A reappraisal of successive negative contrast in two populations of domestic dogs

When an anticipated food reward is unexpectedly reduced in quality or quantity, many mammals show a successive negative contrast (SNC) effect, i.e. a reduction in instrumental or consummatory responses below the level shown by control animals that have only ever received the lower-value reward. SNC effects are believed to reflect an aversive emotional state, caused by the discrepancy between the expected and the actual reward. Furthermore, how animals respond to such discrepancy has been suggested to be a sign of animals’ background mood state. However, the occurrence and interpretation of SNC effects are not unequivocal, and there is a relative lack of studies conducted outside of laboratory conditions. Here, we tested two populations of domestic dogs (24 owned pet dogs and 21 dogs from rescue kennels) in a SNC paradigm following the methodology by Bentosela et al. (J Comp Psychol 123:125–130, 2009), using a design that allowed a within-, as well as a between-, subjects analysis. We found no evidence of a SNC effect in either population using a within- or between-subjects design. Indeed, the within-subjects analysis revealed a reverse SNC effect, with subjects in the shifted condition showing a significantly higher level of response, even after they received an unexpected reduction in reward quality. Using a within-, rather than a between-, subjects design may be beneficial in studies of SNC due to higher sensitivity and statistical power; however, order effects on subject performance need to be considered. These results suggest that this particular SNC paradigm may not be sufficiently robust to replicate easily in a range of environmental contexts and populations.     

The sunk cost effect across species: A review of persistence in a course of action due to prior investment

The sunk cost effect is the bias or tendency to persist in a course of action due to prior investments of effort, money or time. At the time of the only review on the sunk cost effect across species (Arkes & Ayton, 1999), research with nonhuman animals had been ecological in its nature, and the findings about the effect of past investments on current choice were inconclusive. However, in the last decade a new line of experimental laboratory‐based research has emerged with the promise of revolutionizing the way we approach the study of the sunk cost effect in nonhumans. In the present review we challenge Arkes and Ayton's conclusion that the sunk cost effect is exclusive to humans, and describe evidence for the sunk cost effect in nonhuman animals. By doing so, we also challenge the current explanations for the sunk cost effect in humans, as they are not applicable to nonhumans. We argue that a unified theory is called for, because different independent variables, in particular, investment amount, have the same influence on the sunk cost effect across species. Finally, we suggest possible psychological mechanisms shared across different species, contrast and depreciation, that could explain the sunk cost effect.     

The Experience of Deployment for Partners of Military Personnel: A Qualitative Meta-Synthesis

It is well acknowledged that deployment can have a significant impact on military personnel; however, the effect on their partners who remain on the homefront is less researched. This meta-synthesis aimed to explore the experience of deployment for partners of military personnel to provide a greater understanding of the challenges and responses involved for them. Noblit and Hare's (1988) meta-ethnographic approach was adopted to synthesize 11 qualitative studies that met the inclusion and exclusion criteria. The five core concepts to emerge from the meta-synthesis were the multitude of emotions; methods of coping; communication with their partner; relentless responsibilities; and positive outcomes. These findings provide a developed understanding of how challenges of deployment are managed, including negative outcomes and protective psychological responses and behaviors. The limitations of these findings are discussed, as are clinical implications and recommendations for future research.     

Event-related potentials reveal the relations between feature representations at different levels of abstraction

In this paper, we use behavioural methods and event-related potentials (ERPs) to explore the relations between informational and instantiated features, as well as the relation between feature abstraction and rule type. Participants are trained to categorize two species of fictitious animals and then identify perceptually novel exemplars. Critically, two groups are given a perfectly predictive counting rule that, according to Hannah and Brooks (2009. Featuring familiarity: How a familiar feature instantiation influences categorization. Canadian Journal of Experimental Psychology/Revue Canadienne de Psychologie Expérimentale, 63, 263–275. Retrieved from http://doi.org/10.1037/a0017919), should orient them to using abstract informational features when categorizing the novel transfer items. A third group is taught a feature list rule, which should orient them to using detailed instantiated features. One counting-rule group were taught their rule before any exposure to the actual stimuli, and the other immediately after training, having learned the instantiations first. The feature-list group were also taught their rule after training. The ERP results suggest that at test, the two counting-rule groups processed items differently, despite their identical rule. This not only supports the distinction that informational and instantiated features are qualitatively different feature representations, but also implies that rules can readily operate over concrete inputs, in contradiction to traditional approaches that assume that rules necessarily act on abstract inputs.     

Midlife Transitions in Women: Cultural and Individual Factors

Traditional views of women at midlife are often inaccurate and may be deleterious to the emotional and physical well‐being of women. The author reviews quantitative and qualitative research that may help guide counselors in their work with midlife women.