Acquired equivalence of cues by presentation in a common context in rats

It is well established that humans and other animals may treat two perceptually different cues alike, if the cues have been individually paired with a common antecedent or a common consequence. Recently, Molet et al. (Psychon Bull Rev 18:618–623, 2011) reported evidence for a new form of acquired equivalence in human conditional discrimination, namely context-mediated equivalence. In the present research, using a flavor conditioning procedure, we asked whether rats would show similar context-mediated equivalence to demonstrate that this new form of acquired equivalence is a general phenomenon. Rats experienced two flavor cues A and B each presented either in the same context, X, or each in its own distinctive context, X or Y. Subsequently, the rats experienced B with sucrose in a third context, Z, and then the generalization of conditioning to A was assessed. When tested in Context Z, consumption of A was more marked when A and B had both been presented in the same context than when they had been presented in two different contexts. Thus, importantly, in the absence of the training context, cues that shared a common context at different times came to be treated as equivalent. This represents the first evidence of context-mediated equivalence in a nonhuman species.     

Does the A-not-B error in adult pet dogs indicate sensitivity to human communication?

Recent dog-infant comparisons have indicated that the experimenter's communicative signals in object hide-and-search tasks increase the probability of perseverative (A-not-B) errors in both species (Topál et al. 2009). These behaviourally similar results, however, might reflect different mechanisms in dogs and in children. Similar errors may occur if the motor response of retrieving the object during the A trials cannot be inhibited in the B trials or if the experimenter's movements and signals toward the A hiding place in the B trials ('sham-baiting') distract the dogs' attention. In order to test these hypotheses, we tested dogs similarly to Topál et al. (2009) but eliminated the motor search in the A trials and 'sham-baiting' in the B trials. We found that neither an inability to inhibit previously rewarded motor response nor insufficiencies in their working memory and/or attention skills can explain dogs' erroneous choices. Further, we replicated the finding that dogs have a strong tendency to commit the A-not-B error after ostensive-communicative hiding and demonstrated the crucial effect of socio-communicative cues as the A-not-B error diminishes when location B is ostensively enhanced. These findings further support the hypothesis that the dogs' A-not-B error may reflect a special sensitivity to human communicative cues. Such object-hiding and search tasks provide a typical case for how susceptibility to human social signals could (mis)lead domestic dogs.     

The bank of standardized stimuli (BOSS): comparison between French and English norms

Throughout the last decades, numerous picture data sets have been developed, such as the Snodgrass and Vanderwart (1980) set, and have been normalized for variables such as name and familiarity; however, due to cultural and linguistic differences, norms can vary from one country to another. The effect due specifically to culture has already been demonstrated by comparing samples from different countries where the same language is spoken. On the other hand, it is still not clear how differences between languages may affect norms. The present study explores this issue by collecting and comparing norms on names and many other features from French Canadian speakers and English Canadian speakers living in Montreal, who thus live in similar cultural environments. Norms were collected for the photos of objects from the Bank of Standardized Stimuli (BOSS) by asking participants to name the objects, to categorize them, and to rate their familiarity, visual complexity, object agreement, viewpoint agreement, and manipulability. Names and ratings from the French speakers are available in Appendix A, available in the supplemental materials. The results show that most of the norms are comparable across linguistic groups and also that the ratings given are correlated across linguistic groups. The only significant group differences were found in viewpoint agreement and visual complexity. Overall, there was good concordance between the norms collected from French and English native speakers living in the same cultural setting.     

Paw preference is not affected by postural demand in a nonprimate mammal (Felis silvestris catus)

Previously, it has been thought that handedness is unique to humans. Recently, it has been found that hand or paw preferences are common among a variety of vertebrate species. Different models have been put forth to describe the evolution of primate handedness. In this study we aimed to explore whether these models can also be used to predict manual laterality in nonprimate mammalian groups. The cat (Felis silvestris catus) is a good nonprimate model for manual laterality, as cats frequently use paws to catch and hold prey. Cats were exposed to two standardized manual laterality tasks, differing in postural demand. Subjects (N = 28) were forced to use either a stable or unstable body posture (i.e., sitting or standing vs. vertical clinging) to extract food items from a plastic box attached at two different heights. We revealed that cats exhibited paw preferences at an individual level with about 40% left, 30% right, 30% nonlateralized subjects. Postural demand was linked to task difficulty: the unstable body posture was found to be significantly more difficult than the stable body posture. However, these differences in postural demand and task difficulty did not lead to differences in direction or strength of paw preference. Findings suggested that nonprimate mammals differ from primates in their sensitivity to task related factors, such as postural demand. Results coincide with those of some prosimians, providing support for the hypothesis that postural demand and the associated task complexity became influencing factors on manual laterality in the course of primate evolution.     

Reciprocal relations between recovery and work engagement: the moderating role of job stressors

In this paper, we examined the within-person relations between morning recovery level (i.e., feeling refreshed and replenished) and work engagement throughout the day, and between work engagement throughout the day and the subsequent recovery level at the end of the workday. We hypothesized that job stressors (situational constraints, job demands) moderate these relations. A diary study over 1 workweek with 2 measurement occasions per day (N = 111 persons) provided support for most of the hypotheses: Morning recovery level predicted work engagement, and work engagement predicted subsequent recovery level at the end of the workday after controlling for morning recovery level. As predicted, situational constraints attenuated these relations, but job demands did not. The results suggest that recovery translates into employee work engagement, and work engagement, in turn, prevents a loss in recovery level throughout the day, particularly when situational constraints are low. Situational constraints seem to interrupt the reciprocal processes between recovery level and work engagement.     

I like you but I don't know why: Objective facial resemblance to significant others influences snap judgments

Does a new person's objective facial resemblance to a significant other influence snap judgments of liking, and if so, does this effect occur even when individuals are not consciously aware of the resemblance? Participants (romantic couples) made trait judgments about 24 novel faces, each shown for 500 ms. Objective facial resemblance was manipulated using morphing techniques such that half of the novel faces resembled participants' partner and half did not. We found that women's evaluations of novel men who resembled their partner (vs. those who did not) were more positive, but men's evaluations of novel women were not appreciably affected by facial resemblance. These results held even when individuals were not consciously aware of the resemblance. Moreover, the effect of facial resemblance on judgments of liking was more pronounced for individuals who were more satisfied in their relationship, suggesting that these results were due to activating the specific partner representation (rather than familiarity). This research shows that objective facial resemblance to a significant other influences snap judgments of liking automatically, effortlessly, and without conscious awareness.     

One first? Acquisition of the cardinal and ordinal uses of numbers in preschoolers

We studied the acquisition of the ordinal meaning of number words and examined its development relative to the acquisition of the cardinal meaning. Three groups of 3-, 4-, and 5-year-old children were tested in two tasks requiring the use of number words in both cardinal and ordinal contexts. Understanding of the counting principles was also measured by asking the children to assess the correctness of a cartoon character's counting in both contexts. In general, the children performed cardinal tasks significantly better than ordinal ones. Tasks requiring the production of the number for a given quantity or position were solved more accurately than those testing the ability to select a set of n objects or the object in the nth position. Different profiles were obtained for the principles; those principles shared by the two contexts were mastered earlier in the cardinal context. Regarding order (ir)relevance, older children adhered to rigid ways of counting, producing better results in the ordinal context and incorrect rejections in the cardinal trials. Altogether, our data indicate that the acquisitions of cardinal and ordinal meanings of numbers are related, and cardinality precedes the development of ordinality.     

Goal relevance moderates evaluative conditioning effects

An important process by which preferences emerge is evaluative conditioning, defined as a change in the evaluation of a stimulus by pairing it repeatedly and consistently with an affective stimulus. The current research focuses on the role of motivation in this learning process. Specifically, it was investigated whether a conditioning procedure that is relevant to an individual's current goals is more effective than an irrelevant procedure. To this end, beverages were conditioned with either disgusted faces (relevant) or fearful faces (irrelevant). The results showed that thirsty(rather than non-thirsty) participants’ choice and evaluation of beverages were influenced by pairing beverages with disgust but not with fear. As similar results were obtained under optimal and suboptimal presentation of the conditioned stimuli, it is suggested that goals can affect automatic, associative learning, adding to the emerging body of research demonstrating that goals unconsciously affect evaluative processes.     

Development of a Facebook Addiction Scale

The Bergen Facebook Addiction Scale (BFAS), initially a pool of 18 items, three reflecting each of the six core elements of addiction (salience, mood modification, tolerance, withdrawal, conflict, and relapse), was constructed and administered to 423 students together with several other standardized self-report scales (Addictive Tendencies Scale, Online Sociability Scale, Facebook Attitude Scale, NEO-FFI, BIS/BAS scales, and Sleep questions). That item within each of the six addiction elements with the highest corrected item-total correlation was retained in the final scale. The factor structure of the scale was good (RMSEA = .046, CFI = .99) and coefficient alpha was .83. The 3-week test-retest reliability coefficient was .82. The scores converged with scores for other scales of Facebook activity. Also, they were positively related to Neuroticism and Extraversion, and negatively related to Conscientiousness. High scores on the new scale were associated with delayed bedtimes and rising times.