable shock. Unlike learned helplessness studies in other animals, no decrease in general activity was observed. Furthermore, we did not observe a "freezing" response to inescapable aversive stimuli-a phenomenon, thus far, consistently observed in learned helplessness tests with other species. The bees, instead, continued to move back and forth between compartments despite punishment in the incorrect compartment. These findings suggest that, although traditional escape methods may not be suitable, honey bees display learned helplessness in passive avoidance procedures. Thus, regardless of behavioral differences from other species, honey bees can be a unique invertebrate model organism for the study of learned helplessness. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Lessons Learned.

ERIC Educational Resources Information Center

Hassell, Kim Dale

2000-01-01

Discusses the common mistakes in school design and construction and how to avoid them. Mistake avoidance in mastering planning, site acquisition, drawing changes, budgeting, school design process, construction management, and the architect's role are highlighted. (GR)

Impairment of learning and memory after photothrombosis of the prefrontal cortex in rat brain: effects of Noopept.

PubMed

Romanova, G A; Shakova, F M; Gudasheva, T A; Ostrovskaya, R U

2002-12-01

Experiments were performed on rats trained conditioned passive avoidance response. Acquisition and retention of memory traces were impaired after photothrombosis of the prefrontal cortex. The acyl-prolyl-containing dipeptide Noopept facilitated retention and retrieval of a conditioned passive avoidance response, normalized learning capacity in animals with ischemic damage to the cerebral cortex, and promoted finish training in rats with hereditary learning deficit. These results show that Noopept improves all three stages of memory. It should be emphasized that the effect of Noopept was most pronounced in animals with impaired mnesic function.

Aversive olfactory associative memory loses odor specificity over time

PubMed Central

König, Christian; Antwi-Adjei, Emmanuel; Ganesan, Mathangi; Kilonzo, Kasyoka; Viswanathan, Vignesh; Durairaja, Archana; Voigt, Anne

2017-01-01

ABSTRACT Avoiding associatively learned predictors of danger is crucial for survival. Aversive memories can, however, become counter-adaptive when they are overly generalized to harmless cues and contexts. In a fruit fly odor–electric shock associative memory paradigm, we found that learned avoidance lost its specificity for the trained odor and became general to novel odors within a day of training. We discuss the possible neural circuit mechanisms of this effect and highlight the parallelism to over-generalization of learned fear behavior after an incubation period in rodents and humans, with due relevance for post-traumatic stress disorder. PMID:28468811

Co-Evolution of Social Learning and Evolutionary Preparedness in Dangerous Environments

PubMed Central

Lindström, Björn; Selbing, Ida; Olsson, Andreas

2016-01-01

Danger is a fundamental aspect of the lives of most animals. Adaptive behavior therefore requires avoiding actions, objects, and environments associated with danger. Previous research has shown that humans and non-human animals can avoid such dangers through two types of behavioral adaptions, (i) genetic preparedness to avoid certain stimuli or actions, and (ii) social learning. These adaptive mechanisms reduce the fitness costs associated with danger but still allow flexible behavior. Despite the empirical prevalence and importance of both these mechanisms, it is unclear when they evolve and how they interact. We used evolutionary agent-based simulations, incorporating empirically based learning mechanisms, to clarify if preparedness and social learning typically both evolve in dangerous environments, and if these mechanisms generally interact synergistically or antagonistically. Our simulations showed that preparedness and social learning often co-evolve because they provide complimentary benefits: genetic preparedness reduced foraging efficiency, but resulted in a higher rate of survival in dangerous environments, while social learning generally came to dominate the population, especially when the environment was stochastic. However, even in this case, genetic preparedness reliably evolved. Broadly, our results indicate that the relationship between preparedness and social learning is important as it can result in trade-offs between behavioral flexibility and safety, which can lead to seemingly suboptimal behavior if the evolutionary environment of the organism is not taken into account. PMID:27487079

Co-Evolution of Social Learning and Evolutionary Preparedness in Dangerous Environments.

PubMed

Lindström, Björn; Selbing, Ida; Olsson, Andreas

2016-01-01

Danger is a fundamental aspect of the lives of most animals. Adaptive behavior therefore requires avoiding actions, objects, and environments associated with danger. Previous research has shown that humans and non-human animals can avoid such dangers through two types of behavioral adaptions, (i) genetic preparedness to avoid certain stimuli or actions, and (ii) social learning. These adaptive mechanisms reduce the fitness costs associated with danger but still allow flexible behavior. Despite the empirical prevalence and importance of both these mechanisms, it is unclear when they evolve and how they interact. We used evolutionary agent-based simulations, incorporating empirically based learning mechanisms, to clarify if preparedness and social learning typically both evolve in dangerous environments, and if these mechanisms generally interact synergistically or antagonistically. Our simulations showed that preparedness and social learning often co-evolve because they provide complimentary benefits: genetic preparedness reduced foraging efficiency, but resulted in a higher rate of survival in dangerous environments, while social learning generally came to dominate the population, especially when the environment was stochastic. However, even in this case, genetic preparedness reliably evolved. Broadly, our results indicate that the relationship between preparedness and social learning is important as it can result in trade-offs between behavioral flexibility and safety, which can lead to seemingly suboptimal behavior if the evolutionary environment of the organism is not taken into account.

Critical role of CA1 muscarinic receptors on memory acquisition deficit induced by total (TSD) and REM sleep deprivation (RSD).

PubMed

Javad-Moosavi, Bibi-Zahra; Vaezi, Gholamhassan; Nasehi, Mohammad; Haeri-Rouhani, Seyed-Ali; Zarrindast, Mohammad-Reza

2017-10-03

Despite different theories regarding sleep physiological function, an overall census indicates that sleep is useful for neural plasticity which eventually strengthens cognition and brain performance. Different studies show that sleep deprivation (SD) leads to impaired learning and hippocampus dependent memory. According to some studies, cholinergic system plays an important role in sleep (particularly REM sleep), learning, memory, and its retrieval. So this study has been designed to investigate the effect of CA1 Cholinergic Muscarinic Receptors on memory acquisition deficit induced by total sleep deprivation (TSD) and REM sleep deprivation (RSD). A modified water box (locomotor activity may be provide a limiting factor in this method of SD) or multiple platforms were used for induction of TSD or RSD, respectively. Inhibitory passive avoidance apparatus has been used to determine the effects of SD and its changes by physostigmine (as cholinesterase inhibitor) or scopolamine (muscarinic receptor antagonist) on memory formation. Because locomotor activity and pain perception induce critical roles in passive avoidance memory formation, we also measured these factors by open field and hot-plate instruments, respectively. The results showed that TSD and RSD for 24 hours impaired memory formation but they did not alter locomotor activity. TSD also induced analgesia effect, but RSD did not alter it. Intra-CA1 injection of physostigmine (0.0001μg/rat) and scopolamine (0.01μg/rat) did not alter memory acquisition in the sham-TSD or sham-RSD, by themselves. Moreover, intra-CA1 injection of sub-threshold dose of physostigmine (0.0001μg/rat) and scopolamine (0.01μg/rat) could restore the memory acquisition deficit induced by RSD, while scopolamine could restore TSD-induced amnesia. Both drugs reversed analgesia induced by TSD. None of previous interventions altered locomotor activity. According to this study, CA1 cholinergic muscarinic receptors play an important role in amnesia induced by both TSD and RSD. However further studies are needed for showing cellular and molecular mechanisms of surprising result of similar pharmacological effects using compounds with opposite profiles. Copyright © 2016. Published by Elsevier Inc.

Effects of problem-based learning by learning style in medical education.

PubMed

Chae, Su-Jin

2012-12-01

Although problem-based learning (PBL) has been popularized in many colleges, few studies have analyzed the relationship between individual differences and PBL. The purpose of this study was to analyze the relationship between learning style and the perception on the effects of PBL. Grasha-Riechmann Student Learning Style Scales was used to assess the learning styles of 38 students at Ajou University School of Medicine who were enrolled in a respiratory system course in 2011. The data were analyzed by regression analysis and Spearman correlation analysis. By regression analysis, dependent beta=0.478) and avoidant styles (beta=-0.815) influenced the learner's satisfaction with PBL. By Spearman correlation analysis, there was significant link between independent, dependent, and avoidant styles and the perception of the effect of PBL. There are few significant relationships between learning style and the perception of the effects of PBL. We must determine how to teach students with different learning styles and the factors that influence PBL.

Learning to speciate: The biased learning of mate preferences promotes adaptive radiation

PubMed Central

Gilman, R. Tucker; Kozak, Genevieve M.

2015-01-01

Bursts of rapid repeated speciation called adaptive radiations have generated much of Earth's biodiversity and fascinated biologists since Darwin, but we still do not know why some lineages radiate and others do not. Understanding what causes assortative mating to evolve rapidly and repeatedly in the same lineage is key to understanding adaptive radiation. Many species that have undergone adaptive radiations exhibit mate preference learning, where individuals acquire mate preferences by observing the phenotypes of other members of their populations. Mate preference learning can be biased if individuals also learn phenotypes to avoid in mates, and shift their preferences away from these avoided phenotypes. We used individual‐based computational simulations to study whether biased and unbiased mate preference learning promotes ecological speciation and adaptive radiation. We found that ecological speciation can be rapid and repeated when mate preferences are biased, but is inhibited when mate preferences are learned without bias. Our results suggest that biased mate preference learning may play an important role in generating animal biodiversity through adaptive radiation. PMID:26459795

Avoidance of Heights on the Visual Cliff in Newly Walking Infants

ERIC Educational Resources Information Center

Witherington, David C.; Campos, Joseph J.; Anderson, David I.; Lejeune, Laure; Seah, Eileen

2005-01-01

Work with infants on the "visual cliff" links avoidance of drop-offs to experience with self-produced locomotion. Adolph's (2002) research on infants' perception of slope and gap traversability suggests that learning to avoid falling down is highly specific to the postural context in which it occurs. Infants, for example, who have…

The development of inhibitory control in preschool children: effects of "executive skills" training.

PubMed

Dowsett, S M; Livesey, D J

2000-03-01

As one of several processes involved in the executive functioning of the cognitive system, inhibitory control plays a significant role in determining how various mental processes work together in the successful performance of a task. Studies of response inhibition have shown that although 3-year-old children have the cognitive capacity to learn the rules required for response control, indicated by the correct verbal response, developmental constraints prevent them from withholding the correct response (Bell & Livesey, 1985; Livesey & Morgan, 1991). Some argue that these abulic dissociations are relative to children's ability to reflect on the rules required for response control (Zelazo, Reznick, & Pinon, 1995). The current study showed that repeated exposure to tasks facilitating the acquisition of increasingly complex rule structures could improve inhibitory control (as measured by a go/no-go discrimination learning task), even in children aged 3 years. These tasks included a variant of Diamond and Boyer's (1989) modified version of the Wisconsin Card Sort Task and a simplification of the change paradigm (Logan & Burkell, 1986). It is argued that experience with these tasks increased the acquisition of complex rules by placing demands on executive processes. This includes response control and other executive functions, such as representational flexibility, the ability to maintain information in working memory, the selective control of attention, and proficiency at error correction. The role of experiential variables in the development of inhibitory control is discussed in terms of the interaction between neural development and appropriate executive task experience in the early years. Copyright 2000 John Wiley & Sons, Inc.

Estrogenic involvement in social learning, social recognition and pathogen avoidance.

PubMed

Choleris, Elena; Clipperton-Allen, Amy E; Phan, Anna; Valsecchi, Paola; Kavaliers, Martin

2012-04-01

Sociality comes with specific cognitive skills that allow the proper processing of information about others (social recognition), as well as of information originating from others (social learning). Because sociality and social interactions can also facilitate the spread of infection among individuals the ability to recognize and avoid pathogen threat is also essential. We review here various studies primarily from the rodent literature supporting estrogenic involvement in the regulation of social recognition, social learning (socially acquired food preferences and mate choice copying) and the recognition and avoidance of infected and potentially infected individuals. We consider both genomic and rapid estrogenic effects involving estrogen receptors α and β, and G-protein coupled estrogen receptor 1, along with their interactions with neuropeptide systems in the processing of social stimuli and the regulation and expression of these various socially relevant behaviors. Copyright © 2012 Elsevier Inc. All rights reserved.

Deficient inhibitory processing in trait anxiety: Evidence from context-dependent fear learning, extinction recall and renewal.

PubMed

Haaker, J; Lonsdorf, T B; Schümann, D; Menz, M; Brassen, S; Bunzeck, N; Gamer, M; Kalisch, R

2015-10-01

Impaired fear inhibition has been described as a hallmark of pathological anxiety. We aimed at further characterizing the relation between fear inhibition and anxiety by extending previous work to contextual safety stimuli as well as to dimensional scores of trait anxiety in a large sample. We employed a validated paradigm for context-dependent fear acquisition/extinction (day 1) and retrieval/expression (day 2) in 377 healthy individuals. This large sample size allowed the employment of a dimensional rather than binary approach with respect to individual differences in trait anxiety. We observed a positive correlation on day 1 between trait anxiety with all CSs that possess an inherent inhibitory component, conveyed either by reliable non-reinforcement of a specific CS in a dangerous context (safe cue) or by the context itself (i.e., safe context). No correlation however was observed for a CS that possesses excitatory (threatening) properties only. These results were observed during fear learning (day 1) for US expectancy and fear ratings but not for SCRs. No such pattern was evident during fear and extinction retrieval/expression (day 2). We provide further evidence that high trait anxiety is associated with the inability to take immediate advantage of environmental safety cues (cued and contextual), which might represent a promising trans-diagnostic marker for different anxiety disorders. Consequently, the incorporation of methods to optimize inhibitory learning in current cognitive behavioral therapy (CBT) treatments might open up a promising avenue for precision medicine in anxiety disorders. We did not include patients diagnosed with anxiety disorders. Copyright © 2015. Published by Elsevier B.V.

Action Learning: Avoiding Conflict or Enabling Action

ERIC Educational Resources Information Center

Corley, Aileen; Thorne, Ann

2006-01-01

Action learning is based on the premise that action and learning are inextricably entwined and it is this potential, to enable action, which has contributed to the growth of action learning within education and management development programmes. However has this growth in action learning lead to an evolution or a dilution of Revan's classical…

A Method of Cross-Level Frequent Pattern Mining for Web-Based Instruction

ERIC Educational Resources Information Center

Huang, Yueh-Min; Chen, Juei-Nan; Cheng, Shu-Chen

2007-01-01

Due to the rise of e-Learning, more and more useful learning materials are open to public access. Therefore, an appropriate learning suggestion mechanism is an important tool to enable learners to work more efficiently. A smoother learning process increases the learning effect, avoiding unnecessarily difficult concepts and disorientation during…

The Effects of Integrating Social Learning Environment with Online Learning

ERIC Educational Resources Information Center

Raspopovic, Miroslava; Cvetanovic, Svetlana; Medan, Ivana; Ljubojevic, Danijela

2017-01-01

The aim of this paper is to present the learning and teaching styles using the Social Learning Environment (SLE), which was developed based on the computer supported collaborative learning approach. To avoid burdening learners with multiple platforms and tools, SLE was designed and developed in order to integrate existing systems, institutional…

Stop Saying That It Is Wrong! Psychophysiological, Cognitive, and Metacognitive Markers of Children’s Sensitivity to Punishment

PubMed Central

Gonzalez-Gadea, Maria Luz; Scheres, Anouk; Tobon, Carlos Andres; Damm, Juliane; Baez, Sandra; Huepe, David; Marino, Julian; Marder, Sandra; Manes, Facundo; Abrevaya, Sofia; Ibanez, Agustin

2015-01-01

Neurodevelopmental evidence suggests that children’s main decision-making strategy is to avoid options likely to induce punishment. However, the cognitive and affective factors contributing to children’s avoidance to high punishment frequency remain unknown. The present study explored psychophysiological, cognitive, and metacognitive processes associated with sensitivity to punishment frequency. We evaluated 54 participants (between 8 and 15 years old) with a modified Iowa Gambling Task for children (IGT-C) which included options with varying long-term profit and punishment frequencies. Skin conductance responses (SCRs) were recorded during this task. Additionally, we assessed IGT-C metacognitive knowledge, fluid intelligence, and executive functions. Participants exhibited behavioral avoidance and high anticipatory SCRs to options with high frequency of punishment. Moreover, age, IGT-C metacognitive knowledge, and inhibitory control were associated with individual differences in sensitivity to punishment frequency. Our results suggest that children’s preference for infrequently punished decisions is partially explained by psychophysiological signals as well as task complexity and development of cognitive control. PMID:26218584

Stop Saying That It Is Wrong! Psychophysiological, Cognitive, and Metacognitive Markers of Children's Sensitivity to Punishment.

PubMed

Gonzalez-Gadea, Maria Luz; Scheres, Anouk; Tobon, Carlos Andres; Damm, Juliane; Baez, Sandra; Huepe, David; Marino, Julian; Marder, Sandra; Manes, Facundo; Abrevaya, Sofia; Ibanez, Agustin

2015-01-01

Neurodevelopmental evidence suggests that children's main decision-making strategy is to avoid options likely to induce punishment. However, the cognitive and affective factors contributing to children's avoidance to high punishment frequency remain unknown. The present study explored psychophysiological, cognitive, and metacognitive processes associated with sensitivity to punishment frequency. We evaluated 54 participants (between 8 and 15 years old) with a modified Iowa Gambling Task for children (IGT-C) which included options with varying long-term profit and punishment frequencies. Skin conductance responses (SCRs) were recorded during this task. Additionally, we assessed IGT-C metacognitive knowledge, fluid intelligence, and executive functions. Participants exhibited behavioral avoidance and high anticipatory SCRs to options with high frequency of punishment. Moreover, age, IGT-C metacognitive knowledge, and inhibitory control were associated with individual differences in sensitivity to punishment frequency. Our results suggest that children's preference for infrequently punished decisions is partially explained by psychophysiological signals as well as task complexity and development of cognitive control.

Preferential Representation of Past Outcome Information and Future Choice Behavior by Putative Inhibitory Interneurons Rather Than Putative Pyramidal Neurons in the Primate Dorsal Anterior Cingulate Cortex.

PubMed

Kawai, Takashi; Yamada, Hiroshi; Sato, Nobuya; Takada, Masahiko; Matsumoto, Masayuki

2018-05-02

The dorsal anterior cingulate cortex (dACC) plays crucial roles in monitoring the outcome of a choice and adjusting a subsequent choice behavior based on the outcome information. In the present study, we investigated how different types of dACC neurons, that is, putative pyramidal neurons and putative inhibitory interneurons, contribute to these processes. We analyzed single-unit database obtained from the dACC in monkeys performing a reversal learning task. The monkey was required to adjust choice behavior from past outcome experiences. Depending on their action potential waveforms, the recorded neurons were classified into putative pyramidal neurons and putative inhibitory interneurons. We found that these neurons do not equally contribute to outcome monitoring and behavioral adjustment. Although both neuron types evenly responded to the current outcome, a larger proportion of putative inhibitory interneurons than putative pyramidal neurons stored the information about the past outcome. The putative inhibitory interneurons further represented choice-related signals more frequently, such as whether the monkey would shift the last choice to an alternative at the next choice opportunity. Our findings suggest that putative inhibitory interneurons, which are thought not to project to brain areas outside the dACC, preferentially transmit signals that would adjust choice behavior based on past outcome experiences.

[Delayed reactions of active avoidance in white rats under conditions of an alternative choice].

PubMed

Ioseliani, T K; Sikharulidze, N I; Kadagishvili, A Ia; Mitashvili, E G

1995-01-01

It was shown that if the rats had been learned and then tested using conventional pain punishment of erroneous choice they were able to solve the problem of alternative choice only in the period of immediate action of conditioned stimuli. If the pain punishment for erroneously chosen compartment had not been applied in animal learning and testing, rats successfully solved the problem of alternative choice even after 5-second delay. Introduction of pain punishment led to the frustration of earlier elaborated delayed avoidance reactions. Analysis of the obtained results allows us to argue that the apparent incapability of white rats for solving the problems of delayed avoidance is caused by simultaneous action of two different mechanisms, i.e., those of the active and passive avoidance rather than short-term memory deficit.

Cross-lagged relations between teacher and parent ratings of children's task avoidance and different literacy skills.

PubMed

Georgiou, George K; Hirvonen, Riikka; Manolitsis, George; Nurmi, Jari-Erik

2017-09-01

Task avoidance is a significant predictor of literacy skills. However, it remains unclear whether the relation between the two is reciprocal and whether it is affected by the type of literacy outcome, who is rating children's task avoidance, and the children's gender. The purpose of this longitudinal study was to examine the cross-lagged relations between teacher and parent ratings of children's task avoidance and different literacy skills. One hundred and seventy-two Greek children (91 girls, 81 boys) were followed from Grade 1 to Grade 3. Children were assessed on reading accuracy, reading fluency, and spelling to dictation. Parents and teachers rated the children's task-avoidant behaviour. Results of structural equation modelling showed that the cross-lagged relations varied as a function of the literacy outcome, who rated the children's task avoidance, and children's gender. Earlier reading and spelling performance predicted subsequent parent-rated task avoidance, but parent-rated task avoidance did not predict subsequent reading and spelling performance (with the exception of spelling in Grade 3). Teacher-rated task avoidance and reading fluency/spelling had a reciprocal relationship over time. In addition, the effects of teacher-rated task avoidance on future spelling were significantly stronger in boys than in girls. This suggests that poor reading and spelling performance can lead to subsequent task avoidance in both classroom and home situations. The fact that task avoidance permeates across different learning environments is alarming and calls for joint action from both parents and teachers to mitigate its negative impact on learning. © 2017 The British Psychological Society.

E-I balance emerges naturally from continuous Hebbian learning in autonomous neural networks.

PubMed

Trapp, Philip; Echeveste, Rodrigo; Gros, Claudius

2018-06-12

Spontaneous brain activity is characterized in part by a balanced asynchronous chaotic state. Cortical recordings show that excitatory (E) and inhibitory (I) drivings in the E-I balanced state are substantially larger than the overall input. We show that such a state arises naturally in fully adapting networks which are deterministic, autonomously active and not subject to stochastic external or internal drivings. Temporary imbalances between excitatory and inhibitory inputs lead to large but short-lived activity bursts that stabilize irregular dynamics. We simulate autonomous networks of rate-encoding neurons for which all synaptic weights are plastic and subject to a Hebbian plasticity rule, the flux rule, that can be derived from the stationarity principle of statistical learning. Moreover, the average firing rate is regulated individually via a standard homeostatic adaption of the bias of each neuron's input-output non-linear function. Additionally, networks with and without short-term plasticity are considered. E-I balance may arise only when the mean excitatory and inhibitory weights are themselves balanced, modulo the overall activity level. We show that synaptic weight balance, which has been considered hitherto as given, naturally arises in autonomous neural networks when the here considered self-limiting Hebbian synaptic plasticity rule is continuously active.

The Current Status of Somatostatin-Interneurons in Inhibitory Control of Brain Function and Plasticity

PubMed Central

2016-01-01

The mammalian neocortex contains many distinct inhibitory neuronal populations to balance excitatory neurotransmission. A correct excitation/inhibition equilibrium is crucial for normal brain development, functioning, and controlling lifelong cortical plasticity. Knowledge about how the inhibitory network contributes to brain plasticity however remains incomplete. Somatostatin- (SST-) interneurons constitute a large neocortical subpopulation of interneurons, next to parvalbumin- (PV-) and vasoactive intestinal peptide- (VIP-) interneurons. Unlike the extensively studied PV-interneurons, acknowledged as key components in guiding ocular dominance plasticity, the contribution of SST-interneurons is less understood. Nevertheless, SST-interneurons are ideally situated within cortical networks to integrate unimodal or cross-modal sensory information processing and therefore likely to be important mediators of experience-dependent plasticity. The lack of knowledge on SST-interneurons partially relates to the wide variety of distinct subpopulations present in the sensory neocortex. This review informs on those SST-subpopulations hitherto described based on anatomical, molecular, or electrophysiological characteristics and whose functional roles can be attributed based on specific cortical wiring patterns. A possible role for these subpopulations in experience-dependent plasticity will be discussed, emphasizing on learning-induced plasticity and on unimodal and cross-modal plasticity upon sensory loss. This knowledge will ultimately contribute to guide brain plasticity into well-defined directions to restore sensory function and promote lifelong learning. PMID:27403348

Peripersonal Space and Margin of Safety around the Body: Learning Visuo-Tactile Associations in a Humanoid Robot with Artificial Skin.

PubMed

Roncone, Alessandro; Hoffmann, Matej; Pattacini, Ugo; Fadiga, Luciano; Metta, Giorgio

2016-01-01

This paper investigates a biologically motivated model of peripersonal space through its implementation on a humanoid robot. Guided by the present understanding of the neurophysiology of the fronto-parietal system, we developed a computational model inspired by the receptive fields of polymodal neurons identified, for example, in brain areas F4 and VIP. The experiments on the iCub humanoid robot show that the peripersonal space representation i) can be learned efficiently and in real-time via a simple interaction with the robot, ii) can lead to the generation of behaviors like avoidance and reaching, and iii) can contribute to the understanding the biological principle of motor equivalence. More specifically, with respect to i) the present model contributes to hypothesizing a learning mechanisms for peripersonal space. In relation to point ii) we show how a relatively simple controller can exploit the learned receptive fields to generate either avoidance or reaching of an incoming stimulus and for iii) we show how the robot can select arbitrary body parts as the controlled end-point of an avoidance or reaching movement.

Investigation of Neuropsychopharmacological Effects of a Polyherbal Formulation on the Learning and Memory Process in Rats

PubMed Central

Shah, JS; Goyal, RK

2011-01-01

Objective: To investigate the neuropsychopharmacological effect of a polyherbal formulation (PHF) on the learning and memory processes in rats. Materials and Methods: PHF contains Withania somnifera (Ashwagandha), Nardostachys jatamansi (Jatamansi), Rauwolfia serpentina (Sarpagandha), Evolvulus alsinoides (Shankhpushpi), Asparagus racemosus (Shatavari), Emblica officinalis (Amalki), Mucuna pruriens (Kauch bij extract), Hyoscyamus niger (Khurasani Ajmo), Mineral resin (Shilajit), Pearl (Mukta Shukhti Pishti), and coral calcium (Praval pishti). Its effect (500 mg / kg, p.o.) on the learning and memory processes was tested. The activity of PHF on memory acquisition and retention was studied using passive avoidance learning and elevated plus maze model (EPM) in rats. Results: The animals treated with PHF showed a significant decrease in transfer latency as compared to the control group in EPM. PHF also produced significant improvement in passive avoidance acquisition and memory retrieval, as compared to the controls and reduced the latency to reach the shock free zone (SFZ) after 24 hours. Conclusion: The PHF produces significant improvement in passive avoidance acquisition and memory retrieval in rats, which needs further investigation. PMID:21731356

Amnesia of inhibitory avoidance by scopolamine is overcome by previous open-field exposure

PubMed Central

Colettis, Natalia C.; Snitcofsky, Marina; Kornisiuk, Edgar E.; Gonzalez, Emilio N.; Quillfeldt, Jorge A.

2014-01-01

The muscarinic cholinergic receptor (MAChR) blockade with scopolamine either extended or restricted to the hippocampus, before or after training in inhibitory avoidance (IA) caused anterograde or retrograde amnesia, respectively, in the rat, because there was no long-term memory (LTM) expression. Adult Wistar rats previously exposed to one or two open-field (OF) sessions of 3 min each (habituated), behaved as control animals after a weak though over-threshold training in IA. However, after OF exposure, IA LTM was formed and expressed in spite of an extensive or restricted to the hippocampus MAChR blockade. It was reported that during and after OF exposure and reexposure there was an increase in both hippocampal and cortical ACh release that would contribute to “prime the substrate,” e.g., by lowering the synaptic threshold for plasticity, leading to LTM consolidation. In the frame of the “synaptic tagging and capture” hypothesis, plasticity-related proteins synthesized during/after the previous OF could facilitate synaptic plasticity for IA in the same structure. However, IA anterograde amnesia by hippocampal protein synthesis inhibition with anisomycin was also prevented by two OF exposures, strongly suggesting that there would be alternative interpretations for the role of protein synthesis in memory formation and that another structure could also be involved in this “OF effect.” PMID:25322799

Cognitive deficits in adult rats by lead intoxication are related with regional specific inhibition of cNOS.

PubMed

García-Arenas, Guadalupe; Ramírez-Amaya, Victor; Balderas, Israela; Sandoval, Jimena; Escobar, Martha L; Ríos, Camilo; Bermúdez-Rattoni, Federico

2004-02-04

It is well known that lead can affect several cognitive abilities in developing animals. In this work, we investigate the effects of different sub-chronic lead doses (0, 65, 125, 250 and 500 ppm of lead acetate in their drinking water for 14 days) in the performance of male adult rats in a water maze, cue maze and inhibitory avoidance tasks. We found that the acquisition of these tasks was not affected by lead, however, the highest dosage of lead (500 ppm) impaired memory consolidation in spatial and inhibitory avoidance tasks, but not in cue maze task while the 250 ppm dose only affected retrieval of spatial memory. Additionally, hippocampal long-term potentiation (LTP) induction in the perforant path after exposing adult rats to different doses of lead was studied. LTP induction was affected in a dose-dependent manner, and treatments of 250 and 500 ppm completely blocked LTP. We investigated the effects of lead intoxication on the activity of constitutive nitric oxide synthase (cNOS) in different brain regions of adult animals. The activity of cNOS was significantly inhibited in the hippocampus and cerebellum but not in the frontal cortex and brain stem, although lead had accumulated in all brain regions. These results suggest that lead intoxication can impair memory in adult animals and this impairment might be related with region-specific effects on cNOS activity.

Cybernetic Service-Learning Course Development: Lessons Learned

ERIC Educational Resources Information Center

Marx, Jonathan I.; Miller, Lee Q.

2009-01-01

Although the title of the course, Combating Loneliness among Older People in Contemporary Society, states a clear goal, our service-learning class was shaped by five guiding parameters. By avoiding certain things, we allowed the course to self-organize and evolve into a learning experience beyond the one originally envisioned. This paper…

The Role of Inhibition in Avoiding Distraction by Salient Stimuli.

PubMed

Gaspelin, Nicholas; Luck, Steven J

2018-01-01

Researchers have long debated whether salient stimuli can involuntarily 'capture' visual attention. We review here evidence for a recently discovered inhibitory mechanism that may help to resolve this debate. This evidence suggests that salient stimuli naturally attempt to capture attention, but capture can be avoided if the salient stimulus is suppressed before it captures attention. Importantly, the suppression process can be more or less effective as a result of changing task demands or lapses in cognitive control. Converging evidence for the existence of this suppression mechanism comes from multiple sources, including psychophysics, eye-tracking, and event-related potentials (ERPs). We conclude that the evidence for suppression is strong, but future research will need to explore the nature and limits of this mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

Discrimination and avoidance learning in adult mice following developmental exposure to diisopropylfluorophosphate.

PubMed

Levi, Yifat; Kofman, Ora; Schwebel, Margalit; Shaldubina, Alona

2008-02-01

Exposure to acetylcholinesterase inhibitors during development was shown in the past to induce sex-dependent changes in locomotion and specific cognitive and emotional tests in rodents. Adult mice that had been treated with 0.5 mg/kg diisopropylfluorphosphate (DFP), on post-natal days 14-20 were tested on active avoidance and a set-shifting task. DFP pre-treatment did not affect the active avoidance task, but impaired performance on the extra-dimensional shift task. DFP-treated females showed more general deficits in the acquisition of simple discrimination, intra-dimensional shift, extra-dimensional shift and reversal learning. These data suggest that pre-weanling exposure to cholinesterase inhibitors may have long-term consequences on attentional capabilities.

Critical roles for anterior insula and dorsal striatum in punishment-based avoidance learning.

PubMed

Palminteri, Stefano; Justo, Damian; Jauffret, Céline; Pavlicek, Beth; Dauta, Aurélie; Delmaire, Christine; Czernecki, Virginie; Karachi, Carine; Capelle, Laurent; Durr, Alexandra; Pessiglione, Mathias

2012-12-06

The division of human learning systems into reward and punishment opponent modules is still a debated issue. While the implication of ventral prefrontostriatal circuits in reward-based learning is well established, the neural underpinnings of punishment-based learning remain unclear. To elucidate the causal implication of brain regions that were related to punishment learning in a previous functional neuroimaging study, we tested the effects of brain damage on behavioral performance, using the same task contrasting monetary gains and losses. Cortical and subcortical candidate regions, the anterior insula and dorsal striatum, were assessed in patients presenting brain tumor and Huntington disease, respectively. Both groups exhibited selective impairment of punishment-based learning. Computational modeling suggested complementary roles for these structures: the anterior insula might be involved in learning the negative value of loss-predicting cues, whereas the dorsal striatum might be involved in choosing between those cues so as to avoid the worst. Copyright © 2012 Elsevier Inc. All rights reserved.

Fostering Intrinsic Motivation, Learning Goals, and Fluid Beliefs of Intelligence among Struggling Readers: An Intervention Study

ERIC Educational Resources Information Center

Orkin, Melissa

2013-01-01

Beginning in elementary school, those students who struggle to acquire basic reading skills tend to demonstrate a stronger tendency towards task avoidance. As a result of their avoidant behaviors, students' reading ability progresses at a slower rate, which leads to further task evasion. The current study addressed task avoidance among…

The Developmental Dynamics of Task-Avoidant Behavior and Math Performance in Kindergarten and Elementary School

ERIC Educational Resources Information Center

Hirvonen, Riikka; Tolvanen, Asko; Aunola, Kaisa; Nurmi, Jari-Erik

2012-01-01

Besides cognitive factors, children's learning at school may be influenced by more dynamic phenomena, such as motivation and achievement-related task-avoidant behavior. The present study examined the developmental dynamics of task-avoidant behavior and math performance from kindergarten to Grade 4. A total of 225 children were tested for their…

Palatable food avoidance and acceptance learning with different stressors in female rats.

PubMed

Liang, N-C; Smith, M E; Moran, T H

2013-04-03

Stress activates the hypothalamus-pituitary-adrenal (HPA) axis leading to the release of glucocorticoids (GC). Increased activity of the HPA axis and GC exposure has been suggested to facilitate the development of obesity and metabolic syndrome. Nonetheless, different stressors can produce distinct effects on food intake and may support different directions of food learning e.g. avoidance or acceptance. This study examined whether interoceptive (LiCl and exendin-4) and restraint stress (RS) support similar or distinct food learning. Female rats were exposed to different stressors after their consumption of a palatable food (butter icing). After four palatable food-stress pairings, distinct intakes of the butter icing were observed in rats treated with different stressors. Rats that received butter icing followed by intraperitoneal injections of LiCl (42.3mg/kg) and exendin-4 (10μg/kg) completely avoided the palatable food with subsequent presentations. In contrast, rats experiencing RS paired with the palatable food increased their consumption of butter icing across trials and did so to a greater degree than rats receiving saline injections. These data indicate that interoceptive and psychosocial stressors support conditioned food avoidance and acceptance, respectively. Examination of c-Fos immunoreactivity revealed distinct neural activation by interoceptive and psychosocial stressors that could provide the neural basis underlying opposite direction of food acceptance learning. Published by Elsevier Ltd.

Palatable food avoidance and acceptance learning with different stressors in female rats

PubMed Central

Liang, Nu-Chu; Smith, Megan E.; Moran, Timothy H.

2013-01-01

Stress activates the hypothalamus- pituitary-adrenal (HPA) axis leading to the release of glucocorticoids (GC). Increased activity of the HPA axis and GC exposure has been suggested to facilitate the development of obesity and metabolic syndrome. Nonetheless, different stressors can produce distinct effects on food intake and may support different directions of food learning e.g. avoidance or acceptance. This study examined whether interoceptive (LiCl and exendin-4) and restraint stress support similar or distinct food learning. Female rats were exposed to different stressors after their consumption of a palatable food (butter icing). After 4 palatable food-stress pairings, distinct intakes of the butter icing were observed in rats treated with different stressors. Rats that received butter icing followed by intraperitoneal injections of LiCl (42.3 mg/Kg) and exendin-4 (10 μg/Kg) completely avoided the palatable food with subsequent presentations. In contrast, rats experiencing restraint stress paired with the palatable food increased their consumption of butter icing across trials and did so to a greater degree than rats receiving saline injections. These data indicate that interoceptive and psychosocial stressors support conditioned food avoidance and acceptance, respectively. Examination of c-Fos immunoreactivity revealed distinct neural activation by interoceptive and psychosocial stressors that could provide the neural basis underlying opposite direction of food acceptance learning. PMID:23380501

Integrating Book, Digital Content and Robot for Enhancing Elementary School Students' Learning of English

ERIC Educational Resources Information Center

Chen, Nian-Shing; Quadir, Benazir; Teng, Daniel C.

2011-01-01

Early school years are an important period to lay out the foundation for learning a second language. In addition to mastering the basic language skills and keeping the learning process fun, promoting a lifelong learning habit should also be emphasised. Motivating elementary school students to learn English and avoiding misconceptions associated…

The CD94/NKG2 family of receptors: from molecules and cells to clinical relevance.

PubMed

Borrego, Francisco; Masilamani, Madhan; Marusina, Alina I; Tang, Xiaobin; Coligan, John E

2006-01-01

Immune responses must be tightly regulated to avoid hyporesponsiveness on one hand or excessive inflammation and the development of autoimmunity (hyperresponsiveness) on the other hand. This balance is attained through the throttling of activating signals by inhibitory signals that ideally leads to an adequate immune response against an invader without excessive and extended inflammatory signals that promote the development of autoimmunity. The CD94/NKG2 family of receptors is composed of members with activating or inhibitory potential. These receptors are expressed predominantly on NK cells and a subset of CD8+ T cells, and they have been shown to play an important role in regulating responses against infected and tumorigenic cells. In this review, we discuss the current knowledge about this family of receptors, including ligand and receptor interaction, signaling, membrane dynamics, regulation of gene expression and their roles in disease regulation, infections, and cancer, and bone marrow transplantation.

Odor-evoked inhibition of olfactory sensory neurons drives olfactory perception in Drosophila.

PubMed

Cao, Li-Hui; Yang, Dong; Wu, Wei; Zeng, Xiankun; Jing, Bi-Yang; Li, Meng-Tong; Qin, Shanshan; Tang, Chao; Tu, Yuhai; Luo, Dong-Gen

2017-11-07

Inhibitory response occurs throughout the nervous system, including the peripheral olfactory system. While odor-evoked excitation in peripheral olfactory cells is known to encode odor information, the molecular mechanism and functional roles of odor-evoked inhibition remain largely unknown. Here, we examined Drosophila olfactory sensory neurons and found that inhibitory odors triggered outward receptor currents by reducing the constitutive activities of odorant receptors, inhibiting the basal spike firing in olfactory sensory neurons. Remarkably, this odor-evoked inhibition of olfactory sensory neurons elicited by itself a full range of olfactory behaviors from attraction to avoidance, as did odor-evoked olfactory sensory neuron excitation. These results indicated that peripheral inhibition is comparable to excitation in encoding sensory signals rather than merely regulating excitation. Furthermore, we demonstrated that a bidirectional code with both odor-evoked inhibition and excitation in single olfactory sensory neurons increases the odor-coding capacity, providing a means of efficient sensory encoding.

Plasticity of cortical inhibition in dystonia is impaired after motor learning and Paired-Associative Stimulation

PubMed Central

Meunier, Sabine; Russmann, Heike; Shamim, Ejaz; Lamy, Jean-Charles; Hallett, Mark

2012-01-01

Summary Artificial induction of plasticity by paired associative stimulation (PAS) in healthy subjects (HV) demonstrates Hebbian-like plasticity in selected inhibitory networks as well as excitatory ones. In a group of 17 patients with focal hand dystonia and a group of 19 HV, we evaluated how PAS and the learning of a simple motor task influence the circuits supporting long interval intracortical inhibition (LICI, reflecting activity of GABAB interneurons) and long latency afferent inhibition (LAI, reflecting activity of somatosensory inputs to the motor cortex). In HV, PAS and motor learning induced LTP-like plasticity of excitatory networks and a lasting decrease of LAI and LICI in the motor representation of the targeted or trained muscle. The better the motor performance, the larger was the decrease of LAI. Although motor performance in the patient group was similar to that of the control group, LAI did not decrease during the motor learning as it did in the control group. In contrast, LICI was normally modulated. In patients the results after PAS did not match those obtained after motor learning: LAI was paradoxically increased and LICI did not exhibit any change. In the normal situation, decreased excitability in inhibitory circuits after induction of LTP-like plasticity may help to shape the cortical maps according to the new sensorimotor task. In patients, the abnormal or absent modulation of afferent and intracortical long-interval inhibition might indicate maladaptive plasticity that possibly contributes to the difficulty that they have to learn a new sensorimotor task.“ PMID:22429246

Internationalizing Student Learning and Development

ERIC Educational Resources Information Center

Roberts, Dennis C.; Komives, Susan R.

2016-01-01

Best practices in internationalizing student learning and development require cultural critical analysis before transferring, adapting, hedging, or avoiding existing practices in cross-border applications both in and beyond the classroom.

GABAergic Synapses at the Axon Initial Segment of Basolateral Amygdala Projection Neurons Modulate Fear Extinction.

PubMed

Saha, Rinki; Knapp, Stephanie; Chakraborty, Darpan; Horovitz, Omer; Albrecht, Anne; Kriebel, Martin; Kaphzan, Hanoch; Ehrlich, Ingrid; Volkmer, Hansjürgen; Richter-Levin, Gal

2017-01-01

Inhibitory synaptic transmission in the amygdala has a pivotal role in fear learning and its extinction. However, the local circuits formed by GABAergic inhibitory interneurons within the amygdala and their detailed function in shaping these behaviors are not well understood. Here we used lentiviral-mediated knockdown of the cell adhesion molecule neurofascin in the basolateral amygdala (BLA) to specifically remove inhibitory synapses at the axon initial segment (AIS) of BLA projection neurons. Quantitative analysis of GABAergic synapse markers and measurement of miniature inhibitory postsynaptic currents in BLA projection neurons after neurofascin knockdown ex vivo confirmed the loss of GABAergic input. We then studied the impact of this manipulation on anxiety-like behavior and auditory cued fear conditioning and its extinction as BLA related behavioral paradigms, as well as on long-term potentiation (LTP) in the ventral subiculum-BLA pathway in vivo. BLA knockdown of neurofascin impaired ventral subiculum-BLA-LTP. While this manipulation did not affect anxiety-like behavior and fear memory acquisition and consolidation, it specifically impaired extinction. Our findings indicate that modification of inhibitory synapses at the AIS of BLA projection neurons is sufficient to selectively impair extinction behavior. A better understanding of the role of distinct GABAergic synapses may provide novel and more specific targets for therapeutic interventions in extinction-based therapies.

Longitudinal attentional engagement rescues mice from age-related cognitive declines and cognitive inflexibility

PubMed Central

Matzel, Louis D.; Light, Kenneth R.; Wass, Christopher; Colas-Zelin, Danielle; Denman-Brice, Alexander; Waddel, Adam C.; Kolata, Stefan

2011-01-01

Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement. PMID:21521768

Longitudinal attentional engagement rescues mice from age-related cognitive declines and cognitive inflexibility.

PubMed

Matzel, Louis D; Light, Kenneth R; Wass, Christopher; Colas-Zelin, Danielle; Denman-Brice, Alexander; Waddel, Adam C; Kolata, Stefan

2011-01-01

Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement.

Asymptotically Optimal Motion Planning for Learned Tasks Using Time-Dependent Cost Maps

PubMed Central

Bowen, Chris; Ye, Gu; Alterovitz, Ron

2015-01-01

In unstructured environments in people’s homes and workspaces, robots executing a task may need to avoid obstacles while satisfying task motion constraints, e.g., keeping a plate of food level to avoid spills or properly orienting a finger to push a button. We introduce a sampling-based method for computing motion plans that are collision-free and minimize a cost metric that encodes task motion constraints. Our time-dependent cost metric, learned from a set of demonstrations, encodes features of a task’s motion that are consistent across the demonstrations and, hence, are likely required to successfully execute the task. Our sampling-based motion planner uses the learned cost metric to compute plans that simultaneously avoid obstacles and satisfy task constraints. The motion planner is asymptotically optimal and minimizes the Mahalanobis distance between the planned trajectory and the distribution of demonstrations in a feature space parameterized by the locations of task-relevant objects. The motion planner also leverages the distribution of the demonstrations to significantly reduce plan computation time. We demonstrate the method’s effectiveness and speed using a small humanoid robot performing tasks requiring both obstacle avoidance and satisfaction of learned task constraints. Note to Practitioners Motivated by the desire to enable robots to autonomously operate in cluttered home and workplace environments, this paper presents an approach for intuitively training a robot in a manner that enables it to repeat the task in novel scenarios and in the presence of unforeseen obstacles in the environment. Based on user-provided demonstrations of the task, our method learns features of the task that are consistent across the demonstrations and that we expect should be repeated by the robot when performing the task. We next present an efficient algorithm for planning robot motions to perform the task based on the learned features while avoiding obstacles. We demonstrate the effectiveness of our motion planner for scenarios requiring transferring a powder and pushing a button in environments with obstacles, and we plan to extend our results to more complex tasks in the future. PMID:26279642

The role of social cognition in parasite and pathogen avoidance.

PubMed

Kavaliers, Martin; Choleris, Elena

2018-07-19

The acquisition and use of social information are integral to social behaviour and parasite/pathogen avoidance. This involves social cognition which encompasses mechanisms for acquiring, processing, retaining and acting on social information. Social cognition entails the acquisition of social information about others (i.e. social recognition) and from others (i.e. social learning). Social cognition involves assessing other individuals and their infection status and the pathogen and parasite threat they pose and deciding about when and how to interact with them. Social cognition provides a framework for examining pathogen and parasite avoidance behaviours and their associated neurobiological mechanisms. Here, we briefly consider the relationships between social cognition and olfactory-mediated pathogen and parasite avoidance behaviours. We briefly discuss aspects of (i) social recognition of actual and potentially infected individuals and the impact of parasite/pathogen threat on mate and social partner choice; (ii) the roles of 'out-groups' (strangers, unfamiliar individuals) and 'in-groups' (familiar individuals) in the expression of parasite/pathogen avoidance behaviours; (iii) individual and social learning, i.e. the utilization of the pathogen recognition and avoidance responses of others; and (iv) the neurobiological mechanisms, in particular the roles of the nonapeptide, oxytocin and steroid hormones (oestrogens) associated with social cognition and parasite/pathogen avoidance.This article is part of the Theo Murphy meeting issue 'Evolution of pathogen and parasite avoidance behaviours'. © 2018 The Author(s).

The Impact of Chemotherapy, Radiation and Epigenetic Modifiers in Cancer Cell Expression of Immune Inhibitory and Stimulatory Molecules and Anti-Tumor Efficacy.

PubMed

Chacon, Jessica Ann; Schutsky, Keith; Powell, Daniel J

2016-11-14

Genomic destabilizers, such as radiation and chemotherapy, and epigenetic modifiers are used for the treatment of cancer due to their apoptotic effects on the aberrant cells. However, these therapies may also induce widespread changes within the immune system and cancer cells, which may enable tumors to avoid immune surveillance and escape from host anti-tumor immunity. Genomic destabilizers can induce immunogenic death of tumor cells, but also induce upregulation of immune inhibitory ligands on drug-resistant cells, resulting in tumor progression. While administration of immunomodulatory antibodies that block the interactions between inhibitory receptors on immune cells and their ligands on tumor cells can mediate cancer regression in a subset of treated patients, it is crucial to understand how genomic destabilizers alter the immune system and malignant cells, including which inhibitory molecules, receptors and/or ligands are upregulated in response to genotoxic stress. Knowledge gained in this area will aid in the rational design of trials that combine genomic destabilizers, epigenetic modifiers and immunotherapeutic agents that may be synergized to improve clinical responses and prevent tumor escape from the immune system. Our review article describes the impact genomic destabilizers, such as radiation and chemotherapy, and epigenetic modifiers have on anti-tumor immunity and the tumor microenvironment. Although genomic destabilizers cause DNA damage on cancer cells, these therapies can also have diverse effects on the immune system, promote immunogenic cell death or survival and alter the cancer cell expression of immune inhibitor molecules.

Manifold optimization-based analysis dictionary learning with an ℓ1∕2-norm regularizer.

PubMed

Li, Zhenni; Ding, Shuxue; Li, Yujie; Yang, Zuyuan; Xie, Shengli; Chen, Wuhui

2018-02-01

Recently there has been increasing attention towards analysis dictionary learning. In analysis dictionary learning, it is an open problem to obtain the strong sparsity-promoting solutions efficiently while simultaneously avoiding the trivial solutions of the dictionary. In this paper, to obtain the strong sparsity-promoting solutions, we employ the ℓ 1∕2 norm as a regularizer. The very recent study on ℓ 1∕2 norm regularization theory in compressive sensing shows that its solutions can give sparser results than using the ℓ 1 norm. We transform a complex nonconvex optimization into a number of one-dimensional minimization problems. Then the closed-form solutions can be obtained efficiently. To avoid trivial solutions, we apply manifold optimization to update the dictionary directly on the manifold satisfying the orthonormality constraint, so that the dictionary can avoid the trivial solutions well while simultaneously capturing the intrinsic properties of the dictionary. The experiments with synthetic and real-world data verify that the proposed algorithm for analysis dictionary learning can not only obtain strong sparsity-promoting solutions efficiently, but also learn more accurate dictionary in terms of dictionary recovery and image processing than the state-of-the-art algorithms. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Influence of Task Involvement on the Use of Learning Strategies.

ERIC Educational Resources Information Center

Nolen, Susan Bobbitt

The relationship between goal orientation and the use of learning strategies and their effects on learning outcomes were investigated. The three goal orientations considered were: (1) task orientation, which involves learning for its own sake; (2) ego orientation, which involves a desire to perform better than others; and (3) work avoidance, which…

Learning Under the Influence.

ERIC Educational Resources Information Center

Galef, Bennett G., Jr.

1997-01-01

Discusses how animals learn from companions, especially among Norway rats. Rats begin early eating foods that other rats eat. Adults also choose to eat a food largely because companions are eating it even if they had learned to avoid the food at an earlier time. Other animals also learn from watching companions' eating techniques, reactions to…

Resisting an Isolated Learning Discourse

ERIC Educational Resources Information Center

Tanggaard, Lene

2009-01-01

The primary objective of this paper is to suggest that researchers on workplace learning avoid an isolated learning discourse. The point at issue is that being a learner is just one aspect of people's sometimes complicated lives in the workplace, and that people may sometimes--for good reasons--resist a learning discourse if it is linked…

Effects of intrahippocampal aniracetam treatment on Y-maze avoidance learning performance and behavioral long-term potentiation in dentate gyrus in rat.

PubMed

Rao, Y; Xiao, P; Xu, S

2001-02-09

Effects of intrahippocampal treatment of aniracetam, a selective agonist for DL-alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproionic acid (AMPA) receptors, on Y-maze avoidance learning task and behavioral long-term potentiation (LTP) in perforant path-dentate gyrus were studied in freely moving rats by using in vivo electrophysiology combined with behavioral tests. The results were as follows: (1) intrahippocampal treatment of aniracetam reversibly enhanced basal synaptic transmission in perforant path to dentate gyrus in a dosage dependent manner; (2) aniracetam produced improvement in Y-maze learning performance when administration occurred 5 min prior to maze learning; (3) aniracetam administration significantly facilitated behavioral LTP in dentate gyrus, while the maximal amplitude of LTP has no significant difference when compared to saline group. The present results indicate that hippocampal AMPA receptors are involved in learning and memory.

Correct machine learning on protein sequences: a peer-reviewing perspective.

PubMed

Walsh, Ian; Pollastri, Gianluca; Tosatto, Silvio C E

2016-09-01

Machine learning methods are becoming increasingly popular to predict protein features from sequences. Machine learning in bioinformatics can be powerful but carries also the risk of introducing unexpected biases, which may lead to an overestimation of the performance. This article espouses a set of guidelines to allow both peer reviewers and authors to avoid common machine learning pitfalls. Understanding biology is necessary to produce useful data sets, which have to be large and diverse. Separating the training and test process is imperative to avoid over-selling method performance, which is also dependent on several hidden parameters. A novel predictor has always to be compared with several existing methods, including simple baseline strategies. Using the presented guidelines will help nonspecialists to appreciate the critical issues in machine learning. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Assessing the Role of Inhibition in Stabilizing Neocortical Networks Requires Large-Scale Perturbation of the Inhibitory Population

PubMed Central

Mrsic-Flogel, Thomas D.

2017-01-01

Neurons within cortical microcircuits are interconnected with recurrent excitatory synaptic connections that are thought to amplify signals (Douglas and Martin, 2007), form selective subnetworks (Ko et al., 2011), and aid feature discrimination. Strong inhibition (Haider et al., 2013) counterbalances excitation, enabling sensory features to be sharpened and represented by sparse codes (Willmore et al., 2011). This balance between excitation and inhibition makes it difficult to assess the strength, or gain, of recurrent excitatory connections within cortical networks, which is key to understanding their operational regime and the computations that they perform. Networks that combine an unstable high-gain excitatory population with stabilizing inhibitory feedback are known as inhibition-stabilized networks (ISNs) (Tsodyks et al., 1997). Theoretical studies using reduced network models predict that ISNs produce paradoxical responses to perturbation, but experimental perturbations failed to find evidence for ISNs in cortex (Atallah et al., 2012). Here, we reexamined this question by investigating how cortical network models consisting of many neurons behave after perturbations and found that results obtained from reduced network models fail to predict responses to perturbations in more realistic networks. Our models predict that a large proportion of the inhibitory network must be perturbed to reliably detect an ISN regime robustly in cortex. We propose that wide-field optogenetic suppression of inhibition under promoters targeting a large fraction of inhibitory neurons may provide a perturbation of sufficient strength to reveal the operating regime of cortex. Our results suggest that detailed computational models of optogenetic perturbations are necessary to interpret the results of experimental paradigms. SIGNIFICANCE STATEMENT Many useful computational mechanisms proposed for cortex require local excitatory recurrence to be very strong, such that local inhibitory feedback is necessary to avoid epileptiform runaway activity (an “inhibition-stabilized network” or “ISN” regime). However, recent experimental results suggest that this regime may not exist in cortex. We simulated activity perturbations in cortical networks of increasing realism and found that, to detect ISN-like properties in cortex, large proportions of the inhibitory population must be perturbed. Current experimental methods for inhibitory perturbation are unlikely to satisfy this requirement, implying that existing experimental observations are inconclusive about the computational regime of cortex. Our results suggest that new experimental designs targeting a majority of inhibitory neurons may be able to resolve this question. PMID:29074575

The effects of low dose MK-801 administration on NMDAR dependent executive functions in pigeons.

PubMed

Gökhan, Nurper; Neuwirth, Lorenz S; Meehan, Edward F

2017-05-01

An avian analogue of human fronto-executive dysfunction was used to study the long-term effects of a repeated low dose of MK-801. MK-801 is known to selectively antagonize the excitatory N-methyl-d-aspartate receptors (NMDA R ) and indirectly impair inhibitory related processes (GABA- AR ). First, eight pigeons were divided into two groups, receiving either 0.15mg/kg MK-801 or saline (i.p.) 1-hour prior to each session. Thirty 90-min sessions of a Differential Reinforcement of Low Rate of Response (DRL-10s) schedule were run over 3-months. Both overall number of responses and efficiency were unaffected by treatment, establishing a sub-threshold motoric dose. Then, another eight pigeons, treated identically, were given an operant visual discrimination task. Results demonstrated impairment of the fronto-striatal function of both excitatory and inhibitory processes in the MK-801 group during the entire 3-months. A 30-session treatment cross-over showed that the Saline-to-MK-801 group was unaffected, whereas the MK-801-to-Saline group exhibited rapid recovery of inhibitory control, however excitatory control did not fully recover. Together, these results suggested that the NMDA R system is involved in the acquisition of excitatory learning, but only in the expression of inhibitory learning. Our findings were discussed in terms of the value of avian models in translational research. Furthermore, our results were examined within the context of the NIH Research Domain of Criteria initiative and the role of NMDA R disruption, which underlie executive dysfunction in various neuropsychiatric disorders. Finally, our findings suggested that the potential long-term effects of the clinical and recreational use of NMDA R antagonists require further study. Copyright © 2017 Elsevier Inc. All rights reserved.

Freewheel running prevents learned helplessness/behavioral depression: role of dorsal raphe serotonergic neurons.

PubMed

Greenwood, Benjamin N; Foley, Teresa E; Day, Heidi E W; Campisi, Jay; Hammack, Sayamwong H; Campeau, Serge; Maier, Steven F; Fleshner, Monika

2003-04-01

Serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) are implicated in mediating learned helplessness (LH) behaviors, such as poor escape responding and expression of exaggerated conditioned fear, induced by acute exposure to uncontrollable stress. DRN 5-HT neurons are hyperactive during uncontrollable stress, resulting in desensitization of 5-HT type 1A (5-HT1A) inhibitory autoreceptors in the DRN. 5-HT1A autoreceptor downregulation is thought to induce transient sensitization of DRN 5-HT neurons, resulting in excessive 5-HT activity in brain areas that control the expression of learned helplessness behaviors. Habitual physical activity has antidepressant/anxiolytic properties and results in dramatic alterations in physiological stress responses, but the neurochemical mediators of these effects are unknown. The current study determined the effects of 6 weeks of voluntary freewheel running on LH behaviors, uncontrollable stress-induced activity of DRN 5-HT neurons, and basal expression of DRN 5-HT1A autoreceptor mRNA. Freewheel running prevented the shuttle box escape deficit and the exaggerated conditioned fear that is induced by uncontrollable tail shock in sedentary rats. Furthermore, double c-Fos/5-HT immunohistochemistry revealed that physical activity attenuated tail shock-induced activity of 5-HT neurons in the rostral-mid DRN. Six weeks of freewheel running also resulted in a basal increase in 5-HT1A inhibitory autoreceptor mRNA in the rostral-mid DRN. Results suggest that freewheel running prevents behavioral depression/LH and attenuates DRN 5-HT neural activity during uncontrollable stress. An increase in 5-HT1A inhibitory autoreceptor expression may contribute to the attenuation of DRN 5-HT activity and the prevention of LH in physically active rats.

PAM multiplicity marks genomic target sites as inhibitory to CRISPR-Cas9 editing.

PubMed

Malina, Abba; Cameron, Christopher J F; Robert, Francis; Blanchette, Mathieu; Dostie, Josée; Pelletier, Jerry

2015-12-08

In CRISPR-Cas9 genome editing, the underlying principles for selecting guide RNA (gRNA) sequences that would ensure for efficient target site modification remain poorly understood. Here we show that target sites harbouring multiple protospacer adjacent motifs (PAMs) are refractory to Cas9-mediated repair in situ. Thus we refine which substrates should be avoided in gRNA design, implicating PAM density as a novel sequence-specific feature that inhibits in vivo Cas9-driven DNA modification.

PAM multiplicity marks genomic target sites as inhibitory to CRISPR-Cas9 editing

PubMed Central

Malina, Abba; Cameron, Christopher J. F.; Robert, Francis; Blanchette, Mathieu; Dostie, Josée; Pelletier, Jerry

2015-01-01

In CRISPR-Cas9 genome editing, the underlying principles for selecting guide RNA (gRNA) sequences that would ensure for efficient target site modification remain poorly understood. Here we show that target sites harbouring multiple protospacer adjacent motifs (PAMs) are refractory to Cas9-mediated repair in situ. Thus we refine which substrates should be avoided in gRNA design, implicating PAM density as a novel sequence-specific feature that inhibits in vivo Cas9-driven DNA modification. PMID:26644285

The medial prefrontal cortex and memory of cue location in the rat.

PubMed

Rawson, Tim; O'Kane, Michael; Talk, Andrew

2010-01-01

We developed a single-trial cue-location memory task in which rats experienced an auditory cue while exploring an environment. They then recalled and avoided the sound origination point after the cue was paired with shock in a separate context. Subjects with medial prefrontal cortical (mPFC) lesions made no such avoidance response, but both lesioned and control subjects avoided the cue itself when presented at test. A follow up assessment revealed no spatial learning impairment in either group. These findings suggest that the rodent mPFC is required for incidental learning or recollection of the location at which a discrete cue occurred, but is not required for cue recognition or for allocentric spatial memory. Copyright 2009 Elsevier Inc. All rights reserved.

Long-Term Interference Effect: An Alternative to "Learned Helplessness"

ERIC Educational Resources Information Center

Glazer, Howard I.; Weiss, Jay M.

1976-01-01

Presents three experiments that explore whether inescapable shock of long duration and moderate intensity (LoShk) produces an avoidance-escape deficit (called an interference effect) by causing animals to learn to respond less actively or by causing them to learn to be "helpless". (Editor)

Academic goals and learning quality in higher education students.

PubMed

Valle, Antonio; Núñez, José C; Cabanach, Ramón G; González-Pienda, Julio A; Rodríguez, Susana; Rosário, Pedro; Muñoz-Cadavid, María A; Cerezo, Rebeca

2009-05-01

In this paper, the relations between academic goals and various indicators that define the quality of the learning process are analyzed. The purpose was to determine to what extent high, moderate, or low levels of academic goals were positively or negatively related to effort regulation, the value assigned to academic tasks, meta-cognitive self-regulation, self-efficacy, beliefs about learning control, and management of time and study environment. The investigation was carried out with a sample of 632 university students (70% female and 30% male) and mean age of 21.22 (SD=2.2).The results show that learning goals, or task orientation, are positively related to all the indictors of learning quality considered herein. Although for other kinds of goals-work-avoidance goals, performance-approach goals, and performance-avoidance goals-significant relations were not found with all the indicators, there was a similar tendency of significant results in all cases; the higher the levels of these goals, the lower the levels of the indicators of learning quality.

[Effect of agonist and antagonist of 5-HT(1A) receptors on learning in female rats during ovarian cycle].

PubMed

Fedotova, Iu O; Ordian, N E

2010-01-01

The involvement of 5-HT(1A) receptors in learning/memory processes during ovary cycle was assessed in the adult female rats. 8-OH-DPAT (0.05 mg/kg, s.c.), 5-HT(1A) receptor agonist and NAN-190 (0.1 mg/kg, i.p.), 5-HT(1A) receptor antagonist were injected chronically to adult female rats. Learning of these animals was assessed in different models: passive avoidance performance and Morris water maze. Chronic NAN-190 administration to females resulted in the appearance of the passive avoidance performance in proestrous and estrous, as distinct from the control animals, but failed to change the dynamics of spatial learning in Morris water maze. Chronic 8-OH-DPAT administration similarly impaired non-spatial and spatial learning in females during all phases of ovary cycle. The results of the study suggest modulating role of 5-HT(1A) receptors in learning/memory processes during ovary cycle in the adult female rats.

Skill learning and the evolution of social learning mechanisms.

PubMed

van der Post, Daniel J; Franz, Mathias; Laland, Kevin N

2016-08-24

Social learning is potentially advantageous, but evolutionary theory predicts that (i) its benefits may be self-limiting because social learning can lead to information parasitism, and (ii) these limitations can be mitigated via forms of selective copying. However, these findings arise from a functional approach in which learning mechanisms are not specified, and which assumes that social learning avoids the costs of asocial learning but does not produce information about the environment. Whether these findings generalize to all kinds of social learning remains to be established. Using a detailed multi-scale evolutionary model, we investigate the payoffs and information production processes of specific social learning mechanisms (including local enhancement, stimulus enhancement and observational learning) and their evolutionary consequences in the context of skill learning in foraging groups. We find that local enhancement does not benefit foraging success, but could evolve as a side-effect of grouping. In contrast, stimulus enhancement and observational learning can be beneficial across a wide range of environmental conditions because they generate opportunities for new learning outcomes. In contrast to much existing theory, we find that the functional outcomes of social learning are mechanism specific. Social learning nearly always produces information about the environment, and does not always avoid the costs of asocial learning or support information parasitism. Our study supports work emphasizing the value of incorporating mechanistic detail in functional analyses.

Learning to avoid spiders: fear predicts performance, not competence.

PubMed

Luo, Xijia; Becker, Eni S; Rinck, Mike

2018-01-05

We used an immersive virtual environment to examine avoidance learning in spider-fearful participants. In 3 experiments, participants were asked to repeatedly lift one of 3 virtual boxes, under which either a toy car or a spider appeared and then approached the participant. Participants were not told that the probability of encountering a spider differed across boxes. When the difference was large (Exps. 1 and 2), spider-fearfuls learned to avoid spiders by lifting the few-spiders-box more often and the many-spiders-box less often than non-fearful controls did. However, they hardly managed to do so when the probability differences were small (Exp. 3), and they did not escape from threat more quickly (Exp. 2). In contrast to the observed performance differences, spider-fearfuls and non-fearfuls showed equal competence, that is comparable post-experimental knowledge about the probability to encounter spiders under the 3 boxes. The limitations and implications of the present study are discussed.

Out with the old and in with the new: Synaptic mechanisms of extinction in the amygdala

PubMed Central

Maren, Stephen

2014-01-01

Considerable research indicates that long-term synaptic plasticity in the amygdala underlies the acquisition of emotional memories, including those learned during Pavlovian fear conditioning. Much less is known about the synaptic mechanisms involved in other forms of associative learning, including extinction, that update fear memories. Extinction learning might reverse conditioning-related changes (e.g., depotentiation) or induce plasticity at inhibitory synapses (e.g., long-term potentiation) to suppress conditioned fear responses. Either mechanism must account for fear recovery phenomena after extinction, as well as savings of extinction after fear recovery. PMID:25312830

Alcohol cues impair learning inhibitory signals in beer drinkers

PubMed Central

Laude, Jennifer R.; Fillmore, Mark T.

2015-01-01

Background Models of drug addiction emphasize the reciprocal influence of incentive-motivational properties of drug-related cues and poor impulse control resulting in drug use. Recent studies have shown that alcohol-related cues can impair response inhibition. What is unknown is whether these cues also disrupt learning of inhibitory associations. Methods Participants performed a Conditioned Inhibition (CI) task and were required to learn that a neutral image was a conditioned inhibitor when presented in the context of either an alcohol image intended to draw their attention away from the to-be-trained inhibitor, or a control condition in which the alcohol image was absent. After training, subjects in each condition rated the likelihood that the neutral image would signal the outcome. Eye tracking was used to verify that attention to the neutral image was in fact reduced when the alcohol image was present. Results Compared with controls those trained in the alcohol image condition reported a greater likelihood that the presence of the inhibitor would be followed by the outcome and thus were less able to acquire CI. Measures of eye-tracking verified that attention to the alcohol cue was associated with this maladaptive behavior. Conclusions When alcohol cues are present, there is a reduced ability to learn that such information is irrelevant to an outcome, and this impairs ones’ ability to inhibit perseveration of a response. This has implications for persistence of a drinking episode. PMID:25872597

Low-Cost Avoidance Behaviors are Resistant to Fear Extinction in Humans

PubMed Central

Vervliet, Bram; Indekeu, Ellen

2015-01-01

Elevated levels of fear and avoidance are core symptoms across the anxiety disorders. It has long been known that fear serves to motivate avoidance. Consequently, fear extinction has been the primary focus in pre-clinical anxiety research for decades, under the implicit assumption that removing the motivator of avoidance (fear) would automatically mitigate the avoidance behaviors as well. Although this assumption has intuitive appeal, it has received little scientific scrutiny. The scarce evidence from animal studies is mixed, while the assumption remains untested in humans. The current study applied an avoidance conditioning protocol in humans to investigate the effects of fear extinction on the persistence of low-cost avoidance. Online danger-safety ratings and skin conductance responses documented the dynamics of conditioned fear across avoidance and extinction phases. Anxiety- and avoidance-related questionnaires explored individual differences in rates of avoidance. Participants first learned to click a button during a predictive danger signal, in order to cancel an upcoming aversive electrical shock (avoidance conditioning). Next, fear extinction was induced by presenting the signal in the absence of shocks while button-clicks were prevented (by removing the button in Experiment 1, or by instructing not to click the button in Experiment 2). Most importantly, post-extinction availability of the button caused a significant return of avoidant button-clicks. In addition, trait-anxiety levels correlated positively with rates of avoidance during a predictive safety signal, and with the rate of pre- to post-extinction decrease during this signal. Fear measures gradually decreased during avoidance conditioning, as participants learned that button-clicks effectively canceled the shock. Preventing button-clicks elicited a sharp increase in fear, which subsequently extinguished. Fear remained low during avoidance testing, but danger-safety ratings increased again when button-clicks were subsequently prevented. Together, these results show that low-cost avoidance behaviors can persist following fear extinction and induce increased threat appraisal. On the other hand, fear extinction did reduce augmented rates of unnecessary avoidance during safety in trait-anxious individuals, and instruction-based response prevention was more effective than removal of response cues. More research is needed to characterize the conditions under which fear extinction might mitigate avoidance. PMID:26733837

[Interaction of immobilization stress and food-getting learning].

PubMed

Levshina, I P; Stashkevich, I S; Shuĭkin, N N

2009-01-01

The behavioral effects of emotional negative stress (immobilization) were studied in Wistar rats intact and those that had previous positive emotion experience. The food-getting learning has been chosen as positive emotion experience. Animals were trained in food pellet-reaching task by their preferred paw. It was shown that immobilization of intact rats leads to suppression of motor activity and increasing the duration of grooming. These effects indicate enhancement of passive-avoidance reactions. It was also shown that motor learning in group of rats with food reinforcement before immobilisation significantly reduces appearance of passive-avoidance reactions. It was found that immobilization stress does not inverse the initial direction of limb preference in majority of rats.

[GSH fermentation process modeling using entropy-criterion based RBF neural network model].

PubMed

Tan, Zuoping; Wang, Shitong; Deng, Zhaohong; Du, Guocheng

2008-05-01

The prediction accuracy and generalization of GSH fermentation process modeling are often deteriorated by noise existing in the corresponding experimental data. In order to avoid this problem, we present a novel RBF neural network modeling approach based on entropy criterion. It considers the whole distribution structure of the training data set in the parameter learning process compared with the traditional MSE-criterion based parameter learning, and thus effectively avoids the weak generalization and over-learning. Then the proposed approach is applied to the GSH fermentation process modeling. Our results demonstrate that this proposed method has better prediction accuracy, generalization and robustness such that it offers a potential application merit for the GSH fermentation process modeling.

Brain Aging and AD-Like Pathology in Streptozotocin-Induced Diabetic Rats

PubMed Central

Wang, Jian-Qin; Yin, Jie; Song, Yan-Feng; Zhang, Lang; Ren, Ying-Xiang; Wang, De-Gui; Gao, Li-Ping; Jing, Yu-Hong

2014-01-01

Objective. Numerous epidemiological studies have linked diabetes mellitus (DM) with an increased risk of developing Alzheimer's disease (AD). However, whether or not diabetic encephalopathy shows AD-like pathology remains unclear. Research Design and Methods. Forebrain and hippocampal volumes were measured using stereology in serial coronal sections of the brain in streptozotocin- (STZ-) induced rats. Neurodegeneration in the frontal cortex, hypothalamus, and hippocampus was evaluated using Fluoro-Jade C (FJC). Aβ aggregation in the frontal cortex and hippocampus was tested using immunohistochemistry and ELISA. Dendritic spine density in the frontal cortex and hippocampus was measured using Golgi staining, and western blot was conducted to detect the levels of synaptophysin. Cognitive ability was evaluated through the Morris water maze and inhibitory avoidant box. Results. Rats are characterized by insulin deficiency accompanied with polydipsia, polyphagia, polyuria, and weight loss after STZ injection. The number of FJC-positive cells significantly increased in discrete brain regions of the diabetic rats compared with the age-matched control rats. Hippocampal atrophy, Aβ aggregation, and synapse loss were observed in the diabetic rats compared with the control rats. The learning and memory of the diabetic rats decreased compared with those of the age-matched control rats. Conclusions. Our results suggested that aberrant metabolism induced brain aging as characterized by AD-like pathologies. PMID:25197672

Spike Train Auto-Structure Impacts Post-Synaptic Firing and Timing-Based Plasticity

PubMed Central

Scheller, Bertram; Castellano, Marta; Vicente, Raul; Pipa, Gordon

2011-01-01

Cortical neurons are typically driven by several thousand synapses. The precise spatiotemporal pattern formed by these inputs can modulate the response of a post-synaptic cell. In this work, we explore how the temporal structure of pre-synaptic inhibitory and excitatory inputs impact the post-synaptic firing of a conductance-based integrate and fire neuron. Both the excitatory and inhibitory input was modeled by renewal gamma processes with varying shape factors for modeling regular and temporally random Poisson activity. We demonstrate that the temporal structure of mutually independent inputs affects the post-synaptic firing, while the strength of the effect depends on the firing rates of both the excitatory and inhibitory inputs. In a second step, we explore the effect of temporal structure of mutually independent inputs on a simple version of Hebbian learning, i.e., hard bound spike-timing-dependent plasticity. We explore both the equilibrium weight distribution and the speed of the transient weight dynamics for different mutually independent gamma processes. We find that both the equilibrium distribution of the synaptic weights and the speed of synaptic changes are modulated by the temporal structure of the input. Finally, we highlight that the sensitivity of both the post-synaptic firing as well as the spike-timing-dependent plasticity on the auto-structure of the input of a neuron could be used to modulate the learning rate of synaptic modification. PMID:22203800

Peripersonal Space and Margin of Safety around the Body: Learning Visuo-Tactile Associations in a Humanoid Robot with Artificial Skin

PubMed Central

Roncone, Alessandro; Fadiga, Luciano; Metta, Giorgio

2016-01-01

This paper investigates a biologically motivated model of peripersonal space through its implementation on a humanoid robot. Guided by the present understanding of the neurophysiology of the fronto-parietal system, we developed a computational model inspired by the receptive fields of polymodal neurons identified, for example, in brain areas F4 and VIP. The experiments on the iCub humanoid robot show that the peripersonal space representation i) can be learned efficiently and in real-time via a simple interaction with the robot, ii) can lead to the generation of behaviors like avoidance and reaching, and iii) can contribute to the understanding the biological principle of motor equivalence. More specifically, with respect to i) the present model contributes to hypothesizing a learning mechanisms for peripersonal space. In relation to point ii) we show how a relatively simple controller can exploit the learned receptive fields to generate either avoidance or reaching of an incoming stimulus and for iii) we show how the robot can select arbitrary body parts as the controlled end-point of an avoidance or reaching movement. PMID:27711136

Effect of pregabalin on fear-based conditioned avoidance learning and spatial learning in a mouse model of scopolamine-induced amnesia.

PubMed

Sałat, Kinga; Podkowa, Adrian; Malikowska, Natalia; Trajer, Jędrzej

2017-03-01

Cognitive deficits are one of the frequent symptoms accompanying epilepsy or its treatment. In this study, the effect on cognition of intraperitoneally administered antiepileptic drug, pregabalin (10 mg/kg), was investigated in scopolamine-induced memory-impaired mice in the passive avoidance task and Morris water maze task. The effect of scopolamine and pregabalin on animals' locomotor activity was also studied. In the retention phase of the passive avoidance task, pregabalin reversed memory deficits induced by scopolamine (p < 0.05). During the acquisition phase of the Morris water maze pregabalin-treated memory-impaired mice performed the test with longer escape latencies than the vehicle-treated mice (significant at p < 0.05 on Day 5, and at p < 0.001 on Day 6). There were no differences in this parameter between the scopolamine-treated control group and pregabalin-treated memory-impaired mice, which indicated that pregabalin had no influence on spatial learning in this task. During the probe trial a significant difference (p < 0.05) was observed in terms of the mean number of target crossings between vehicle-treated mice and pregabalin-treated memory-impaired mice but there was no difference between the scopolamine-treated control group and mice treated with pregabalin + scopolamine. Pregabalin did not influence locomotor activity increased by scopolamine. In passive avoidance task, pregabalin reversed learning deficits induced by scopolamine. In the Morris water maze, pregabalin did not influence spatial learning deficits induced by scopolamine. These results are relevant for epileptic patients treated with pregabalin and those who use it for other therapeutic indications (anxiety, pain).

Thymus Polypeptide Preparation Tactivin Restores Learning and Memory in Thymectomied Rats.

PubMed

Novoseletskaya, A V; Kiseleva, N M; Zimina, I V; Bystrova, O V; Belova, O V; Inozemtsev, A N; Arion, V Ya; Sergienko, V I

2015-09-01

We studied the effects of tactivin and splenic polypeptides on learning and memory of thymectomized animals. In 3-week rats, thymectomy blocked active avoidance conditioning. Injections of tactivin (0.5 mg/kg) during 1 month after surgery restored learning capacity; splenic polypeptides were ineffective.

Solid-State Lighting. Early Lessons Learned on the Way to Market

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandahl, L. J.; Cort, K. A.; Gordon, K. L.

2014-01-01

Analysis of issues and lessons learned during the early stages of solid-state lighting market introduction in the U.S., which also summarizes early actions taken to avoid potential problems anticipated based on lessons learned from the market introduction of compact fluorescent lamps.

Extinction and recovery of an avoidance memory impaired by scopolamine.

PubMed

Navarro, N M; Krawczyk, M C; Boccia, M M; Blake, M G

2017-03-15

Pre-training administration of scopolamine (SCP) resembles situations of cholinergic dysfunction, leading to memory impairment of mice trained in an inhibitory avoidance task. We suggest here that SCP does not impair memory formation, but acquisition is affected in a way that reduces the strength of the stored memory, thus making this memory less able to control behavior when tested. Hence, a memory trace is stored, but is poorly expressed during the test. Although weakly expressed, this memory shows extinction during successive tests, and can be strengthened by using a reminder. Our results indicate that memories stored under cholinergic dysfunction conditions seem absent or lost, but are in fact present and experience common memory processes, such as extinction, and could be even recovered by using appropriate protocols. Copyright © 2017 Elsevier Inc. All rights reserved.

Age moderates the effect of acute dopamine depletion on passive avoidance learning.

PubMed

Kelm, Mary Katherine; Boettiger, Charlotte Ann

2015-04-01

Despite extensive links between reinforcement-based learning and dopamine (DA), studies to date have not found consistent effects of acute DA reduction on reinforcement learning in both men and women. Here, we tested the effects of reducing DA on reward- and punishment-based learning using the deterministic passive avoidance learning (PAL) task. We tested 16 (5 female) adults (ages 22-40) in a randomized, cross-over design to determine whether reducing global DA by administering an amino acid beverage deficient in the DA precursors, phenylalanine and tyrosine (P/T[-]), would affect PAL task performance. We found that P/T[-] beverage effects on PAL performance were modulated by age. Specifically, we found that P/T depletion significantly improved learning from punishment with increasing participant age. Participants committed 1.49 fewer passive avoidance errors per additional year of age (95% CI, -0.71 - -2.27, r=-0.74, p=0.001). Moreover, P/T depletion improved learning from punishment in adults (ages 26-40) while it impaired learning from punishment in emerging adults (ages 22-25). We observed similar, but non-significant trends in learning from reward. While there was no overall effect of P/T-depletion on reaction time (RT), there was a relationship between the effect of P/T depletion on PAL performance and RT; those who responded more slowly on the P/T[-] beverage also made more errors on the P/T[-] beverage. When P/T-depletion slowed RT after a correct response, there was a worsening of PAL task performance; there was no similar relationship for the RT after an incorrect response and PAL task performance. Moreover, among emerging adults, changes in mood on the P/T[-] beverage negatively correlated with learning from reward on the P/T[-] beverage. Together, we found that both reward- and punishment-based learning are sensitive to central catecholamine levels, and that these effects of acute DA reduction vary with age. Copyright © 2015 Elsevier Inc. All rights reserved.

The neural mechanisms of learning from competitors.

PubMed

Howard-Jones, Paul A; Bogacz, Rafal; Yoo, Jee H; Leonards, Ute; Demetriou, Skevi

2010-11-01

Learning from competitors poses a challenge for existing theories of reward-based learning, which assume that rewarded actions are more likely to be executed in the future. Such a learning mechanism would disadvantage a player in a competitive situation because, since the competitor's loss is the player's gain, reward might become associated with an action the player should themselves avoid. Using fMRI, we investigated the neural activity of humans competing with a computer in a foraging task. We observed neural activity that represented the variables required for learning from competitors: the actions of the competitor (in the player's motor and premotor cortex) and the reward prediction error arising from the competitor's feedback. In particular, regions positively correlated with the unexpected loss of the competitor (which was beneficial to the player) included the striatum and those regions previously implicated in response inhibition. Our results suggest that learning in such contexts may involve the competitor's unexpected losses activating regions of the player's brain that subserve response inhibition, as the player learns to avoid the actions that produced them. Copyright 2010 Elsevier Inc. All rights reserved.

Overcoming Conditioned Helplessness in Mathematics.

ERIC Educational Resources Information Center

Wieschenberg, Agnes Arvai

1994-01-01

A discussion of mathematics anxiety and learned helplessness in mathematics focuses on student failure and avoidance in college mathematics learning. It explores possible causes and suggests classroom activities to foster students' interest and success. (MSE)

Social and Emotional Learning Hikes Interest and Resiliency

ERIC Educational Resources Information Center

Beland, Kathy

2007-01-01

Social Emotional Learning (SEL) is the process by which people develop the skills to recognize and manage emotions, form positive relationships, solve problems that arise, motivate themselves to accomplish a goal, make responsible decisions, and avoid risky behavior. The Collaborative for Social and Emotional Learning (CASEL), at the University of…

Olfactory learning without the mushroom bodies: Spiking neural network models of the honeybee lateral antennal lobe tract reveal its capacities in odour memory tasks of varied complexities

PubMed Central

2017-01-01

The honeybee olfactory system is a well-established model for understanding functional mechanisms of learning and memory. Olfactory stimuli are first processed in the antennal lobe, and then transferred to the mushroom body and lateral horn through dual pathways termed medial and lateral antennal lobe tracts (m-ALT and l-ALT). Recent studies reported that honeybees can perform elemental learning by associating an odour with a reward signal even after lesions in m-ALT or blocking the mushroom bodies. To test the hypothesis that the lateral pathway (l-ALT) is sufficient for elemental learning, we modelled local computation within glomeruli in antennal lobes with axons of projection neurons connecting to a decision neuron (LHN) in the lateral horn. We show that inhibitory spike-timing dependent plasticity (modelling non-associative plasticity by exposure to different stimuli) in the synapses from local neurons to projection neurons decorrelates the projection neurons’ outputs. The strength of the decorrelations is regulated by global inhibitory feedback within antennal lobes to the projection neurons. By additionally modelling octopaminergic modification of synaptic plasticity among local neurons in the antennal lobes and projection neurons to LHN connections, the model can discriminate and generalize olfactory stimuli. Although positive patterning can be accounted for by the l-ALT model, negative patterning requires further processing and mushroom body circuits. Thus, our model explains several–but not all–types of associative olfactory learning and generalization by a few neural layers of odour processing in the l-ALT. As an outcome of the combination between non-associative and associative learning, the modelling approach allows us to link changes in structural organization of honeybees' antennal lobes with their behavioural performances over the course of their life. PMID:28640825

Altered consolidation of extinction-like inhibitory learning in genotype-specific dysfunctional coping fostered by chronic stress in mice.

PubMed

Campus, P; Maiolati, M; Orsini, C; Cabib, S

2016-12-15

Genetic and stress-related factors interact to foster mental disorders, possibly through dysfunctional learning. In a previous study we reported that a temporary experience of reduced food availability increases forced swim (FS)-induced helplessness tested 14days after a first experience in mice of the standard inbred C57BL/6(B6) strain but reduces it in mice of the genetically unrelated DBA/2J (D2) strain. Because persistence of FS-induced helplessness influences adaptive coping with stress challenge and involve learning processes the present study tested whether the behavioral effects of restricted feeding involved altered consolidation of FS-related learning. First, we demonstrated that restricted feeding does not influence behavior expressed on the first FS experience, supporting a specific effect on persistence rather then development of helplessness. Second, we found that FS-induced c-fos expression in the infralimbic cortex (IL) was selectively enhanced in food-restricted (FR) B6 mice and reduced in FR D2 mice, supporting opposite alterations of consolidation processes involving this brain area. Third, we demonstrated that immediate post-FS inactivation of IL prevents 24h retention of acquired helplessness by continuously free-fed mice of both strains, indicating the requirement of a functioning IL for consolidation of FS-related learning in either mouse strain. Finally, in line with the known role of IL in consolidation of extinction memories, we found that restricted feeding selectively facilitated 24h retention of an acquired extinction in B6 mice whereas impairing it in D2 mice. These findings support the conclusion that an experience of reduced food availability strain-specifically affects persistence of newly acquired passive coping strategies by altering consolidation of extinction-like inhibitory learning. Copyright © 2016 Elsevier B.V. All rights reserved.

Olfactory learning without the mushroom bodies: Spiking neural network models of the honeybee lateral antennal lobe tract reveal its capacities in odour memory tasks of varied complexities.

PubMed

MaBouDi, HaDi; Shimazaki, Hideaki; Giurfa, Martin; Chittka, Lars

2017-06-01

The honeybee olfactory system is a well-established model for understanding functional mechanisms of learning and memory. Olfactory stimuli are first processed in the antennal lobe, and then transferred to the mushroom body and lateral horn through dual pathways termed medial and lateral antennal lobe tracts (m-ALT and l-ALT). Recent studies reported that honeybees can perform elemental learning by associating an odour with a reward signal even after lesions in m-ALT or blocking the mushroom bodies. To test the hypothesis that the lateral pathway (l-ALT) is sufficient for elemental learning, we modelled local computation within glomeruli in antennal lobes with axons of projection neurons connecting to a decision neuron (LHN) in the lateral horn. We show that inhibitory spike-timing dependent plasticity (modelling non-associative plasticity by exposure to different stimuli) in the synapses from local neurons to projection neurons decorrelates the projection neurons' outputs. The strength of the decorrelations is regulated by global inhibitory feedback within antennal lobes to the projection neurons. By additionally modelling octopaminergic modification of synaptic plasticity among local neurons in the antennal lobes and projection neurons to LHN connections, the model can discriminate and generalize olfactory stimuli. Although positive patterning can be accounted for by the l-ALT model, negative patterning requires further processing and mushroom body circuits. Thus, our model explains several-but not all-types of associative olfactory learning and generalization by a few neural layers of odour processing in the l-ALT. As an outcome of the combination between non-associative and associative learning, the modelling approach allows us to link changes in structural organization of honeybees' antennal lobes with their behavioural performances over the course of their life.

Plasticity of cortical inhibition in dystonia is impaired after motor learning and paired-associative stimulation.

PubMed

Meunier, Sabine; Russmann, Heike; Shamim, Ejaz; Lamy, Jean-Charles; Hallett, Mark

2012-03-01

Artificial induction of plasticity by paired associative stimulation (PAS) in healthy volunteers (HV) demonstrates Hebbian-like plasticity in selected inhibitory networks as well as excitatory networks. In a group of 17 patients with focal hand dystonia and a group of 19 HV, we evaluated how PAS and the learning of a simple motor task influence the circuits supporting long-interval intracortical inhibition (LICI, reflecting activity of GABA(B) interneurons) and long-latency afferent inhibition (LAI, reflecting activity of somatosensory inputs to the motor cortex). In HV, PAS and motor learning induced long-term potentiation (LTP)-like plasticity of excitatory networks and a lasting decrease of LAI and LICI in the motor representation of the targeted or trained muscle. The better the motor performance, the larger was the decrease of LAI. Although motor performance in the patient group was similar to that of the control group, LAI did not decrease during the motor learning as it did in the control group. In contrast, LICI was normally modulated. In patients the results after PAS did not match those obtained after motor learning: LAI was paradoxically increased and LICI did not exhibit any change. In the normal situation, decreased excitability in inhibitory circuits after induction of LTP-like plasticity may help to shape the cortical maps according to the new sensorimotor task. In patients, the abnormal or absent modulation of afferent and intracortical long-interval inhibition might indicate maladaptive plasticity that possibly contributes to the difficulty that they have to learn a new sensorimotor task. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Negative Priming in Free Recall Reconsidered

ERIC Educational Resources Information Center

Hanczakowski, Maciej; Beaman, C. Philip; Jones, Dylan M.

2016-01-01

Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and…

Testing the disgust conditioning theory of food-avoidance in adolescents with recent onset anorexia nervosa.

PubMed

Hildebrandt, Tom; Grotzinger, Andrew; Reddan, Marianne; Greif, Rebecca; Levy, Ifat; Goodman, Wayne; Schiller, Daniela

2015-08-01

Anorexia nervosa is characterized by chronic food avoidance that is resistant to change. Disgust conditioning offers one potential unexplored mechanism for explaining this behavioral disturbance because of its specific role in facilitating food avoidance in adaptive situations. A food based reversal learning paradigm was used to study response flexibility in 14 adolescent females with restricting subtype anorexia nervosa (AN-R) and 15 healthy control (HC) participants. Expectancy ratings were coded as a behavioral measure of flexibility and electromyography recordings from the levator labii (disgust), zygomaticus major (pleasure), and corrugator (general negative affect) provided psychophysiological measures of emotion. Response inflexibility was higher for participants with AN-R, as evidenced by lower extinction and updated expectancy ratings during reversal. EMG responses to food stimuli were predictive of both extinction and new learning. Among AN-R patients, disgust specific responses to food were associated with impaired extinction, as were elevated pleasure responses to the cued absence of food. Disgust conditioning appears to influence food learning in acutely ill patients with AN-R and may be maintained by counter-regulatory acquisition of a pleasure response to food avoidance and an aversive response to food presence. Developing strategies to target disgust may improve existing interventions for patients with AN. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stress increases descending inhibition in mouse and human colon.

PubMed

Reed, D E; Zhang, Y; Beyak, M J; Lourenssen, S; Blennerhassett, M G; Paterson, W G; Vanner, S J

2016-04-01

A relationship between stress and the symptoms of irritable bowel syndrome (IBS) has been well established but the cellular mechanisms are poorly understood. Therefore, we investigated effects of stress and stress hormones on colonic descending inhibition and transit in mouse models and human tissues. Stress was applied using water avoidance stress (WAS) in the animal model or mimicked using stress hormones, adrenaline (5 nM), and corticosterone (1 μM). Intracellular recordings were obtained from colonic circular smooth muscle cells in isolated smooth muscle/myenteric plexus preparations and the inhibitory junction potential (IJP) was elicited by nerve stimulation or balloon distension oral to the site of recording. Water avoidance stress increased the number of fecal pellets compared to control (p < 0.05). WAS also caused a significant increase in IJP amplitude following balloon distension. Stress hormones also increased the IJP amplitude following nerve stimulation and balloon distension (p < 0.05) in control mice but had no effect in colons from stressed mice. No differences were observed with application of ATP between stress and control tissues, suggesting the actions of stress hormones were presynaptic. Stress hormones had a large effect in the nerve stimulated IJP in human colon (increased >50%). Immunohistochemical studies identified alpha and beta adrenergic receptor immunoreactivity on myenteric neurons in human colon. These studies suggest that WAS and stress hormones can signal via myenteric neurons to increase inhibitory neuromuscular transmission. This could lead to greater descending relaxation, decreased transit time, and subsequent diarrhea. © 2016 John Wiley & Sons Ltd.

Chronic corticosterone administration facilitates aversive memory retrieval and increases GR/NOS immunoreactivity.

PubMed

Santos, Thays B; Céspedes, Isabel C; Viana, Milena B

2014-07-01

Glucocorticoids are stress hormones that mediate the organism's reaction to stress. It has been previously proposed that the facilitation of emotional aversive conditioning induced by these hormones may involve nitric oxide-pathways. The purpose of the present study was to address this question. For that, male Wistar rats were surgically implanted with slow-release corticosterone (CORT) pellets (21 days) and tested in a step-down inhibitory avoidance task. Additional groups of animals were also submitted to the same treatment conditions and on the 21st day of treatment assayed for GR (glucocorticoid receptors)-nNOS (neuronal nitric oxide synthase) immunoreactivity (GRi-nNOSi) or measurements of plasma CORT. Results showed that CORT treatment induced facilitation of step-down inhibitory avoidance. This same treatment also significantly increased CORT plasma levels and GRi in the medial, basolateral and basomedial amygdala, in the paraventricular hypothalamic nucleus (PVN), in the ventral and dorsal dentate gyrus, in the ventral CA1 region and in the dorsal CA1 and CA3 regions. Furthermore, nNOSi and GRi-nNOSi were significantly increased by CORT treatment in the medial amygdala and basolateral amygdaloid complex, in the PVN, subiculum, in the dorsal CA3 region and in the ventral CA1 and CA3 regions. These results indicate that the facilitation of aversive conditioning induced by CORT involves GR-nNOS pathways activation, what may be of relevance for a better understanding of stress-related psychiatric conditions. Copyright © 2014 Elsevier B.V. All rights reserved.

Closing your eyes to follow your heart: Avoiding information to protect a strong intuitive preference.

PubMed

Woolley, Kaitlin; Risen, Jane L

2018-02-01

Rationally, people should want to receive information that is costless and relevant for a decision. But people sometimes choose to remain ignorant. The current paper identifies intuitive-deliberative conflict as a driver of information avoidance. Moreover, we examine whether people avoid information not only to protect their feelings or experiences, but also to protect the decision itself. We predict that people avoid information that could encourage a more thoughtful, deliberative decision to make it easier to enact their intuitive preference. In Studies 1 and 2, people avoid learning the calories in a tempting dessert and compensation for a boring task to protect their preferences to eat the dessert and work on a more enjoyable task. The same people who want to avoid the information, however, use it when it is provided. In Studies 3-5, people decide whether to learn how much money they could earn by accepting an intuitively unappealing bet (that a sympathetic student performs poorly or that a hurricane hits a third-world country). Although intuitively unappealing, the bets are financially rational because they only have financial upside. If people avoid information in part to protect their intuitive preference, then avoidance should be greater when an intuitive preference is especially strong and when information could influence the decision. As predicted, avoidance is driven by the strength of the intuitive preference (Study 3) and, ironically, information avoidance is greater before a decision is made, when the information is decision relevant, than after, when the information is irrelevant for the decision (Studies 4 and 5). (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Using Formal Game Design Methods to Embed Learning Outcomes into Game Mechanics and Avoid Emergent Behaviour

ERIC Educational Resources Information Center

Grey, Simon; Grey, David; Gordon, Neil; Purdy, Jon

2017-01-01

This paper offers an approach to designing game-based learning experiences inspired by the Mechanics-Dynamics-Aesthetics (MDA) model (Hunicke et al., 2004) and the elemental tetrad model (Schell, 2008) for game design. A case for game based learning as an active and social learning experience is presented including arguments from both teachers and…

Avoiding Misinterpretations of Piaget and Vygotsky: Mathematical Teaching without Learning, Learning without Teaching, or Helpful Learning-Path Teaching?

ERIC Educational Resources Information Center

Fuson, Karen C.

2009-01-01

This article provides an overview of some perspectives about special issues in classroom mathematical teaching and learning that have stemmed from the huge explosion of research in children's mathematical thinking stimulated by Piaget. It concentrates on issues that are particularly important for less-advanced learners and for those who might be…

Attribution and Motivation: Gender, Ethnicity, and Religion Differences among Indonesian University Students

ERIC Educational Resources Information Center

Sutantoputri, Novita W.; Watt, Helen M. G.

2013-01-01

The study explores the possibilities of gender, ethnicity, and religion differences on attributions (locus of control, stability, personal and external control), motivational goals (learning, performance approach, performance avoidance, and work avoidance), self-efficacy, intelligence beliefs, religiosity, racial/ethnic identity, and academic…

[Influence of stimulation and blockade of α4β2 nicotinic acetylcholine receptors on learning of female rats in basic phases of ovary cycle].

PubMed

Fedotova, Iu O

2014-03-01

The present work was devoted to the comparative analysis of α4β2 nicotinic acetylcholine receptors (nAChRs) in learning/memory processes during ovary cycle in the adult female rats. RJR-2403 (1.0 mg/kg, i. p.), α4β2 nAChRs agonist and mecamylamine (1.0 mg/kg, i. p.), α4β2 nAChRs antagonist were injected chronically during 14 days. The processes of learning/memory were assessed in different models of learning: passive avoidance performance and Morris water maze. Chronic RJR-2403 administration to females improved the passive avoidance performance in proestrous and estrous as compared to the control animals. Also, RJR-2403 restored spatial learning of rats during proestrous phases in Morris water maze, and stimulated the dynamics of spatial learning during estrous phases. On the contrary, the chronic mecamylamine administration impaired non-spatial, and especially, spatial learning in females during key phases of ovary cycle. The results of the study suggest positive effect of α4β2 nAChRs stimulation in learning/memory processes during ovary cycle in the adult female rats.

Proactive interference and concurrent inhibitory processes do not differentially affect item and associative recognition: Implication for the age-related associative memory deficit.

PubMed

Guez, Jonathan; Naveh-Benjamin, Moshe

2016-09-01

Previous studies have suggested an associative deficit hypothesis [Naveh-Benjamin, M. ( 2000 ). Adult age differences in memory performance: Tests of an associative deficit hypothesis. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 1170-1187] to explain age-related episodic memory declines. The hypothesis attributes part of the deficient episodic memory performance in older adults to a difficulty in creating and retrieving cohesive episodes. In this article, we further evaluate this hypothesis by testing two alternative processes that potentially mediate associative memory deficits in older adults. Four experiments are presented that assess whether failure of inhibitory processes (proactive interference in Experiments 1 and 2), and concurrent inhibition (in Experiments 3 and 4) are mediating factors in age-related associative deficits. The results suggest that creating conditions that require the operation of inhibitory processes, or that interfere with such processes, cannot simulate associative memory deficit in older adults. Instead, such results support the idea that associative memory deficits reflect a unique binding failure in older adults. This failure seems to be independent of other cognitive processes, including inhibitory and other resource-demanding processes.

Effects of cooperative learning strategy on undergraduate kinesiology students' learning styles.

PubMed

Meeuwsen, Harry J; King, George A; Pederson, Rockie

2005-10-01

A growing body of research supports cooperative learning as an effective teaching strategy. A specific cooperative learning strategy, Team-based Learning, was applied to a convenience sample of four undergraduate sophomore-level motor behavior courses over four semesters from Fall 2002 to Spring 2004 to examine whether this strategy would affect students' learning styles. The data from the Grasha-Reichmann Student Learning Style Scales indicated that this teaching strategy was associated with a significant decrease in the negative Avoidant and Dependent learning styles and an improvement in the positive Participant learning style.

Response inhibition predicts painful task duration and performance in healthy individuals performing a cold pressor task in a motivational context.

PubMed

Karsdorp, P A; Geenen, R; Vlaeyen, J W S

2014-01-01

Long-term avoidance of painful activities has shown to be dysfunctional in chronic pain. Pain may elicit escape or avoidance responses automatically, particularly when pain-related fear is high. A conflict may arise between opposing short-term escape/avoidance goals to reduce pain and long-term approach goals to receive a reward. An inhibitory control system may resolve this conflict. It was hypothesized that reduced response inhibition would be associated with greater escape/avoidance during pain, particularly among subjects with higher pain-related fear. Response inhibition was measured with the stop-signal task, and pain-related fear with the Fear of Pain Questionnaire. Participants completed a tone-detection task (TDT) in which they could earn money while being exposed to cold pressor pain. Escape/avoidance was operationalized as the hand immersion time during a cold pressor task (CPT) and the performance on the TDT. Poorer response inhibition was associated with shorter CPT immersion duration and with worse TDT performance. Pain after the CPT was associated with pain-related fear, but not with response inhibition. No supportive evidence was found for the hypothesis that the relation between inhibition and escape/avoidance would be most pronounced for those with higher pain-related fear. In contrast, the relation between response inhibition and number of hits on the TDT was most pronounced for those with lower pain-related fear. The findings suggest that individuals with a stronger ability to inhibit responses in a stop-signal task are better able to inhibit escape/avoidance responses elicited by pain, in the service of a conflicting approach goal. © 2013 European Pain Federation - EFIC®

Learned helplessness: unique features and translational value of a cognitive depression model.

PubMed

Vollmayr, Barbara; Gass, Peter

2013-10-01

The concept of learned helplessness defines an escape or avoidance deficit after uncontrollable stress and is regarded as a depression-like coping deficit in aversive but avoidable situations. Based on a psychological construct, it ideally complements other stress-induced or genetic animal models for major depression. Because of excellent face, construct, and predictive validity, it has contributed to the elaboration of several pathophysiological concepts and has brought forward new treatment targets. Whereas learned helplessness can be modeled not only in a broad variety of mammals, but also in fish and Drosophila, we will focus here on the use of this model in rats and mice, which are today the most common species for preclinical in vivo research in psychiatry.

Light adaptation alters the source of inhibition to the mouse retinal OFF pathway

PubMed Central

Mazade, Reece E.

2013-01-01

Sensory systems must avoid saturation to encode a wide range of stimulus intensities. One way the retina accomplishes this is by using both dim-light-sensing rod and bright-light-sensing cone photoreceptor circuits. OFF cone bipolar cells are a key point in this process, as they receive both excitatory input from cones and inhibitory input from AII amacrine cells via the rod pathway. However, in addition to AII amacrine cell input, other inhibitory inputs from cone pathways also modulate OFF cone bipolar cell light signals. It is unknown how these inhibitory inputs to OFF cone bipolar cells change when switching between rod and cone pathways or whether all OFF cone bipolar cells receive rod pathway input. We found that one group of OFF cone bipolar cells (types 1, 2, and 4) receive rod-mediated inhibitory inputs that likely come from the rod-AII amacrine cell pathway, while another group of OFF cone bipolar cells (type 3) do not. In both cases, dark-adapted rod-dominant light responses showed a significant contribution of glycinergic inhibition, which decreased with light adaptation and was, surprisingly, compensated by an increase in GABAergic inhibition. As GABAergic input has distinct timing and spatial spread from glycinergic input, a shift from glycinergic to GABAergic inhibition could significantly alter OFF cone bipolar cell signaling to downstream OFF ganglion cells. Larger GABAergic input could reflect an adjustment of OFF bipolar cell spatial inhibition, which may be one mechanism that contributes to retinal spatial sensitivity in the light. PMID:23926034

The Impact of Chemotherapy, Radiation and Epigenetic Modifiers in Cancer Cell Expression of Immune Inhibitory and Stimulatory Molecules and Anti-Tumor Efficacy

PubMed Central

Chacon, Jessica Ann; Schutsky, Keith; Powell, Daniel J.

2016-01-01

Genomic destabilizers, such as radiation and chemotherapy, and epigenetic modifiers are used for the treatment of cancer due to their apoptotic effects on the aberrant cells. However, these therapies may also induce widespread changes within the immune system and cancer cells, which may enable tumors to avoid immune surveillance and escape from host anti-tumor immunity. Genomic destabilizers can induce immunogenic death of tumor cells, but also induce upregulation of immune inhibitory ligands on drug-resistant cells, resulting in tumor progression. While administration of immunomodulatory antibodies that block the interactions between inhibitory receptors on immune cells and their ligands on tumor cells can mediate cancer regression in a subset of treated patients, it is crucial to understand how genomic destabilizers alter the immune system and malignant cells, including which inhibitory molecules, receptors and/or ligands are upregulated in response to genotoxic stress. Knowledge gained in this area will aid in the rational design of trials that combine genomic destabilizers, epigenetic modifiers and immunotherapeutic agents that may be synergized to improve clinical responses and prevent tumor escape from the immune system. Our review article describes the impact genomic destabilizers, such as radiation and chemotherapy, and epigenetic modifiers have on anti-tumor immunity and the tumor microenvironment. Although genomic destabilizers cause DNA damage on cancer cells, these therapies can also have diverse effects on the immune system, promote immunogenic cell death or survival and alter the cancer cell expression of immune inhibitor molecules. PMID:27854240

Working Memory: Its Role in Dyslexia and Other Specific Learning Difficulties

ERIC Educational Resources Information Center

Jeffries, Sharman; Everatt, John

2004-01-01

This paper reports a study contrasting dyslexic children against a control group of children without special educational needs (SEN) and a group with varied SENs. Children's abilities were compared on tasks assessing phonological processing, visuo-spatial/motor coordination and executive/inhibitory functioning; being targeted for assessment based…

Theoretical Framework for Educational Assessment: A Synoptic Review

ERIC Educational Resources Information Center

Ghaicha, Abdallah

2016-01-01

At this age of accountability, it is acknowledged that assessment is a powerful lever that can either boost or undermine students' learning. Hitherto, much of the regular institutional and instructional practices show that assessments remain inhibitory or void rather than constructive as these lack the assessment formative aspect. This denotes…

Charting Early Trajectories of Executive Control with the Shape School

ERIC Educational Resources Information Center

Clark, Caron A. C.; Sheffield, Tiffany D.; Chevalier, Nicolas; Nelson, Jennifer Mize; Wiebe, Sandra A.; Espy, Kimberly Andrews

2013-01-01

Despite acknowledgement of the importance of executive control for learning and behavior, there is a dearth of research charting its developmental trajectory as it unfolds against the background of children's sociofamilial milieus. Using a prospective, cohort-sequential design, this study describes growth trajectories for inhibitory control…

SPATIAL REVERSAL LEARNING IN AROCLOR 1254-EXPOSED RATS: SEX-SPECIFIC DEFICITS IN ASSOCIATIVE ABILITY AND INHIBITORY CONTROL. (R825812)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Evidence-Based Management Education

ERIC Educational Resources Information Center

Burke-Smalley, Lisa A.

2014-01-01

In this rejoinder to "Let's Burn Them All: Reflections on the Learning-Inhibitory Nature of Introduction to Management and Introduction to Organizational Behavior Textbooks," by Robert A. Snyder (see EJ1039748), Lisa Burke-Smalley touches upon a number of Snyder's claims and explores questions sparked by his essay. She argues…

Extinction Circuits for Fear and Addiction Overlap in Prefrontal Cortex

ERIC Educational Resources Information Center

Peters, Jamie; Kalivas, Peter W.; Quirk, Gregory J.

2009-01-01

Extinction is a form of inhibitory learning that suppresses a previously conditioned response. Both fear and drug seeking are conditioned responses that can lead to maladaptive behavior when expressed inappropriately, manifesting as anxiety disorders and addiction, respectively. Recent evidence indicates that the medial prefrontal cortex (mPFC) is…

The correlation between achievement goals, learning strategies, and motivation in medical students.

PubMed

Kim, Sun; Hur, Yera; Park, Joo Hyun

2014-03-01

The purpose of this study is to investigate the pursuit of achievement goals in medical students and to assess the relationship between achievement goals, learning strategy, and motivation. Two hundred seventy freshman and sophomore premedical students and sophomore medical school students participated in this study, which used the Achievement Goals Scale and the Self-Regulated Learning Strategy Questionnaire. The achievement goals of medical students were oriented toward moderate performance approach levels, slightly high performance avoidance levels, and high mastery goals. About 40% of the students were high or low in all three achievement goals. The most successful adaptive learners in the areas of learning strategies, motivation, and school achievement were students from group 6, who scored high in both performance approach and mastery goals but low in performance avoidance goals. And goal achievement are related to the academic self-efficacy, learning strategies, and motivation in medical students. In the context of academic achievement, mastery goals and performance approach goals are adaptive goals.

Constraints on decision making: implications from genetics, personality, and addiction.

PubMed

Baker, Travis E; Stockwell, Tim; Holroyd, Clay B

2013-09-01

An influential neurocomputational theory of the biological mechanisms of decision making, the "basal ganglia go/no-go model," holds that individual variability in decision making is determined by differences in the makeup of a striatal system for approach and avoidance learning. The model has been tested empirically with the probabilistic selection task (PST), which determines whether individuals learn better from positive or negative feedback. In accordance with the model, in the present study we examined whether an individual's ability to learn from positive and negative reinforcement can be predicted by genetic factors related to the midbrain dopamine system. We also asked whether psychiatric and personality factors related to substance dependence and dopamine affect PST performance. Although we found characteristics that predicted individual differences in approach versus avoidance learning, these observations were qualified by additional findings that appear inconsistent with the predictions of the go/no-go model. These results highlight a need for future research to validate the PST as a measure of basal ganglia reward learning.

Consequences of Learned Helplessness and Recognition of the State of Cognitive Exhaustion in Persons with Mild Intellectual Disability

PubMed Central

Gacek, Michał; Smoleń, Tomasz; Pilecka, Władysława

2017-01-01

Persons with intellectual disability are a group at risk of being exposed to overly demanding problem-solving situations, which may produce learned helplessness. The research was based on the informational model of learned helplessness. The consequences of exposure to an unsolvable task and the ability to recognize the symptoms of cognitive exhaustion were tested in 120 students with mild intellectual disability. After the exposure to the unsolvable task, persons in the experimental group obtained lower results than the control group in the escape/avoidance learning task, but a similar result was found in the divergent thinking fluency task. Also, participants in the experimental group had difficulties recognizing the symptoms of the cognitive exhaustion state. After a week’s time, the difference in escape/avoidance learning performance was still observed. The results indicate that exposure to unsolvable tasks may negatively influence the cognitive performance in persons with intellectual disability, although those persons may not identify the cognitive state related to lowered performance. PMID:28479937

Consequences of Learned Helplessness and Recognition of the State of Cognitive Exhaustion in Persons with Mild Intellectual Disability.

PubMed

Gacek, Michał; Smoleń, Tomasz; Pilecka, Władysława

2017-01-01

Persons with intellectual disability are a group at risk of being exposed to overly demanding problem-solving situations, which may produce learned helplessness . The research was based on the informational model of learned helplessness. The consequences of exposure to an unsolvable task and the ability to recognize the symptoms of cognitive exhaustion were tested in 120 students with mild intellectual disability. After the exposure to the unsolvable task, persons in the experimental group obtained lower results than the control group in the escape/avoidance learning task, but a similar result was found in the divergent thinking fluency task. Also, participants in the experimental group had difficulties recognizing the symptoms of the cognitive exhaustion state. After a week's time, the difference in escape/avoidance learning performance was still observed. The results indicate that exposure to unsolvable tasks may negatively influence the cognitive performance in persons with intellectual disability, although those persons may not identify the cognitive state related to lowered performance.

Two spatiotemporally distinct value systems shape reward-based learning in the human brain.

PubMed

Fouragnan, Elsa; Retzler, Chris; Mullinger, Karen; Philiastides, Marios G

2015-09-08

Avoiding repeated mistakes and learning to reinforce rewarding decisions is critical for human survival and adaptive actions. Yet, the neural underpinnings of the value systems that encode different decision-outcomes remain elusive. Here coupling single-trial electroencephalography with simultaneously acquired functional magnetic resonance imaging, we uncover the spatiotemporal dynamics of two separate but interacting value systems encoding decision-outcomes. Consistent with a role in regulating alertness and switching behaviours, an early system is activated only by negative outcomes and engages arousal-related and motor-preparatory brain structures. Consistent with a role in reward-based learning, a later system differentially suppresses or activates regions of the human reward network in response to negative and positive outcomes, respectively. Following negative outcomes, the early system interacts and downregulates the late system, through a thalamic interaction with the ventral striatum. Critically, the strength of this coupling predicts participants' switching behaviour and avoidance learning, directly implicating the thalamostriatal pathway in reward-based learning.

The Role of Informative and Ambiguous Feedback in Avoidance Behavior: Empirical and Computational Findings

PubMed Central

Moustafa, Ahmed A.; Sheynin, Jony; Myers, Catherine E.

2015-01-01

Avoidance behavior is a critical component of many psychiatric disorders, and as such, it is important to understand how avoidance behavior arises, and whether it can be modified. In this study, we used empirical and computational methods to assess the role of informational feedback and ambiguous outcome in avoidance behavior. We adapted a computer-based probabilistic classification learning task, which includes positive, negative and no-feedback outcomes; the latter outcome is ambiguous as it might signal either a successful outcome (missed punishment) or a failure (missed reward). Prior work with this task suggested that most healthy subjects viewed the no-feedback outcome as strongly positive. Interestingly, in a later version of the classification task, when healthy subjects were allowed to opt out of (i.e. avoid) responding, some subjects (“avoiders”) reliably avoided trials where there was a risk of punishment, but other subjects (“non-avoiders”) never made any avoidance responses at all. One possible interpretation is that the “non-avoiders” valued the no-feedback outcome so positively on punishment-based trials that they had little incentive to avoid. Another possible interpretation is that the outcome of an avoided trial is unspecified and that lack of information is aversive, decreasing subjects’ tendency to avoid. To examine these ideas, we here tested healthy young adults on versions of the task where avoidance responses either did or did not generate informational feedback about the optimal response. Results showed that provision of informational feedback decreased avoidance responses and also decreased categorization performance, without significantly affecting the percentage of subjects classified as “avoiders.” To better understand these results, we used a modified Q-learning model to fit individual subject data. Simulation results suggest that subjects in the feedback condition adjusted their behavior faster following better-than-expected outcomes, compared to subjects in the no-feedback condition. Additionally, in both task conditions, “avoiders” adjusted their behavior faster following worse-than-expected outcomes, and treated the ambiguous no-feedback outcome as less rewarding, compared to non-avoiders. Together, results shed light on the important role of ambiguous and informative feedback in avoidance behavior. PMID:26630279

Effects of voluntary and treadmill exercise on spontaneous withdrawal signs, cognitive deficits and alterations in apoptosis-associated proteins in morphine-dependent rats.

PubMed

Mokhtari-Zaer, Amin; Ghodrati-Jaldbakhan, Shahrbanoo; Vafaei, Abbas Ali; Miladi-Gorji, Hossein; Akhavan, Maziar M; Bandegi, Ahmad Reza; Rashidy-Pour, Ali

2014-09-01

Chronic exposure to morphine results in cognitive deficits and alterations of apoptotic proteins in favor of cell death in the hippocampus, a brain region critically involved in learning and memory. Physical activity has been shown to have beneficial effects on brain health. In the current work, we examined the effects of voluntary and treadmill exercise on spontaneous withdrawal signs, the associated cognitive defects, and changes of apoptotic proteins in morphine-dependent rats. Morphine dependence was induced through bi-daily administrations of morphine (10mg/kg) for 10 days. Then, the rats were trained under two different exercise protocols: mild treadmill exercise or voluntary wheel exercise for 10 days. After exercise training, their spatial learning and memory and aversive memory were examined by a water maze and by an inhibitory avoidance task, respectively. The expression of the pro-apoptotic protein Bax and the anti-apoptotic protein Bcl-2 in the hippocampus were determined by immunoblotting. We found that chronic exposure to morphine impaired spatial and aversive memory and remarkably suppressed the expression of Bcl-2, but Bax expression remained constant. Both voluntary and treadmill exercise alleviated memory impairment, increased the expression of Bcl-2 protein, and only the later suppressed the expression of Bax protein in morphine-dependent animals. Moreover, both exercise protocols diminished the occurrence of spontaneous morphine withdrawal signs. Our findings showed that exercise reduces the spontaneous morphine-withdrawal signs, blocks the associated impairment of cognitive performance, and overcomes morphine-induced alterations in apoptotic proteins in favor of cell death. Thus, exercise may be a useful therapeutic strategy for cognitive and behavioral deficits in addict individuals. Copyright © 2014 Elsevier B.V. All rights reserved.

Distributed Cerebellar Motor Learning: A Spike-Timing-Dependent Plasticity Model

PubMed Central

Luque, Niceto R.; Garrido, Jesús A.; Naveros, Francisco; Carrillo, Richard R.; D'Angelo, Egidio; Ros, Eduardo

2016-01-01

Deep cerebellar nuclei neurons receive both inhibitory (GABAergic) synaptic currents from Purkinje cells (within the cerebellar cortex) and excitatory (glutamatergic) synaptic currents from mossy fibers. Those two deep cerebellar nucleus inputs are thought to be also adaptive, embedding interesting properties in the framework of accurate movements. We show that distributed spike-timing-dependent plasticity mechanisms (STDP) located at different cerebellar sites (parallel fibers to Purkinje cells, mossy fibers to deep cerebellar nucleus cells, and Purkinje cells to deep cerebellar nucleus cells) in close-loop simulations provide an explanation for the complex learning properties of the cerebellum in motor learning. Concretely, we propose a new mechanistic cerebellar spiking model. In this new model, deep cerebellar nuclei embed a dual functionality: deep cerebellar nuclei acting as a gain adaptation mechanism and as a facilitator for the slow memory consolidation at mossy fibers to deep cerebellar nucleus synapses. Equipping the cerebellum with excitatory (e-STDP) and inhibitory (i-STDP) mechanisms at deep cerebellar nuclei afferents allows the accommodation of synaptic memories that were formed at parallel fibers to Purkinje cells synapses and then transferred to mossy fibers to deep cerebellar nucleus synapses. These adaptive mechanisms also contribute to modulate the deep-cerebellar-nucleus-output firing rate (output gain modulation toward optimizing its working range). PMID:26973504

Countertherapeutic Styles When Counseling the Learning-Disabled College Student.

ERIC Educational Resources Information Center

Lutwak, Nita; Fine, Elaine

1983-01-01

Reviews the literature on learning disabilities, focusing on countertherapeutic styles of interacting with college students. Illustrates problems in the counseling process (e.g., limiting client options, negative dependency, avoidance, premature termination) through a case example. (WAS)

Effect of Flumethrin on Survival and Olfactory Learning in Honeybees

PubMed Central

Tan, Ken; Yang, Shuang; Wang, Zhengwei; Menzel, Randolf

2013-01-01

Flumethrin has been widely used as an acaricide for the control of Varroa mites in commercial honeybee keeping throughout the world for many years. Here we test the mortality of the Asian honeybee Apis cerana cerana after treatment with flumethrin. We also ask (1) how bees react to the odor of flumethrin, (2) whether its odor induces an innate avoidance response, (3) whether its taste transmits an aversive reinforcing component in olfactory learning, and (4) whether its odor or taste can be associated with reward in classical conditioning. Our results show that flumethrin has a negative effect on Apis ceranàs lifespan, induces an innate avoidance response, acts as a punishing reinforcer in olfactory learning, and interferes with the association of an appetitive conditioned stimulus. Furthermore flumethrin uptake within the colony reduces olfactory learning over an extended period of time. PMID:23785490

Telencephalic neural activation following passive avoidance learning in a terrestrial toad.

PubMed

Puddington, Martín M; Daneri, M Florencia; Papini, Mauricio R; Muzio, Rubén N

2016-12-15

The present study explores passive avoidance learning and its neural basis in toads (Rhinella arenarum). In Experiment 1, two groups of toads learned to move from a lighted compartment into a dark compartment. After responding, animals in the experimental condition were exposed to an 800-mM strongly hypertonic NaCl solution that leads to weight loss. Control animals received exposure to a 300-mM slightly hypertonic NaCl solution that leads to neither weight gain nor loss. After 10 daily acquisition trials, animals in the experimental group showed significantly longer latency to enter the dark compartment. Additionally, 10 daily trials in which both groups received the 300-mM NaCl solution after responding eliminated this group effect. Thus, experimental animals showed gradual acquisition and extinction of a passive avoidance respond. Experiment 2 replicated the gradual acquisition effect, but, after the last trial, animals were sacrificed and neural activation was assessed in five brain regions using AgNOR staining for nucleoli-an index of brain activity. Higher activation in the experimental animals, relative to controls, was observed in the amygdala and striatum. Group differences in two other regions, lateral pallium and septum, were borderline, but nonsignificant, whereas group differences in the medial pallium were nonsignificant. These preliminary results suggest that a striatal-amygdala activation could be a key component of the brain circuit controlling passive avoidance learning in amphibians. The results are discussed in relation to the results of analogous experiments with other vertebrates. Copyright © 2016 Elsevier B.V. All rights reserved.

High School Students' Motivation to Learn Mathematics: The Role of Multiple Goals

ERIC Educational Resources Information Center

Ng, Chi-hung Clarence

2018-01-01

Using a sample of 310 Year 10 Chinese students from Hong Kong, this survey study examined the effects of multiple goals in learning mathematics. Independent variables were mastery, performance-approach, performance-avoidance, and pro-social goals. Dependent variables included perceived classroom goal structures, teacher's support, learning motives…

Using a Scholarly Approach to Improve Teaching and Learning in Biochemistry Higher Education

ERIC Educational Resources Information Center

Loertscher, Jennifer

2012-01-01

Although the biochemistry education community is far from avoiding conversations about improving teaching and learning, reexamining individual and community teaching practices through the lens of the scholarship of teaching and learning (SoTL) is critical for continued growth and improvement. The contemporary vision of SoTL, which has been…

Fail Better: Toward a Taxonomy of E-Learning Error

ERIC Educational Resources Information Center

Priem, Jason

2010-01-01

The study of student error, important across many fields of educational research, has begun to attract interest in the field of e-learning, particularly in relation to usability. However, it remains unclear when errors should be avoided (as usability failures) or embraced (as learning opportunities). Many domains have benefited from taxonomies of…

Setting Learning Analytics in Context: Overcoming the Barriers to Large-Scale Adoption

ERIC Educational Resources Information Center

Ferguson, Rebecca; Macfadyen, Leah P.; Clow, Doug; Tynan, Belinda; Alexander, Shirley; Dawson, Shane

2014-01-01

A core goal for most learning analytic projects is to move from small-scale research towards broader institutional implementation, but this introduces a new set of challenges because institutions are stable systems, resistant to change. To avoid failure and maximize success, implementation of learning analytics at scale requires explicit and…

Graduate Students' Readiness and Perceptions of the Pedagogical Application of Collaborative Video Logs

ERIC Educational Resources Information Center

Fox, Heather L.; Cayari, Christopher

2016-01-01

Group work projects are common components of graduate course curricula. Instructors often try to mitigate the benefits of group work projects for students while avoiding negative effects. Informal learning and participatory culture practices like video logs can enhance learning environments. Video logs that promote both informal learning and…

Different Futures of Adaptive Collaborative Learning Support

ERIC Educational Resources Information Center

Rummel, Nikol; Walker, Erin; Aleven, Vincent

2016-01-01

In this position paper we contrast a Dystopian view of the future of adaptive collaborative learning support (ACLS) with a Utopian scenario that--due to better-designed technology, grounded in research--avoids the pitfalls of the Dystopian version and paints a positive picture of the practice of computer-supported collaborative learning 25 years…

Improving Open Access through Prior Learning Assessment

ERIC Educational Resources Information Center

Yin, Shuangxu; Kawachi, Paul

2013-01-01

This paper explores and presents new data on how to improve open access in distance education through using prior learning assessments. Broadly there are three types of prior learning assessment (PLAR): Type-1 for prospective students to be allowed to register for a course; Type-2 for current students to avoid duplicating work-load to gain…

Operant conditioning of autobiographical memory retrieval.

PubMed

Debeer, Elise; Raes, Filip; Williams, J Mark G; Craeynest, Miet; Hermans, Dirk

2014-01-01

Functional avoidance is considered as one of the key mechanisms underlying overgeneral autobiographical memory (OGM). According to this view OGM is regarded as a learned cognitive avoidance strategy, based on principles of operant conditioning; i.e., individuals learn to avoid the emotionally painful consequences associated with the retrieval of specific negative memories. The aim of the present study was to test one of the basic assumptions of the functional avoidance account, namely that autobiographical memory retrieval can be brought under operant control. Here 41 students were instructed to retrieve personal memories in response to 60 emotional cue words. Depending on the condition, they were punished with an aversive sound for the retrieval of specific or nonspecific memories in an operant conditioning procedure. Analyzes showed that the course of memory specificity significantly differed between conditions. After the procedure participants punished for nonspecific memories retrieved significantly more specific memories compared to participants punished for specific memories. However, whereas memory specificity significantly increased in participants punished for specific memories, it did not significantly decrease in participants punished for nonspecific memories. Thus, while our findings indicate that autobiographical memory retrieval can be brought under operant control, they do not support a functional avoidance view on OGM.

Learning by stimulation avoidance: A principle to control spiking neural networks dynamics

PubMed Central

Sinapayen, Lana; Ikegami, Takashi

2017-01-01

Learning based on networks of real neurons, and learning based on biologically inspired models of neural networks, have yet to find general learning rules leading to widespread applications. In this paper, we argue for the existence of a principle allowing to steer the dynamics of a biologically inspired neural network. Using carefully timed external stimulation, the network can be driven towards a desired dynamical state. We term this principle “Learning by Stimulation Avoidance” (LSA). We demonstrate through simulation that the minimal sufficient conditions leading to LSA in artificial networks are also sufficient to reproduce learning results similar to those obtained in biological neurons by Shahaf and Marom, and in addition explains synaptic pruning. We examined the underlying mechanism by simulating a small network of 3 neurons, then scaled it up to a hundred neurons. We show that LSA has a higher explanatory power than existing hypotheses about the response of biological neural networks to external simulation, and can be used as a learning rule for an embodied application: learning of wall avoidance by a simulated robot. In other works, reinforcement learning with spiking networks can be obtained through global reward signals akin simulating the dopamine system; we believe that this is the first project demonstrating sensory-motor learning with random spiking networks through Hebbian learning relying on environmental conditions without a separate reward system. PMID:28158309

A Looping-Based Model for Quenching Repression

PubMed Central

Pollak, Yaroslav; Goldberg, Sarah; Amit, Roee

2017-01-01

We model the regulatory role of proteins bound to looped DNA using a simulation in which dsDNA is represented as a self-avoiding chain, and proteins as spherical protrusions. We simulate long self-avoiding chains using a sequential importance sampling Monte-Carlo algorithm, and compute the probabilities for chain looping with and without a protrusion. We find that a protrusion near one of the chain’s termini reduces the probability of looping, even for chains much longer than the protrusion–chain-terminus distance. This effect increases with protrusion size, and decreases with protrusion-terminus distance. The reduced probability of looping can be explained via an eclipse-like model, which provides a novel inhibitory mechanism. We test the eclipse model on two possible transcription-factor occupancy states of the D. melanogaster eve 3/7 enhancer, and show that it provides a possible explanation for the experimentally-observed eve stripe 3 and 7 expression patterns. PMID:28085884

Individual Differences in Children's Corepresentation of Self and Other in Joint Action.

PubMed

Milward, Sophie J; Kita, Sotaro; Apperly, Ian A

2017-05-01

Previous research has shown that children aged 4-5 years, but not 2-3 years, show adult-like interference from a partner when performing a joint task (Milward, Kita, & Apperly, 2014). This raises questions about the cognitive skills involved in the development of such "corepresentation (CR)" of a partner (Sebanz, Knoblich, & Prinz, 2003). Here, individual differences data from one hundred and thirteen 4- to 5-year-olds showed theory of mind (ToM) and inhibitory control (IC) as predictors of ability to avoid CR interference, suggesting that children with better ToM abilities are more likely to succeed in decoupling self and other representations in a joint task, while better IC is likely to help children avoid interference from a partner's response when selecting their own response on the task. © 2016 The Authors. Child Development published by Wiley Periodicals, Inc. on behalf of Society for Research in Child Development.

Hippocampal awake replay in fear memory retrieval

PubMed Central

Wu, Chun-Ting; Haggerty, Daniel; Kemere, Caleb; Ji, Daoyun

2017-01-01

Hippocampal place cells are key to episodic memories. How these cells participate in memory retrieval remains unclear. Here, after rats acquired a fear memory by receiving mild foot-shocks at a shock zone of a track, we analyzed place cells when the animals were placed back to the track and displayed an apparent memory retrieval behavior: avoidance of the shock zone. We found that place cells representing the shock zone were reactivated, despite the fact that the animals did not enter the shock zone. This reactivation occurred in ripple-associated awake replay of place cell sequences encoding the paths from the animal’s current positions to the shock zone, but not in place cell sequences within individual cycles of theta oscillation. The result reveals a specific place cell pattern underlying the inhibitory avoidance behavior and provides strong evidence for the involvement of awake replay in fear memory retrieval. PMID:28218916

Cross State-dependent Learning Interaction Between Scopolamine and Morphine in Mice: The Role of Dorsal Hippocampus

PubMed Central

Maleki, Morteza; Hassanpour-Ezatti, Majid; Navaeian, Majid

2017-01-01

Introduction: The current study aimed at investigating the existence of the cross state-dependent learning between morphine and scopolamine (SCO) in mice by passive avoidance method, pointing to the role of CA1 area. Methods: The effects of pre-training SCO (0.75, 1.5, and 3 μg, Intra-CA1), or morphine (1, 3, and 6 mg/kg, intraperitoneal (i.p.) was evaluated on the retrieval of passive avoidance learning using step-down task in mice (n=10). Then, the effect of pretest administration of morphine (1.5, 3, and 6 mg/kg, i.p.) was examined on passive avoidance retrieval impairment induced by pre-training SCO (3 μg/mice, Intra-CA1). Next, the effect of pretest Intra-CA1 injection of scopolamine (0.75, 1.5, and 3 μg/mice) was evaluated on morphine (6 mg/kg, i.p.) pre-training deficits in this task in mice. Results: The pre-training Intra-CA1 injection of scopolamine (1.5 and 3 μg/mouse), or morphine (3 and 6 mg/kg, i.p.) impaired the avoidance memory retrieval when it was tested 24 hours later. Pretest injection of both drugs improved its pre-training impairing effects on mice memory. Moreover, the amnesia induced by the pre-training injections of scopolamine (3 μg/mice) was restored significantly (P<0.01) by pretest injections of morphine (3 and 6 mg/kg, i.p.). Similarly, pretest injection of scopolamine (3 μg/mice) restored amnesia induced by the pre-training injections of morphine (6 mg/kg, i.p.), significantly (P<0.01). Conclusion: The current study findings indicated a cross state-dependent learning between SCO and morphine at CA1 level. Therefore, it seems that muscarinic and opioid receptors may act reciprocally on modulation of passive avoidance memory retrieval, at the level of dorsal hippocampus, in mice. PMID:28781727

Information Seeking and Avoidance Behavior in School Library Distance Learning

ERIC Educational Resources Information Center

Du, Yunfei

2010-01-01

Library science students in school librarianship were surveyed to determine their information seeking and avoidance behaviors in Web-based online environments. Two coping styles were identified among students. Barriers to student online collaboration, such as individual preferences, concerns on efficiency, and lack of mutual trust, were observed.…

Steps to Take with the Board to Avoid Walking the Plank.

ERIC Educational Resources Information Center

Papallo, William R.

1990-01-01

A veteran superintendent outlines an eight-step method for achieving success, including assessing the situation, avoiding board overload, coping with stress, deemphasizing egoism, learning to live in the gray zone between policy formation and administration, ensuring effective board decisions, identifying prospective board members, and knowing…

Avoiding Consumer Frauds and Misrepresentations. A Learning Module.

ERIC Educational Resources Information Center

Garman, E. Thomas; Monroe, Sarah D.

Focusing on avoiding consumer frauds and misrepresentations, this document is one in a series of three consumer education modules developed to educate individual adult consumers in important areas of consumer affairs. An introductory section provides an overview of the module contents, suggested approaches for using the module, and suggestions for…

Self-Protection Profiles of Worth and Academic Goals in University Students

ERIC Educational Resources Information Center

Ferradás, María del Mar; Freire, Carlos; Núñez, José Carlos

2017-01-01

This work analyzes the possible existence of self-protection profiles based on a combination of self-handicapping (behavioral and claimed) strategies and defensive pessimism in university students. Similarly, the relationship between these profiles and academic goals (learning, performance-approach, performance-avoidance, and work-avoidance) is…

Cognitive Defusion versus thought Distraction in the Mitigation of Learned Helplessness

ERIC Educational Resources Information Center

Hooper, Nic; McHugh, Louise

2013-01-01

Recent research suggests that attempting to avoid unwanted psychological events is maladaptive. Contrastingly, cognitive defusion, which is an acceptance-based method for managing unwanted thoughts, may provide a plausible alternative. The current study was designed to compare defusion and experiential avoidance as strategies for coping with…

Psychological Determinants of University Students' Academic Performance: An Empirical Study

ERIC Educational Resources Information Center

Gebka, Bartosz

2014-01-01

This study utilises an integrated conceptual model of academic performance which captures a series of psychological factors: cognitive style; self-theories such as self-esteem and self-efficacy; achievement goals such as mastery, performance, performance avoidance and work avoidance; study-processing strategies such as deep and surface learning;…

Control of Excitation/Inhibition Balance in a Hippocampal Circuit by Calcium Sensor Protein Regulation of Presynaptic Calcium Channels.

PubMed

Nanou, Evanthia; Lee, Amy; Catterall, William A

2018-05-02

Activity-dependent regulation controls the balance of synaptic excitation to inhibition in neural circuits, and disruption of this regulation impairs learning and memory and causes many neurological disorders. The molecular mechanisms underlying short-term synaptic plasticity are incompletely understood, and their role in inhibitory synapses remains uncertain. Here we show that regulation of voltage-gated calcium (Ca 2+ ) channel type 2.1 (Ca V 2.1) by neuronal Ca 2+ sensor (CaS) proteins controls synaptic plasticity and excitation/inhibition balance in a hippocampal circuit. Prevention of CaS protein regulation by introducing the IM-AA mutation in Ca V 2.1 channels in male and female mice impairs short-term synaptic facilitation at excitatory synapses of CA3 pyramidal neurons onto parvalbumin (PV)-expressing basket cells. In sharp contrast, the IM-AA mutation abolishes rapid synaptic depression in the inhibitory synapses of PV basket cells onto CA1 pyramidal neurons. These results show that CaS protein regulation of facilitation and inactivation of Ca V 2.1 channels controls the direction of short-term plasticity at these two synapses. Deletion of the CaS protein CaBP1/caldendrin also blocks rapid depression at PV-CA1 synapses, implicating its upregulation of inactivation of Ca V 2.1 channels in control of short-term synaptic plasticity at this inhibitory synapse. Studies of local-circuit function revealed reduced inhibition of CA1 pyramidal neurons by the disynaptic pathway from CA3 pyramidal cells via PV basket cells and greatly increased excitation/inhibition ratio of the direct excitatory input versus indirect inhibitory input from CA3 pyramidal neurons to CA1 pyramidal neurons. This striking defect in local-circuit function may contribute to the dramatic impairment of spatial learning and memory in IM-AA mice. SIGNIFICANCE STATEMENT Many forms of short-term synaptic plasticity in neuronal circuits rely on regulation of presynaptic voltage-gated Ca 2+ (Ca V ) channels. Regulation of Ca V 2.1 channels by neuronal calcium sensor (CaS) proteins controls short-term synaptic plasticity. Here we demonstrate a direct link between regulation of Ca V 2.1 channels and short-term synaptic plasticity in native hippocampal excitatory and inhibitory synapses. We also identify CaBP1/caldendrin as the calcium sensor interacting with Ca V 2.1 channels to mediate rapid synaptic depression in the inhibitory hippocampal synapses of parvalbumin-expressing basket cells to CA1 pyramidal cells. Disruption of this regulation causes altered short-term plasticity and impaired balance of hippocampal excitatory to inhibitory circuits. Copyright © 2018 the authors 0270-6474/18/384430-11$15.00/0.

Phenotypic transformation affects associative learning in the desert locust.

PubMed

Simões, Patrício M V; Niven, Jeremy E; Ott, Swidbert R

2013-12-02

In desert locusts, increased population densities drive phenotypic transformation from the solitarious to the gregarious phase within a generation [1-4]. Here we show that when presented with odor-food associations, the two extreme phases differ in aversive but not appetitive associative learning, with solitarious locusts showing a conditioned aversion more quickly than gregarious locusts. The acquisition of new learned aversions was blocked entirely in acutely crowded solitarious (transiens) locusts, whereas appetitive learning and prior learned associations were unaffected. These differences in aversive learning support phase-specific feeding strategies. Associative training with hyoscyamine, a plant alkaloid found in the locusts' habitat [5, 6], elicits a phase-dependent odor preference: solitarious locusts avoid an odor associated with hyoscyamine, whereas gregarious locusts do not. Remarkably, when solitarious locusts are crowded and then reconditioned with the odor-hyoscyamine pairing as transiens, the specific blockade of aversive acquisition enables them to override their prior aversive memory with an appetitive one. Under fierce food competition, as occurs during crowding in the field, this provides a neuroecological mechanism enabling locusts to reassign an appetitive value to an odor that they learned previously to avoid. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Intern(euron)al affairs : The role of specific neocortical interneuron classes in the interaction between acetylcholine and GABAergic anesthetics].

PubMed

Liebig, L; Grasshoff, C; Hentschke, H

2016-08-01

Acetylcholine is a neuromodulator which is released throughout the central nervous system and plays an essential role in consciousness and cognitive processes including attention and learning. Due to its 'activating' effect on the neuronal and behavioral level its interaction with anesthetics has long been of interest to anesthesiologists. It is widely held that a reduction of the release of acetylcholine by general anesthetics constitutes part of the anesthetic effect. This notion is backed by numerous human and animal studies, but is also in seeming contradiction to findings that acetylcholine activates specific classes of inhibitory neurons: if acetylcholine excites elements within the neuronal network responsible for the release of the inhibitory neurotransmitter γ-aminobutyric acid (GABA), its withdrawal should diminish, not enhance, the effect of anesthetics.Focusing on cortical circuits, we present an overview of recent advances in cellular neurophysiology, particularly the interactions between inhibitory neuron classes, which provide insights on the interaction between acetylcholine and GABA.

Learning place cells, grid cells and invariances with excitatory and inhibitory plasticity

PubMed Central

2018-01-01

Neurons in the hippocampus and adjacent brain areas show a large diversity in their tuning to location and head direction, and the underlying circuit mechanisms are not yet resolved. In particular, it is unclear why certain cell types are selective to one spatial variable, but invariant to another. For example, place cells are typically invariant to head direction. We propose that all observed spatial tuning patterns – in both their selectivity and their invariance – arise from the same mechanism: Excitatory and inhibitory synaptic plasticity driven by the spatial tuning statistics of synaptic inputs. Using simulations and a mathematical analysis, we show that combined excitatory and inhibitory plasticity can lead to localized, grid-like or invariant activity. Combinations of different input statistics along different spatial dimensions reproduce all major spatial tuning patterns observed in rodents. Our proposed model is robust to changes in parameters, develops patterns on behavioral timescales and makes distinctive experimental predictions. PMID:29465399

Differences in Active Avoidance Conditioning in Male and Female Rats with Experimental Anxiety-Depressive Disorder.

PubMed

Khlebnikova, N N; Krupina, N A; Kushnareva, E Yu; Orlova, I N

2015-07-01

Using rat model of experimental anxiety-depressive disorder caused by postnatal administration of methionyl-2(S)-cyanopyrrolidine, an inhibitor of dipeptidyl peptidase IV, we compared conditioned active avoidance response and memory retention in males and females. In experimental males and females, conditioning was impaired in comparison with the control. In experimental groups, females were worse learners than males, while in control groups, females were better learners than males. Memory retention in experimental animals did not differ from that in controls 24 h after learning. Two months after learning, control females demonstrated better retention than control males.

Learning and the persistence of appetite: extinction and the motivation to eat and overeat.

PubMed

Bouton, Mark E

2011-04-18

The modern world is saturated with highly palatable and highly available food, providing many opportunities to associate food with environmental cues and actions (through Pavlovian and operant or instrumental learning, respectively). Basic learning processes can often increase the tendency to approach and consume food, whereas extinction, in which Pavlovian and operant behaviors decline when the reinforcer is withheld, weakens but does not erase those tendencies. Contemporary research suggests that extinction involves an inhibitory form of new learning that appears fragile because it is highly dependent on the context for expression. These ideas are supported by the phenomena of renewal, spontaneous recovery, resurgence, reinstatement, and rapid reacquisition in appetitive learning, which together may help explain why overeating may be difficult to suppress permanently, and why appetitive behavior may seem so persistent. Copyright © 2010. Published by Elsevier Inc.

[Effect of serotonin-modulated anticonsolidation protein on formation of long-term memory in carps Cyprinus carpio in the model of active avoidance learning].

PubMed

Garina, D V; Mekhtiev, A A

2014-01-01

Effect of serotonin-modulated anticonsolidation protein (SMAP) that has property of disturbing formation of memory trace in mammals and of learning and memory in teleost fish was studied in the model of active avoidance learning. The experiment was performed in three stages: (1) fry of carps Cyprinus carpio L. was injected intracerebrovenricularly with the SMAP protein at a dose of 0.3 μg/g; control individuals were administered with equal amount of the buffered saline for poikilothermic animals; (2) 24 h after the injection, fish were learnt during 8 sèances for 2 days the conditioned reflex of active avoidance; (3) 48 h after the learning the testing of the skill was performed. The administration of the protein was shown to lead to disturbance of reproduction of the skill in the fish: the latent time of the skill reproduction in experimental individuals exceeded that in control fish more than two times, while the number of individuals succeeding the task in the experimental group was non-significantly lower than in the control group. However, unlike mammals, injection of the SMAP protein in this model produced no effect on the process of learning in carps. Thus, there was first demonstrated the inhibiting effect of the SMAP protein whose concentration correlated positively with the content of the neurotransmitter serotonin in brain on consolidation of memory traces in teleost fish.

Teaching Fluid Mechanics to the Beginning Graduate Student--An Objective-Oriented Approach.

ERIC Educational Resources Information Center

Liu, Henry

A premature embarkation in specialized areas of fluid mechanics by the beginning graduate student, without having first thoroughly learned the basics, leads to learning difficulties and destroys zeal for learning. To avoid these problems, many schools in the U.S. offer beginning graduate courses in fluid mechanics (BGCFM). Because the success or…

Introducing Blended Learning: An Experience of Uncertainty for Students in the United Arab Emirates

ERIC Educational Resources Information Center

Kemp, Linzi J.

2013-01-01

The cultural dimension of Uncertainty Avoidance is analysed in this study of an introduction to blended learning for international students. Content analysis was conducted on the survey narratives collected from three cohorts of management undergraduates in the United Arab Emirates. Interpretation of certainty with blended learning was found in:…

Coral Reefs, Convicts, Cadavers, Coffee Shops and Couture: Customizing Experiential Learning to Increase Comfort and Engagement

ERIC Educational Resources Information Center

Grabowsky, Gail L.; Hargis, Jace; Davidson, Janet; Paynter, Allison; Suh, Junghwa; Wright, Claire

2017-01-01

Experiential learning (EL) can offer a high impact educational opportunity that benefits students from diverse backgrounds, creating an inclusive learning environment. Barriers to the generalization of EL can include a lack of institutional support, risk avoidance, time, and faculty instructional ability. As well EL require additional efforts from…

To Tan or Not to Tan?: Students Learn About Sunscreens through an Inquiry Activity Based on the Learning Cycle

ERIC Educational Resources Information Center

Keen-Rocha, Linda

2005-01-01

Science instructors sometimes avoid inquiry-based activities due to limited classroom time. Inquiry takes time, as students choose problems, design experiments, obtain materials, conduct investigations, gather data, communicate results, and discuss their experiments. While there are no quick solutions to time concerns, the 5E learning cycle seeks…

Metacognitive Monkeys or Associative Animals? Simple Reinforcement Learning Explains Uncertainty in Nonhuman Animals

ERIC Educational Resources Information Center

Le Pelley, M. E.

2012-01-01

Monkeys will selectively and adaptively learn to avoid the most difficult trials of a perceptual discrimination learning task. Couchman, Coutinho, Beran, and Smith (2010) have recently demonstrated that this pattern of responding does not depend on animals receiving trial-by-trial feedback for their responses; it also obtains if experience of the…

Computer-Mediated Counter-Arguments and Individual Learning

ERIC Educational Resources Information Center

Hsu, Jack Shih-Chieh; Huang, Hsieh-Hong; Linden, Lars P.

2011-01-01

This study explores a de-bias function for a decision support systems (DSS) that is designed to help a user avoid confirmation bias by increasing the user's learning opportunities. Grounded upon the theory of mental models, the use of DSS is viewed as involving a learning process, whereby a user is directed to build mental models so as to reduce…

Towards Personalising Learning in School Science: Making This Learning More Relevant

ERIC Educational Resources Information Center

Prain, Vaughan; Waldrip, Bruce; Sbaglia, Rob; Lovejoy, Val

2017-01-01

In this paper, we report on a case study of how three teachers personalised learning in science through supporting a group of Year 8 students to engage in individual inquiry projects. The case study demonstrated how heavily transmissive teaching can be avoided by restructuring classes to optimise student group and individual work and timely…

Age Moderates the Effect of Acute Dopamine Depletion on Passive Avoidance Learning

PubMed Central

Kelm, Mary Katherine; Boettiger, Charlotte Ann

2015-01-01

Despite extensive links between reinforcement-based learning and dopamine (DA), studies to date have not found consistent effects of acute DA reduction on reinforcement learning in both men and women. Here, we tested the effects of reducing DA on reward- and punishment-based learning using the deterministic passive avoidance learning (PAL) task We tested 16 (5 female) adults (ages 22–40) in a randomized, cross-over design to determine whether reducing global DA by administering an amino acid beverage deficient in the DA precursors, phenylalanine and tyrosine (P/T[−]), would affect performance on the PAL task. We found that P/T[−] beverage effects on PAL performance were modulated by age. In particular, we found that P/T depletion significantly improved learning from punishment with increasing participant age. Participants committed 1.49 fewer passive avoidance errors per additional year of age (95% CI, −0.71 – −2.27, r=−0.74, p=0.001). Moreover, in this small sample, P/T depletion improved learning from punishment in adults (ages 26–40) while it impaired learning from punishment in emerging adults (ages 22–25). We observed similar, but non-significant trends in learning from reward. While there was no overall effect of P/T-depletion on reaction time (RT), there was a relationship between the effect of P/T depletion on PAL performance and RT; those who responded more slowly on the P/T[−] beverage also made more errors on the P/T[−] beverage. When P/T-depletion slowed RT after a correct response, there was a worsening of PAL task performance; there was no similar relationship for the RT after an incorrect response and PAL task performance. Moreover, among emerging adults, changes in mood on the P/T[−] beverage negatively correlated with learning from reward on the P/T[−] beverage. Together, we found that both reward- and punishment-based learning are sensitive to central catecholamine levels, and that these effects of acute DA reduction vary with age. PMID:25636601

Using signals associated with safety in avoidance learning: computational model of sex differences

PubMed Central

Beck, Kevin D.; Pang, Kevin C.H.; Myers, Catherine E.

2015-01-01

Avoidance behavior involves learning responses that prevent upcoming aversive events; these responses typically extinguish when the aversive events stop materializing. Stimuli that signal safety from aversive events can paradoxically inhibit extinction of avoidance behavior. In animals, males and females process safety signals differently. These differences help explain why women are more likely to be diagnosed with an anxiety disorder and exhibit differences in symptom presentation and course compared to men. In the current study, we extend an existing model of strain differences in avoidance behavior to simulate sex differences in rats. The model successfully replicates data showing that the omission of a signal associated with a period of safety can facilitate extinction in females, but not males, and makes novel predictions that this effect should depend on the duration of the period, the duration of the signal itself, and its occurrence within that period. Non-reinforced responses during the safe period were also found to be important in the expression of these patterns. The model also allowed us to explore underlying mechanisms for the observed sex effects, such as whether safety signals serve as occasion setters for aversive events, to determine why removing them can facilitate extinction of avoidance. The simulation results argue against this account, and instead suggest the signal may serve as a conditioned reinforcer of avoidance behavior. PMID:26213650

The challenges for scientists in avoiding plagiarism.

PubMed

Fisher, E R; Partin, K M

2014-01-01

Although it might seem to be a simple task for scientists to avoid plagiarism and thereby an allegation of research misconduct, assessment of trainees in the Responsible Conduct of Research and recent findings from the National Science Foundation Office of Inspector General regarding plagiarism suggests otherwise. Our experiences at a land-grant academic institution in assisting researchers in avoiding plagiarism are described. We provide evidence from a university-wide multi-disciplinary course that understanding how to avoid plagiarism in scientific writing is more difficult than it might appear, and that a failure to learn the rules of appropriate citation may cause dire consequences. We suggest that new strategies to provide training in avoiding plagiarism are required.

Emotions in Reading: Disgust, Empathy and the Contextual Learning Hypothesis

ERIC Educational Resources Information Center

Silva, Catarina; Montant, Marie; Ponz, Aurelie; Ziegler, Johannes C.

2012-01-01

Emotion effects in reading have typically been investigated by manipulating words' emotional valence and arousal in lexical decision. The standard finding is that valence and arousal can have both facilitatory and inhibitory effects, which is hard to reconcile with current theories of emotion processing in reading. Here, we contrasted these…

Preparing for the Worst: Psychological Excellence of First Responders - A Katrina Lessons Learned Study

DTIC Science & Technology

2008-01-01

cases on human cognition and performance. For instance, when you learn to fly an airplane, you will be instructed to use a simple rule to avoid...Existing Training Technologies; First Responders; Katrina; Lesson Learned 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER... student . Based in Maryland, the training institute prepares first responders using online learning courses or training exercises. Such topics

Developing an in silico minimum inhibitory concentration panel test for Klebsiella pneumoniae

DOE PAGES

Nguyen, Marcus; Brettin, Thomas; Long, S. Wesley; ...

2018-01-11

Here, antimicrobial resistant infections are a serious public health threat worldwide. Whole genome sequencing approaches to rapidly identify pathogens and predict antibiotic resistance phenotypes are becoming more feasible and may offer a way to reduce clinical test turnaround times compared to conventional culture-based methods, and in turn, improve patient outcomes. In this study, we use whole genome sequence data from 1668 clinical isolates of Klebsiella pneumoniae to develop a XGBoost-based machine learning model that accurately predicts minimum inhibitory concentrations (MICs) for 20 antibiotics. The overall accuracy of the model, within ± 1 two-fold dilution factor, is 92%. Individual accuracies aremore » >= 90% for 15/20 antibiotics. We show that the MICs predicted by the model correlate with known antimicrobial resistance genes. Importantly, the genome-wide approach described in this study offers a way to predict MICs for isolates without knowledge of the underlying gene content. This study shows that machine learning can be used to build a complete in silico MIC prediction panel for K. pneumoniae and provides a framework for building MIC prediction models for other pathogenic bacteria.« less

Developing an in silico minimum inhibitory concentration panel test for Klebsiella pneumoniae

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, Marcus; Brettin, Thomas; Long, S. Wesley

Here, antimicrobial resistant infections are a serious public health threat worldwide. Whole genome sequencing approaches to rapidly identify pathogens and predict antibiotic resistance phenotypes are becoming more feasible and may offer a way to reduce clinical test turnaround times compared to conventional culture-based methods, and in turn, improve patient outcomes. In this study, we use whole genome sequence data from 1668 clinical isolates of Klebsiella pneumoniae to develop a XGBoost-based machine learning model that accurately predicts minimum inhibitory concentrations (MICs) for 20 antibiotics. The overall accuracy of the model, within ± 1 two-fold dilution factor, is 92%. Individual accuracies aremore » >= 90% for 15/20 antibiotics. We show that the MICs predicted by the model correlate with known antimicrobial resistance genes. Importantly, the genome-wide approach described in this study offers a way to predict MICs for isolates without knowledge of the underlying gene content. This study shows that machine learning can be used to build a complete in silico MIC prediction panel for K. pneumoniae and provides a framework for building MIC prediction models for other pathogenic bacteria.« less

School Bullying: Tools for Avoiding Harm and Liability

ERIC Educational Resources Information Center

McGrath, Mary Jo

2006-01-01

Every hour of every day, students experience bullying and harassment at school by their peers. The immediate and long-term impact on the victims' learning capabilities, emotional health, and self-esteem is staggering. " School Bullying: Tools for Avoiding Harm and Liability" tackles this critical problem with an easy-to-use framework that guides…

Pain-Relief Learning in Flies, Rats, and Man: Basic Research and Applied Perspectives

ERIC Educational Resources Information Center

Gerber, Bertram; Yarali, Ayse; Diegelmann, Sören; Wotjak, Carsten T.; Pauli, Paul; Fendt, Marcus

2014-01-01

Memories relating to a painful, negative event are adaptive and can be stored for a lifetime to support preemptive avoidance, escape, or attack behavior. However, under unfavorable circumstances such memories can become overwhelmingly powerful. They may trigger excessively negative psychological states and uncontrollable avoidance of locations,…

Motivation across Domains: Do Goals and Attributions Change with Subject Matter for Grades 4 and 5 Students?

ERIC Educational Resources Information Center

Vogler, Jane S.; Bakken, Linda

2007-01-01

This study explored a theory for motivation which included aspects of both attribution theory and goal theory. Motivational variables included beliefs about intelligence (entity or incremental), goal orientation (mastery/learning, performance-approach, performance-avoidance) and avoidant behaviours. Grades 4 and 5 students from a large,…

Flexibility in the face of fear: Hippocampal-prefrontal regulation of fear and avoidance.

PubMed

Moscarello, Justin M; Maren, Stephen

2018-02-01

Generating appropriate defensive behaviors in the face of threat is essential to survival. Although many of these behaviors are 'hard-wired', they are also flexible. For example, Pavlovian fear conditioning generates learned defensive responses, such as conditioned freezing, that can be suppressed through extinction. The expression of extinguished responses is highly context-dependent, allowing animals to engage behavioral responses appropriate to the contexts in which threats are encountered. Likewise, animals and humans will avoid noxious outcomes if given the opportunity. In instrumental avoidance learning, for example, animals overcome conditioned defensive responses, including freezing, in order to actively avoid aversive stimuli. Recent work has greatly advanced understanding of the neural basis of these phenomena and has revealed common circuits involved in the regulation of fear. Specifically, the hippocampus and medial prefrontal cortex play pivotal roles in gating fear reactions and instrumental actions, mediated by the amygdala and nucleus accumbens, respectively. Because an inability to adaptively regulate fear and defensive behavior is a central component of many anxiety disorders, the brain circuits that promote flexible responses to threat are of great clinical significance.

Pre-exposure to cocaine or morphine attenuates taste avoidance conditioning in adolescent rats: Drug specificity in the US pre-exposure effect.

PubMed

Clasen, Matthew M; Hempel, Briana J; Riley, Anthony L

2017-05-01

Although the attenuating effects of drug history on conditioned taste avoidance (CTA) learning have been widely investigated in adults, such effects in adolescents have not been well characterized. Recent research has suggested that the display of the drug pre-exposure effect during adolescence may be drug dependent given that pre-exposure to ethanol attenuates subsequent conditioning, whereas pre-exposure to the classic emetic lithium chloride (LiCl) fails to do so. The present study began investigating the possible drug-dependent nature of the effects of drug pre-exposure by pre-exposing and conditioning adolescent male Sprague-Dawley rats to drugs from two additional classes, specifically psychostimulants (cocaine; Experiment 1) and opioids (morphine; Experiment 2). Consistent with prior work with ethanol (but not LiCl), prior exposure to both cocaine and morphine attenuated taste avoidance induced by these compounds. Although this work supports the view of drug-dependent pre-exposure effects on taste avoidance learning during adolescence, research is needed to assess its mechanisms. © 2017 Wiley Periodicals, Inc.

Spatial learning in the genetically heterogeneous NIH-HS rat stock and RLA-I/RHA-I rats: revisiting the relationship with unconditioned and conditioned anxiety.

PubMed

Martínez-Membrives, Esther; López-Aumatell, Regina; Blázquez, Gloria; Cañete, Toni; Tobeña, Adolf; Fernández-Teruel, Alberto

2015-05-15

To characterize learning/memory profiles for the first time in the genetically heterogeneous NIH-HS rat stock, and to examine whether these are associated with anxiety, we evaluated NIH-HS rats for spatial learning/memory in the Morris water maze (MWM) and in the following anxiety/fear tests: the elevated zero-maze (ZM; unconditioned anxiety), a context-conditioned fear test and the acquisition of two-way active avoidance (conditioned anxiety). NIH-HS rats were compared with the Roman High- (RHA-I) and Low-Avoidance (RLA-I) rat strains, given the well-known differences between the Roman strains/lines in anxiety-related behavior and in spatial learning/memory. The results show that: (i) As expected, RLA-I rats were more anxious in the ZM test, displayed more frequent context-conditioned freezing episodes and fewer avoidances than RHA-I rats. (ii) Scores of NIH-HS rats in these tests/tasks mostly fell in between those of the Roman rat strains, and were usually closer to the values of the RLA-I strain. (iii) Pigmented NIH-HS (only a small part of NIH-HS rats were albino) rats were the best spatial learners and displayed better spatial memory than the other three (RHA-I, RLA-I and NIH-HS albino) groups. (iv) Albino NIH-HS and RLA-I rats also showed better learning/memory than the RHA-I strain. (v) Within the NIH-HS stock, the most anxious rats in the ZM test presented the best learning and/or memory efficiency (regardless of pigmentation). In summary, NIH-HS rats display a high performance in spatial learning/memory tasks and a passive coping strategy when facing conditioned conflict situations. In addition, unconditioned anxiety in NIH-HS rats predicts better spatial learning/memory. Copyright © 2015 Elsevier Inc. All rights reserved.

Panic-modulating effects of alprazolam, moclobemide and sumatriptan in the rat elevated T-maze.

PubMed

Sant'Ana, Ana Beatriz; Weffort, Luiz Fernando; de Oliveira Sergio, Thatiane; Gomes, Rafael Calsoni; Frias, Alana Tercino; Matthiesen, Melina; Vilela-Costa, Heloisa Helena; Yamashita, Paula Shimene de Melo; Vasconcelos, Alex Teles; de Bortoli, Valquiria; Del-Ben, Cristina Marta; Zangrossi, Helio

2016-12-15

The elevated T-maze was developed to test the hypothesis that serotonin plays an opposing role in the regulation of defensive behaviors associated with anxiety and panic. Previous pharmacological exploitation of this test supports the association between inhibitory avoidance acquisition and escape expression with anxiety and fear/panic, respectively. In the present study, we extend the pharmacological validation of this test by investigating the effects of other putative or clinically effective anxiety- and panic-modulating drugs. The results showed that chronic, but not acute injection of the reversible monoamine oxidase-A inhibitor moclobemide (3, 10 and 30mg/kg) inhibited escape expression, indicating a panicolytic-like effect. The same effect was observed after either acute or chronic treatment with alprazolam (1, 2 and 4mg/kg), a high potency benzodiazepine. This drug also impaired inhibitory avoidance acquisition, suggesting an anxiolytic effect. On the other hand, subcutaneous administration of the 5-HT1D/1B receptor agonist sumatriptan (0.1, 0.5 and 2.5μg/kg) facilitated escape performance, indicating a panicogenic-like effect, while treatment with α-para-chlorophenylalanine (p-CPA; 4days i.p injections of 100mg/kg, or a single i.p injection of 300mg/kg), which caused marked 5-HT depletion in the amygdala and striatum, was without effect. Altogether, these results are in full agreement with the clinical effects of these compounds and offer further evidence that the elevated T-maze has broad predictive validity for the effects of anxiety- and panic-modulating drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

Sex and the housing: Effects on behavior, cortisol levels and weight in zebrafish.

PubMed

Reolon, Gustavo Kellermann; de Melo, Gabriela Madalena; da Rosa, João Gabriel Dos Santos; Barcellos, Leonardo José Gil; Bonan, Carla Denise

2018-01-15

Studies with zebrafish use acclimatizing periods of at least one week immediately before the experiments. During this time, animals can be housed in sexually segregated conditions (only females or males in the tank) or in mixed-sex conditions (both sexes in the tank). The influence of sex and housing conditions regarding the presence of one or two sexes is largely unknown in zebrafish. Our aim was to evaluate the influence that sex and housing regarding the sex of animals had in the open tank task, in the inhibitory avoidance memory test, in cortisol levels and weight in zebrafish. Four groups of animals were used: 1) segregated housed females (only females were kept in the tank); 2) segregated housed males (only males were kept in the tank); 3) mixed-sex housed females (only females were analyzed from a tank containing 50% ratio of each sex); 4) mixed-sex housed males (only males were analyzed from a tank containing 50% ratio of each sex). Males showed higher total distance travelled and mean speed when compared to females. In the inhibitory avoidance memory, sexually segregated animals had higher latencies than their mixed-sex counterparts in the 1day test and sexually segregated females presented a memory that persisted longer and was able to be reinstated. Whole-body cortisol levels were higher in mixed-sex animals while weight was lower in these fish. To the best of our knowledge, this is the first time that effects of sex and housing regarding sex were investigated in behavior and physiology of zebrafish. Copyright © 2017 Elsevier B.V. All rights reserved.

Cocaine Drives Aversive Conditioning via Delayed Activation of Dopamine-Responsive Habenular and Midbrain Pathways

PubMed Central

Good, Cameron H.; Rowley, Courtney S.; Xu, Sheng-ping; Wang, Huikun; Burnham, Nathan W.; Hoffman, Alexander F.; Lupica, Carl R.; Ikemoto, Satoshi

2013-01-01

Many strong rewards, including abused drugs, also produce aversive effects that are poorly understood. For example, cocaine can produce aversive conditioning after its rewarding effects have dissipated, consistent with opponent process theory, but the neural mechanisms involved are not well known. Using electrophysiological recordings in awake rats, we found that some neurons in the lateral habenula (LHb), where activation produces aversive conditioning, exhibited biphasic responses to single doses of intravenous cocaine, with an initial inhibition followed by delayed excitation paralleling cocaine's shift from rewarding to aversive. Recordings in LHb slice preparations revealed similar cocaine-induced biphasic responses and further demonstrated that biphasic responses were mimicked by dopamine, that the inhibitory phase depended on dopamine D2-like receptors, and that the delayed excitation persisted after drug washout for prolonged durations consistent with findings in vivo. c-Fos experiments further showed that cocaine-activated LHb neurons preferentially projected to and activated neurons in the rostromedial tegmental nucleus (RMTg), a recently identified target of LHb axons that is activated by negative motivational stimuli and inhibits dopamine neurons. Finally, pharmacological excitation of the RMTg produced conditioned place aversion, whereas cocaine-induced avoidance behaviors in a runway operant paradigm were abolished by lesions of LHb efferents, lesions of the RMTg, or by optogenetic inactivation of the RMTg selectively during the period when LHb neurons are activated by cocaine. Together, these results indicate that LHb/RMTg pathways contribute critically to cocaine-induced avoidance behaviors, while also participating in reciprocally inhibitory interactions with dopamine neurons. PMID:23616555

Anti-HIV drugs nevirapine and efavirenz affect anxiety-related behavior and cognitive performance in mice.

PubMed

Romão, Pedro R T; Lemos, Joelson C; Moreira, Jeverson; de Chaves, Gisele; Moretti, Morgana; Castro, Adalberto A; Andrade, Vanessa M; Boeck, Carina R; Quevedo, João; Gavioli, Elaine C

2011-01-01

Nevirapine (NVP) and efavirenz (EFV) belong to the class of anti-HIV drugs called non-nucleoside reverse transcriptase inhibitors (NNRTIs), commonly used as part of highly active antiretroviral therapy (HAART). Although the HAART is able to bring down viral load to undetectable levels and restore immune function, their prolonged use causes several adverse effects. It has been demonstrated that both NVP and EFV are able to cross the blood-brain barrier, causing important central nervous system-related side effects. Thus, this study investigated the effects of chronic administration of EFV (10 mg/kg) and NVP (3.3 mg/kg) in mice submitted to two distinct series of experiments, which aimed to evaluate: (1) the emotional behavior (elevated plus-maze, forced swimming, and open-field test) and (2) the cognitive performance (object recognition and inhibitory avoidance test) of mice. Our results demonstrated that EFV, but not NVP, reduced the exploration to open arms in the elevated plus-maze test. Neither NVP nor EFV altered mouse behavior in the forced swimming and open-field tests. Both drugs reduced the recognition index in the object recognition test, but only EFV significantly impaired the aversive memory assessed in the inhibitory avoidance test 24 h after training. In conclusion, our findings point to a genuine anxiogenic-like effect to EFV, since it reduced exploration to open arms of elevated plus-maze test without affecting spontaneous locomotion. Additionally, both drugs impaired recognition memory, while only the treatment with EFV impaired significantly aversive memory.

Acquisition and extinction of human avoidance behavior: attenuating effect of safety signals and associations with anxiety vulnerabilities.

PubMed

Sheynin, Jony; Beck, Kevin D; Servatius, Richard J; Myers, Catherine E

2014-01-01

While avoidance behavior is often an adaptive strategy, exaggerated avoidance can be detrimental and result in the development of psychopathologies, such as anxiety disorders. A large animal literature shows that the acquisition and extinction of avoidance behavior in rodents depends on individual differences (e.g., sex, strain) and might be modulated by the presence of environmental cues. However, there is a dearth of such reports in human literature, mainly due to the lack of adequate experimental paradigms. In the current study, we employed a computer-based task, where participants control a spaceship and attempt to gain points by shooting an enemy spaceship that appears on the screen. Warning signals predict on-screen aversive events; the participants can learn a protective response to escape or avoid these events. This task has been recently used to reveal facilitated acquisition of avoidance behavior in individuals with anxiety vulnerability due to female sex or inhibited personality. Here, we extended the task to include an extinction phase, and tested the effect of signals that appeared during "safe" periods. Healthy young adults (n = 122) were randomly assigned to a testing condition with or without such signals. Results showed that the addition of safety signals during the acquisition phase impaired acquisition (in females) and facilitated extinction of the avoidance behavior. We also replicated our recent finding of an association between female sex and longer avoidance duration and further showed that females continued to demonstrate more avoidance behavior even on extinction trials when the aversive events no longer occurred. This study is the first to show sex differences on the acquisition and extinction of human avoidance behavior and to demonstrate the role of safety signals in such behavior, highlighting the potential relevance of safety signals for cognitive therapies that focus on extinction learning to treat anxiety symptoms.

Acquisition and Extinction of Human Avoidance Behavior: Attenuating Effect of Safety Signals and Associations with Anxiety Vulnerabilities

PubMed Central

Sheynin, Jony; Beck, Kevin D.; Servatius, Richard J.; Myers, Catherine E.

2014-01-01

While avoidance behavior is often an adaptive strategy, exaggerated avoidance can be detrimental and result in the development of psychopathologies, such as anxiety disorders. A large animal literature shows that the acquisition and extinction of avoidance behavior in rodents depends on individual differences (e.g., sex, strain) and might be modulated by the presence of environmental cues. However, there is a dearth of such reports in human literature, mainly due to the lack of adequate experimental paradigms. In the current study, we employed a computer-based task, where participants control a spaceship and attempt to gain points by shooting an enemy spaceship that appears on the screen. Warning signals predict on-screen aversive events; the participants can learn a protective response to escape or avoid these events. This task has been recently used to reveal facilitated acquisition of avoidance behavior in individuals with anxiety vulnerability due to female sex or inhibited personality. Here, we extended the task to include an extinction phase, and tested the effect of signals that appeared during “safe” periods. Healthy young adults (n = 122) were randomly assigned to a testing condition with or without such signals. Results showed that the addition of safety signals during the acquisition phase impaired acquisition (in females) and facilitated extinction of the avoidance behavior. We also replicated our recent finding of an association between female sex and longer avoidance duration and further showed that females continued to demonstrate more avoidance behavior even on extinction trials when the aversive events no longer occurred. This study is the first to show sex differences on the acquisition and extinction of human avoidance behavior and to demonstrate the role of safety signals in such behavior, highlighting the potential relevance of safety signals for cognitive therapies that focus on extinction learning to treat anxiety symptoms. PMID:25309373

Social stress alters inhibitory synaptic input to distinct subpopulations of raphe serotonin neurons.

PubMed

Crawford, LaTasha K; Rahman, Shumaia F; Beck, Sheryl G

2013-01-16

Anxiety disorders are among the most prevalent psychiatric disorders, yet much is unknown about the underlying mechanisms. The dorsal raphe (DR) is at the crux of the anxiety-inducing effects of uncontrollable stress, a key component of models of anxiety. Though DR serotonin (5-HT) neurons play a prominent role, anxiety-associated changes in the physiology of 5-HT neurons remain poorly understood. A 5-day social defeat model of anxiety produced a multifaceted, anxious phenotype in intruder mice that included increased avoidance behavior in the open field test, increased stress-evoked grooming, and increased bladder and heart weights when compared to control mice. Intruders were further compared to controls using electrophysiology recordings conducted in midbrain slices wherein recordings targeted 5-HT neurons of the ventromedial (vmDR) and lateral wing (lwDR) subfields of the DR. Though defining membrane characteristics of 5-HT neurons were unchanged, γ-aminobutyric-acid-mediated (GABAergic) synaptic regulation of 5-HT neurons was altered in a topographically specific way. In the vmDR of intruders, there was a decrease in the frequency and amplitude of GABAergic spontaneous inhibitory postsynaptic currents (sIPSCs). However, in the lwDR, there was an increase in the strength of inhibitory signals due to slower sIPSC kinetics. Synaptic changes were selective for GABAergic input, as glutamatergic synaptic input was unchanged in intruders. The distinct inhibitory regulation of DR subfields provides a mechanism for increased 5-HT output in vmDR target regions and decreased 5-HT output in lwDR target regions, divergent responses to uncontrollable stress that have been reported in the literature but were previously poorly understood.

Loganin enhances long-term potentiation and recovers scopolamine-induced learning and memory impairments.

PubMed

Hwang, Eun-Sang; Kim, Hyun-Bum; Lee, Seok; Kim, Min-Ji; Lee, Sung-Ok; Han, Seung-Moo; Maeng, Sungho; Park, Ji-Ho

2017-03-15

Although the incidence rate of dementia is rapidly growing in the aged population, therapeutic and preventive reagents are still suboptimal. Various model systems are used for the development of such reagents in which scopolamine is one of the favorable pharmacological tools widely applied. Loganin is a major iridoid glycoside obtained from Corni fructus (Cornusofficinalis et Zucc) and demonstrated to have anti-inflammatory, anti-tumor and osteoporosis prevention effects. It has also been found to attenuate Aβ-induced inflammatory reactions and ameliorate memory deficits induced by scopolamine. However, there has been limited information available on how loganin affects learning and memory both electrophysiologically and behaviorally. To assess its effect on learning and memory, we investigated the influence of acute loganin administration on long-term potentiation (LTP) using organotypic cultured hippocampal tissues. In addition, we measured the effects of loganin on the behavior performance related to avoidance memory, short-term spatial navigation memory and long-term spatial learning and memory in the passive avoidance, Y-maze, and Morris water maze learning paradigms, respectively. Loganin dose-dependently increased the total activity of fEPSP after high frequency stimulation and attenuated scopolamine-induced blockade of fEPSP in the hippocampal CA1 area. In accordance with these findings, loganin behaviorally attenuated scopolamine-induced shortening of step-through latency in the passive avoidance test, reduced the percent alternation in the Y-maze, and increased memory retention in the Morris water maze test. These results indicate that loganin can effectively block cholinergic muscarinic receptor blockade -induced deterioration of LTP and memory related behavioral performance. Based on these findings, loganin may aid in the prevention and treatment of Alzheimer's disease and learning and memory-deficit disorders in the future. Copyright © 2017 Elsevier Inc. All rights reserved.

The effect of para-chlorophenylalanine and scopolamine on passive avoidance in chicks.

PubMed

Mattingly, B A; Zolman, J F

1981-05-01

Four-day-old Vantress x Arbor Acre chicks were treated for key-peck passive avoidance (PA) learning following intraperitoneal injections of parachlorophenylalanine (PCPA) and/or scopolamine. In Experiment 1, chicks were pre-treated with either three or five injections of PCPA (150 mg/kg) or saline across th first three posthatch days and then tested for PA learning on the fourth posthatch day. In Experiment 2, chicks were first pre-treated with three injections of PCPA (150 mg/kg) or saline, and then injected with either scopolamine (0.5 mg/kg) or saline 20 min prior to PA testing on the fourth posthatch day. Major findings were: (a) Chicks pre-treated with PCPA did not significantly differ from saline control chicks in either the acquisition or maintenance of response suppression during PA testing; (b) chicks injected with scopolamine were significantly disrupted in PA learning as compared to saline control chicks; and (c) PCPA pre-treatment did not significantly affect the scopolamine-induced disruption of PA learning. These findings, therefore, suggest that cholinergic, but not serotonergic, mechanisms are involved in PA learning of the young chick.

Biases in probabilistic category learning in relation to social anxiety

PubMed Central

Abraham, Anna; Hermann, Christiane

2015-01-01

Instrumental learning paradigms are rarely employed to investigate the mechanisms underlying acquired fear responses in social anxiety. Here, we adapted a probabilistic category learning paradigm to assess information processing biases as a function of the degree of social anxiety traits in a sample of healthy individuals without a diagnosis of social phobia. Participants were presented with three pairs of neutral faces with differing probabilistic accuracy contingencies (A/B: 80/20, C/D: 70/30, E/F: 60/40). Upon making their choice, negative and positive feedback was conveyed using angry and happy faces, respectively. The highly socially anxious group showed a strong tendency to be more accurate at learning the probability contingency associated with the most ambiguous stimulus pair (E/F: 60/40). Moreover, when pairing the most positively reinforced stimulus or the most negatively reinforced stimulus with all the other stimuli in a test phase, the highly socially anxious group avoided the most negatively reinforced stimulus significantly more than the control group. The results are discussed with reference to avoidance learning and hypersensitivity to negative socially evaluative information associated with social anxiety. PMID:26347685

Carryover effects associated with the single-trial passive avoidance learning task in the young chick.

PubMed

Crowe, Simon F; Hale, Matthew W

2002-09-01

The single-trial passive avoidance task is a useful procedure for examining learning and memory in the young chick. However, it has recently been suggested that discrepant results reported by different laboratories are due to differences in training procedure. The present study investigated a number of parameters surrounding the passive avoidance task, using day-old White Leghorn, Black Australorp cockerels. The results suggested that presentation of a water-dipped bead immediately after the aversive bead significantly altered retention levels. In addition, when the water-dipped bead was presented after the aversive bead, chicks failed to discriminate between beads for a period of 10 min following exposure to the aversant experience. A novel variant of the passive avoidance procedure, involving pretraining with a water-dipped red bead, training with an aversant-coated red bead, and testing with a dry red bead, was evaluated. A measure of avoidance was calculated using all three trials. It is suggested that the use of a single bead, measured both before and after the training experience and using both aversant- and water-trained controls, results in the most concise characterization of memory-related phenomena in the chick which is not contaminated by a carryover effect from the aversive training experience to the nonaversive bead.

The effect of combined avoidance and control training on implicit food evaluation and choice.

PubMed

Kakoschke, Naomi; Kemps, Eva; Tiggemann, Marika

2017-06-01

Continual exposure to food cues in the environment contributes to unhealthy eating behaviour. According to dual-process models, such behaviour is partly determined by automatic processing of unhealthy food cues (e.g., approach bias), which fails to be regulated by controlled processing (e.g., inhibitory control). The current study aimed to investigate the effect of combined avoidance and control training on implicit evaluation (liking), choice, and consumption of unhealthy snack food. Participants were 240 undergraduate women who were randomly allocated to one of four experimental conditions of a 2 (avoidance training: training versus control) x 2 (control training: training versus control) between-subjects design. The combined training group had a more negative implicit evaluation of unhealthy food than either of the two training conditions alone or the control condition. In addition, participants trained to avoid unhealthy food cues subsequently made fewer unhealthy snack food choices. No significant group differences were found for food intake. Participants were women generally of a healthy weight. Overweight or obese individuals may derive greater benefit from combined training. Results lend support to the theoretical predictions of dual-process models, as the combined training reduced implicit liking of unhealthy food. At a practical level, the findings have implications for the effectiveness of interventions targeting unhealthy eating behaviour. Copyright © 2017 Elsevier Ltd. All rights reserved.

Avoiding the Attendance Slump: Strategies to Maximize Learning Time in June. A TASC Resource Guide

ERIC Educational Resources Information Center

Traill, Saskia; Brohawn, Katie

2014-01-01

The After-School Corporation (TASC) works to build education enrichment into an expanded school day because extra time spent in engaging learning activities leads to better outcomes in school and beyond. There's one month, however, when students in many schools lose learning time: June. In 2013, NYC elementary and middle schools saw their average…

Mangling Expertise Using Post-Coding Analysis to Complexify Teacher Learning

ERIC Educational Resources Information Center

Mills, Tammy

2017-01-01

A recent movement in teacher education research encompasses working with and through theory. In response to the call from Jackson and Mazzei (2013) to use theory to think with data and use data to think with theory, the author hopes to portray the complexities of teacher learning by avoiding models of teacher learning and development that tend to…

A Virtual Learning Environment for the Continuation of Education and Its Relationship with the Mental Well-Being of Chronically Ill Adolescents

ERIC Educational Resources Information Center

Zhu, Chang; Van Winkel, Lies

2016-01-01

Research has shown that the continuation of education by chronically ill adolescents is an important way to avoid social isolation, psychosocial problems and the accumulation of learning difficulties. In this light, virtual learning environments (VLEs), which connect sick adolescents to their schools, play an important role in ensuring that the…

Influence of Problem-Based Learning Strategy on Enhancing Student's Industrial Oriented Competences Learned: An Action Research on Learning Weblog Analysis

ERIC Educational Resources Information Center

Chung, Pansy; Yeh, Ron Chuen; Chen, Yi-Cheng

2016-01-01

In order to respond to the ever-changing global economic environment, the technological and vocational education system in Taiwan needs to be dramatically reformed to the changing needs of the domestic industrial structure. Integrating practical talents with practical industrial experiences and competences can help avoid discrepancy and close the…

Making a Difference--The Impact of the Confidential Inquiry into Premature Deaths of People with Learning Disabilities

ERIC Educational Resources Information Center

Heslop, Pauline; Marriott, Anna

2015-01-01

The Confidential Inquiry into premature deaths of people with learning disabilities (CIPOLD) was commissioned by the Department of Health in England in 2010 to investigate the avoidable or premature deaths of people with learning disabilities through retrospective reviews of deaths. Both the process of conducting CIPOLD and the findings of the…

Trust-based learning and behaviors for convoy obstacle avoidance

NASA Astrophysics Data System (ADS)

Mikulski, Dariusz G.; Karlsen, Robert E.

2015-05-01

In many multi-agent systems, robots within the same team are regarded as being fully trustworthy for cooperative tasks. However, the assumption of trustworthiness is not always justified, which may not only increase the risk of mission failure, but also endanger the lives of friendly forces. In prior work, we addressed this issue by using RoboTrust to dynamically adjust to observed behaviors or recommendations in order to mitigate the risks of illegitimate behaviors. However, in the simulations in prior work, all members of the convoy had knowledge of the convoy goal. In this paper, only the lead vehicle has knowledge of the convoy goals and the follow vehicles must infer trustworthiness strictly from lead vehicle performance. In addition, RoboTrust could only respond to observed performance and did not dynamically learn agent behavior. In this paper, we incorporate an adaptive agent-specific bias into the RoboTrust algorithm that modifies its trust dynamics. This bias is learned incrementally from agent interactions, allowing good agents to benefit from faster trust growth and slower trust decay and bad agents to be penalized with slower trust growth and faster trust decay. We then integrate this new trust model into a trust-based controller for decentralized autonomous convoy operations. We evaluate its performance in an obstacle avoidance mission, where the convoy attempts to learn the best speed and following distances combinations for an acceptable obstacle avoidance probability.

Passive avoidance and complex maze learning in the senescence accelerated mouse (SAM): age and strain comparisons of SAM P8 and R1.

PubMed

Spangler, Edward L; Patel, Namisha; Speer, Dorey; Hyman, Michael; Hengemihle, John; Markowska, Alicja; Ingram, Donald K

2002-02-01

Two strains of the senescence accelerated mouse, P8 and R1,were tested in footshock-motivated passive avoidance (PA; P8, 3-21 months; R1, 3-24 months) and 14-unit T-maze (P8 and R1, 9, and 15 months) tasks. For PA, entry to a dark chamber from a lighted chamber was followed by a brief shock. Latency to enter the dark chamber 24 hours later served as a measure of retention. Two days of active avoidance training in a straight runway preceded 2 days (8 trials/day) of testing in the 14-unit T-maze. For PA retention, older P8 mice entered the dark chamber more quickly than older R1 mice, whereas no differences were observed between young P8 or R1 mice. In the 14-unit T-maze, age-related learning performance deficits were reflected in higher error scores for older mice. P8 mice were actually superior learners; that is, they had lower error scores compared with those of age-matched R1 counterparts. Although PA learning results were in agreement with other reports, results obtained in the 14-unit T-maze were not consistent with previous reports of learning impairments in the P8 senescence accelerated mouse.

How to Avoid a Learning Curve in Stapedotomy: A Standardized Surgical Technique.

PubMed

Kwok, Pingling; Gleich, Otto; Dalles, Katharina; Mayr, Elisabeth; Jacob, Peter; Strutz, Jürgen

2017-08-01

To evaluate, whether a learning curve for beginners in stapedotomy can be avoided by using a prosthesis with thermal memory-shape attachment in combination with a standardized laser-assisted surgical technique. Retrospective case review. Tertiary referral center. Fifty-eight ears were operated by three experienced surgeons and compared with a group of 12 cases operated by a beginner in stapedotomy. Stapedotomy. Difference of pure-tone audiometry thresholds measured before and after surgery. The average postoperative gain for air conduction in the frequencies below 2 kHz was 20 to 25 dB and decreased for the higher frequencies. Using the Mann-Whitney-U test for comparing mean gain between experienced and inexperienced surgeons showed no significant difference (p = 0.281 at 4 kHz and p > 0.7 for the other frequencies). A Spearman rank correlation of the postoperative gain for air- and bone-conduction thresholds was obtained at each test frequency for the first 12 patients consecutively treated with a thermal memory-shape attachment prosthesis by two experienced and one inexperienced surgeon. This analysis does not support the hypothesis of a "learning effect" that should be associated with an improved outcome for successively treated patients. It is possible to avoid a learning curve in stapes surgery by applying a thermal memory-shape prosthesis in a standardized laser-assisted surgical procedure.

Theories of addiction: methamphetamine users' explanations for continuing drug use and relapse.

PubMed

Newton, Thomas F; De La Garza, Richard; Kalechstein, Ari D; Tziortzis, Desey; Jacobsen, Caitlin A

2009-01-01

A variety of preclinical models have been constructed to emphasize unique aspects of addiction-like behavior. These include Negative Reinforcement ("Pain Avoidance"), Positive Reinforcement ("Pleasure Seeking"), Incentive Salience ("Craving"), Stimulus Response Learning ("Habits"), and Inhibitory Control Dysfunction ("Impulsivity"). We used a survey to better understand why methamphetamine-dependent research volunteers (N = 73) continue to use methamphetamine, or relapse to methamphetamine use after a period of cessation of use. All participants met DSM-IV criteria for methamphetamine abuse or dependence, and did not meet criteria for other current Axis I psychiatric disorders or dependence on other drugs of abuse, other than nicotine. The questionnaire consisted of a series of face-valid questions regarding drug use, which in this case referred to methamphetamine use. Examples of questions include: "Do you use drugs mostly to make bad feelings like boredom, loneliness, or apathy go away?", "Do you use drugs mostly because you want to get high?", "Do you use drugs mostly because of cravings?", "Do you find yourself getting ready to take drugs without thinking about it?", and "Do you impulsively take drugs?". The scale was anchored at 1 (not at all) and 7 (very much). For each question, the numbers of participants rating each question negatively (1 or 2), neither negatively or affirmatively (3-5), and affirmatively (6 or 7) were tabulated. The greatest number of respondents (56%) affirmed that they used drugs due to "pleasure seeking." The next highest categories selected were "impulsivity" (27%) and "habits"(25%). Surprisingly, many participants reported that "pain avoidance" (30%) and "craving" (30%) were not important for their drug use. Results from this study support the contention that methamphetamine users (and probably other drug users as well) are more heterogeneous than is often appreciated, and imply that treatment development might be more successful if treatments targeted subtypes of patients, though a range of limitations to the approach used are acknowledged.

Negative Priming in Free Recall Reconsidered

PubMed Central

2015-01-01

Negative priming in free recall is the finding of impaired memory performance when previously ignored auditory distracters become targets of encoding and retrieval. This negative priming has been attributed to an aftereffect of deploying inhibitory mechanisms that serve to suppress auditory distraction and minimize interference with learning and retrieval of task-relevant information. In 6 experiments, we tested the inhibitory account of the effect of negative priming in free recall against alternative accounts. We found that ignoring auditory distracters is neither sufficient nor necessary to produce the effect of negative priming in free recall. Instead, the effect is more readily accounted for by a buildup of proactive interference occurring whenever 2 successively presented lists of words are drawn from the same semantic category. PMID:26595066

Effects of the modern food environment on striatal function, cognition and regulation of ingestive behavior

PubMed Central

Burke, Mary V; Small, Dana M

2017-01-01

Emerging evidence from human and animal studies suggest that consumption of palatable foods rich in fat and/or carbohydrates may produce deleterious influences on brain function independently of body weight or metabolic disease. Here we consider two mechanisms by which diet can impact striatal circuits to amplify food cue reactivity and impair inhibitory control. First, we review findings demonstrating that the energetic properties of foods regulate nucleus accumbens food cue reactivity, a demonstrated predictor of weight gain susceptibility, which is then sensitized by chronic consumption of an energy dense diet. Second, we consider evidence for diet-induced adaptations in dorsal striatal dopamine signaling that is associated with impaired inhibitory control and negative outcome learning. PMID:29619405

Sleep supports inhibitory operant conditioning memory in Aplysia.

PubMed

Vorster, Albrecht P A; Born, Jan

2017-06-01

Sleep supports memory consolidation as shown in mammals and invertebrates such as bees and Drosophila. Here, we show that sleep's memory function is preserved in Aplysia californica with an even simpler nervous system. Animals performed on an inhibitory conditioning task ("learning that a food is inedible") three times, at Training, Retrieval 1, and Retrieval 2, with 17-h intervals between tests. Compared with Wake animals, remaining awake between Training and Retrieval 1, Sleep animals with undisturbed post-training sleep, performed significantly better at Retrieval 1 and 2. Control experiments testing retrieval only after ∼34 h, confirmed the consolidating effect of sleep occurring within 17 h after training. © 2017 Vorster and Born; Published by Cold Spring Harbor Laboratory Press.

Teaching Project Management

ERIC Educational Resources Information Center

Portz, Stephen M.

2014-01-01

Many studies support the fact that students participating in projectbased learning experiences show significantly higher learning gains than traditional instructional methods (Frank and Barzilai, 2006). Stephen Portz believes many educators recognize this, but because TPBL is fraught with so many challenges, many teachers avoid it or use it only…

Sesquiterpenes and a monoterpenoid with acetylcholinesterase (AchE) inhibitory activity from Valeriana officinalis var. latiofolia in vitro and in vivo.

PubMed

Chen, Heng-Wen; He, Xuan-Hui; Yuan, Rong; Wei, Ben-Jun; Chen, Zhong; Dong, Jun-Xing; Wang, Jie

2016-04-01

Acetylcholinesterase Inhibitor (AchEI) is the most extensive in all anti-dementia drugs. The extracts and isolated compounds from the Valeriana genus have shown anti-dementia bioactivity. Four new sesquiterpenoids (1-4) and a new monoterpenoid (5) were isolated from the root of Valeriana officinalis var. latiofolia. The acetylcholinesterase (AchE) inhibitory activity of isolates was evaluated by modified Ellman method in vitro. Learning and memory ability of compound 4 on mice was evaluated by the Morris water maze. The contents of acetylcholine (Ach), acetylcholine transferase (ChAT) and AchE in mice brains were determined by colorimetry. The results showed IC50 of compound 4 was 0.161 μM in vitro. Compared with the normal group, the learning and memory ability of mice and the contents of Ach and ChAT decreased in model group mice (P<0.01), while the AchE increased (P<0.01). Compared with the model group, Ach and ChAT in the positive control group, the high-dose group and the medium-dose group increased (P<0.01), while the AchE decreased (P<0.01). Compound 4 can improve the learning and memory abilities of APPswe/PSΔE9 double-transgenic mice, and the mechanism may be related to the regulation of the relative enzyme in the cholinergic system. Copyright © 2016 Elsevier B.V. All rights reserved.

A meta-analytic examination of the goal orientation nomological net.

PubMed

Payne, Stephanie C; Youngcourt, Satoris S; Beaubien, J Matthew

2007-01-01

The authors present an empirical review of the literature concerning trait and state goal orientation (GO). Three dimensions of GO were examined: learning, prove performance, and avoid performance along with presumed antecedents and proximal and distal consequences of these dimensions. Antecedent variables included cognitive ability, implicit theory of intelligence, need for achievement, self-esteem, general self-efficacy, and the Big Five personality characteristics. Proximal consequences included state GO, task-specific self-efficacy, self-set goal level, learning strategies, feedback seeking, and state anxiety. Distal consequences included learning, academic performance, task performance, and job performance. Generally speaking, learning GO was positively correlated, avoid performance GO was negatively correlated, and prove performance GO was uncorrelated with these variables. Consistent with theory, state GO tended to have stronger relationships with the distal consequences than did trait GO. Finally, using a meta-correlation matrix, the authors found that trait GO predicted job performance above and beyond cognitive ability and personality. These results demonstrate the value of GO to organizational researchers. 2007 APA, all rights reserved

Proline-containing dipeptide GVS-111 retains nootropic activity after oral administration.

PubMed

Ostrovskaya, R U; Mirsoev, T K; Romanova, G A; Gudasheva, T A; Kravchenko, E V; Trofimov, C C; Voronina, T A; Seredenin, S B

2001-10-01

Experiments on rats trained passive avoidance task showed that N-phenyl-acetyl-L-prolyl-glycyl ethyl ester, peptide analog of piracetam (GVS-111, Noopept) after oral administration retained antiamnesic activity previously observed after its parenteral administration. Effective doses were 0.5-10 mg/kg. Experiments on a specially-developed model of active avoidance (massive one-session learning schedule) showed that GVS-111 stimulated one-session learning after single administration, while after repeated administration it increased the number of successful learners among those animals who failed after initial training. In this respect, GVS-111 principally differs from its main metabolite cycloprolylglycine and standard nootropic piracetam.

Time Course of Brain Network Reconfiguration Supporting Inhibitory Control.

PubMed

Popov, Tzvetan; Westner, Britta U; Silton, Rebecca L; Sass, Sarah M; Spielberg, Jeffrey M; Rockstroh, Brigitte; Heller, Wendy; Miller, Gregory A

2018-05-02

Hemodynamic research has recently clarified key nodes and links in brain networks implementing inhibitory control. Although fMRI methods are optimized for identifying the structure of brain networks, the relatively slow temporal course of fMRI limits the ability to characterize network operation. The latter is crucial for developing a mechanistic understanding of how brain networks shift dynamically to support inhibitory control. To address this critical gap, we applied spectrally resolved Granger causality (GC) and random forest machine learning tools to human EEG data in two large samples of adults (test sample n = 96, replication sample n = 237, total N = 333, both sexes) who performed a color-word Stroop task. Time-frequency analysis confirmed that recruitment of inhibitory control accompanied by slower behavioral responses was related to changes in theta and alpha/beta power. GC analyses revealed directionally asymmetric exchanges within frontal and between frontal and parietal brain areas: top-down influence of superior frontal gyrus (SFG) over both dorsal ACC (dACC) and inferior frontal gyrus (IFG), dACC control over middle frontal gyrus (MFG), and frontal-parietal exchanges (IFG, precuneus, MFG). Predictive analytics confirmed a combination of behavioral and brain-derived variables as the best set of predictors of inhibitory control demands, with SFG theta bearing higher classification importance than dACC theta and posterior beta tracking the onset of behavioral response. The present results provide mechanistic insight into the biological implementation of a psychological phenomenon: inhibitory control is implemented by dynamic routing processes during which the target response is upregulated via theta-mediated effective connectivity within key PFC nodes and via beta-mediated motor preparation. SIGNIFICANCE STATEMENT Hemodynamic neuroimaging research has recently clarified regional structures in brain networks supporting inhibitory control. However, due to inherent methodological constraints, much of this research has been unable to characterize the temporal dynamics of such networks (e.g., direction of information flow between nodes). Guided by fMRI research identifying the structure of brain networks supporting inhibitory control, results of EEG source analysis in a test sample ( n = 96) and replication sample ( n = 237) using effective connectivity and predictive analytics strategies advance a model of inhibitory control by characterizing the precise temporal dynamics by which this network operates and exemplify an approach by which mechanistic models can be developed for other key psychological processes. Copyright © 2018 the authors 0270-6474/18/384348-09$15.00/0.

Metacognition in Upper-Division Biology Students: Awareness Does Not Always Lead to Control

PubMed Central

Dye, Kathryn Morris; Stanton, Julie Dangremond

2017-01-01

Students with awareness and control of their own thinking can learn more and perform better than students who are not metacognitive. Metacognitive regulation is how you control your thinking in order to learn. It includes the skill of evaluation, which is the ability to appraise your approaches to learning and then modify future plans based on those appraisals. We asked when, why, and how upper-division biology students evaluated their approaches to learning. We used self-evaluation assignments to identify students with potentially high metacognition and conducted semistructured interviews to collect rich qualitative data from them. Through content analysis, we found that students evaluated their approaches to learning when their courses presented novel challenges. Most students evaluated in response to an unsatisfactory grade. While evaluating study strategies, many students considered performance and learning simultaneously. We gained insights on the barriers students face when they try to change their approaches to learning based on their evaluations. A few students continued to use ineffective study strategies even though they were aware of the ineffectiveness of those strategies. A desire to avoid feeling uncomfortable was the primary reason they avoided strategies that they knew were more effective. We examined the behavioral change literature to help interpret these findings. PMID:28495935

The Effects of Donepezil, an Acetylcholinesterase Inhibitor, on Impaired Learning and Memory in Rodents.

PubMed

Shin, Chang Yell; Kim, Hae-Sun; Cha, Kwang-Ho; Won, Dong Han; Lee, Ji-Yun; Jang, Sun Woo; Sohn, Uy Dong

2018-05-01

A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of donepezil in humans and animals is unclear. This study aimed to characterize the effective concentration of donepezil on AChE inhibition and impaired learning and memory in rodents. A pharmacokinetic study of donepezil showed a mean peak plasma concentration of donepezil after oral treatment (3 and 10 mg/kg) of approximately 1.2 ± 0.4 h and 1.4 ± 0.5 h, respectively; absolute bioavailability was calculated as 3.6%. Further, AChE activity was inhibited by increasing plasma concentrations of donepezil, and a maximum inhibition of 31.5 ± 5.7% was observed after donepezil treatment in hairless rats. Plasma AChE activity was negatively correlated with plasma donepezil concentration. The pharmacological effects of donepezil are dependent upon its concentration and AChE activity; therefore, we assessed the effects of donepezil on learning and memory using a Y-maze in mice. Donepezil treatment (3 mg/kg) significantly prevented the progression of scopolamine-induced memory impairment in mice. As the concentration of donepezil in the brain increased, the recovery of spontaneous alternations also improved; maximal improvement was observed at 46.5 ± 3.5 ng/g in the brain. In conclusion, our findings suggest that the AChE inhibitory activity and pharmacological effects of donepezil can be predicted by the concentration of donepezil. Further, 46.5 ± 3.5 ng/g donepezil is an efficacious target concentration in the brain for treating learning and memory impairment in rodents.

Native language change during early stages of second language learning.

PubMed

Bice, Kinsey; Kroll, Judith F

2015-11-11

Research on proficient bilinguals has demonstrated that both languages are always active, even when only one is required. The coactivation of the two languages creates both competition and convergence, facilitating the processing of cognate words, but slowing lexical access when there is a requirement to engage control mechanisms to select the target language. Critically, these consequences are evident in the native language (L1) as well as in the second language (L2). The present study questioned whether L1 changes can be detected at early stages of L2 learning and how they are modulated by L2 proficiency. Native English speakers learning Spanish performed an English (L1) lexical decision task that included cognates while event-related potentials were recorded. They also performed verbal fluency, working memory, and inhibitory control tasks. A group of matched monolinguals performed the same tasks in English only. The results revealed that intermediate learners demonstrate a reduced N400 for cognates compared with noncognates in English (L1), and an emerging effect is visually present in beginning learners as well; however, no behavioral cognate effect was present for either group. In addition, slower reaction times in English (L1) are related to a larger cognate N400 magnitude in English (L1) and Spanish (L2), and to better inhibitory control for learners but not for monolinguals. The results suggest that contrary to the claim that L2 affects L1 only when L2 speakers are highly proficient, L2 learning begins to impact L1 early in the development of the L2 skill.

Blocking of conditioned taste avoidance induced by wheel running.

PubMed

Pierce, W David; Heth, C Donald

2010-01-01

In Experiment 1, compared to non-reinforced presentation of a food stimulus (A-->no US), the association of a food stimulus with wheel running (A-->US) blocked subsequent avoidance of a distinctive flavor (X), when both the food and flavor were followed by wheel running (AX-->US). Experiment 2 replicated and extended the blocking effect, demonstrating that the amount of avoidance of X after AX-->wheel training depended on the correlation between A-alone trials and wheel running-the predictiveness of the A stimulus. The present study is the first to demonstrate associative blocking of conditioned taste avoidance (CTA) induced by wheel running and strongly implicates associative learning as the basis for this kind of avoidance. 2009 Elsevier B.V. All rights reserved.

Higher threat avoidance costs reduce avoidance behaviour which in turn promotes fear extinction in humans.

PubMed

Rattel, Julina A; Miedl, Stephan F; Blechert, Jens; Wilhelm, Frank H

2017-09-01

Theoretical models specifying the underlying mechanisms of the development and maintenance of anxiety and related disorders state that fear responses acquired through classical Pavlovian conditioning are maintained by repeated avoidance behaviour; thus, it is assumed that avoidance prevents fear extinction. The present study investigated behavioural avoidance decisions as a function of avoidance costs in a naturalistic fear conditioning paradigm. Ecologically valid avoidance costs - manipulated between participant groups - were represented via time-delays during a detour in a gamified computer task. After differential acquisitions of shock-expectancy to a predictive conditioned stimulus (CS+), participants underwent extinction where they could either take a risky shortcut, while anticipating shock signaled by the CS+, or choose a costly avoidance option (lengthy detour); thus, they were faced with an approach-avoidance conflict. Groups with higher avoidance costs (longer detours) showed lower proportions of avoiders. Avoiders gave heightened shock-expectancy ratings post-extinction, demonstrating 'protecting from extinction', i.e. failure to extinguish. Moreover, there was an indirect effect of avoidance costs on protection from extinction through avoidance behaviour. No moderating role of trait-anxiety was found. Theoretical implications of avoidance behaviour are discussed, considering the involvement of instrumental learning in the maintenance of fear responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

Semantic Representation of Newly Learned L2 Words and Their Integration in the L2 Lexicon

ERIC Educational Resources Information Center

Bordag, Denisa; Kirschenbaum, Amit; Rogahn, Maria; Opitz, Andreas

2017-01-01

The present semantic priming study explores the integration of newly learnt L2 German words into the L2 semantic network of German advanced learners. It provides additional evidence in support of earlier findings reporting semantic inhibition effects for emergent representations. An inhibitory mechanism is proposed that temporarily decreases the…

Nonassociative Learning Processes Determine Expression and Extinction of Conditioned Fear in Mice

ERIC Educational Resources Information Center

Kamprath, Kornelia; Wotjak, Carsten T.

2004-01-01

Freezing to a tone following auditory fear conditioning is commonly considered as a measure of the strength of the tone-shock association. The decrease in freezing on repeated nonreinforced tone presentation following conditioning, in turn, is attributed to the formation of an inhibitory association between tone and shock that leads to a…

Vagus Nerve Stimulation Reduces Cocaine Seeking and Alters Plasticity in the Extinction Network

ERIC Educational Resources Information Center

Childs, Jessica E.; DeLeon, Jaime; Nickel, Emily; Kroener, Sven

2017-01-01

Drugs of abuse cause changes in the prefrontal cortex (PFC) and associated regions that impair inhibitory control over drug-seeking. Breaking the contingencies between drug-associated cues and the delivery of the reward during extinction learning reduces rates of relapse. Here we used vagus nerve stimulation (VNS) to induce targeted synaptic…

Interaction of Inhibitory and Facilitatory Effects of Conditioning Trials on Long-Term Memory Formation

ERIC Educational Resources Information Center

Hosono, Shouhei; Matsumoto, Yukihisa; Mizunami, Makoto

2016-01-01

Animals learn through experience and consolidate the memories into long-time storage. Conditioning parameters to induce protein synthesis-dependent long-term memory (LTM) have been the subject of extensive studies in many animals. Here we found a case in which a conditioning trial inhibits or facilitates LTM formation depending on the intervals…

Mechanisms of social avoidance learning can explain the emergence of adaptive and arbitrary behavioral traditions in humans.

PubMed

Lindström, Björn; Olsson, Andreas

2015-06-01

Many nonhuman animals preferentially copy the actions of others when the environment contains predation risk or other types of danger. In humans, the role of social learning in avoidance of danger is still unknown, despite the fundamental importance of social learning for complex social behaviors. Critically, many social behaviors, such as cooperation and adherence to religious taboos, are maintained by threat of punishment. However, the psychological mechanisms allowing threat of punishment to generate such behaviors, even when actual punishment is rare or absent, are largely unknown. To address this, we used both computer simulations and behavioral experiments. First, we constructed a model where simulated agents interacted under threat of punishment and showed that mechanisms' (a) tendency to copy the actions of others through social learning, together with (b) the rewarding properties of avoiding a threatening punishment, could explain the emergence, maintenance, and transmission of large-scale behavioral traditions, both when punishment is common and when it is rare or nonexistent. To provide empirical support for our model, including the 2 mechanisms, we conducted 4 experiments, showing that humans, if threatened with punishment, are exceptionally prone to copy and transmit the behavior observed in others. Our results show that humans, similar to many nonhuman animals, use social learning if the environment is perceived as dangerous. We provide a novel psychological and computational basis for a range of human behaviors characterized by the threat of punishment, such as the adherence to cultural norms and religious taboos. (c) 2015 APA, all rights reserved).

Extinction Generates Outcome-Specific Conditioned Inhibition.

PubMed

Laurent, Vincent; Chieng, Billy; Balleine, Bernard W

2016-12-05

Extinction involves altering a previously established predictive relationship between a cue and its outcome by repeatedly presenting that cue alone. Although it is widely accepted that extinction generates some form of inhibitory learning [1-4], direct evidence for this claim has been lacking, and the nature of the associative changes induced by extinction have, therefore, remained a matter of debate [5-8]. In the current experiments, we used a novel behavioral approach that we recently developed and that provides a direct measure of conditioned inhibition [9] to compare the influence of extinguished and non-extinguished cues on choice between goal-directed actions. Using this approach, we provide direct evidence that extinction generates outcome-specific conditioned inhibition. Furthermore, we demonstrate that this inhibitory learning is controlled by the infralimbic cortex (IL); inactivation of the IL using M4 DREADDs abolished outcome-specific inhibition and rendered the cue excitatory. Importantly, we found that context modulated this inhibition. Outside its extinction context, the cue was excitatory and functioned as a specific predictor of its previously associated outcome, biasing choice toward actions earning the same outcome. In its extinction context, however, the cue acted as a specific inhibitor and biased choice toward actions earning different outcomes. Context modulation of these excitatory and inhibitory memories was mediated by the dorsal hippocampus (HPC), suggesting that the HPC and IL act in concert to control the influence of conditioned inhibitors on choice. These findings demonstrate for the first time that extinction turns a cue into a net inhibitor that can influence choice via counterfactual action-outcome associations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Interaction of inhibitory and facilitatory effects of conditioning trials on long-term memory formation

PubMed Central

Hosono, Shouhei; Matsumoto, Yukihisa

2016-01-01

Animals learn through experience and consolidate the memories into long-time storage. Conditioning parameters to induce protein synthesis-dependent long-term memory (LTM) have been the subject of extensive studies in many animals. Here we found a case in which a conditioning trial inhibits or facilitates LTM formation depending on the intervals from preceding trials. We studied the effects of conditioning parameters on LTM formation in olfactory conditioning of maxillary-palpi extension response with sucrose reward in the cockroach Periplaneta americana. We found, at first, that translation- and transcription-dependent LTM forms 1 h after training, the fastest so far reported in insects. Second, we observed that multiple-trial training with an intertrial interval (ITI) of 20 or 30 sec, often called massed training, is more effective than spaced training for LTM formation, an observation that differs from the results of most studies in other animals. Third, we found that a conditioning trial inhibits LTM formation when the intervals from preceding trials were in the range of 10–16 min. This inhibitory effect is pairing-specific and is not due to decreased motivation for learning (overtraining effect). To our knowledge, no similar inhibition of LTM formation by a conditioning trial has been reported in any animals. We propose a model to account for the effects of trial number and ITIs on LTM formation. Olfactory conditioning in cockroaches should provide pertinent materials in which to study neuronal and molecular mechanisms underlying the inhibitory and facilitatory processes for LTM formation. PMID:27918270