Search

Full list of authors: Jorstad, S. G.; Marscher, A. P.; Raiteri, C. M.; Villata, M.; Weaver, Z. R.; Zhang, H.; Dong, L.; Gomez, J. L.; Perel, M., V; Savchenko, S. S.; Larionov, V. M.; Carosati, D.; Chen, W. P.; Kurtanidze, O. M.; Marchini, A.; Matsumoto, K.; Mortari, F.; Aceti, P.; Acosta-Pulido, J. A.; Andreeva, T.; Apolonio, G.; Arena, C.; Arkharov, A.; Bachev, R.; Bonnoli, G.; Borman, G. A.; Bozhilov, V; Carnerero, M., I; Damljanovic, G.; Ehgamberdiev, S. A.; Elsasser, D.; Frasca, A.; Gabellini, D.; Grishina, T. S.; Gupta, A. C.; Hagen-Thorn, V. A.; Hallum, M. K.; Hart, M.; Hasuda, K.; Hemrich, F.; Hsiao, H. Y.; Ibryamov, S.; Irsmambetova, T. R.; Ivanov, D., V; Joner, M. D.; Kimeridze, G. N.; Klimanov, S. A.; Knoett, J.; Kopatskaya, E. N.; Kurtanidze, S. O.; Kurtenkov, A.; Kuutma, T.; Larionova, E. G.; Leonini, S.; Lin, H. C.; Lorey, C.; Mannheim, K.; Marino, G.; Minev, M.; Mirzaqulov, D. O.; Morozova, D. A.; Nikiforova, A. A.; Nikolashvili, M. G.; Ovcharov, E.; Papini, R.; Pursimo, T.; Rahimov, I; Reinhart, D.; Sakamoto, T.; Salvaggio, F.; Semkov, E.; Shakhovskoy, D. N.; Sigua, L. A.; Steineke, R.; Stojanovic, M.; Strigachev, A.; Troitskaya, Y., V; Troitskiy, I. S.; Tsai, A.; Valcheva, A.; Vasilyev, A. A.; Vince, O.; Waller, L.; Zaharieva, E.; Chatterjee, R., Blazars are active galactic nuclei (AGN) with relativistic jets whose non-thermal radiation is extremely variable on various timescales1,2,3. This variability seems mostly random, although some quasi-periodic oscillations (QPOs), implying systematic processes, have been reported in blazars and other AGN. QPOs with timescales of days or hours are especially rare4 in AGN and their nature is highly debated, explained by emitting plasma moving helically inside the jet5, plasma instabilities6,7 or orbital motion in an accretion disc7,8. Here we report results of intense optical and γ-ray flux monitoring of BL Lacertae (BL Lac) during a dramatic outburst in 2020 (ref. 9). BL Lac, the prototype of a subclass of blazars10, is powered by a 1.7 × 108 MSun (ref. 11) black hole in an elliptical galaxy (distance = 313 megaparsecs (ref. 12)). Our observations show QPOs of optical flux and linear polarization, and γ-ray flux, with cycles as short as approximately 13 h during the highest state of the outburst. The QPO properties match the expectations of current-driven kink instabilities6 near a recollimation shock about 5 parsecs (pc) from the black hole in the wake of an apparent superluminal feature moving down the jet. Such a kink is apparent in a microwave Very Long Baseline Array (VLBA) image. © 2022 Springer Nature Limited., The research reported here is based on work supported in part by US National Science Foundation grants AST-2108622 and AST-2107806, and NASA Fermi GI grants 80NSSC20K1567, 80NSSC21K1917 and 80NSSC21K1951; by Shota Rustaveli National Science Foundation of Georgia under contract FR-19-6174; by the Bulgarian National Science Fund of the Ministry of Education and Science under grants DN 18-10/2017, DN 18-13/2017, KP-06-H28/3 (2018), KP-06-H38/4 (2019) and KP-06-KITAJ/2 (2020), and by National RI Roadmap Project D01-383/18.12.2020 of the Ministry of Education and Science of the Republic of Bulgaria; by JSPS KAKENHI grant #19K03930 of Japan; by the Ministry of Education, Science and Technological Development of the Republic of Serbia (contract 451-03-9/2021-14/200002) and observing grant support from the Institute of Astronomy and Rozhen NAO BAS through the bilateral joint research project ‘Gaia Celestial Reference Frame (CRF) and fast variable astronomical objects’; by the Agenzia Spaziale Italiana (ASI) through contracts I/037/08/0, I/058/10/0, 2014-025-R.0, 2014-025-R.1.2015 and 2018-24-HH.0 to the Italian Istituto Nazionale di Astrofisica (INAF). H.Z. is supported by the NASA Postdoctoral Program at Goddard Space Flight Center, administered by ORAU. M.V.P. is partially supported by the Russian Foundation for Basic Research grant 20-02-00490. G.B. acknowledges support from the State Agency for Research of the Spanish MCIU through the ‘Center of Excellence Severo Ochoa’ award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709) and from the Spanish ‘Ministerio de Ciencia e Innovacíon’ (MICINN) through grant PID2019-107847RB-C44. M.D.J. thanks the Brigham Young University Department of Physics and Astronomy for continued support of the extragalactic monitoring programme under way at the West Mountain Observatory. R.C. thanks ISRO for support under the AstroSat archival data utilization programme and BRNS for support through a project grant (sanction no. 57/14/10/2019-BRNS). The measurements at the Hans Haffner Observatory, Hettstadt, Germany, were supported by Baader Planetarium, Mammendorf, Germany. This study was based (in part) on observations conducted using the 1.8-m Perkins Telescope Observatory (PTO) in Arizona, USA, which is owned and operated by Boston University. These results made use of the Lowell Discovery Telescope (LDT) at Lowell Observatory. Lowell Observatory is a private, non-profit institution dedicated to astrophysical research and public appreciation of astronomy, and operates the LDT in partnership with Boston University, the University of Maryland and the University of Toledo. This paper is partly based on observations made with the IAC-80 operated on the island of Tenerife by the Instituto de Astrofisica de Canarias in the Spanish Observatorio del Teide and on observations made with the LCOGT telescopes, one of whose nodes is located at the Observatorios de Canarias del IAC on the island of Tenerife in the Observatorio del Teide. This paper is partly based on observations made with the Nordic Optical Telescope, owned in collaboration by the University of Turku and Aarhus University, and operated jointly by Aarhus University, the University of Turku and the University of Oslo, representing Denmark, Finland and Norway, the University of Iceland and Stockholm University at the Observatorio del Roque de los Muchachos, La Palma, Spain, of the Instituto de Astrofisica de Canarias. The VLBA is an instrument of the NRAO, USA. The NRAO is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Mammals respond to an unexpected reward omission or reduction with a variety of behavioral and physiological responses consistent with an aversive emotion traditionally called frustrative nonreward. This review focuses on two aspects of frustrative nonreward, namely (1) the evidence for an aversive emotional state activated by the surprising omission or reduction of a rewarding outcome, and (2) the adaptive value of frustration. Frustrative nonreward has been mainly studied in terms of its mechanisms, across development in rats and across vertebrate species in comparative research. However, its adaptive function remains obscure. Following Domjan's approach to animal learning, this article explores a specific adaptive function hypothesis of frustrative nonreward called the incentive disengagement hypothesis. According to this hypothesis, the adaptive function of frustrative nonreward is to break an attachment to a site, situation, or stimulus that no longer yields appetitive resources (especially food and fluids) to promote the search for rewards in alternative locations. This function is of particular relevance given that mammals are especially vulnerable to reward loss due to their high metabolic rate and the energy demands of their relatively large brain.

In 2021 BL Lacertae underwent an extraordinary activity phase, which was intensively followed by the Whole Earth Blazar Telescope (WEBT) Collaboration. We present the WEBT optical data in the BVRI bands acquired at 36 observatories around the world. In mid 2021 the source showed its historical maximum, with R = 11.14. The light curves display many episodes of intraday variability, whose amplitude increases with source brightness, in agreement with a geometrical interpretation of the long-term flux behaviour. This is also supported by the long-term spectral variability, with an almost achromatic trend with brightness. In contrast, short-term variations are found to be strongly chromatic and are ascribed to energetic processes in the jet. We also analyse the optical polarimetric behaviour, finding evidence of a strong correlation between the intrinsic fast variations in flux density and those in polarisation degree, with a time delay of about 13 h. This suggests a common physical origin. The overall behaviour of the source can be interpreted as the result of two mechanisms: variability on time scales greater than several days is likely produced by orientation effects, while either shock waves propagating in the jet, or magnetic reconnection, possibly induced by kink instabilities in the jet, can explain variability on shorter time scales. The latter scenario could also account for the appearance of quasi-periodic oscillations, with periods from a few days to a few hours, during outbursts, when the jet is more closely aligned with our line of sight and the time scales are shortened by relativistic effects., Comment: 15 pages, 16 figures, submitted to MNRAS

This paper presents 2109 times of minima for 965 objects acquired by 59 members and cooperating observers of the Variable Star and Exoplanet Section of the Czech Astronomical Society (B.R.N.O. Observing project).These observations were submitted to the website of the Variable Star and Exoplanet Section of the Czech Astronomical Society between November 2016 and March 2018.

In Pavlovian autoshaping, sign-tracking responses (lever pressing) to a conditioned stimulus (CS) are usually invigorated under partial reinforcement (PR) compared to continuous reinforcement (CR). This effect, called the PR acquisition effect (PRAE), can be interpreted in terms of increased incentive hope or frustration-induced drive derived from PR training. Incentive hope and frustration have been related to dopaminergic and GABAergic activity, respectively. We examined the within-trial dynamics of sign and goal tracking in rats exposed to 20-s-long lever presentations during autoshaping acquisition under PR vs. CR conditions under the effects of drugs tapping on dopamine and GABA activity. There was no evidence of the PRAE in these results, both groups showing high, stable sign-tracking response rates. However, the pharmacological treatments affected behavior as revealed in within-trial changes. The dopamine D2 receptor agonist pramipexole (0.4 mg/kg) suppressed lever pressing and magazine entries relative to saline controls in a within-subject design, but only in PR animals. The allosteric benzodiazepine chlordiazepoxide (5 mg/kg) failed to affect either sign or goal tracking in either CR or PR animals. These results emphasize the roles of dopamine and GABA receptors in autoshaping performance, but remain inconclusive with respect to incentive hope and frustration theories. Some aspects of within-trial changes in sign and goal tracking are consistent with a mixture of reward timing and response competition.

Life experience involving unexpected incentive loss (e.g., loss of job or a significant other) may result in negative emotional reactions (frustration) and promote alcohol drinking. Similarly, animals exposed to a frustrative 32-to-4% sucrose downshift increase their preference for alcohol (2%) vs. water. This result was interpreted as reflecting emotional self-medication-the consumption of substances that reduce negative emotions. We conducted three experiments examining parametric manipulations of the animal model: (1) effects of a severe reward downshift (32-to-4% sucrose) on consumption of various alcohol concentrations (Experiment 1); (2) effects of different magnitudes of reward downshifts on consumption of 32% alcohol (Experiment 2); and (3) effects of partial reinforcement (an intervention that increases resistance to frustration) on 2% alcohol intake induced by a 32-to-4% sucrose downshift (Experiment 3). The results show that (1) a 32-to-4% sucrose downshift leads to an increase in alcohol intake over a wide range of alcohol concentrations; (2) the greater the reward downshift, the higher the relative increase in alcohol consumption; and (3) a treatment that increases resistance to frustration (partial reinforcement) also attenuates alcohol consumption after a sucrose downshift. These data are discussed in relation to the role of frustrative nonreward in alcohol consumption.

Prior research with terrestrial toads (Rhinella arenarum) in a water-reinforced instrumental situation indicated a direct relationship between acquisition rate and reward magnitude. However, a reward downshift produced a gradual adjustment of instrumental performance and a rapid adjustment of consummatory performance, rather than the abrupt and transient deterioration of behavior typical of a successive negative contrast effect. In Experiment 1, using a two-chamber box, a downshift from deionized water (which supports maximal rehydration) to 250-mM sodium chloride solution (which supports a lower rehydration), also yielded a gradual adjustment of instrumental behavior. In this experiment, animals received one trial per day and were allowed 300 s of access to the reward in the goal box. Experiment 2 used the same procedure, except that animals were allowed access to the solution in the goal box for 600 s. Under these conditions, reward downshift led to longer latencies (instrumental) and lower rehydration levels (consummatory) than those of unshifted controls, providing evidence for successive negative contrast. Unlike in similar experiments with mammals, the effect was not transient, but persisted relatively unmodified over twelve daily postshift trials. In this case, the possibility of adaptation of the peripheral mechanisms for water uptake is considered. The comparative relevance of these results is discussed in terms of habit formation versus expectancy-guided behavior in vertebrate learning.

Assessing the role of cannabinoid (CB) receptors in behavior is relevant given the trend toward the legalization of medicinal and recreational marijuana. The present research aims at bridging a gap in our understanding of CB-receptor function in animal models of frustrative nonreward. These experiments were designed to (1) determine the effects of chronic administration of the nonselective CB1-receptor agonist WIN 55,212-2 (WIN) on reward downshift in rats and (2) determine whether the effects of chronic WIN were reducible to acute effects. In Experiment 1, chronic WIN (7 daily injections, 10 mg/kg, ip) accelerated the recovery of consummatory behavior after a 32-to-4% sucrose downshift relative to vehicle controls. In addition, chronic WIN eliminated the preference for an unshifted lever when the other lever was subject to a 12-to-2 pellet downshift in free-choice trials, but only in animals with previous experience with a sucrose downshift. In Experiment 2, acute WIN (1 mg/kg, ip) reduced consummatory behavior, but did not affect recovery from a 32-to-4% sucrose downshift. The antagonist SR 141716A (3 mg/kg, ip) also failed to interfere with recovery after the sucrose downshift. In Experiment 3, acute WIN administration (1 mg/kg, ip) did not affect free-choice behavior after a pellet downshift, although it reduced lever pressing and increased magazine entries relative to vehicle controls. The effects of chronic WIN on frustrative nonreward were not reducible to acute effects of the drug. Chronic WIN treatment in rats, like chronic marijuana use in humans, seems to increase resistance to the effects of frustrative nonreward.

This revised third edition provides an up to date, comprehensive overview of the field of comparative psychology, integrating both evolutionary and developmental studies of brain and behavior. This book provides a unique combination of areas normally covered independently to satisfy the requirements of comparative psychology courses. Papini ensures thorough coverage of topics like the fundamentals of neural function, the cognitive and associative capacities of animals, the development of the central nervous system and behavior, and the fossil record of animals including human ancestors. This text includes many examples drawn from the study of human behavior, highlighting general and basic principles that apply broadly to the animal kingdom. New topics introduced in this edition include genetics, epigenetics, neurobiological, and cognitive advances made in recent years into this evolutionary-developmental framework. An essential textbook for upper level undergraduate and graduate courses in comparative psychology, animal behavior, and evolutionary psychology, developmental psychology, neuroscience and behavioral biology.

Successive negative contrast (SNC) involves a disruption of behavior when the paired reward is unexpectedly reduced from a large to a small amount, relative to a control always receiving the small amount. Five experiments with rats explored SNC in the Pavlovian autoshaping procedure in which a retractable lever is paired with the delivery of food pellets. In Experiment 1, a 12-to-2 pellet downshift either early in training (after 3 sessions) or late in training (after 20 sessions) yielded no significant evidence of SNC either in terms of lever pressing or goal entries. Experiment 2 showed that presession feeding (another form of reward devaluation) suppressed lever pressing in nonreinforced tests early in training. However, no statistical evidence of lever pressing suppression was found late in training. Presession feeding also suppressed lever pressing late in training if the test session included reinforcements. Experiment 3, using reward downshift, showed that adding a nontarget lever produced no statistical evidence of response suppression to the target lever during the downshift. Lever pressing to the target lever increased and goal entries tended to decrease after a 12-to-2 pellet downshift. Using a within-subject design and two target levers with distinct reward values (Experiment 4), reward downshift produced evidence of lever pressing enhancement in single-lever trials, but lever pressing suppression and a switch in preference to the unshifted lever in nonreinforced free-choice trials. Experiment 5 replicated these within-subject SNC effects, but found only modest evidence for a successive positive contrast effect in free-choice behavior. These results suggest that autoshaping in rats may induce response invigoration in forced-choice situations, but response suppression in free-choice situations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Does recovery from reward devaluation or partial reinforcement (PR) involve the counterconditioning of frustration? Transfer among tasks involving reward loss was used to uncover frustration counterconditioning. In Experiment 1, Phase 1 training in consummatory successive negative contrast (cSNC; 32-to-4% sucrose devaluation) eliminated Phase 2 iSNC in one-way avoidance (40-to-3 s safety-time reduction), but the opposite sequence generated no detectable transfer. In Experiment 2, transfer from Phase 1 cSNC to Phase 2 autoshaping extinction after continuous reinforcement increased lever pressing in previously downshifted animals relative to unshifted controls. However, Phase 1 training in autoshaping under partial reinforcement (PR) had no effect on Phase 2 cSNC. Transfer from PR to cSNC also failed when sucrose pellets were used in autoshaping (Experiment 3), when autoshaping acquisition was extended from 100 to 300 trials (Experiment 4), and when preshift training in cSNC was extended from 10 to 20 sessions (Experiment 5). In Experiment 6, Phase 1 training in PR for licking enhanced Phased 2 cSNC, also involving licking, and in Experiment 7 Phase 1 PR training in autoshaping enhanced Phase 2 cSNC after a 22-to-4% sucrose downshift. Whereas prior exposure to cSNC (consummatory task) increased resistance to extinction in autoshaped lever pressing, prior training in one-way avoidance, PR in autoshaping, or PR in taste conditioning (all anticipatory tasks) either had no effect or they enhanced the cSNC effect. Frustration counterconditioning developed during these tasks, but the type of transfer effect depends on task sequence.

Frustration or psychological pain refers to a negative emotional experience derived from unexpected incentive loss. The scientific study of frustration with non-human animals is abundant and consistent, whereas human research on this topic seems to be more fragmentary because of the variety of conceptual, theoretical and experimental approaches. The main aim of this paper was to conduct a narrative review of the scientific literature about the psychological construct of frustration. With this goal in mind, we first described the consummatory successive negative contrast, a widely used animal model of psychological pain and frustration. We also conducted a systematic search of experimental studies aimed at inducing frustration in humans, reviewed studies focused on analyzing the relationship between physical and psychological pain, and selected experiments involving the manipulation (omission, devaluation) of social stimuli. A discussion of the implications of the results for basic and clinical research was finally included, with an especial emphasis in the current COVID-19 pandemic, a worldwide experience of incentive loss with relevant psychological consequences. © 2021, Sociedad Interamericana de Psicologia. All rights reserved.

Rodents are generally reluctant to consume high concentrations of alcohol. However, few experiments have reported the behavior of rats when they are given access to high alcohol concentrations. Four experiments with food-deprived Wistar rats were designed to determine whether 66% alcohol could be used as a positive reinforcer for operant responses. In Experiment 1, animals learned to lick an empty sipper to gain access to 66% alcohol in a second tube; licking extinguished after it if provided a only access to water (operant licking task, OL). Experiment 2 used the OL task combined with a progressive ratio (PR) schedule in a within-subject design with the order of alcohol concentrations counterbalanced across subjects. The breakpoint (the last completed ratio in the PR schedule) was higher for 10% and 66% alcohol concentrations than for water. In Experiment 3, animals trained in the same PR task gained access to water, 10%, or 66% alcohol in a between-subject design. Breakpoints were higher for 66% alcohol than for water, but not for 10% alcohol relative to water. Experiment 4 tested the effects of the orexin-1 receptor antagonist SB-334,867 on licking reinforced with access to 66% alcohol in the PR task. The antagonist reduced the breakpoint at 1- and 5-mg/kg doses, but not at 10 mg/kg. These results suggest that 66% alcohol can be used to reinforce operant behavior. Although the effects were modest, they were reliable. The estimated amount of alcohol consumed in the OL task suggests that these reinforcing effects were not dependent on the pharmacological effects of 66% alcohol, but could perhaps reflect a sensation-seeking effect.

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 relationto the results of analogous experiments with other vertebrates. Fil: Puddington, Martin Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Psicología; Argentina Fil: Daneri, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Psicología; Argentina Fil: Papini, Mauricio Roberto. Texas Christian University; Estados Unidos Fil: Muzio, Ruben Nestor. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Psicología; Argentina

The role of the central amygdala (CeA) in the adjustment to a 32-to-2% sucrose downshift in the consummatory successive negative contrast (cSNC) task and in a free-choice 10% alcohol-water preference task (PT) was studied using chemogenetic inactivation. cSNC is a model of frustrative nonreward that enhances alcohol consumption. In Experiment 1, sessions 1–10 involved 5-min access to 32% sucrose and sessions 11–12 involved access to 2% sucrose. Vehicle or clozapine N-oxide (CNO; 1 or 3 mg/kg, ip), used later to activate the inhibitory designer receptor, was administered 30 min before sessions 11–12. There was no evidence that CNO affected consummatory behavior after the sucrose downshift. In Experiment 2, all animals received an infusion of the inhibitory designer receptor hM4D(Gi) into the CeA. After recovery, animals received access to either 32% or 2% sucrose on sessions 1–10, followed by 2% sucrose on sessions 11–12. Immediately after each 5-min sucrose session, animals received a 2-bottle, 1-h PT with 10% alcohol and water. CNO (3 mg/kg, ip) or vehicle was administered 30 min before sessions 11–12. CeA inactivation prior to sucrose downshift eliminated the cSNC effect, which was observed in vehicle controls. However, there was no evidence that CeA inactivation affected preference for 10% alcohol over water. These results support the hypothesis that CeA activity is critical for cSNC effect, an outcome consistent with the view that the amygdala plays a central role in frustrative nonreward.

Using animal models in addiction and pain research is pivotal to unravel new pathways and mechanisms for the treatment of these disorders. Reward devaluation through a consummatory successive negative contrast (cSNC) task has shown the ability to reduce physical pain sensitivity (hypoalgesia) and increase oral ethanol consumption in rats. The procedure is based on exposing the experimental animals to a 32% sucrose solution during several sessions (preshift sessions) followed by a devaluation to 4% sucrose during the next few sessions (postshift sessions). The cSNC effect can be monitored by comparing the experimental group to an unshifted control that had access to 4% sucrose throughout the entire experiment (preshift and postshift sessions). The cSNC phenomenon is defined by lower consumption of sucrose in the downshifted group than in the unshifted group during postshfit sessions.

This study analyzed the effects of LHb lesions on appetitive extinction and alcohol consumption. Eighteen male Wistar rats received neurochemical lesions of the LHb (quinolinic acid) and 12 received a vehicle infusion (PBS). In a runway instrumental task, rats received acquisition (12 pellets/trial, 6 trials/session, 10 sessions) and extinction training (5 sessions). In a consummatory task, rats had daily access to 32% sucrose (5 min, 10 sessions) followed by access to water (5 sessions). Then, animals received 2 h preference tests with escalating alcohol concentrations (2%–24%), followed by two 24 h preference tests with 24% alcohol. Relative to Shams, LHb lesions delayed extinction, as indicated by lower response latencies (instrumental task) and higher fluid consumption (consummatory task). LHb lesions did not affect alcohol consumption regardless of alcohol concentration or test duration. The LHb modulates appetitive extinction and needs to be considered as part of the brain circuit underlying reward loss.

After ten 5-min sessions of access to 32% sucrose, a reward downshift (RD) to 2% sucrose induces a transient rejection of the reward. Animals were segregated according to the speed of recovery from RD into Fast-recovery and Slow-recovery subgroups. Animals were subsequently trained in an operant licking (OL) task in which licking at an empty tube provided 10 s of access to a second tube containing 66% alcohol. Licking on the first tube was subjected to a progressive ratio (PR) schedule with a step of 4 licks. Fast-recovery animals (both males and females) licked to a higher ratio than Slow-recovery animals. Animals were also exposed to a well-lit open field (OF) for 20 min. Fast- and Slow-recovery males and females exhibited equal levels of activity in the OF. Tissue samples from tails were assessed for two well-known allelic variations of the human opioid receptor gene, OPRM1, known to affect mu opioid sensitivity: The C17T and A118G single nucleotide polymorphisms. There was no evidence of a relationship between genotype and behavior, suggesting that these genetic mechanisms in humans do not account for the individual differences in recovery from RD and OL for alcohol in rats.

Rats exposed to spaced (S) conditions of training, with intertrial intervals (ITIs) averaging 90 s, acquired autoshaping performance (contact with a retractable lever presented 10 s before the response-independent delivery of 5 food pellets) faster than rats exposed to massed (M) training, with ITIs averaging 15 s. Gradual or abrupt transitions between S and M training were followed by concomitant gradual and abrupt changes in behavior. However, S-to-M and M-to-S transitions supported different levels of adjustment. S-to-M transitions were generally less open to competition between sign and goal tracking than M-to-S transitions. These results suggest that responses that become dominant early in training regulate terminal performance after extensive training. Thus, initial massed training promotes strong goal tracking that interferes with sign tracking even under conditions that would otherwise promote sign tracking. By contrast, initial spaced training tends to promote sign tracking that can interfere with goal tracking even when ITI duration favors goal tracking. These results are discussed in the context of the theoretical issue of path dependence. Their implications for learning theory and their potential applicability to the nature of sign and goal tracking endophenotypes in relation to substance use disorders are briefly discussed.

Rats and pigeons exhibit different extinction profiles after instrumental acquisition with large vs. small rewards. In rats, extinction is faster after large-reward training, but in pigeons, extinction is faster after small-reward training. Two experiments extended these findings to a progressive-ratio schedule with acquisition training with two reward magnitudes administered either between or within subjects. Both rats and pigeons, under both between- and within-subject conditions, exhibited higher breakpoints (the last completed ratio) when responding for 5 pellets per ratio vs. 1 pellet per ratio. However, between-subject training yielded faster extinction after training with 5 pellets than 1 pellet for rats, but the opposite trend for pigeons. Extinction effects were eliminated in within-subject training for rats, but remained unchanged for pigeons. These results are discussed in the context of frustration theory and the strengthening/weakening principle of learning.

The dorsomedial striatum (DMS) has been implicated in the acquisition of reward representations, a proposal leading to the hypothesis that it should play a role in situations involving reward loss. We report the results of an experiment in which the effects of DMS excitotoxic lesions were tested in consummatory successive negative contrast (reward devaluation), autoshaping training with partial vs. continuous reinforcement (reward uncertainty), and appetitive extinction (reward omission). Animals with DMS lesions exhibited reduced lever pressing responding, but enhanced goal entries, during partial reinforcement training in autoshaping. However, they showed normal negative contrast, acquisition under continuous reinforcement (CR), appetitive extinction, and response facilitation in early extinction trials. Open-field testing also indicated normal motor behavior. Thus, DMS lesions selectively affected the behavioral adjustment to a situation involving reward uncertainty, producing a behavioral reorganization according to which goal tracking (goal entries) became predominant at the expense of sign tracking (lever pressing). This pattern of results shows that the function of the DMS in situations involving reward loss is not general, but restricted to reward uncertainty. We suggest that a nonassociative, drive-related process induced by reward uncertainty requires normal output from DMS neurons.

Although research suggests an interplay between identity development and self-esteem, most studies focused on the role of identity commitment and measured only level of self-esteem. This study examined longitudinal associations between Berzonsky’s (2011) styles of identity exploration and two distinct features of self-esteem: level of self-esteem and contingent self-esteem. Participants were 167 college students (mean age = 19 years; 66% female) who completed questionnaires tapping into identity styles and features of self-esteem at two measurement waves separated by a 4-month interval. Both information-oriented and normative styles were found to be predicted by contingent self-esteem. Follow-up analyses demonstrated that the content of contingent self-esteem predicting both identity styles was different. A diffuse-avoidant identity style was predicted mainly by low levels of self-esteem. Although we also observed some effects of identity styles on the self-esteem variables, the self-esteem variables had overall a more consistent influence on the identity styles than the other way around.

Emotional counterconditioning resulting from pairings between a state of frustration and food reward explains transfer across situations involving reward omission. This experiment explored the hypothesis that a similar emotional counterconditioning mechanism is also involved in recovery from reward devaluation. Inbred Roman high- and low-avoidance rat strains (RHA-I and RLA-I) were trained in consummatory and instrumental successive negative contrast tasks (cSNC and iSNC) in counterbalanced order. RLA-I rats have consistently shown high levels of anxiety in a variety of situations, relative to RHA-I rats. Therefore, a stronger evidence of transfer was expected in RLA-I rats than in RHA-I rats. Whereas both strains showed the effects in the original training phase, only RLA-I rats benefitted from prior exposure to one reward devaluation task. The transfer was positive and symmetrical (i.e., exposure to one SNC task attenuated the second effect). RHA-I rats produced no evidence of transfer. The results suggest that emotional counterconditioning is involved in recovery from reward devaluation tasks. Despite extensive psychogenetic selection for low-avoidance/high-anxiety behavior, RLA-I rats showed the ability to develop resilience as a function of prior experience.

Rats exposed to a downshift from a large reward (32% sucrose) to a small reward (4% sucrose) show less consummatory behavior than unshifted rats always exposed to the small reward—an effect called consummatory successive negative contrast (cSNC). Four experiments studied the effects of shifts in deprivation level between preshift and postshift sessions on the size of the cSNC effect. This manipulation is designed to test the general proposition that the cSNC effect depends not only on external factors (e.g., reward disparity), but also on the internal state of the organism either at the time it first experiences the rewards (incentive learning), at the time of reward downshift (reward need), or as a function of the transition of states from pre- to postshift sessions (state dependency). Experiments 1–2 adjusted deprivation level during a 10-day interval between the last preshift and first postshift sessions. During this interval, food deprivation was either maintained or changed (increased or reduced) relative to preshift sessions. Experiments 3–4 maintained all animals at 81–85% of their ad lib weight during the entire experiment, but they were either fed before each session (nondeprivation condition) or fed after the session (deprivation condition). This procedure avoided the 10-day interval used in previous experiments. In three of the four experiments, the size of the cSNC effect increased when animals were deprived while exposed to the large reward (32% sucrose) during preshift sessions, independently of postshift deprivation conditions. The remaining experiment yielded inconclusive results. Of the three tested hypothesis, the incentive learning view received the strongest support. According to this view, the incentive value of the large reward is partly determined by the deprivation state of the organism at the time of learning.

Individuals trained under partial reinforcement (PR) typically show a greater resistance to extinction than individuals exposed to continuous reinforcement (CR). This phenomenon is referred to as the PR extinction effect (PREE) and is interpreted as a consequence of uncertainty-induced frustration counterconditioning. In this study, we assessed the effects of PR and CR in acquisition and extinction in two strains of rats, the inbred Roman high- and low-avoidance (RHA and RLA, respectively) rats. These two strains mainly differ in the expression of anxiety, the RLA rats showing more anxiety-related behaviors (hence, more sensitive to frustration) than the RHA rats. At a neurobiological level, mild stress is known to elevate corticosterone in RLA rats and dopamine in RHA rats. We tested four groups of rats (RHA/CR, RHA/PR, RLA/CR, and RLA/PR) in two successive acquisition-extinction phases to try to consolidate the behavioral effects. Animals received training in a Pavlovian autoshaping procedure with retractable levers as the conditioned stimulus, food pellets as the unconditioned stimulus, and lever presses as the conditioned response. In Phase 1, we observed a PREE in lever pressing in both strains, but this effect was larger and longer lasting in RHA/PR than in RLA/PR rats. In Phase 2, reacquisition was fast and the PREE persisted in both strains, although the two PR groups no longer differed in lever pressing. The results are discussed in terms of frustration theory and of uncertainty-induced sensitization of dopaminergic neurons.

Rats exposed to reward downshift (from 32 to 4% sucrose) increase 2% alcohol intake in a 2-h, free-choice preference test which also offered water. This effect was accompanied by augmented general activity in the elevated plus maze (Donaire et al., 2018, Behav Proc, 150, 59-65). In the present study we analyzed the effect of alcohol consumption induced by reward downshift on anxiety behaviors registered in the hole-board (HB) test. Sixteen food-deprived female Wistar rats received 32% sucrose for ten 5-min daily sessions and were then downshifted to 4% sucrose for two 5-min daily sessions (postshift). Sessions also involved testing animals in a 2-h, 2-bottle preference task with 2% alcohol vs. water (Group A), or water vs. water (Group W). On postshift sessions, animals were exposed to a 6-min HB test after the preference task. Reward devaluation significantly reduced sucrose intake in Groups A and W, and increased alcohol consumption in Group A, but had no effect on water consumption in Group W. Increased alcohol consumption was followed by higher head-dipping frequency in the HB test compared with Group W. The results are discussed in terms of the impact of reward loss on anxiety behaviors in the HB test and the anxiolytic effects of alcohol in situations involving negative affect.

The consummatory successive negative contrast (cSNC) task typically involves administering food-deprived rats 10 daily 5-min sessions of access to 32 % sucrose (preshift) followed by a few sessions in which the concentration is reduced to 4 % sucrose (postshift). Such sucrose downshift leads to transient suppression of consummatory behavior. Reward downshifts were used to determine whether food-deprived rats treat sucrose solutions as food, because sweetness is a proxy for its caloric content, or as water, because a solution has hydration content. In Experiment 1, a cSNC effect was obtained in food-deprived animals, but not in water-deprived animals. This suggested that food deprivation focused attention on the feeding dimension of sucrose, whereas water deprivation focused attention on the drinking dimension of sucrose. Sucrose downshift results in a greater caloric change than in hydration content because both concentrations continue to provide fluid. Experiments 2 and 3 offered presession access to rewards either before preshift or before postshift sessions, respectively. Consistent with this attentional view, presession access to water (which should focus attention on the feeding dimension), but not to food (which should focus attention on the drinking dimension), suppressed consummatory behavior after a sucrose downshift. Presession access to food, like water deprivation, enhanced the hydration properties of the sucrose solution at the expense of its caloric properties. These results are consistent with an attentional hypothesis according to which the internal state, manipulated via deprivation or presession reward access, determines which dimension of the sucrose reward would control consummatory behavior.

Various sources of stress induce alcohol intake in rodents, including inescapable shocks, physical restraint, and reward loss. One hypothesis maintains that alcohol intake increases because its anxiolytic properties reduce negative emotion. A series of experiments explored this hypothesis using escapable vs. inescapable exposure to the well-lit circular platform of a Barnes maze in a master/yoked (M/Y) design, with pairs of rats matched in the amount of time on the lighted platform, but differing in terms of the presence vs. absence of an escape box. In Experiment 1 the M/Y design was validated as a means of producing rapid acquisition of escape behavior in master animals. In Experiment 2, immediate postsession access to a 2-h, 2-bottle preference test with 8 % alcohol and water resulted in a higher increase in preference for alcohol over water across sessions in yoked animals compared to master animals. Group differences were not observed when animals had access to water in both bottles. Higher preference for 8 % alcohol in yoked vs. master animals was also observed when the Barnes maze and preference test were separated by a 1-h interval (Experiment 3). However, voluntary alcohol consumption was similar in master and yoked animals when the order of exposure to the Barnes maze and fluid consumption was reversed (Experiment 4) or when the threat level was reduced by using a dim light over the Barnes maze (Experiment 5). Increased preference for alcohol after inescapable exposure to the Barnes maze is consistent with the hypothesis that alcohol alleviates negative mood and anxiety induced by an inescapable threat. This animal model is relevant to an understanding of the initial stages of co-morbidity between depression, anxiety, and alcohol use.

Rats exposed to unexpected reward loss increase voluntary oral consumption of ethanol. Such consumption has been assumed to attenuate loss-induced negative affect (called emotional self-medication). To test this assumption, food-deprived male Wistar rats were exposed to 10 sessions of access to 32% sucrose followed by 5 sessions of access to 4% sucrose (reward downshift). A two-bottle preference test was initiated immediately after each consummatory session to assess ethanol intake. The experimental group received access to 2% ethanol and water, whereas the control group received access to two water bottles. On sessions 11, 12, and 15, immediately after the preference test, animals were tested in the elevated plus maze (EPM) for signs of anxiety. Sucrose consumption was reduced after the 32-to-4% sucrose downshift on sessions 11 and 12, but behavior recovered by session 15. Consummatory suppression was followed by increased ethanol intake in the preference test after sessions 11 and 12, but intake was reduced to preshift levels by session 15; no changes were observed in water controls. Finally, general activity (closed-arm entries and total arm entries) in the EPM increased in the ethanol group on session 12, but not on session 15, relative to water controls. The increase in ethanol consumption induced by reward downshift had measurable effects on activity as assessed in the EPM. These results show that voluntary oral 2% ethanol consumption after reward downshift can affect subsequent behavior, but fall short of providing unambiguous evidence that such ethanol consumption reduces negative affect.

The present research aimed at determining the role played by the amygdala in reward devaluation using transient inactivation induced by lidocaine microinfusions into the centromedial region. Two situations involving reward devaluation were tested in rats: consummatory successive negative contrast (cSNC) and anticipatory negative contrast (ANC). In cSNC, rats exposed to a downshift from 32% to 4% sucrose consume less 4% sucrose than rats always exposed to 4% sucrose. Extensive evidence suggests that reward devaluation in the cSNC situation is accompanied by negative emotion. In ANC, rats consume less 4% sucrose when each session is closely followed by access to 32% sucrose rather than by 4% sucrose. Evidence suggests that reward devaluation in the ANC situation does not involve negative emotions; rather, ANC appears to involve Pavlovian anticipation of the higher value solution. To test the effects of lidocaine microinfusions in a situation known to induce negative emotion, but unrelated to reward devaluation, animals were also exposed to a lighted open field. Centromedial amygdala inactivation reduced the cSNC effect and increased exploratory behavior in the open field, both effects consistent with a reduction in negative emotional state. However, no detectable effects of amygdala inactivation were observed in the ANC situation. These results suggest that, first, the function of the amygdala is not unique to reward devaluation and, second, it is concerned with tagging the devaluation experience with aversive valence.

a b s t r a c t Rats increased preference for ethanol after sessions of appetitive extinction, but not after acquisition (reinforced) sessions (Manzo et al., 2014). Drinking was not influenced by appetitive extinction in control groups with postsession access to water, rather than ethanol. Because ethanol has anxiolytic properties in tasks involving reward loss, these results were interpreted as anti-anxiety self-medication. The present experiment tested the potential for self-medication with the prescription anxiolytic chlordiazepoxide, a benzodiazepine with an addictive profile used in the treatment of anxiety disorders. To test this hypoth- esis, Wistar rats exposed to a 32-to-4% sucrose devaluation received a two-bottle, 2-h preference test immediately after consummatory training. One bottle contained 1 mg/kg of chlordiazepoxide, 2% ethanol, or water for different groups (the second bottle contained water for all groups). Three additional groups received the same postsession preference tests, but were exposed to 4% sucrose during consumma- tory training. Rats showed suppression of consummatory behavior after reward devaluation relative to unshifted controls. This effect was accompanied by a selective increase in preference for chlordiazepox- ide and ethanol. Downshifted animals with access to water or unshifted controls with access to the anxiolytics failed to exhibit postsession changes in preference. Similar results were observed in terms of absolute consumption and consumption relative to body weight. This study shows for the first time that a prescription anxiolytic supports enhanced voluntary consumption during periods of emotional distress triggered by reward loss. Such anti-anxiety self-medication provides insights into the early stages of addictive behavior. © 2014 Elsevier B.V. All rights reserved.

This study evaluated the hypothesis that relationships between cognitive reasoning processes and the types of identity components (i.e., personal, collective, or social) that individuals emphasize in defining who they are would at least in part be mediated by identity processing styles. Results indicated rational processing was linked positively to a personal identity emphasis and negatively to a social emphasis. Intuitive processing was positively linked to all three identity emphases. As hypothesized, all of the direct relationships were at least partially mediated by identity processing style. Specifically, the positive association between rational processing and a personal identity emphasis was completely mediated by the informational and diffuse-avoidant identity styles. The negative association between rational processing and a social identity emphasis was completely mediated by all three identity styles. The informational and normative styles mediated the structural paths from intuitive processing ...