Wednesday, October 24, 2018

Despite their limited optical resolution, Drosophila melanogaster’s neuronal architecture has the capability to extract & encode a rich feature set that allows flies to re-identify individual conspecifics with surprising accuracy

Schneider J, Murali N, Taylor GW, Levine JD (2018) Can Drosophila melanogaster tell who’s who? PLoS ONE 13(10): e0205043. https://doi.org/10.1371/journal.pone.0205043

Abstract: Drosophila melanogaster are known to live in a social but cryptic world of touch and odours, but the extent to which they can perceive and integrate static visual information is a hotly debated topic. Some researchers fixate on the limited resolution of D. melanogaster’s optics, others on their seemingly identical appearance; yet there is evidence of individual recognition and surprising visual learning in flies. Here, we apply machine learning and show that individual D. melanogaster are visually distinct. We also use the striking similarity of Drosophila’s visual system to current convolutional neural networks to theoretically investigate D. melanogaster’s capacity for visual understanding. We find that, despite their limited optical resolution, D. melanogaster’s neuronal architecture has the capability to extract and encode a rich feature set that allows flies to re-identify individual conspecifics with surprising accuracy. These experiments provide a proof of principle that Drosophila inhabit a much more complex visual world than previously appreciated.

Voters appear to be sorting on non-political neighborhood attributes that covary with partisan preferences rather than explicitly seeking politically congruent neighbors; location must have some influence on political preference, rather than the other way around

Does residential sorting explain geographic polarization? Gregory J. Martin & Steven W. Webster. Political Science Research and Methods, https://doi.org/10.1017/psrm.2018.44

Abstract: Political preferences in the United States are highly correlated with population density, at national, state, and metropolitan-area scales. Using new data from voter registration records, we assess the extent to which this pattern can be explained by geographic mobility. We find that the revealed preferences of voters who move from one residence to another correlate with partisan affiliation, though voters appear to be sorting on non-political neighborhood attributes that covary with partisan preferences rather than explicitly seeking politically congruent neighbors. But, critically, we demonstrate through a simulation study that the estimated partisan bias in moving choices is on the order of five times too small to sustain the current geographic polarization of preferences. We conclude that location must have some influence on political preference, rather than the other way around, and provide evidence in support of this theory.













Jackdaws delayed longest in entering their nest-box after encountering a stimulus that should not move independently, suggesting they recognized the movement as unexpected

Wild jackdaws are wary of objects that violate expectations of animacy. Alison L. Greggor, Guillam E. McIvor, Nicola S. Clayton, Alex Thornton. Royal Society Open Science, DOI: 10.1098/rsos.181070

Abstract: Nature is composed of self-propelled, animate agents and inanimate objects. Laboratory studies have shown that human infants and a few species discriminate between animate and inanimate objects. This ability is assumed to have evolved to support social cognition and filial imprinting, but its ecological role for wild animals has never been examined. An alternative, functional explanation is that discriminating stimuli based on their potential for animacy helps animals distinguish between harmless and threatening stimuli. Using remote-controlled experimental stimulus presentations, we tested if wild jackdaws (Corvus monedula) respond fearfully to stimuli that violate expectations for movement. Breeding pairs (N = 27) were presented at their nests with moving and non-moving models of ecologically relevant stimuli (birds, snakes and sticks) that differed in threat level and propensity for independent motion. Jackdaws were startled by movement regardless of stimulus type and produced more alarm calls when faced with animate objects. However, they delayed longest in entering their nest-box after encountering a stimulus that should not move independently, suggesting they recognized the movement as unexpected. How jackdaws develop expectations about object movement is not clear, but our results suggest that discriminating between animate and inanimate stimuli may trigger information gathering about potential threats.

Canada: Secularized women are found to have lower fertility rates compared with the actively religious; the strictly seculars, a proxy identifier for the atheists, have the lowest fertility & the highest likelihood of remaining childless

Religiosity, Secularity and Fertility in Canada. Maryam Dilmaghani. European Journal of Population, https://link.springer.com/article/10.1007/s10680-018-9487-z

Abstract: Using several cycles of the Canadian General Social Survey covering cohorts born from the early 1900s onwards, this paper examines how religiosity and secularity associate with fertility in Canada. The analysis shows that among multiple dimensions of religiosity, religious attendance is the strongest predictor of higher fertility in the country. For the latest cycle conducted in 2011, three mutually exclusive groups of secularized women are compared with the actively religious in their fertility behaviour and intentions. All these secularized women are found to have lower fertility rates compared with the actively religious. Among them, the strictly seculars, a proxy identifier for the atheists, have the lowest fertility and the highest likelihood of remaining childless. Various implications are discussed.

Keywords: Fertility, Religiosity, Secularity, Canada

The experience of a childhood trauma increases a person’s ability to take the perspective of another and to understand their mental and emotional states, & this impact is long-standing

Elevated empathy in adults following childhood trauma. David M. Greenberg et al. PLOS One, https://doi.org/10.1371/journal.pone.0203886

Abstract: Traumatic events increase the risk of depression, but there is also evidence that adversity can lead to posttraumatic growth, including increased compassion and prosocial behavior. To date there is no empirical research pinpointing childhood trauma to an increase in trait empathy in adulthood. Although somewhat counter-intuitive, this might be predicted if trauma not only increases fear of future threat but also renders the individual more sensitive to suffering in others. We explored this possible link using multiple studies, self-report measures, and non-clinical samples. Results across samples and measures showed that, on average, adults who reported experiencing a traumatic event in childhood had elevated empathy levels compared to adults who did not experience a traumatic event. Further, the severity of the trauma correlated positively with various components of empathy. These findings suggest that the experience of a childhood trauma increases a person’s ability to take the perspective of another and to understand their mental and emotional states, and that this impact is long-standing. Future research needs to test if this is seen on performance measures, and how these findings extend to clinical populations.


Abstinence from social media increased time spent engaged in browsing the Internet, working, childcare, and cooking/cleaning; time in social media was negatively associated with quality of day

Where does the time go? An experimental test of what social media displaces and displaced activities’ associations with affective well-being and quality of day. Jeffrey A Hall, Rebecca M Johnson, Elaina M Ross .New Media & Society, https://doi.org/10.1177/1461444818804775

Abstract: Drawing from media displacement theory, this article explores which activities are displaced when individuals spend time on social media. Community and undergraduate participants (N = 135) were randomly assigned to five conditions: no change in social media use, or abstinence from social media for 1 week, 2 weeks, 3 weeks, or 4 weeks. Participants completed a daily diary measuring how they spent time each day, affective well-being, and quality of day for 28 days. The results indicate that abstinence from social media increased time spent engaged in seven activities, primarily browsing the Internet, working, childcare, and cooking/cleaning. In addition, associations among psychosocial outcomes and the displaced activities were examined. Time spent working, sleeping, and cooking/cleaning were negatively associated with affective well-being and quality of day. On days participants used social media, minutes of use were negatively associated with quality of day. The results suggest that social media primarily displaces unpleasant or neutral activities.

Keywords: Diary study, media displacement, social media use, time, well-being