Iverson Software Co.

We used eye-tracking during natural reading to study how semantic control and representation mechanisms interact for the successful comprehension of sentences, by manipulating sentence context and single-word meaning. Specifically, we examined whether a word’s semantic characteristic (concreteness) affects first fixation and gaze durations (FFDs and GDs) and whether it interacts with the predictability of a word. We used a linear mixed effects model including several possible psycholinguistic covariates. We found a small but reliable main effect of concreteness and replicated predictability effect on FFDs, but we found no interaction between the two. The results parallel previous findings of additive effects of predictability (context) and frequency (lexical level) in fixation times. Our findings suggest that the semantics of a word and the context created by the preceding words additively influence early stages of word processing in natural sentence reading.

Magnabosco, F., & Hauk, O. (2022, September 12). An Eye on Semantics: a study on the influence of concreteness and predictability on early fixations durations. https://doi.org/10.31234/osf.io/wf3ty

In response to intense pressure from policy makers and the public, technology companies have enacted a range of policies aimed at reducing the spread of misinformation online. The enforcement of these policies has, however, led to technology companies being regularly accused of political bias. We argue that even under politically neutral anti-misinformation policies, such political asymmetries in enforcement should be expected, as there is a political asymmetry in the sharing of misinformation. We support this argument with an analysis of Twitter data from 9,000 politically active users during the U.S. 2020 presidential election. While Republicans were indeed substantially more likely to be suspended than Democrats, the Republicans also shared far more links to low quality news sites – even when news quality was determined by politically-balanced groups of laypeople, or groups of only Republicans – and were estimated to have a far higher likelihood of being bots. We also find widespread evidence of ideological asymmetries when analyzing sharing intentions data from 8,597 people across 16 countries. These results demonstrate that social media platforms face a trade-off between effectively reducing the spread of misinformation and maintaining political balance in enforcement.

Mosleh, M., Yang, Q., Zaman, T., Pennycook, G., & Rand, D. G. (2022, April 8). Trade-offs between reducing misinformation and politically-balanced enforcement on social media. https://doi.org/10.31234/osf.io/ay9q5

Institutions explain humans’ exceptional levels of cooperation. Yet institutions are at the mercy of the very problem they are designed to solve. They are themselves cooperative enterprises, so to say that institutions stabilize cooperation just begs the question: what stabilizes institutions? Here, we use a mathematical model to show that reputation can sustain institutions without such a second-order problem. Our premise is that cooperative dilemmas vary in difficulty. Some are easy: they can be solved by reputation alone because cooperation is cheap, behaviors are observable, or interactions occur within small groups of kith and kin. Others are hard: they cannot be solved by reputation alone. Humans need not tackle hard cooperation problems head on. Instead, they can design an institution, which (a) is based on an easy cooperation dilemma, and (b) generates enough new incentives to solve the initial hard cooperation problem. Our model leads us to view institutions as technologies that humans have invented and gradually refined to build the most mutually beneficial social organizations that can be sustained by reputation alone. Just as a pulley system helps lift heavy loads with minimal effort, institutions maximize the potential of limited reputational incentives, helping humans achieve extended levels of cooperation.

Lie-Panis, J., Fitouchi, L., Baumard, N., & André, J. (2023, July 13). A model of endogenous institution formation through limited reputational incentives. https://doi.org/10.31234/osf.io/uftzb

The contraction and relaxation of facial muscles in humans is widely assumed to fulfil communicative and adaptive functions. However, to date most work has focussed either on individual muscle movements (action units) in isolation or on a small set of configurations commonly assumed to express “basic emotions”. As such, it is as yet unclear what information is communicated between individuals during naturalistic social interactions and how contextual cues influence facial activity occurring in these exchanges. The present study investigated whether consistent patterns of facial action units occur during dyadic iterative prisoners’ dilemma games, and what these patterns of facial activity might mean. Using exploratory and confirmatory factor analyses, we identified three distinct and consistent configurations of facial musculature change across three different datasets. These configurations were associated with specific gameplay outcomes, suggesting that they perform psychologically meaningful context-related functions. The first configuration communicated enjoyment and the second communicated affiliation and appeasement, both indicating cooperative intentions after cooperation or defection respectively. The third configuration communicated disapproval and encouraged social partners not to defect again. Future work should validate the occurrence and functionality of these facial configurations across other kinds of social interaction.

Robertson, O. M., Parkinson, B., & Shore, D. M. (2023, July 14). Identifying Meaningful Facial Configurations during Iterative Prisoner’s Dilemma Games. Retrieved from psyarxiv.com/fgk64

Young children have informal knowledge of fractions before learning about fraction symbols in school. In the current study, we followed 103 children in the Mid-Atlantic United States from the fall to the spring of first grade to characterize development of and individual differences in early informal fraction knowledge, as well as its relation to other mathematical and cognitive skills. Most children in our sample showed some early fraction knowledge at the beginning of first grade, especially with nonsymbolic fractions and halving, and this knowledge improved over the school year without explicit instruction in fractions. However, there were large individual differences in early fraction knowledge at the start of first grade, which explained significant variance in math achievement at the end of first grade, even when controlling for whole number knowledge and a variety of cognitive skills. Start-of-year whole number knowledge, but not spatial scaling or proportional reasoning, also predicted early end-of-year fraction knowledge. These data can inform activities for learning in the early years to foster both early fraction and integer knowledge in parallel, which may better prepare students for later formal instruction in fractions.

Viegut, A. A., Resnick, I., Miller-Cotto, D., Newcombe, N., & Jordan, N. (2023, May 26). Tracking Informal Fraction Knowledge and Its Correlates Across First Grade. https://doi.org/10.1037/dev0001581

Liu Long, Shanlao Bi, Jinhua Zhang, Xianfei Zhang, Liyun Zhang, Zhishuai Ge, Tanda Li, Xunzhou Chen, Yaguang Li, Lifei Ye, TianCheng Sun, Jianzhao Zhou

Using data from the Gaia Data Release 3 (Gaia DR3) and Kepler/K2, we present a catalog of 16 open clusters with ages ranging from 4 to 4000 Myr, which provides detailed information on membership, binary systems, and rotation. We assess the memberships in 5D phase space, and estimate the basic parameters of each cluster. Among the 20,160 members, there are 4,381 stars identified as binary candidates and 49 stars as blue straggler stars. The fraction of binaries vary in each cluster, and the range between 9% to 44%. We obtain the rotation periods of 5,467 members, of which 4,304 are determined in this work. To establish a benchmark for the rotation-age-color relation, we construct color-period diagrams. We find that the rotational features of binaries are similar to that of single stars, while features for binaries are more scattered in the rotation period. Moreover, the morphology of the color-period relationship is already established for Upper Scorpius at the age of 19 Myr, and some stars of varying spectral types (i.e. FG-, K-, and M-type) show different spin-down rates after the age of ~110 Myr. By incorporating the effects of stalled spin-down into our analysis, we develop an empirical rotation-age-color relation, which is valid with ages between 700 – 4000 Myr and colors corresponding to a range of 0.5 < (G_BP-G_RP)0 < 2.5 mag.

Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

https://arxiv.org/abs/2307.06596

Beomdu Lim, Jongsuk Hong, Jinhee Lee, Hyeong-Sik Yun, Narae Hwang, Byeong-Gon Park

The star-forming region W5 is a major part of the Cassiopeia OB6 association. Its internal structure and kinematics may provide hints of the star formation process in this region. Here, we present a kinematic study of young stars in W5 using the Gaia data and our radial velocity data. A total 490 out of 2,000 young stars are confirmed as members. Their spatial distribution shows that W5 is highly substructured. We identify a total of eight groups using the k-means clustering algorithm. There are three dense groups in the cavities of H II bubbles, and the other five sparse groups are distributed at the ridge of the bubbles. The three dense groups have almost the same ages (5 Myr) and show a pattern of expansion. The scale of their expansion is not large enough to account for the overall structure of W5. The three northern groups are, in fact, 3 Myr younger than the dense groups, which indicates the independent star formation events. Only one group of them shows the signature of feedback-driven star formation as its members move away from the eastern dense group. The other two groups might have formed in a spontaneous way. On the other hand, the properties of two southern groups are not understood as those of a coeval population. Their origins can be explained by dynamical ejection of stars and multiple star formation. Our results suggest that the substructures in W5 formed through multiple star-forming events in a giant molecular cloud.

Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

https://arxiv.org/abs/2307.06557

So-Myoung Park, Kyungwon Chun, Jihye Shin, Hyunjin Jeong, Joon Hyeop Lee, Mina Pak, Rory Smith, Jae-Woo Kim

We investigate the fraction of quenched satellite galaxies in host galaxy groups and clusters using TNG300 in the IllustrisTNG cosmological magnetohydrodynamical simulations. Simulations show that most satellites are quenched after they fall into their final hosts: post-processing is a more dominant mechanism of galaxy quenching than pre-processing. We find the fraction of quenched satellites at z=0 increases with host mass, which implies that more massive hosts have higher quenching efficiency because more massive hosts have more massive groups infalling. Furthermore, we find that hosts that have many early-infall satellites show a higher fraction of quenched satellites at z=0 than those having many late-infall satellites, which results in a scatter of the quenched fraction of satellites in a given mass range of hosts at z=0. Our results highlight the significance of the mass of hosts and the different infall times of satellites in understanding galaxy quenching.

Astrophysics of Galaxies (astro-ph.GA)

https://arxiv.org/abs/2307.05682

Seoyoung Lyla Jung, N. M. McClure-Griffiths, Ruediger Pakmor, Yik Ki Ma, Alex S. Hill, Cameron L. Van Eck, Craig S. Anderson

Faraday rotation measure (RM) is arguably the most practical observational tracer of magnetic fields in the diffuse circumgalactic medium (CGM). We sample synthetic Faraday rotation skies of Milky Way-like galaxies in IllustrisTNG50 by placing an observer inside the galaxies at a solar circle-like position. Our synthetic RM grids emulate specifications of current and upcoming surveys; the NRAO VLA Sky Survey (NVSS), the Polarisation Sky Survey of the Universe’s Magnetism (POSSUM), and a future Square Kilometre Array (SKA1-mid) polarisation survey. It has been suggested that magnetic fields regulate the survival of high-velocity clouds. However, there is only a small number of observational detections of magnetised clouds thus far. In the first part of the paper, we test conditions for the detection of magnetised circumgalactic clouds. Based on the synthetic RM samplings of clouds in the simulations, we predict upcoming polarimetric surveys will open new opportunities for the detection of even low-mass and distant clouds. In the second part of the paper, we investigate the imprint of the CGM in the all-sky RM distribution. We test whether the RM variation produced by the CGM is correlated with global galaxy properties, such as distance to a satellite, specific star formation rate, neutral hydrogen covering fraction, and accretion rate to the supermassive black hole. We argue that the observed fluctuation in the RM measurements, which has been considered an indication of intergalactic magnetic fields, might in fact incorporate a significant contribution of the Milky Way CGM.

Astrophysics of Galaxies (astro-ph.GA)

https://arxiv.org/abs/2307.05808

Quentin Salomé, Yair Krongold, Anna Lia Longinotti, Manuela Bischetti, Santiago García-Burillo, Olga Vega, Miguel Sánchez-Portal, Chiara Feruglio, María Jesús Jiménez-Donaire, Maria Vittoria Zanchettin

We present the first systematic study of the molecular gas and star formation efficiency in a sample of ten narrow-line Seyfert 1 galaxies selected to have X-ray Ultra Fast Outflows and, therefore, to potentially show AGN feedback effects. CO observations were obtained with the IRAM 30m telescope in six galaxies and from the literature for four galaxies. We derived the stellar mass, star formation rate, AGN and FIR dust luminosities by fitting the multi-band spectral energy distributions with the CIGALE code. Most of the galaxies in our sample lie above the main sequence (MS) and the molecular depletion time is one to two orders of magnitude shorter than the one typically measured in local star-forming galaxies. Moreover, we found a promising correlation between the star formation efficiency and the Eddington ratio, as well as a tentative correlation with the AGN luminosity. The role played by the AGN activity in the regulation of star formation within the host galaxies of our sample remains uncertain (little or no effect? positive feedback?). Nevertheless, we can conclude that quenching by the AGN activity is minor and that star formation will likely stop in a short time due to gas exhaustion by the current starburst episode.

Astrophysics of Galaxies (astro-ph.GA)

https://arxiv.org/abs/2307.06087