Friend versus foe: Neural correlates of prosocial decisions for liked and disliked peers

Although the majority of our social interactions are with people we know, few studies have investigated the neural correlates of sharing valuable resources with familiar others. Using an ecologically valid research paradigm, this functional magnetic resonance imaging study examined the neural correlates of prosocial and selfish behavior in interactions with real-life friends and disliked peers in young adults. Participants (N = 27) distributed coins between themselves and another person, where they could make selfish choices that maximized their own gains or prosocial choices that maximized outcomes of the other. Participants were more prosocial toward friends and more selfish toward disliked peers. Individual prosociality levels toward friends were associated negatively with supplementary motor area and anterior insula activity. Further preliminary analyses showed that prosocial decisions involving friends were associated with heightened activity in the bilateral posterior temporoparietal junction, and selfish decisions involving disliked peers were associated with heightened superior temporal sulcus activity, which are brain regions consistently shown to be involved in mentalizing and perspective taking in prior studies. Further, activation of the putamen was observed during prosocial choices involving friends and selfish choices involving disliked peers. These findings provide insights into the modulation of neural processes that underlie prosocial behavior as a function of a positive or negative relationship with the interaction partner.     

Impact of spatial grouping on mean size estimation

People represent summary statistics of visual scenes, but it is not fully clear whether such summary statistics are extracted automatically. To determine whether different levels of summary representation (i.e., at the perceptual-group or the entire-display level) may be formed differently, in two experiments we investigated how people extracted summary statistics for displays consisting of spatially segregated groups. Participants were asked to report the mean sizes of either entire sets or perceptual groups in precue and postcue conditions. There was no precueing advantage in the mean size estimations of entire sets. However, when these precues identified target perceptual groups, participants reported the perceptual-group means more accurately than when postcues were used. In the postcue condition, participants were biased toward the entire-set mean even when they were probed to report the perceptual-group mean. There was also greater bias toward the entire-set mean for more erroneous perceptual-group summaries. These findings suggest that ensemble representations are extracted more efficiently for the whole than for the perceptual parts and that ensemble perception is not a uniform process across perceptual groups and entire sets.     

Do Women Really Kill for Honor? Conceptualizing Women’s Involvement in Honor Killings

So far, women’s involvement in honor killings has been attempted to explain with the emphasis on either patriarchy or the concept of hegemonic masculinity. However, the current conceptualization of women involved in honor killings is not completely representative of all of the cases. The accurate portrayal of women’s involvement in such killings requires a broader understanding of particular circumstances of the female perpetrators, the whole dynamic behind honor killings, and of the particular relationship between victim and the perpetrator. Through reflecting on the narratives of five female perpetrators, this article aims to provide this missing focus.     

Is retrieval the key? Metamemory judgment and testing as learning strategies

Re-reading is the most common learning strategy, albeit not a very efficient one. Testing is highly efficient, but not perceived by students as a learning strategy. Prospective judgment-of-learning (JOL) reflect the learner's impression of subsequently being able to retrieve the ongoing learning in a cued-recall task. Estimating JOL involves attempting to retrieve the information, as in testing. The few studies that have explored the potential mnemonic benefit of JOL have yielded contradictory results. Our aim was to compare JOL and testing with re-study and to examine the impact of these strategies according to the relative difficulty of the material (cue-target association strength) in two experiments. After a first encoding phase, participants re-studied, provided JOL, or took a test. Forty-eight hours later, they participated in a final cued-recall test, during which their confidence level judgments were collected. The main result was that delayed JOL behaved in the same way as testing, and both yielded better performances than re-study when material was of moderate difficulty. The easy or very difficult material revealed no differences between these strategies. JOL is proposed as an alternative to testing when faced with difficult material.     

Is Event-Based Prospective Memory Resistant to Proactive Interference?

Proactive interference builds up rapidly in recall with the presentation of successive lists comprising items from a single category (e.g., animals). In two experiments, we used a similar build-up paradigm in prospective memory. Interestingly, in Experiment 1, there was no evidence of proactive interference in prospective memory, although build-up emerged in a similar recall task. In Experiment 2, by also showing proactive interference build-up in a recognition task analogous to our prospective memory task, we ruled out the possibility that it was the recognition processes inherent in the prospective memory task that might make the task easier and prevent proactive interference. We suggest that, under normal conditions, prospective memory is resistant to build-up of proactive interference and propose that this resistance is a function of the strengthening afforded by a cue-to-intention association that is a part of prospective memory tasks. We discuss the finding using the classical paired-associate learning framework.     

Age-based discrimination of rival males in western bluebirds

Adaptive social behavior frequently involves discriminating between classes of individuals such as relatives versus non-relatives, older versus younger individuals, or individuals of different status. In the absence of spatial cues, this discrimination may be based on signals that correlate with fitness-related traits (e.g., older or high-status males may sing higher performance songs) or with identity, for example, when receivers distinguish and classify signalers based on their unique signal structure. Here, we examine vocal age-based discrimination in western bluebirds (Sialia mexicana), a North American songbird in which older males have a significant advantage in obtaining extra-pair fertilizations, and therefore pose a significantly higher threat to paternity than younger males. We asked whether western bluebird males showed a higher response to playback of songs of older males compared to younger males relative to their own age. We prepared song stimuli by removing three potential signals of age that have been identified as important in other species: (1) note consistency (which was achieved by playing a single instance of each note repeatedly), (2) note repertoire size, and (3) singing rate (the latter two were equalized across conditions). Even in the absence of these potential signals of age, young males responded more strongly to playback of older males’ songs than to young males’ songs, suggesting that they are able to discriminate between age classes relative to the threat they pose. Further research is required to determine whether this discrimination is based on individual recognition or signal features that are correlated with age.     

Familiarity,relative distinctiveness,and the generation effect

In Experiment 1, psychology experts and novices showed generation effects with both psychology related and other words. In Experiment 2, music experts who were sports novices and sports experts who were music novices showed a generation effect in a recognition test for all words regardless of domain (music or sports). Moreover, the effect was greater for words from the subjects’ “nonexpertise” area. In Experiments 3A and 3B, music experts showed a greater generation effect for sports words than for music words in a free recall test but only when the sports and music words were studied together. These results are inconsistent with the semantic elaboration -requirement for the generation effect that predicts less of an effect, if any, with less familiar materials. Rather, they provide evidence for the idea that the generation effect is influenced by relative distinctiveness of the to-be-remembered items.