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Rats given access to a 32% sucrose solution later reject a 4% solution significantly more than controls that have only received the 4% solution. In Experiment 1, this consummatory successive negative contrast (cSNC) effect was attenuated by previous exposure to 50% partial reinforcement. Furthermore, recovery from cSNC was also facilitated by partial reinforcement. In Experiment 2, the attenuating effects of partial reinforcement on cSNC were eliminated by administration of the benzodiazepine anxiolytic chlordiazepoxide (5mg/kg) before nonreinforced trials. In Experiment 3, the attenuating effect of partial reinforcement was greater after a shift from 32 to 6% solution, than after a shift from 32 to 2% solution. The parallels between the effects of partial reinforcement on consummatory and instrumental behavior are discussed.

Dogs (Canis familiaris) trained to receive a preferred food (dry beef liver) from an experimenter learned to maintain a longer gaze on the experimenter than dogs receiving a less preferred food (dog pellets). Dogs downshifted from dry liver to pellets rejected food more frequently than nonshifted controls. Gaze duration also decreased in downshifted dogs below the level of a group always reinforced with pellets. In addition, downshifted dogs tended to move away from the experimenter, adopting a lying down posture. This phenomenon, called successive negative contrast, has been described in analogous experiments with a variety of mammalian species, but has failed to occur in similar experiments with nonmammalian vertebrates. Unlike similar previous observations, the present data were obtained in an environment involving interspecific communication. Keywords: incentive contrast, frustration, interspecific communication, domestic dogs

Although a growing body of work has established developing regulatory abilities during the second year of life, more work is needed to better understand factors that influence this emerging control. The purpose of the present study was to examine regulation capacities in executive functions (i.e., EF or cognitive control) and emotion regulation (i.e., ER or control focused on modulating negative and sustaining positive emotions) in a Latin American sample, with a focus on how joint attention, social vulnerability, and temperament contribute to performance. Sixty Latin American dyads of mothers and children aged 18 to 24 months completed several EF tasks, a Still-Face Paradigm (SFP) to examine ER (Weinberg et al., 2008), and the Early Social Communication Scale to measure joint attention (Mundy et al., 2003). Parents completed the Early Childhood Behavior Questionnaire Very Short Form to measure temperament (ECBQ-VS, Putnam et al., 2010) and the Social Economic Level Scale (SES) from INDEC (2000). Results revealed the typical responses expected for toddlers of this age in these EF tasks and in the SFP. Also, we found associations between EF and ER and between non-verbal communication related to monitoring infants' attention to objects (i.e., responding to joint attention) and initiation of pointing (e.g., pointing and showing of an object while the child alternates his gaze to an adult) with EF. Regarding social factors, family differences and type of housing contribute to regulation. For temperament, effortful control was associated with both regulatory capacities. Finally, only age predicted EF. These results suggest that many patterns regarding the development of these abilities are duplicated in the first months of life in a Latin American sample while further highlighting the importance of considering how the environment and the individual characteristics of infants may associate to these regulatory abilities, which is particularly relevant to developing public policies to promote their optimal development. [ABSTRACT FROM AUTHOR]

ABSTRACT Consummatory successive negative contrast (cSNC) occurs when organisms repeatedly exposed to a high-magnitude reward are suddenly given a low-magnitude reward. This results in a significant reduction in the consumption of the devalued reinforcer, at a level even below that of a group which had been always exposed to the low-magnitude reinforcer. A scarcity of animal studies assessed the expression of this phenomenon during early development. Three experiments assessed age of cSNC onset in preweanling rats. Percent body weight gained (%BWG) and taste reactions associated with reinforcement devaluation were measured. A reduction in %BWG and a significant increase in emission of aversive hedonic behaviors, indicative of cSNC, occurred on postnatal day 18 (PD 18; Experiments 1 and 2), but not on PD 14 or PD 17 (Experiments 3a and 3b). The neurobiological mechanisms underlying these effects and theoretical implications are discussed. © 2013 Wiley Periodicals, Inc. Dev Psychobiol 56: 989-998, 2014. [ABSTRACT FROM AUTHOR]

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Rats received training in the consummatory successive negative contrast (cSNC) situation in which access to 32% sucrose solution during ten daily trials is followed by a downshift to 4% sucrose. Separate groups were exposed to the hot plate test for pain sensitivity immediately after either the first or the second downshift trial (Trials 11 and 12, respectively). Rats exhibited hypoalgesia after Trial 12 downshift, but not after Trial 11. These results suggest that cSNC induces the release of endogenous opioids that cause hypoalgesia, but only after some experience with the downshifted solution. This interpretation is supported by experiments demonstrating that opioid agonists reduce cSNC, whereas opioid antagonists enhance it. [ABSTRACT FROM AUTHOR]

Two experiments with rats studied the relationship between reinforcer magnitude and frequency, and extinction rate in a consummatory situation with rats. In Experiment 1, groups received access to either a 2% or a 32% sucrose solution during twenty 5-min sessions and were subsequently shifted to extinction (access to an empty sipper tube). Goal tracking time (time spent near the sipper tube) was the dependent measure. Extinction was faster after training with 2% solution than with 32% solution. In Experiment 2, extinction was faster after training with 50% partial reinforcement than with continuous reinforcement. In both experiments, extinction was gradual and rats exhibited spontaneous recovery of goal-tracking behavior. Results are discussed in the context of evidence pointing to a dissociation of consummatory and instrumental behavior. [ABSTRACT FROM AUTHOR]

Explores the surprising omission of an appetitive reinforcer in aggressive behavior. Reduction of aggressive attacks in rats; Increase in sipper approach during the postshift nonreward session; Extinction of appetitive responses in aggressive attacks.

Examines the influence of contextual similarity on the outcome of nonreinforced preexposure. Differences of the contexts in terms of tactile and visual stimuli; Facilitation of discriminative learning in similar stimulus; Use of food as reinforcer and anticipatory activity as dependent measure.

ABSTRACT. Choice behavior of the armadillo Chaetophractus villosus (Edentata. Dasypodidae) was studied under laboratory conditions. Two groups were trained in a simultaneous visual discrimination task with food-reward. One group was trained with a contiguous spatial-temporal relationship between the discriminative stimulus and the reinforcement. For the second group, a spatial-temporal separation of these relevant stimuli was imposed in order to lengthen the presolution period. Attention was directed at determining which one of four positional strategies (alternation, position habit, win-shift/lose-stay, and win-stay/lose-shift) prevailed during the acquisition of the discrimination. There were no obvious differences in choice strategies between the groups, although the immediate spatial-temporal contiguity between the discriminative and reinforcing stimuli produced a significantly faster acquisition. Position habit was the only spatial strategy consistently observed between animals and maintained for a variable number of successive sessions in a given subject. The information gathered in this experiment is related to learning processes and the possible adaptive significance of choice strategies. [ABSTRACT FROM AUTHOR]

SUMMARY This experiment compares spatial learning in the South American opossum (Didelphis albiventris) and armadillo (Chaetophractus villosus) in a Y-maze. Ss learned to turn to one arm of the maze for food reinforcement. To earn further reinforcements, they had to return to the start-box (after consuming the food) where they were restrained for a fixed intertrial interval. The number of entries to the unbaited arm en route to the goal-box (Ri errors), and in the way back to the start-box (Rf errors) were the dependent measures. Opossums and armadillos did not differ in Ri errors. However, only armadillos mastered the task of returning directly to the start-box after each reinforcement. Moreover, a significant within-session improvement m Rf errors was observed in armadillos, but failed to appear in opossums. Results are discussed in terms of species differences in sensitivity to temporal delays. [ABSTRACT FROM AUTHOR]

Abstract: Previous research indicated that the suppression of consummatory behavior that follows incentive downshift in male rats is attenuated by testosterone (T) administration during training. The present experiments were designed to assess the role of pretraining T administration on two incentive contrast situations in consummatory behavior: successive negative contrast (cSNC) and anticipatory negative contrast (cANC). In cSNC (Experiment 1), a downshift from 32% to 4% sucrose leads to behavioral suppression relative to an unshifted, 4% sucrose condition (the cSNC effect). Pretraining T administration enhanced consummatory behavior directed at 4% sucrose, without affecting behavior directed at 32% sucrose. This effect obscured a reduction in the cSNC effect by the T treatment that was only detected when a proportional measure of behavior was used. In cANC (Experiment 2), groups received access to two bottles per day separated by a short midtrial interval. Consumption of 4% sucrose is suppressed when the second bottle offers 32% sucrose, relative to 4% sucrose (the cANC effect). Pretraining T did not affect the cANC effect, known to be insensitive to treatment with anxiolytics. These results suggest an anxiolytic-like effect of testosterone in adjustment to incentive downshifts. [Copyright &y& Elsevier]

Abstract: Domestic dogs (Canis familiaris) have been submitted to a vast process of artificial selection and to date, there are hundreds of breeds that differ in their physical and behavioral features. In addition, dogs possess important skills to communicate with humans. Previous evidence indicates that those abilities are related to the domestication process and are modulated by instrumental learning processes. Very few studies, however, have evaluated breed differences in the use and learning of interspecific communicative responses. In Study 1 Retrievers, German Shepherds and Poodles were compared in the acquisition and extinction of their gaze toward the human face, in a conflict situation involving food within sight but out of reach. The groups did not differ in the acquisition of the response, but throughout the extinction phase Retrievers gazed to the human significantly more than the other groups. In Study 2, similar results were obtained in a test without any previous explicit training. These results suggest that these three major popular breeds differ in gazing to humans in a communicative situation. [Copyright &y& Elsevier]

The performance of middle-aged (14-month old) and young (3-month old) rats was assessed in the consummatory successive negative contrast (cSNC) situation. Rats received 10 daily preshift trials of access to a 32% sucrose solution followed by 5 postshift trials of access to 4% sucrose solution. Unshifted controls had access to the 4% solution in every trial. The retention interval between the last preshift trial and the first postshift trial was either 1 day or 5 days in different groups. cSNC was generally similar in middle-age and young rats in the 1-day retention interval condition. However, middle-age rats recovered faster than young rats from cSNC when a 5-day retention interval was used. This finding is discussed in relation to age-related changes in memory and emotion. [ABSTRACT FROM AUTHOR]

Rats exhibit a sensitive period from the time of birth until postnatal day 10 during which they develop preferences for odors even if those odors are paired with a moderately aversive stimulus. It is still unknown whether pre-exposure to an odor produces alterations on intake responses of basic tastants, and on other patterns that indicate a change in the hedonic value of reward, such as nipple grasping behavior. The current study assessed the effect of pre-exposure to an odor immediately after birth on intake responses of appetitive and aversive tastants. The objectives were to assess if 3-hour-old rats adjust their behaviors to obtain different values of appetitive and aversive rewards in the presence of a familiar odor. Specifically we wanted to determine whether the intake of saccharin or quinine, administered through the artificial nipple, increases in the presence of the familiar odor. Results showed that 3-hour-old rats differentially respond to two different concentrations of saccharin and two concentrations of quinine. In the presence of the pre-exposed odor newborn rats increased intake and grasp responses to the artificial nipple containing quinine. This effect disappeared with a higher concentration of quinine. These results suggest that the pre-exposed odor generated a change in the hedonic value of the aversive reward. [ABSTRACT FROM AUTHOR]

Abstract: Previous research showed that the effects of incentive downshift in male rats are attenuated by a pretrial opportunity to ejaculate. Because ejaculation raises testosterone (T) levels and has anxiolytic-like effects in male rats, the present experiments were designed to assess the role of T and gonadectomy (GDX) on two situations involving incentive downshift. In consummatory successive negative contrast, a downshift from 32% to 4% sucrose leads to consummatory suppression. T alleviates such suppression (Experiment 1), but GDX does not affect it (Experiment 3). In consummatory extinction, animals are downshifted from 32% sucrose to an empty sipper tube. T enhances consummatory extinction (Experiment 2), but GDX does not affect it (Experiment 4). In agreement with published results, T increases (Experiment 2) and GDX reduces (Experiment 4) activity in the central area of an open field, thus behaviorally validating these manipulations. The results are discussed in terms of the anxiolytic-like properties of androgen hormones. [Copyright &y& Elsevier]

Dogs (Canisfamiliaris) trained to receive a preferred food (dry beef liver) from an experimenter learned to maintain a longer gaze on the experimenter than dogs receiving a less preferred food (dog pellets). Dogs downshifted from dry liver to pellets rejected food more frequently than nonshifted controls. Gaze duration also decreased in downshifted dogs below the level of a group always reinforced with pellets. In addition, downshifted dogs tended to move away from the experimenter, adopting a lying down posture. This phenomenon, called successive negative contrast, has been described in analogous experiments with a variety of mammalian species, but has failed to occur in similar experiments with nonmammalian vertebrates. Unlike similar previous observations, the present data were obtained in an environment involving interspecific communication. [ABSTRACT FROM AUTHOR]

Posttraining administration of cholinergic drugs modulates the consolidation of memory processes in several learning tasks. We studied the effect of the administration of atropine (cholinergic antagonist. Experiment 1) and physostigmine (acetylcholinesterase inhibitor. Experiment 2) immediately after the First session of reward downshift, and immediately after the last preshift session (Experiment 3) on a consummatory successive negative contrast procedure. Animals were given access to a high-value reward (32% sucrose solution), and surprisingly shifted to a low-value reward (4% sucrose solution) in a second phase. The results indicate that atropine and physostigmine have no effects on contrast. The role of cholinergic neurotransmission in the memory of surprising reward changes is discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Consummatory suppression due to reward devaluation is a vastly studied phenomenon. [•] This phenomenon might be a byproduct of the increase in alternative competing behaviors. [•] Restraint prevents the occurrence of most alternative competing behaviors. [•] We showed that consummatory suppression occurs in restrained rats. [ABSTRACT FROM AUTHOR]

The objective of the present study was to evaluate the relationships between attachment styles, personality traits, and their effects on frustration intolerance (FI) in a sample of 300 adults. The Argentine Attachment Styles Scale, the Eysenck Revised Personality Questionnaire (EPQ-RA), and the Frustration Intolerance Scale (EIF) was used. In the two Full Latent Variable Models developed, it was determined that neuroticism and avoidant attachment had the greatest mediating effects on FI. Avoidant attachment stood out for its mediating effect on anxious attachment. These two factors were found to explain a considerable percentage of neuroticism and, as a consequence, the four dimensions of FI. It is concluded that it is necessary to reinterpret certain concepts of neuroticism and study them from a perspective that starts from attachment theory.

During extinction a previously learned behavior stops being reinforced. In addition to the decrease in the rate of the instrumental response, it produces an aversive emotional state known as frustration. This state can be assimilated with the fear reactions that occur after aversive stimuli are introduced at both the physiological and behavioral levels. This study evaluated frustration reactions of domestic dogs (Canis familiaris) during a communicative situation involving interactions with a human. The task included the reinforcement and extinction of the gaze response toward the experimenter's face when the dogs tried to obtain inaccessible food. The dog's frustration reactions during extinction involved an increase in withdrawal and side orientation to the location of the human as well as lying down, ambulation, sniffing, and vocalizations compared with the last acquisition trial. These results are especially relevant for domestic dog training situations in which the extinction technique is commonly used to discourage undesirable behaviors.