On the homeostatizing of perturbations (from pupillary dynamics)

This paper explains the homeostatizing of perturbations on a toroidal model of the sensory manifold

Cross-sectional white matter microstructure differences in age and trait mindfulness.

The process of aging can be characterized by a decline in cognitive performance, which may be accompanied by deterioration in specific structural properties of the brain. In this study we sought to investigate to what extent mindfulness changes over the aging process, and which alterations in brain structure can be associated to aging and concomitant changes in mindfulness. We collected Mindful Attention Awareness Scale questionnaire data to assess trait mindfulness and acquired diffusion-weighted imaging data fitted to the diffusion tensor model (DTI) in a group of 97 middle-aged to elderly participants. Our results showed that trait mindfulness increased with age. In terms of white matter structure our results suggested that there was a general increase of omnidirectional diffusion, which favored radial over axial diffusivity, leading to a decrease in fractional anisotropy (FA) in older participants. We further showed that trait mindfulness mediated the FA-age effect in a localized area consisting of the internal and external capsule, as well as the corona radiata. The implication of this mediation analysis is that trait mindfulness may deter age-associated neurocognitive decline, perhaps by preventing age-associated microlesions specifically in cortico-subcortical white matter tracts. This study can be considered a pioneer of using DTI studies to investigate the relationship between age and trait mindfulness

A Neural Model of Mind Wandering

The role of the default-mode network (DMN) in the emergence of mind wandering and task-unrelated thought has been studied extensively. In parallel work, mind wandering has been associated with neuromodulation via the locus coeruleus (LC) norepinephrine (LC-NE) system. Here we propose a neural model that links the two systems in an integrative framework. The model attempts to explain how dynamic changes in brain systems give rise to the subjective experience of mind wandering. The model implies a neural and conceptual distinction between an off-focus state and an active mind-wandering state and provides a potential neural grounding for well-known cognitive theories of mind wandering. Finally, the proposed neural model of mind wandering generates precise, testable predictions at neural and behavioral levels

How video calls affect mimicry and trust during interactions

Many social species, humans included, mimic emotional expressions, with important consequences for social bonding. Although humans increasingly interact via video calls, little is known about the effect of these online interactions on the mimicry of scratching and yawning, and their linkage with trust. The current study investigated whether mimicry and trust are affected by these new communication media. Using participant-confederate dyads (n = 27), we tested the mimicry of four behaviours across three different conditions: watching a pre-recorded video, online video call, and face-to-face. We measured mimicry of target behaviours frequently observed in emotional situations, yawn and scratch and control behaviours, lip-bite and face-touch. In addition, trust in the confederate was assessed via a trust game. Our study revealed that (i) mimicry and trust did not differ between face-to-face and video calls, but were significantly lower in the pre-recorded condition; and (ii) target behaviours were significantly more mimicked than the control behaviours. This negative relationship can possibly be explained by the negative connotation usually associated with the behaviours included in this study. Overall, this study showed that video calls might provide enough interaction cues for mimicry to occur in our student population and during interactions between strangers

Corrigendum to “A purely confirmatory replication study of structural brain-behavior correlations” [Cortex 66 (2015) 115–133]

In our previous study, we reported a purely confirmatory replication study of structural brain-behavior correlations (Boekel et al., 2015). For all but one of the 17 findings under scrutiny, confirmatory Bayesian hypothesis tests indicated evidence in favor of the null hypothesis ranging from anecdotal (Bayes factor &lt; 3) to strong (Bayes factor &gt; 10). In several studies, effect size estimates were substantially lower than in the original studies. We now discovered a mistake in the post-processing pipeline of our diffusion-weighted imaging (DWI) data analyses originally included in this replication study. This led us to recalculate and correct five of the 17 originally reported brain-behavior correlations that were based on DWI data. In short, after reanalyzing the DWI data correctly, the original conclusions for the five corrected analyses did not change. More concretely, we discovered that an extra volume was included in the acquisition protocol which was subsequently incorrectly included in the data analyses. This extra volume was incorporated due to the Philips scanner software version R3. This volume is the average of all the acquired diffusion weighted volumes and was placed at the end of the data file. Such an extra volume can be used to calculate Apparent Diffusion Coefficient (ADC) maps. This extra volume has a b-value of 1000 and bvecs values of 0,0,0. As this is not truly a measured direction or a proper B0 volume, this volume should have been removed. The extra volume, as well as the corresponding extra entries in the bval and bvecs were removed. All DWI data processing was redone with the pre-registered parameter settings. Removing this extra volume from the analyses resulted in considerably different structural DWI measures including fractional anisotropy (FA), mean diffusivity (MD), and λ1 values from the pre-defined regions of interest (ROIs). This mistake also affected tractography results including the calculation of tract strength. Therefore, the previously reported results regarding the failed replications of Forstmann et al. (2010) and Xu et al. (2012) needed to be corrected. After removing the additional volume from the current DWI data set, the analyses pipeline described in the original paper, i.e., section 1.1.1 DWI analyses and 1.1.2. Probabilistic tractography were used. In addition to the mistake in the post-processing pipeline of the DWI data, it came to our attention that the correlation coefficients reported in the text inset of figure 6 were swapped between the two panels. Although this had no influence on the conclusion, we have taken the opportunity to correct this error. In the following we now present the corrected results, tables, and figures of the studies previously reported (Boekel et al., 2015). 3.1. Replication 1: Forstmann et al. (2010) Summary statistics One subject was removed from the analyses (&gt;2.5 SD from the mean). Below are the corrected new summary statistics for the tract strength measure between the right pre-SMA and right striatum as well as the LBA flexibility measures presented. These are based on 32 subjects and are not corrected for age and gender.[figure presented]</p

Action video games do not improve the speed of information processing in simple perceptual tasks

Previous research suggests that playing action video games improves performance on sensory, perceptual, and attentional tasks. For instance, Green, Pouget, and Bavelier (2010) used the diffusion model to decompose data from a motion detection task and estimate the contribution of several underlying psychological processes. Their analysis indicated that playing action video games leads to faster information processing, reduced response caution, and no difference in motor responding. Because perceptual learning is generally thought to be highly context-specific, this transfer from gaming is surprising and warrants corroborative evidence from a large-scale training study. We conducted 2 experiments in which participants practiced either an action video game or a cognitive game in 5 separate, supervised sessions. Prior to each session and following the last session, participants performed a perceptual discrimination task. In the second experiment, we included a third condition in which no video games were played at all. Behavioral data and diffusion model parameters showed similar practice effects for the action gamers, the cognitive gamers, and the nongamers and suggest that, in contrast to earlier reports, playing action video games does not improve the speed of information processing in simple perceptual tasks

Probing the neural signature of mind wandering with simultaneous fMRI-EEG and pupillometry

Mind wandering reflects the shift in attentional focus from task-related cognition driven by external stimuli toward self-generated and internally-oriented thought processes. Although such task-unrelated thoughts (TUTs) are pervasive and detrimental to task performance, their underlying neural mechanisms are only modestly understood. To investigate TUTs with high spatial and temporal precision, we simultaneously measured fMRI, EEG, and pupillometry in healthy adults while they performed a sustained attention task with experience sampling probes. Features of interest were extracted from each modality at the single-trial level and fed to a support vector machine that was trained on the probe responses. Compared to task-focused attention, the neural signature of TUTs was characterized by weaker activity in the default mode network but elevated activity in its anticorrelated network, stronger functional coupling between these networks, widespread increase in alpha, theta, delta, but not beta, frequency power, predominantly reduced amplitudes of late, but not early, event-related potentials, and larger baseline pupil size. Particularly, information contained in dynamic interactions between large-scale cortical networks was predictive of transient changes in attentional focus above other modalities. Together, our results provide insight into the spatiotemporal dynamics of TUTs and the neural markers that may facilitate their detection