Shock avoidance by discrimination learning in the shore crab (Carcinus maenas) is consistent with a key criterion for pain

Nociception allows for immediate reflex withdrawal whereas pain allows for longer-term protection via rapid learning. We examine here whether shore crabs placed within a brightly lit chamber learn to avoid one of two dark shelters when that shelter consistently results in shock. Crabs were randomly selected to receive shock or not prior to making their first choice and were tested again over 10 trials. Those that received shock in trial 2, irrespective of shock in trial 1, were more likely to switch shelter choice in the next trial and thus showed rapid discrimination. During trial 1, many crabs emerged from the shock shelter and an increasing proportion emerged in later trials, thus avoiding shock by entering a normally avoided light area. In a final test we switched distinctive visual stimuli positioned above each shelter and/or changed the orientation of the crab when placed in the chamber for the test. The visual stimuli had no effect on choice, but crabs with altered orientation now selected the shock shelter, indicating that they had discriminated between the two shelters on the basis of movement direction. These data, and those of other recent experiments, are consistent with key criteria for pain experience and are broadly similar to those from vertebrate studies. © 2013. Published by The Company of Biologists Ltd.

Chiral thiouronium salts: synthesis, characterisation and application in NMR enantio-discrimination of chiral oxoanions

Chiral thioureas and functionalised chiral thiouronium salts were synthesised starting from the relatively cheap and easily available chiral amines: (S)-methylbenzylamine and rosin-derived (+)-dehydroabietylamine. The introduction of a delocalised positive charge to the thiourea functionality, by an alkylation reaction at the sulfur atom, enables dynamic rotameric processes: hindered rotations about the delocalised CN and CS bonds. Hence, four different rotamers/isomers may be recognised: syn-syn, syn-anti, anti-syn and anti-anti. Extensive H-1 and C-13 NMR studies have shown that in hydrogen-bond acceptor solvents, such as perdeuteriated dimethyl sulfoxide, the syn-syn conformation is preferable. On the other hand, when using non-polar solvents, such as CDCl3, the mixture of syn-syn and syn-anti isomers is detectable, with an excess of the latter. Apart from this, in the case of S-butyl-N,N'-bis(dehydroabietyl)thiouronium ethanoate in CDCl3, the H-1 NMR spectrum revealed that strong bifurcated hydrogen bonding between the anion and the cation causes global rigidity without signs of hindered rotamerism observable on the NMR time scale. This suggested that these new salts might be used as NMR discriminating agents for chiral oxoanions, and are indeed more effective than their archetypal guanidinium analogues or the neutral thioureas. The best results in recognition of a model substrate, mandelate, were obtained with S-butyl-N,N'-bis(dehydroabietyl) thiouronium bistriflamide. It was confirmed that the chiral recognition occurred not only for carboxylates but also for sulfonates and phosphonates. Further H-1 NMR studies confirmed a 1 : 1 recognition mode between the chiral agent (host) and the substrate (guest); binding constants were determined by H-1 NMR titrations in solutions of DMSO-d(6) in CDCl3. It was also found that the anion of the thiouronium salt had a significant influence on the recognition process: anions with poor hydrogen-bond acceptor abilities led to the best discrimination. The presence of host-guest hydrogen bonding was confirmed in the X-ray crystal structure of S-butyl-N,N'-bis(dehydroabietyl)thiouronium bromide and by computational studies (density functional theory).

Interventions to reduce prejudice and enhance inclusion and respect for ethnic differences in early childhood: A systematic review

A systematic review was conducted of studies evaluating the effects of interventions aimed at reducing ethnic prejudice and discrimination in young children. Articles published between 1980 and 2010 and including children of 8 years and under were identified, harvested, and assessed for quality, both for the exposure/program as well as for the evaluation. In total, 32 studies (14 contact and 18 media or instruction) yielded 62 effects on attitudes and 59 effects on peer relations. An overall count of the positive (40%), non-significant (50%), and negative effects (10%) indicate a mixed picture. Overall, more attitude effects (55%) than peer relations effects (25%) were positive, and media/instruction (47%) was more successful than contact (36%). Most of the effects were observed with children from a majority ethnicity: 67% of the attitude effects were positive, and media/instruction and contact were equally effective at delivering these. Few differences were found as a function of the quality of the exposure and evaluation, but differences were found depending on the context of exposure (naturally occurring or experimental manipulation) and research design (random assignment or self-selection). In conclusion, the findings were more mixed than expected, though sufficiently strong studies exist to provide lessons for future research.


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The Role of Personality Factors in the Reduction of Intergroup Anxiety and Amelioration of Outgroup Attitudes via Intergroup Contact

Two studies investigated the role of personality factors in the amelioration of outgroup attitudes via intergroup contact. In study 1, the effect of extraversion on outgroup attitude operated via an increase in cross-group friendship, whereas openness to experience and agreeableness had a direct effect on outgroup attitude. In study 2, we included intergroup anxiety as a mediator explaining these relationships, and we ruled out ingroup friendship as a potential confound. We found that the relationships between openness to experience and agreeableness on the one hand and outgroup attitude on the other were mediated by reduced intergroup anxiety. In addition, the effect of extraversion on outgroup attitude operated via an increase in cross-group friendship that was in turn associated with lower levels of intergroup anxiety. Across both studies, the friendship–attitude relationship was stronger among those low in agreeableness and extraversion. We discuss the importance of integrating personality and situational approaches to prejudice reduction in optimizing the impact of contact-based interventions. Copyright © 2013 John Wiley & Sons, Ltd.

Out-group trust, intergroup anxiety, and out-group attitude as mediators of the effect of imagined intergroup contact on intergroup behavioural tendencies.

We investigated whether imagining contact with an out-group member would change behavioral tendencies toward the out-group. In Experiment 1, British high school students who imagined talking to an asylum seeker reported a stronger tendency to approach asylum seekers than did participants in a control condition. Path analysis revealed this relationship was mediated by out-group trust and, marginally, by out-group attitude. In Experiment 2, straight undergraduates who imagined an interaction with a gay individual reported a stronger tendency to approach, and a weaker tendency to avoid, gay people. Path analyses showed that these relationships were mediated by out-group trust, out-group attitude, and less intergroup anxiety. These findings highlight the potential practical importance of imagined contact and important mediators of its effects.

'Changing attitudes with a little imagination': Imagined contact effects on young children's intergroup bias

The current research tested a recent development in social psychology, namely 'imagined contact', among young children (n = 123, 5 to 10 years). Children imagined interacting with a physically disabled child, or did not take part in this activity (the control group). Compared with the control group, children who engaged in 'imagined contact' subsequently showed reduced intergroup bias in their general attitude and ratings of warmth and competence. Imagined contact also led to more positive intended friendship behavior towards the disabled, but only among 5 – 6 year olds. This provides partial support for our hypothesis that younger children, perhaps as a result of their lack of outgroup experience, are more likely to benefit from imagined contact. Implications for the development of attitudes towards the disabled, imagined contact theory and the development of classroom-based prejudice-reduction techniques based on imagined contact are discussed.