Correlates of intellectual ability with morphology of the hippocampus and amygdala in healthy adults

Several prior imaging studies of healthy adults have correlated volumes of the hippocampus and amygdala with measures of general intelligence (IQ), with variable results. In this study, we assessed correlations between volumes of the hippocampus and amygdala and full-scale IQ scores (FSIQ) using a method of image analysis that permits detailed regional mapping of this correlation throughout the surface contour of these brain structures. We delineated the hippocampus and amygdala in high-resolution magnetic resonance images of the brain from 34 healthy individuals. We then correlated FSIQ with overall volumes and with the surface morphologies of each of these structures. Hippocampus volumes correlated significantly and inversely with FSIQ independently of gender, age, socioeconomic status, and whole brain volume. Left and right hippocampus volumes correlated respectively with verbal and performance IQ subscales. Higher IQs were significantly associated with large inward deformations of the surface of the anterior hippocampus bilaterally. These findings suggest that a smaller anterior hippocampus contributes to an increased efficiency of neural processing that subserves overall intelligence.     

Are Telecommuters Remotely Good Citizens? Unpacking Telecommuting's Effects on Performance Via I‐Deals and Job Resources

Despite their widespread adoption, concerns remain that virtual work arrangements can harm employee job performance and citizenship behavior. Does telecommuting really hamper these critical dimensions of employee effectiveness? To answer this question, we develop a theoretical framework linking telecommuting to task and contextual performance via a dual set of mechanisms—reflecting proposed effects of i‐deals and job resources. Further, we propose that the meaning of and outcomes from these paths depend on the social context surrounding telecommuting. We test the framework with field data from 323 employees and 143 matched supervisors across a variety of organizations. As predicted, we find that telecommuting is positively associated with task and contextual performance, directly and indirectly via perceived autonomy. These beneficial effects are contingent upon two aspects of the social context: leader‐member exchange and signals of its normative appropriateness among coworkers and one's supervisor.     

Bayesian inference for psychology. Part II: Example applications with JASP

Bayesian hypothesis testing presents an attractive alternative to p value hypothesis testing. Part I of this series outlined several advantages of Bayesian hypothesis testing, including the ability to quantify evidence and the ability to monitor and update this evidence as data come in, without the need to know the intention with which the data were collected. Despite these and other practical advantages, Bayesian hypothesis tests are still reported relatively rarely. An important impediment to the widespread adoption of Bayesian tests is arguably the lack of user-friendly software for the run-of-the-mill statistical problems that confront psychologists for the analysis of almost every experiment: the t-test, ANOVA, correlation, regression, and contingency tables. In Part II of this series we introduce JASP (http://www.jasp-stats.org), an open-source, cross-platform, user-friendly graphical software package that allows users to carry out Bayesian hypothesis tests for standard statistical problems. JASP is based in part on the Bayesian analyses implemented in Morey and Rouder’s BayesFactor package for R. Armed with JASP, the practical advantages of Bayesian hypothesis testing are only a mouse click away.     

Bayesian inference for psychology. Part I: Theoretical advantages and practical ramifications

Bayesian parameter estimation and Bayesian hypothesis testing present attractive alternatives to classical inference using confidence intervals and p values. In part I of this series we outline ten prominent advantages of the Bayesian approach. Many of these advantages translate to concrete opportunities for pragmatic researchers. For instance, Bayesian hypothesis testing allows researchers to quantify evidence and monitor its progression as data come in, without needing to know the intention with which the data were collected. We end by countering several objections to Bayesian hypothesis testing. Part II of this series discusses JASP, a free and open source software program that makes it easy to conduct Bayesian estimation and testing for a range of popular statistical scenarios (Wagenmakers et al. this issue).     

Perception of the Mccolloch Effect Correlates with Activity in Extrastriate Cortex: A Functional MagneticResonance Imaging Study

The McCollough effect is a striking color aftereffect that is linked to the orientation of the patterns used to induce it. To produce the McCollough effect, two differently oriented grating patterns, such as a red-and-black vertical grating and a green-and-black horizontal grating, are viewed alternately for a few minutes. After such colored gratings are viewed, the white sections of avertical black-and-white test grating appear to be tinged with green, and the white sections of a horizontal grating appear to be tinged with pink. We present evidence from a functional magnetic resonance imaging study that the perception of the McCollough effect correlates with increased activation in the lingual and fusiform gyriùextrastriate visual areas that have been implicated in color perception in humans.     

Where there is a way, is there a will? The effect of future choices on self-control

Choices often involve self-control conflicts such that options that are immediately appealing are less desirable in the long run. In the current research, the authors examine how viewing such a choice as one of a series of similar future choices rather than as an isolated decision decreases the preference for items requiring self-control. The authors show that (a) in a choice between a vice and a virtue, the share choosing vice increases when the decision is presented as one of a series of similar future choices versus when the same choice is viewed in isolation, and (b) the overall share choosing a vice increases when decisions are seen in connection with similar future choices. The findings contrast with the general wisdom that broader choice frames lead to the exercise of greater self-control. The authors propose that the context of similar future choices allows people to optimistically believe that they will choose a virtue in the future choice and hence provides them with a guilt-reducing justification to not exercise self-control in the present.