Human behaviour is thought to spread through face-to-face social networks, but it is difficult to identify social influence effects in observational studies, and it is unknown whether online social ...networks operate in the same way. Here we report results from a randomized controlled trial of political mobilization messages delivered to 61 million Facebook users during the 2010 US congressional elections. The results show that the messages directly influenced political self-expression, information seeking and real-world voting behaviour of millions of people. Furthermore, the messages not only influenced the users who received them but also the users' friends, and friends of friends. The effect of social transmission on real-world voting was greater than the direct effect of the messages themselves, and nearly all the transmission occurred between 'close friends' who were more likely to have a face-to-face relationship. These results suggest that strong ties are instrumental for spreading both online and real-world behaviour in human social networks.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Happiness and other emotions spread between people in direct contact, but it is unclear whether massive online social networks also contribute to this spread. Here, we elaborate a novel method for ...measuring the contagion of emotional expression. With data from millions of Facebook users, we show that rainfall directly influences the emotional content of their status messages, and it also affects the status messages of friends in other cities who are not experiencing rainfall. For every one person affected directly, rainfall alters the emotional expression of about one to two other people, suggesting that online social networks may magnify the intensity of global emotional synchrony.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Emotional states can be transferred to others via emotional contagion, leading people to experience the same emotions without their awareness. Emotional contagion is well established in laboratory ...experiments, with people transferring positive and negative emotions to others. Data from a large real-world social network, collected over a 20-y period suggests that longer-lasting moods (e.g., depression, happiness) can be transferred through networks Fowler JH, Christakis NA (2008) BMJ 337:a2338, although the results are controversial. In an experiment with people who use Facebook, we test whether emotional contagion occurs outside of in-person interaction between individuals by reducing the amount of emotional content in the News Feed. When positive expressions were reduced, people produced fewer positive posts and more negative posts; when negative expressions were reduced, the opposite pattern occurred. These results indicate that emotions expressed by others on Facebook influence our own emotions, constituting experimental evidence for massive-scale contagion via social networks. This work also suggests that, in contrast to prevailing assumptions, in-person interaction and nonverbal cues are not strictly necessary for emotional contagion, and that the observation of others’ positive experiences constitutes a positive experience for people.
This study examined how having had a similar experience to a target person’s experience affected three facets of empathy: empathic concern, empathic accuracy, and perceived empathy. Women who had ...never been mothers, who were pregnant with their first child, or who had just given birth to their first child (20 in each group) served as perceivers, watching videotapes of new-mother targets (N = 20) and providing measures of emotional and cognitive empathy. When perceivers had experienced the same life events as the targets, they expressed greater empathic concern and reported greater understanding of targets. However, experience had a much smaller effect on empathic accuracy, limited to comparisons between new-mother and never-pregnant perceivers and only for accuracy at guessing stereotypic attitudes, not individual thoughts. Perceived empathy, in contrast, appeared to be influenced by targets’ knowledge of whether perceivers had experienced similar events.
Researchers often face the problem of needing to protect the privacy of subjects while also needing to integrate data that contains personal information from diverse data sources. The advent of ...computational social science and the enormous amount of data about people that is being collected makes protecting the privacy of research subjects ever more important. However, strict privacy procedures can hinder the process of joining diverse sources of data that contain information about specific individual behaviors. In this paper we present a procedure to keep information about specific individuals from being "leaked" or shared in either direction between two sources of data without need of a trusted third party. To achieve this goal, we randomly assign individuals to anonymous groups before combining the anonymized information between the two sources of data. We refer to this method as the Yahtzee procedure, and show that it performs as predicted by theoretical analysis when we apply it to data from Facebook and public voter records.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This article considers tools to support remote gesture in video systems being used to complete collaborative physical tasks-tasks in which two or more individuals work together manipulating ...three-dimensional objects in the real world. We first discuss the process of conversational grounding during collaborative physical tasks, particularly the role of two types of gestures in the grounding process: pointing gestures, which are used to refer to task objects and locations, and representational gestures, which are used to represent the form of task objects and the nature of actions to be used with those objects. We then consider ways in which both pointing and representational gestures can be instantiated in systems for remote collaboration on physical tasks. We present the results of two studies that use a "surrogate" approach to remote gesture, in which images are intended to express the meaning of gestures through visible embodiments, rather than direct views of the hands. In Study 1, we compare performance with a cursor-based pointing device that allows remote partners to point to objects in a video feed of the work area to performance side-by-side or with the video system alone. In Study 2, we compare performance with two variations of a pen-based drawing tool that allows for both pointing and representational gestures to performance with video alone. The results suggest that simple surrogate gesture tools can be used to convey gestures from remote sites, but that the tools need to be able to convey representational as well as pointing gestures to be effective. The results further suggest that an automatic erasure function, in which drawings disappear a few seconds after they were created, is more beneficial for collaboration than tools requiring manual erasure. We conclude with a discussion of the theoretical and practical implications of the results, as well as several areas for future research.
Objectives The aim of this study was to examine the effect of continuous positive airway pressure (CPAP) therapy on atrial fibrillation (AF) recurrence in patients with obstructive sleep apnea (OSA) ...undergoing pulmonary vein isolation (PVI). Background OSA is a predictor of AF recurrence following PVI. However, the impact of CPAP therapy on PVI outcome in patients with OSA is poorly known. Methods Among 426 patients who underwent PVI between 2007 and 2010, 62 patients had a polysomnography-confirmed diagnosis of OSA. While 32 patients were “CPAP users” the remaining 30 patients were “CPAP nonusers.” The recurrence of any atrial tachyarrhythmia, use of antiarrhythmic drugs, and need for repeat ablations were compared between the groups during a follow-up period of 12 months. Additionally, the outcome of patients with OSA was compared to a group of patients from the same PVI cohort without OSA. Results CPAP therapy resulted in higher AF-free survival rate (71.9% vs. 36.7%; p = 0.01) and AF-free survival off antiarrhythmic drugs or repeat ablation following PVI (65.6% vs. 33.3%; p = 0.02). AF recurrence rate of CPAP-treated patients was similar to a group of patients without OSA (HR: 0.7, p = 0.46). AF recurrence following PVI in CPAP nonuser patients was significantly higher (HR: 2.4, p < 0.02) and similar to that of OSA patients managed medically without ablation (HR: 2.1, p = 0.68). Conclusions CPAP is an important therapy in OSA patients undergoing PVI that improves arrhythmia free survival. PVI offers limited value to OSA patients not treated with CPAP.
Summary Background Memantine has been used off-label to treat frontotemporal lobar degeneration (FTD). A previous 26-week open-label study suggested a transient, modest benefit on neuropsychiatric ...symptoms as measured by the neuropsychiatric inventory (NPI). We aimed to determine whether memantine is an effective treatment for FTD. Methods We did a randomised, parallel group, double-blind, placebo-controlled trial of 20 mg memantine taken orally daily for 26 weeks in patients with FTD. Participants met Neary criteria for behavioural variant FTD (bvFTD) or semantic dementia and had characteristic brain atrophy. Use of acetylcholinesterase inhibitors was prohibited. Individuals were randomly assigned to receive either memantine or matched placebo tablets (1:1) in blocks of two and four patients. All patients and study personnel were masked to treatment assignment. Primary endpoints were the change in total NPI score and clinical global impression of change (CGIC) score after 26 weeks and were analysed by intention to treat. This study is registered with Clinicaltrials.gov , number NCT00545974. Findings Of 100 patients screened, 81 were randomly assigned to receive memantine (39 patients) or placebo (42 patients). Five (6%) patients discontinued, and 76 completed the 26-week treatment. Enrolment numbers were lower than planned because of many patients’ preference to take memantine or cholinesterase inhibitors off-label rather than participate in a clinical trial. Memantine treatment had no effect on either the NPI (mean difference 2·2, 95% CI −3·9 to 8·3, p=0·47) or CGIC (mean difference 0·0, −0·4 to 0·4, p=0·90) after 26 weeks of treatment. Memantine was generally well tolerated; however, patients in the memantine group had more frequent cognitive adverse events (six patients) than those in the placebo group (one). Interpretation Memantine treatment showed no benefit in patients with FTD. These data do not support memantine use in FTD. Funding Forest Research Institute.
Editorial Expression of Concern and Correction Verma, Inder M.; Kramer, Adam D. I.; Guillory, Jamie E. ...
Proceedings of the National Academy of Sciences - PNAS,
07/2014, Letnik:
111, Številka:
29
Journal Article
I analyze the use of emotion words for approximately 100 million Facebook users since September of 2007. "Gross national happiness" is operationalized as a standardized difference between the use of ...positive and negative words, aggregated across days, and present a graph of this metric. I begin to validate this metric by showing that positive and negative word use in status updates covaries with self-reported satisfaction with life (convergent validity), and also note that the graph shows peaks and valleys on days that are culturally and emotionally significant (face validity). I discuss the development and computation of this metric, argue that this metric and graph serves as a representation of the overall emotional health of the nation, and discuss the importance of tracking such metrics.
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