Task switching costs in preschool children and adults

Past research investigating cognitive flexibility has shown that preschool children make many perseverative errors in tasks that require switching between different sets of rules. However, this inflexibility may not necessary hold with easier tasks. The current study investigates the developmental differences in cognitive flexibility using a task-switching procedure that compares reaction times and accuracy in 4- to 6-year-olds to those of adults. The experiment involved simple target detection tasks, and was intentionally designed in a way that the stimulus and response conflicts were minimal, together with a long preparation window. Global mixing costs (performance costs when multiple tasks are relevant in a context), and local switch costs (performance costs due to switching to an alternative task) are typically thought to engage endogenous control processes. If this is the case, we should observe developmental differences with both these costs. Our results show, however, that when the accuracy was good, there were no age differences in cognitive flexibility between children and adults (i.e. the ability to manage multiple tasks and to switch between tasks). Even though preschool children had slower reaction times and were less accurate, the mixing and switch costs associated with task-switching were not reliably larger for preschool children. Preschool children did, however, show more commission errors and greater response repetition effects than adults, which may reflect differences in inhibitory control

Electrophysiological precursors of social conformity

Humans often change their beliefs or behavior due to the behavior or opinions of others. This study explored, with the use of human event-related potentials (ERPs), whether social conformity is based on a general performance-monitoring mechanism. We tested the hypothesis that conflicts with a normative group opinion evoke a feedback-related negativity (FRN) often associated with performance monitoring and subsequent adjustment of behavior. The experimental results show that individual judgments of facial attractiveness were adjusted in line with a normative group opinion. A mismatch between individual and group opinions triggered a frontocentral negative deflection with the maximum at 200 ms, similar to FRN. Overall, a conflict with a normative group opinion triggered a cascade of neuronal responses: from an earlier FRN response reflecting a conflict with the normative opinion to a later ERP component (peaking at 380 ms) reflecting a conforming behavioral adjustment. These results add to the growing literature on neuronal mechanisms of social influence by disentangling the conflict-monitoring signal in response to the perceived violation of social norms and the neural signal of a conforming behavioral adjustment

Does mindfulness meditation increase empathy? An experiment

Cultivating empathy is a presumed benefit of mindfulness, but this possibility has rarely been investigated experimentally. We examined whether a five-minute mindfulness exercise would cultivate empathy relative to two equally brief control exercises: relaxation and mind-wandering. We further examined whether mindfulness would be especially beneficial for people with autistic or narcissistic traits. Results showed no effect of mindfulness relative to both control conditions on mind reading, empathic responding, or prosocial behavior. Mindfulness effects were independent of autistic traits. Unexpectedly, people higher in autistic traits did show increased prosocial behavior across conditions. Intriguingly, mindfulness improved mind reading in non-narcissistic people, but reduced it in narcissistic people. These findings question whether a brief mindfulness exercise is sufficient for building empathy

Hierarchical multiple regression analysis for variables predicting cannabis problem severity (CUDIT-scores) at six-month follow-up in heavy cannabis users (n = 31).

*<p><i>p</i><.05, **<i>p</i><.01, and ***<i>p</i><.001. Model step 1 and 2a <i>R</i>²: 0.36**, adjusted <i>R</i>² 0.29. Model step 1 and 2a <i>R</i>²: 0.50***, adjusted <i>R</i>² 0.42. SE: standard error. CUDIT: Cannabis Use Disorder Identification Test. DLPFC: dorsolateral prefrontal cortex. ACC: anterior cingulate cortex.</p

Schematic representation of the Stimulus Response Compatibility Task.

<p>The SRC consisted of two approach, avoid, and baseline blocks. Trials consisted of a cannabis or control image with a manikin left or right next to it. Approach-block instructions were to move the manikin towards cannabis images but away from other images. Avoid-block instructions were the reversed. The manikin could be moved left and right by pressing the corresponding left and right response box button. Baseline-block Instructions were to press left or right according to the manikin’s position.</p

Sample characteristics.

a<p><i>p</i><.001 for group comparison.</p>b<p><i>p</i><.05 baseline follow-up comparison.</p>c<p><i>p</i><.001 approach avoid comparison.</p>d<p><i>p</i><.01 pre-test post-test comparison. SD: standard deviation. AUDIT: Alcohol Use Disorder Identification Test <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042394#pone.0042394-Saunders1" target="_blank">[32]</a>. FTND: Fagerström Test for Nicotine Dependence <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042394#pone.0042394-Heatherton1" target="_blank">[36]</a>. CUDIT: Cannabis Use Disorder Identification Test <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042394#pone.0042394-Adamson1" target="_blank">[35]</a>. SRC: Stimulus Response Compatibility. RT: reaction time. MCQ: Marijuana Craving Questionnaire <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0042394#pone.0042394-Heishman1" target="_blank">[37]</a>.</p

Cannabis approach-bias activations: main task effect across groups and correlation lifetime cannabis use and change problem severity (CUDIT-scores) at six-month follow-up in heavy cannabis users.

<p>L, left; R, right; MNI, Montreal Neurological Institute; BA, Brodmann Area; MNI coordinates and <i>Z</i>-scores of local maxima are shown for each cluster; Statistical threshold: <i>Z</i> >2.3, whole-brain cluster-corrected at <i>p</i><0.05.</p

Main effect of approach vs. avoid blocks over groups.

<p>Clusters of significant activation in ventral medial frontal gyrus and posterior cingulate gyrus (<i>Z</i> >2.3, whole-brain cluster-corrected at <i>p</i><0.05) are overlaid on a standard MNI brain. Right side of the brain is depicted at right side.</p