Monday, August 27, 2018

Old, from 2017: Hallmarks of Alzheimer’s Disease in Stem-Cell-Derived Human Neurons Transplanted into Mouse Brain

Old, from 2017: Hallmarks of Alzheimer’s Disease in Stem-Cell-Derived Human Neurons Transplanted into Mouse Brain. Ira Espuny-Camacho et al. Neuron, Volume 93, ISSUE 5, P1066-1081.e8 DOI:https://doi.org/10.1016/j.neuron.2017.02.001

Highlights
    Human-mouse chimeric model of Alzheimer’s disease
    PSC-derived human neurons grafted into an AD mouse
    Major degeneration and loss of human neurons in chimeric AD mice
    Absence of tangle pathology in degenerating human neurons in vivo

Summary: Human pluripotent stem cells (PSCs) provide a unique entry to study species-specific aspects of human disorders such as Alzheimer’s disease (AD). However, in vitro culture of neurons deprives them of their natural environment. Here we transplanted human PSC-derived cortical neuronal precursors into the brain of a murine AD model. Human neurons differentiate and integrate into the brain, express 3R/4R Tau splice forms, show abnormal phosphorylation and conformational Tau changes, and undergo neurodegeneration. Remarkably, cell death was dissociated from tangle formation in this natural 3D model of AD. Using genome-wide expression analysis, we observed upregulation of genes involved in myelination and downregulation of genes related to memory and cognition, synaptic transmission, and neuron projection. This novel chimeric model for AD displays human-specific pathological features and allows the analysis of different genetic backgrounds and mutations during the course of the disease.

Until more compelling evidence emerges, however, a propensity to imitate from birth should no longer be considered an established phenomenon

Re-evaluating the neonatal imitation hypothesis. Janine Oostenbroek et al. Developmental Science, DOI: 10.1111/desc.12720

We appreciate Meltzoff et al.’s (2017) detailed commentary on our study of neonatal imitation (Oostenbroek et al., 2016) and the opportunity to clarify critical aspects of the findings. First, however, we wish to highlight that our data were collected as part of a larger longitudinal investigation, in which we set out to examine potential relations between neonatal imitation and later emerging aspects of social cognition (Suddendorf, Oostenbroek, Nielsen, & Slaughter, 2013). Our aim was not to test the veracity of the phenomenon of neonatal imitation, but to assess whether early individual differences predict later imitative and other socio-cognitive capacities, which would support the view of neonatal imitation as the foundation of social cognition (Meltzoff, 2002). When coding was finalized, it became clear that, to our surprise, the data challenged the very existence of the phenomenon whose trajectory and consequences we sought to chart.

Meltzoff et al. (2017) claim that methodological problems biased our results towards null effects. We assert that there is no compelling reason to think that any of these critiques undermine our challenge to the field. For instance, they argue that too many stimuli were used in a within-subjects design, which may have led to neonatal fatigue and disengagement. If that were the case, however, then initial trials should have elicited imitation but not later ones. We found no such order effects in any of our analyses (see Supplementary Material in Oostenbroek et al., 2016). Meltzoff et al. rightly note that infants cannot be expected to imitate behaviors that they are incapable of producing. Our data show, however, that with the exception of the ‘eee’ vocalizations and sad faces, infants produced all target behaviors either occasionally or regularly. [...]

The literature on neonatal imitation has a long history of post-hoc theorizing. In response to early failures to replicate the effect, for example, it was stipulated that neonates should be unfamiliar with the model’s face to maintain interest during the experiment (Meltzoff & Moore, 1983a). Later, however, it was argued that infants imitate familiar faces to communicate recognition (Meltzoff, 2005; Meltzoff & Moore, 1994), and that ‘imitation is not modified by which person serves as the model’ (Meltzoff & Moore, 1992, p. 492). Now, Meltzoff et al. again argue that the model should be unfamiliar, even suggesting that this is the ‘key’ to eliciting neonatal imitation. Setting aside the obvious contradictions here, it seems untenable to claim that the ‘engine and mechanism for the growth of social cognition’ (Meltzoff, 2002, p. 7) would manifest itself only with unfamiliar people.

Individuals with stronger social anxiety perceive their environment as hierarchically organized & their own position relatively low; positive evaluations might mean problems, so a goal could be protection by avoiding making “too good” of an impression

Malaise with praise: A narrative review of 10 years of research on the concept of Fear of Positive Evaluation in social anxiety. Julia Reichenberger, Jens Blechert. Depression and Anxiety, https://doi.org/10.1002/da.22808

Abstract: Social anxiety is characterized by a fear of being negatively evaluated by others (i.e., Fear of Negative Evaluation [FNE]). In 2008, Weeks, Heimberg, and Rodebaugh proposed Fear of Positive Evaluation (FPE) as a second cognitive component in social anxiety. The article presents an overview of FPE, its psycho‐evolutionary theoretical foundation and assessment by the Fear of Positive Evaluation Scale as well as relevant psychometric research on demographic characteristics. The relationship of FPE with a wide range of established dimensions from clinical, personality, and social psychology (i.e., self‐esteem, perfectionism, or quality of life) will be reviewed. The role of FPE for psychological comorbidities such as other anxiety disorders, depression, eating, and substance use disorders as well as for treatment of social anxiety will be discussed. Future research might address questions of causality of FPE relative to related constructs, further data on psychometric properties, as well as on its independence from FNE in longitudinal studies. In sum, FPE seems to be a valid and reliable construct that explains cognitions, emotions, and behavior related to social anxiety at subclinical and clinical levels and therefore enriches the psychometric repertoire in the fields of social psychology, personality, and clinical psychology.


---
A theoretical framework for FPE stems from the psycho-evolutionary model of social anxiety by Gilbert (2001, 2014) and was adapted by Weeks et al. (2008a). Accordingly, individuals with stronger social anxiety perceive their environment as hierarchically organized, and see their own position in the hierarchy as relatively low. Their ultimate goal is supposedly a stable, intermediate position and an avoidance of upward or downward shifts in the social hierarchy. This “inconspicuous” intermediate position is the result of two “regulatory forces”, FNE and FPE (see Figure 1). Specifically, the upward movements in the social hierarchy, implied in positive evaluation, might attract the group's attention, prompting higher-ranking group members to compete and challenge this new “rising star.” Hence, the goal of FPE could be protection from this threat by avoiding making “too good” of an impression, thereby avoiding an upward shift in social hierarchy.

Pink for Girls, Red for Boys, and Blue for Both Genders: Colour Preferences in Children and Adults

Pink for Girls, Red for Boys, and Blue for Both Genders: Colour Preferences in Children and Adults, Domicele Jonauskaite et al. Sex Roles, https://link.springer.com/article/10.1007/s11199-018-0955-z

Abstract: Colours carry social connotations like pink for girls and blue for boys. In a cross-sectional study, we investigated whether such early gender coding might be reflected in absolute colour preferences in children and adults of both genders. In two studies, participants selected their favourite (and least favourite, Study 2) colour from an unrestricted sample of colours. We tested 129 Swiss children (Study 1, 10–14 years-old, 68 boys) and 180 Swiss adults (Study 2, 17–48 years-old, 88 men). In children, we observed that girls chose pink/purple as their favourite hue more often than boys did, the most common favourite hue in girls and boys was blue, and boys chose red as their favourite more often than girls did. In adults, we observed that both genders almost never choose pink as their favourite, blue was a common favourite colour, and women were more likely to favour red than were men. In an additional study (n = 183 Swiss participants, 47 men), we tested whether liking of pink, blue, and red was related to emotion associations with these colours. Pink was associated with positive emotions to the same extent as blue and red. Women further associated more positive emotions with pink than did men. We conclude that some commonalities (blue) and gender differences (pink and red) exist in absolute colour preferences. These differences, however, cannot be fully accounted by emotional associations. We speculate about these gendered colour preferences in relation to gender stereotypes and status differences between men and women.

American adolescents positive trends in four areas: substance use, unprotected sex, crime, & hazardous driving; possible causes are the effects of public policies, closer parent–child relationships, & the social consequences of electronic media use

Arnett, J. J. (2018). Getting better all the time: Trends in risk behavior among American adolescents since 1990. Archives of Scientific Psychology, 6(1), 87-95. http://dx.doi.org/10.1037/arc0000046

Abstract: Contrary to the negative narrative in psychology and in the American public, many trends in the risk behaviors of American adolescents have been positive in recent decades. Evidence is presented for positive trends in four areas: substance use, unprotected sex, crime, and hazardous automobile driving. A comparison of American adolescents to older Americans and to adolescents in other developed countries indicates that the pattern of positive trends is distinct to young Americans and does not apply consistently across age groups and countries. Three explanations for the positive trends are considered: the effects of public policies, closer parent–child relationships, and the social consequences of electronic media use. The most promising hypothesis is that a rise in electronic media use led to a decline in unstructured socializing, which led in turn to lower risk behavior.

Impact Statement: Contrary to the negative narrative in psychology and in the American public, many trends in the risk behaviors of American adolescents have been positive in recent decades. Evidence is presented for positive trends in four areas: substance use, unprotected sex, crime, and hazardous automobile driving. A comparison of American adolescents to older Americans and to adolescents in other developed countries indicates that the pattern of positive trends is distinct to young Americans and does not apply consistently across age groups and countries. Three explanations for the positive trends are considered: the effects of public policies, closer parent–child relationships, and the social consequences of electronic media use. The most promising hypothesis is that a rise in electronic media use led to a decline in unstructured socializing, which led in turn to lower risk behavior.