Sunday, February 3, 2019

The Dynamic Associations Between Cortical Thickness and General Intelligence are Genetically Mediated

The Dynamic Associations Between Cortical Thickness and General Intelligence are Genetically Mediated. J Eric Schmitt  et al. Cerebral Cortex, bhz007, https://doi.org/10.1093/cercor/bhz007

Abstract: The neural substrates of intelligence represent a fundamental but largely uncharted topic in human developmental neuroscience. Prior neuroimaging studies have identified modest but highly dynamic associations between intelligence and cortical thickness (CT) in childhood and adolescence. In a separate thread of research, quantitative genetic studies have repeatedly demonstrated that most measures of intelligence are highly heritable, as are many brain regions associated with intelligence. In the current study, we integrate these 2 streams of prior work by examining the genetic contributions to CT–intelligence relationships using a genetically informative longitudinal sample of 813 typically developing youth, imaged with high-resolution MRI and assessed with Wechsler Intelligence Scales (IQ). In addition to replicating the phenotypic association between multimodal association cortex and language centers with IQ, we find that CT–IQ covariance is nearly entirely genetically mediated. Moreover, shared genetic factors drive the rapidly evolving landscape of CT–IQ relationships in the developing brain.

Keywords: cortical thickness, genetics, intelligence, MRI, neurodevelopment

Why Do Men Report More Opposite-Sex Sexual Partners Than Women? Analysis of the Gender Discrepancy in a British National Probability Survey. Hint: Need for candid reporting

Why Do Men Report More Opposite-Sex Sexual Partners Than Women? Analysis of the Gender Discrepancy in a British National Probability Survey. Kirstin R. Mitchell et al. The Journal of Sex Research, Volume 56, 2019 - Issue 1. https://doi.org/10.1080/00224499.2018.1481193

Abstract: In a closed population and defined time period, the mean number of opposite-sex partners reported by men and women should be equal. However, in all surveys, men report more partners. This inconsistency is pivotal to debate about the reliability of self-reported sexual behavior. We used data from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3), a probability sample survey of the British population, to investigate the extent to which survey sampling, accounting strategies (e.g., estimating versus counting), and (mis)reporting due to social norms might explain the inconsistency. Men reported a mean of 14.14 lifetime partners; women reported 7.12. The gender gap of 7.02 reduced to 5.47 after capping the lifetime partner number at the 99th percentile. In addition, adjusting for counting versus estimation reduced the gender gap to 3.24, and further adjusting for sexual attitudes narrowed it to 2.63. Together, these may account for almost two-thirds of the gender disparity. Sampling explanations (e.g., non-U.K.-resident partners included in counts; sex workers underrepresented) had modest effects. The findings underscore the need for survey methods that facilitate candid reporting and suggest that approaches to encourage counting rather than estimating may be helpful. This study is novel in interrogating a range of potential explanations within the same nationally representative data set.

Weighing outcome vs. intent across societies: How cultural models of mind shape moral reasoning

Weighing outcome vs. intent across societies: How cultural models of mind shape moral reasoning. Rita Anne McNamara et al. Cognition, Volume 182, January 2019, Pages 95-108. https://doi.org/10.1016/j.cognition.2018.09.008

Abstract: Mental state reasoning has been theorized as a core feature of how we navigate our social worlds, and as especially vital to moral reasoning. Judgments of moral wrong-doing and punish-worthiness often hinge upon evaluations of the perpetrator’s mental states. In two studies, we examine how differences in cultural conceptions about how one should think about others’ minds influence the relative importance of intent vs. outcome in moral judgments. We recruit participation from three societies, differing in emphasis on mental state reasoning: Indigenous iTaukei Fijians from Yasawa Island (Yasawans) who normatively avoid mental state inference in favor of focus on relationships and consequences of actions; Indo-Fijians who normatively emphasize relationships but do not avoid mental state inference; and North Americans who emphasize individual autonomy and interpreting others’ behaviors as the direct result of mental states. In study 1, Yasawan participants placed more emphasis on outcome than Indo-Fijians or North Americans by judging accidents more harshly than failed attempts. Study 2 tested whether underlying differences in the salience of mental states drives study 1 effects by inducing Yasawan and North American participants to think about thoughts vs. actions before making moral judgments. When induced to think about thoughts, Yasawan participants shifted to judge failed attempts more harshly than accidents. Results suggest that culturally-transmitted concepts about how to interpret the social world shape patterns of moral judgments, possibly via mental state inference.

Check also The Minds of God(s) and Humans: Differences in Mind Perception in Fiji and North America. Aiyana K. Willard, Rita A. McNamara. Cognitive Science, https://www.bipartisanalliance.com/2019/01/the-minds-of-gods-and-humans.html

When humans behave like monkeys: Feedback delays and extensive practice increase the efficiency of speeded decisions

When humans behave like monkeys: Feedback delays and extensive practice increase the efficiency of speeded decisions. Nathan J.Evans, Guy E.Hawkins. Cognition, Volume 184, March 2019, Pages 11-18. https://doi.org/10.1016/j.cognition.2018.11.014

Abstract: The study of non-human primates has been foundational in understanding the neural origins of human decision processes, yet the approach rests on the assumption that one can validly extrapolate from the animal to the human. In the context of decision making, this requires constancy across species in physiological and cognitive processes. The former cannot be experimentally validated and therefore remains assumed, and recent findings have called into question the latter: non-human primates become increasingly urgent as the time spent making a decision increases, but humans do not; from a normative perspective, monkeys are making closer-to-optimal decisions than humans. Rather than presuming species differences, here we test an alternative hypothesis: previously overlooked differences in methodological procedures from the two research traditions implicitly reinforced fundamentally different decision strategies across the two species. We show that when humans experience decision contexts matched to those experienced by non-human primates – extensive task practice, or time-based penalties – they display increasing levels of urgency as decision time grows longer, in precisely the same manner as non-human primates. Our findings indicate that previously observed differences in decision strategy between humans and non-human primates are eliminated when the decision environment is more closely matched across species, placing a constraint on the interpretation and mapping of neurophysiological results in non-human primates to humans when there are fundamental differences in the task design.

Models about others are formed through psychological adaptations designed to acquire information from the environment; pornography provides information about mating strategies/perception of promiscuity

How pornography calibrates our perception of women's sexuality. Hilary R Keil. California State Univ. at Fullerton, Master's Thesis, Fall 2018. https://search.proquest.com/openview/36902c3e23bc3779e1c8054316d6dcc4/1?pq-origsite=gscholar&cbl=18750&diss=y

Abstract: Models about others are formed through psychological adaptations designed to acquire information from the environment. These adaptations may begin with prior probabilities. Pornography provides information about mating strategies and men’s and women’s sexual behaviors. Information updating allows the individual to adjust according to cues gathered from their environment combined with their previous cue-based beliefs. Given that cue-updating is occurring continuously, in the present study, cognitive and evolutionary psychology approaches were used to understand how pornography consumption affects perceptions of women’s promiscuity and engagement in atypical sexual practices. Participants (N = 617) were asked to complete an online questionnaire assessing their weekly pornography consumption, perceptions of women’s sexuality, and social desirability. Results suggest that pornography consumption influences perceptions of women’s promiscuity and engagement in atypical sexual practices in both men and women. Additionally, men are using more pornography overall than women. Taken together, these results suggest that cue updating from pornography is occurring in both men and women, and perceptions of women’s sexuality is calibrated based on experiencing in the local environment. 

Keywords: Pornography, Women’s Sexuality, Bayesian Development, Cue-Updating

The individual functional connectome is unique and stable over months to years; we don't know if even from utero

The individual functional connectome is unique and stable over months to years. Corey Horien et al. NeuroImage, https://doi.org/10.1016/j.neuroimage.2019.02.002

Highlights
•    Used 4 longitudinal datasets to generate functional connectivity matrices.
•    Whole-brain matrices are unique and stable across months to years.
•    Medial frontal and frontoparietal networks tended to be both unique and stable.
•    Edges in the frontal and parietal cortices tended to be most discriminative.

Abstract: Functional connectomes computed from fMRI provide a means to characterize individual differences in the patterns of BOLD synchronization across regions of the entire brain. Using four resting-state fMRI datasets with a wide range of ages, we show that individual differences of the functional connectome are stable across 3 months to 1–2 years (and even detectable at above-chance levels across 3 years). Medial frontal and frontoparietal networks appear to be both unique and stable, resulting in high ID rates, as did a combination of these two networks. We conduct analyses demonstrating that these results are not driven by head motion. We also show that edges contributing the most to a successful ID tend to connect nodes in the frontal and parietal cortices, while edges contributing the least tend to connect cross-hemispheric homologs. Our results demonstrate that the functional connectome is stable across years and that high ID rates are not an idiosyncratic aspect of a specific dataset, but rather reflect stable individual differences in the functional connectivity of the brain.