Inter-brain co-activations during mindfulness meditation. Implications for devotional and clinical settings

Mindfulness meditation usually takes place as personal, introspective activity. It is not known if this practice activates the brain differently when done alone or with someone else.Sixteen couples of expert meditators performed mindfulness-oriented meditation (MOM) and instructed mind-wandering (IMW) tasks in two conditions: once sitting in the same room (SR) and once in two different rooms (DR). Spontaneous electroencephalographic (EEG) data was collected during 7-minute recording sessions in the four experimental settings (MOM/SR, MOM/DR, IMW/SR, IMW/DR). Power in band was computed in separate clusters of independent components of the EEG signals.In addition to significant task effects, found in frontolimbic (MOM > IMW in gamma) and frontoparietal locations (MOM < IMW in theta), significant condition effects were found in frontal (SR > DR in delta) and in temporo-occipital regions (SR > DR in theta and alpha). Moreover, a significant interaction between task and condition revealed higher gamma activity in limbic areas during MOM/SR vs. MOM/DR settings. This effect was not attributable to gender, age nor the meditation expertise of participants.We thus show that the brains of two people work differently when they are doing something together or alone; some of these differences are specific to mindfulness meditation. Implications for devotional and clinical settings are discussed.     

Masked and unmasked priming in schizophrenia

Dehaene et al. (2003) showed an absence of conscious, but not masked, conflict effects when patients with schizophrenia performed a number-categorisation priming task. We aimed to replicate these influential results using a different word-categorisation priming task. Counter to Dehaene et al.’s findings, 21 patients and 20 healthy controls showed similar congruence effects for both masked and visible primes. Within patients, a reduced congruence effect for visible primes associated with longer duration of illness and more severe behavioural disorganisation. Patients, unlike controls, were no slower to respond to targets that followed visible compared to masked primes. Conscious conflict effects on priming tasks are not universally reduced in schizophrenia but may associate with chronicity and behavioural disorganisation. That patients were no slower when the preceding primes were clearly visible accords with evidence elsewhere that information processing in schizophrenia is driven more by immediate conscious experience and constrained less by prior events.     

Neural correlates of subliminally presented visual sexual stimuli

In the context of forensic psychiatry, it is crucial that diagnoses of deviant sexual interests are resistant to manipulation. In a first attempt to promote the development of such tools, the current fMRI study focusses on the examination of hemodynamic responses to preferred, in contrast to non-preferred, sexual stimuli with and without explicit sexual features in 24 healthy heterosexual subjects. The subliminal stimulus presentation of sexual stimuli could be a new approach to reduce vulnerability to manipulation. Meaningful images and scrambled images were applied as masks. Recognition performance was low, but interestingly, sexual preference and explicitness modulated stimulus visibility, suggesting interactions between networks of sexual arousal and consciousness. With scrambled masks, higher activations for sexually preferred images and for explicit images were found in areas associated with sexual arousal (Stoleru, Fonteille, Cornelis, Joyal, & Moulier, 2012). We conclude that masked sexual stimuli can evoke activations in areas associated with supraliminal induced sexual arousal.     

The brain mechanism that reduces the vividness of negative imagery

The present study attempts to locate brain regions that are related to vividness control, a hypothesized mechanism that reduces the vividness of negative imagery by controlling memory retrieval and emotion processing. The results showed that BOLD response in the left posterior cingulate gyrus in the negative imagery condition, in which activation of vividness control mechanisms was considered to be strong, was greater than that in the positive imagery condition, in which the activation of control mechanisms was considered to be weak. Moreover, the activation of this region negatively correlated with the subjective vividness of negative imagery. These results support the idea that the posterior cingulate gyrus may be involved in the suppression of imagery generation. Several previous studies have suggested that the posterior cingulate cortex is involved in both memory and emotion processing. Therefore, the current results indicate that the posterior cingulate gyrus may function as the vividness control mechanism.     

Laterality of the frontal aslant tract (FAT) explains externalizing behaviors through its association with executive function

We investigated the development of a recently identified white matter pathway, the frontal aslant tract (FAT) and its association with executive function and externalizing behaviors in a sample of 129 neurotypical male and female human children ranging in age from 7 months to 19 years. We found that the FAT could be tracked in 92% of those children, and that the pathway showed age‐related differences into adulthood. The change in white matter microstructure was very rapid until about 6 years, and then plateaued, only to show age‐related increases again after the age of 11 years. In a subset of those children (5–18 years; n = 70), left laterality of the microstructural properties of the FAT was associated with greater attention problems as measured by the Child Behavior Checklist (CBCL). However, this relationship was fully mediated by higher executive dysfunction as measured by the Behavior Rating Inventory of Executive Function (BRIEF). This relationship was specific to the FAT—we found no relationship between laterality of a control pathway, or of the white matter of the brain in general, and attention and executive function. These findings suggest that the degree to which the developing brain favors a right lateralized structural dominance of the FAT is directly associated with executive function and attention. This novel finding provides a new potential structural biomarker to assess attention deficit hyperactivity disorder (ADHD) and associated executive dysfunction during development.     

双价效应及其认知机制

任务转换时, 如果一个刺激不仅包含当前任务的特征还包含另一任务的关联特征, 这样的刺激被称为双价刺激。双价刺激能影响个体对单价刺激的加工, 使个体对后续所有单价刺激的反应减慢, 这种现象被称为双价效应(bivalency effect)。研究者发现双价效应具有一定的普遍性和稳定性。对双价效应的理论解释主要有情境捆绑说和基于经验的预测模型。双价效应的产生与额外视觉特征的提取及自上而下的认知控制调整有关, 前者主要与颞-顶联合区的激活有关, 后者主要与背侧前扣带回以及前辅助运动区的激活相关。     

Action monitoring and perfectionism in anorexia nervosa

To study action monitoring in anorexia nervosa, behavioral and EEG measures were obtained in underweight anorexia nervosa patients (n=17) and matched healthy controls (n=19) while performing a speeded choice-reaction task. Our main measures of interest were questionnaire outcomes, reaction times, error rates, and the error-related negativity ERP component. Questionnaire and behavioral results indicated increased perfectionism in patients with anorexia nervosa. In line with their perfectionism and controlled response style patients made significantly less errors than controls. However, when controlling for this difference in error rates, the EEG results demonstrated a reduced error-related negativity in the patient group. These seemingly contradictory outcomes of improved performance and reduced error monitoring are discussed in relation with indications of anterior cingulate cortex hypoactivity in anorexia nervosa patients.     

Numerical and non-numerical ordinality processing in children with and without developmental dyscalculia: Evidence from fMRI

Ordinality is – beyond numerical magnitude (i.e., quantity) – an important characteristic of the number system. There is converging empirical evidence that (intra)parietal brain regions mediate number magnitude processing. Furthermore, recent findings suggest that the human intraparietal sulcus (IPS) supports magnitude and ordinality in a domain-general way. However, the latter findings are derived from adult studies and with respect to children (i.e., developing brain systems) both the neural correlates of ordinality processing and the precise role of the IPS (domain-general vs. domain-specific) in ordinality processing are thus far unknown. The present study aims at filling this gap by employing functional magnetic resonance imaging (fMRI) to investigate numerical and non-numerical ordinality knowledge in children with and without developmental dyscalculia. In children (without DD) processing of numerical and non-numerical ordinality alike is supported by (intra)parietal cortex, thus extending the notion of a domain-general (intra)parietal cortex to developing brain systems. Moreover, activation extents in response to numerical ordinality processing differ significantly between children with and without dyscalculia in inferior parietal regions (supramarginal gyrus and IPS).     

Neural correlates of Traditional Chinese Medicine induced advantageous risk-taking decision making

This fMRI study examined the neural correlates of the observed improvement in advantageous risk-taking behavior, as measured by the number of adjusted pumps in the Balloon Analogue Risk Task (BART), following a 60-day course of a Traditional Chinese Medicine (TCM) recipe, specifically designed to regulate impulsiveness in order to modulate risk-taking behavior. The 14 participants recruited for this study were randomly assigned to the experimental and control groups and the TCM recipe (Panax, 520 mg; Astragalus membranaceous Bunge, 520 mg; Masnetitum, 840 mg; Ostrea gigas Thumb, 470 mg; Thinleaf Milkwort Root Radix Polygalae, 450 mg; and Os Draconis, 470 mg) was administered, as a diet supplement, to the seven participants in the experimental group. The neural activity of the two groups was monitored by a 3T MRI scanner, before and after the 60-day treatment. Associated with the improved advantageous risk-taking behavior seen in the experimental group, significantly stronger blood oxygenation level dependent (BOLD) responses were observed in the bilateral dorsolateral prefrontal cortex (DLPFC), left putamen, left thalamus, right insula, and right anterior cingulate cortex (ACC), regions which have previously been reported as being involved in risk-taking decision making. The effect of the TCM in improving advantageous risk-taking decision making appears to have been related to the enhanced efficiency of the cognitive affective system, the PFC–ACC–insula–striatum network, which functions to inhibit impulsiveness, to sensitize reward-related information, and to allow the opportunity, during risk estimation, to evaluate potential gains and losses. The findings of this study suggest that interventions acting on factors modulating risk-taking decision making could have a beneficial effect in terms of optimizing risk-taking behavior.     

Brain correlates of aesthetic expertise: a parametric fMRI study

Several studies have demonstrated that acquired expertise influences aesthetic judgments. In this paradigm we used functional magnetic resonance imaging (fMRI) to study aesthetic judgments of visually presented architectural stimuli and control-stimuli (faces) for a group of architects and a group of non-architects. This design allowed us to test whether level of expertise modulates neural activity in brain areas associated with either perceptual processing, memory, or reward processing. We show that experts and non-experts recruit bilateral medial orbitofrontal cortex (OFC) and subcallosal cingulate gyrus differentially during aesthetic judgment, even in the absence of behavioural aesthetic rating differences between experts and non-experts. By contrast, activity in nucleus accumbens (NAcc) exhibits a differential response profile compared to OFC and subcallosal cingulate gyrus, suggesting a dissociable role between these regions in the reward processing of expertise. Finally, categorical responses (irrespective of aesthetic ratings) resulted in expertise effects in memory-related areas such as hippocampus and precuneus. These results highlight the fact that expertise not only modulates cognitive processing, but also modulates the response in reward related brain areas.