Thursday, November 1, 2018

Congenital Amusia: Understanding of the Musical Mind and Brain

Lee, Harin. 2018. “Congenital Amusia: Understanding of the Musical Mind and Brain.” PsyArXiv. November 1. doi:10.31234/

Abstract: The current paper aims to provide a comprehensive review of some of the recent researches on congenital amusia, demonstrating how the behavioural, brain-imaging, and genetic studies have extended our understanding of the musical mind and brain. Moreover, it discusses the gaps in the literature that needs to be addressed in future research.

Peretz and her colleagues (2007) investigated 9 large families of amusic probands with 71 members with matched control of 10 families with 75 members. The study showed that the disorder is a defect in pitch discrimination but not timing in music, and it is heritable. While the prevalence of the disorder was only 3% among first-degree relatives of control families, 39% was present in the amusic families. In a twin study of 136 monozygotic and 148 dizygotic twin pairs, participants were asked to discriminate the wrong note in a well-known song melody, and genetic model-fitting showed that shared genes were greater determinant than shared environment with estimate of 70 to 80% heritability (Drayna, Manichaikul, de Lange, Snieder, & Spector, 2001). Likewise, some studies argue that individuals’ musicality in general are more dependent to genetic basis compared to number of practice hours in the context of musical achievement (Peretz, 2016). Even the motivation to commit more hours of practice seems to be genetically influenced. The topic of whether musicality is innate or shaped through the environment is an on-going debate.

Nevertheless, recent studies have also demonstrated that amusia can be improved through laboratory training and raises a more interesting question (Liu, Jiang, Francart, Chan, & Wong, 2017; Whiteford & Oxenham, 2017, 2018). In a study conducted by Whiteford and Oxenham (2017), 20 amusics and matched pair of controls undertook four sessions to train in pitch-discrimination task. After the training, 11 of the amusics no longer met the criteria of MBEA and one year follow up test showed that the improvement is maintained (Whiteford & Oxenham, 2018). This is controversial to the previous findings that amusia is a life-long deficit and questions the current diagnosis of MBEA and whether the disorder is influenced by genetics.

Identification of depression subtypes and relevant brain regions using a data-driven approach

Identification of depression subtypes and relevant brain regions using a data-driven approach. Tomoki Tokuda, Junichiro Yoshimoto, Yu Shimizu, Go Okada, Masahiro Takamura, Yasumasa Okamoto, Shigeto Yamawaki & Kenji Doya. Scientific Reports, volume 8, Article number: 14082 (2018).

Abstract: It is well known that depressive disorder is heterogeneous, yet little is known about its neurophysiological subtypes. In the present study, we identified neurophysiological subtypes of depression related to specific neural substrates. We performed cluster analysis for 134 subjects (67 depressive subjects and 67 controls) using a high-dimensional dataset consisting of resting state functional connectivity measured by functional MRI, clinical questionnaire scores, and various biomarkers. Applying a newly developed, multiple co-clustering method to this dataset, we identified three subtypes of depression that are characterized by functional connectivity between the right Angular Gyrus (AG) and other brain areas in default mode networks, and Child Abuse Trauma Scale (CATS) scores. These subtypes are also related to Selective Serotonin-Reuptake Inhibitor (SSRI) treatment outcomes, which implies that we may be able to predict effectiveness of treatment based on AG-related functional connectivity and CATS.

Maternal Age and Child Development: Each year the mother delays a first birth is associated with an increase in school achievement & a similar-sized reduction in behavior problems

Maternal Age and Child Development. Greg J. Duncan, Kenneth T. H. Lee, Maria Rosales-Rueda, Ariel Kalil. Demography,

Abstract: Although the consequences of teen births for both mothers and children have been studied for decades, few studies have taken a broader look at the potential payoffs—and drawbacks—of being born to older mothers. A broader examination is important given the growing gap in maternal ages at birth for children born to mothers with low and high socioeconomic status. Drawing data from the Children of the NLSY79, our examination of this topic distinguishes between the value for children of being born to a mother who delayed her first birth and the value of the additional years between her first birth and the birth of the child whose achievements and behaviors at ages 10–13 are under study. We find that each year the mother delays a first birth is associated with a 0.02 to 0.04 standard deviation increase in school achievement and a similar-sized reduction in behavior problems. Coefficients are generally as large for additional years between the first and given birth. Results are fairly robust to the inclusion of cousin and sibling fixed effects, which attempt to address some omitted variable concerns. Our mediational analyses show that the primary pathway by which delaying first births benefits children is by enabling mothers to complete more years of schooling.

Keywords: Child development Maternal age Fertility Child achievement

Gay females are happier cohabiting, whereas marriage has a stronger well-being effect on gay males

Subjective Well-being and Partnership Dynamics: Are Same-Sex Relationships Different? Shuai Chen, Jan C. van Ours. Demography,

Abstract: We analyze Dutch panel data to investigate whether partnership has a causal effect on subjective well-being. As in previous studies, we find that, on average, being in a partnership improves well-being. Well-being gains of marriage are larger than those of cohabitation. The well-being effects of partnership formation and disruption are symmetric. We also find that marriage improves well-being for both younger and older cohorts, whereas cohabitation benefits only the younger cohort. Our main contribution to the literature is on well-being effects of same-sex partnerships. We find that these effects are homogeneous to sexual orientation. Gender differences exist in the well-being effects of same-sex partnerships: females are happier cohabiting, whereas marriage has a stronger well-being effect on males.

Testing the Kundera Hypothesis: Does Every Woman (But Not Every Man) Prefer Her Child to Her Mate? Almost.

Testing the Kundera Hypothesis: Does Every Woman (But Not Every Man) Prefer Her Child to Her Mate? Carlos Hernández Blasi, Laura Mondéjar. Evolutionary Psychology,

Abstract: The context of a famous novel by Milan Kundera (Immortality) suggests that when faced with a life-or-death situation, every woman would prefer to save her child than her husband, left hanging whether every man would do the same. We labeled this as the Kundera hypothesis, and the purpose of this study was to test it empirically as we believe it raises a thought-provoking question in evolutionary terms. Specifically, 197 college students (92 women) were presented a questionnaire where they had to make different decisions about four dilemmas about who to save (their mate or their offspring) in two hypothetical life-or-death situations: a home fire and a car crash. These dilemmas involved two different mate ages (a 25- or a 40-year-old mate) and two offspring ages (1- or a 6-year-old child). For comparative purposes, we also included complementary life-or-death dilemmas on both a sibling and an offspring, and a sibling and a cousin. The results generally supported the Kundera hypothesis: Although the majority of men and women made the decision to save their offspring instead of their mate, about 18% of men on average (unlike the 5% of women) consistently decided to save their mate across the four dilemmas in the two life-or-death situations. These data were interpreted with reference to Hamilton’s inclusive fitness theory, the preferential role of women as kin keepers, and the evolution of altruism toward friends and mates.

Keywords: altruism, kin selection, inclusive fitness, mating, life-or-death situations, evolutionary psychology

Hot Hand Fallacy & Robust Evidence That Belief in the Hot Hand Is Justified, and that expert observers can predict which shooters have a tendency to become hot

Miller, Joshua B., and Adam Sanjurjo. 2018. “A Cold Shower for the Hot Hand Fallacy: Robust Evidence That Belief in the Hot Hand Is Justified.” OSF Preprints. November 1. doi:10.31219/

Abstract: The hot hand fallacy has long been considered a massive and widespread cognitive illusion with important implications in economics and finance. We develop a novel empirical strategy to correct for limitations in the canonical study and replications, conduct an improved field experiment to test for the hot hand in its original domain (basketball shooting), and gather all extant controlled shooting data. In contrast with the previous results, we find strong evidence of hot hand shooting in every dataset, and that expert observers can predict which shooters have a tendency to become hot