高社交焦虑者识别动态情绪面孔的神经机制

近年来, 大量的研究对高社交焦虑者的情绪面孔加工和社交焦虑的干预进行了考察, 取得了丰富成果, 但仍存在以下不足: (1) 在以往的中国动态情绪面孔库存中, 刺激材料的情绪类别、视频维度以及视频持续时间的种类偏少; (2) 高社交焦虑者识别动态情绪面孔的神经机制未被系统探讨; (3) 注意偏向训练的效果存在争议, 即一些研究者发现注意偏向训练对社交焦虑有明显的缓解作用, 而其他研究者却未发现注意偏向训练的效果。针对这些不足, 当前项目建设的中国人动态情绪面孔库拟增加刺激材料的情绪类别、视频维度以及视频持续时间的类型, 此外运用神经科学的技术系统探究高社交焦虑者对动态情绪面孔的识别机制, 最后采用工作记忆训练改善高社交焦虑者对动态生气面孔识别的注意偏向。本研究团队提出了高社交焦虑个体识别动态情绪面孔的神经机制模型, 该模型主要包括机制和干预两个部分。本项目的开展不仅为动态情绪面孔加工和社交焦虑研究提供了新视角, 还突破原有单一的研究方法, 拟从行为、电生理和脑成像三个层次进行研究。研究成果将促进社交焦虑干预工作的开展, 从而缓解社交焦虑个体的心理健康问题, 对于提高他们的幸福感和生命质量有重要价值。     

Implicit processing of emotional words by children with Post-Traumatic Stress Disorder: An fMRI investigation

Background/ObjectiveIn the last decade, socio-political violence in Colombia (South America) has created an environment of extreme/chronic stress. In this study, brain imaging technology (fMRI) and behavioral task performance were used to measure potential deficits in executive functioning for emotional processing in Colombian children.MethodParticipants (22 Post-Traumatic Stress Disorder, PTSD and 22 neurotypical, NT) were asked to perform a word task with implicit emotional salience, which required them to report the color of the ink in which a positive, negative or neutral word was printed.ResultsMixed design analysis of variance showed no group differences in accuracy for determining ink color when presented as a positive or neutral word. However, PTSD children were significantly less accurate (negative words) and notably slower (both positive and negative words) at determining ink color when presented in the context of an emotional word. PTSD processing of positive and negative words was associated with hypoactivation in the superior and middle frontal gyri of the right hemisphere in comparison to NT children.ConclusionsThese results may reflect a deficit in executive functioning for emotionally laden stimuli, perhaps induced as a by-product of their traumatic experiences.     

Aggression is associated with greater subsequent alcohol consumption: A shared neural basis in the ventral striatum

Alcohol use and abuse (e.g., binge drinking) are among the most reliable causes of aggressive behavior. Conversely, people with aggressive dispositions (e.g., intermittent explosive disorder) are at greater risk for subsequent substance abuse. Yet it remains unknown why aggression might promote subsequent alcohol use. Both aggressive acts and alcohol use are rewarding and linked to greater activity in neural reward circuitry. Through this shared instantiation of reward, aggression may then increase subsequent alcohol consumption. Supporting this mechanistic hypothesis, participants’ aggressive behavior directed at someone who had recently rejected them, was associated with more subsequent beer consumption on an ad‐lib drinking task. Using functional MRI, both aggressive behavior and beer consumption were associated with greater activity in the bilateral ventral striatum during acts of retaliatory aggression. These results imply that aggression is linked to subsequent alcohol abuse, and that a mechanism underlying this effect is likely to be the activation of the brain's reward circuitry during aggressive acts.

     

fMRI evidence for dorsal stream processing abnormality in adults born preterm

We investigated the consequences of premature birth on the functional neuroanatomy of the dorsal stream of visual processing. fMRI was recorded while sixteen healthy participants, 8 (two men) adults (19 years 6 months old, SD 10 months) born premature (mean gestational age 30 weeks), referred to as Premas, and 8 (two men) matched controls (20 years 1 month old, SD 13 months), performed a 1-back memory task of Object or Grip information using a hand grasping a drinking vessel as stimulus. While history of prematurity did not significantly affect task performance, Group by Task analysis of variance in regions of interest spanning the occipital, temporal and parietal lobes revealed main effects of Task and interactions between the two factors. Object processing activated the left inferior occipital cortex and bilateral ventral temporal regions, belonging to the ventral stream, with no effect of Group. Grip processing across groups activated the early visual cortex and the left supramarginal gyrus belonging to the dorsal stream. Group effect on the brain activity during Grip suggested that Controls represented the actions’ goal while Premas relied more on low-level visual information. This shift from higher- to lower-order visual processing between Controls and Premas may reflect a more general trend, in which Premas inadequately recruit higher-order visual functions for dorsal stream task performance, and rely more on lower-level functions.     

Comparing the neural correlates of affective and cognitive theory of mind using fMRI: Involvement of the basal ganglia in affective theory of mind

Theory of Mind (ToM) is the ability to infer other people’s mental states like intentions or desires. ToM can be differentiated into affective (i.e., recognizing the feelings of another person) and cognitive (i.e., inferring the mental state of the counterpart) subcomponents. Recently, subcortical structures such as the basal ganglia (BG) have also been ascribed to the multifaceted concept ToM and most BG disorders have been reported to elicit ToM deficits. In order to assess both the correlates of affective and cognitive ToM as well as involvement of the basal ganglia, 30 healthy participants underwent event-related fMRI scanning, neuropsychological testing, and filled in questionnaires concerning different aspects of ToM and empathy. Directly contrasting affective (aff) as well as cognitive (cog) ToM to the control (phy) condition, activation was found in classical ToM regions, namely parts of the temporal lobe including the superior temporal sulcus, the supplementary motor area, and parietal structures in the right hemisphere. The contrast aff > phy yielded additional activation in the orbitofrontal cortex on the right and the cingulate cortex, the precentral and inferior frontal gyrus and the cerebellum on the left. The right BG were recruited in this contrast as well. The direct contrast aff > cog showed activation in the temporoparietal junction and the cingulate cortex on the right as well as in the left supplementary motor area. The reverse contrast cog > aff however did not yield any significant clusters. In summary, affective and cognitive ToM partly share neural correlates but can also be differentiated anatomically. Furthermore, the BG are involved in affective ToM and thus their contribution is discussed as possibly providing a motor component of simulation processes, particularly in affective ToM.     

How reading acquisition changes children’s spoken language network

To examine the influence of age and reading proficiency on the development of the spoken language network, we tested 6- and 9-years-old children listening to native and foreign sentences in a slow event-related fMRI paradigm. We observed a stable organization of the peri-sylvian areas during this time period with a left dominance in the superior temporal sulcus and inferior frontal region. A year of reading instruction was nevertheless sufficient to increase activation in regions involved in phonological representations (posterior superior temporal region) and sentence integration (temporal pole and pars orbitalis). A top-down activation of the left inferior temporal cortex surrounding the visual word form area, was also observed but only in 9 year-olds (3 years of reading practice) listening to their native language. These results emphasize how a successful cultural practice, reading, slots in the biological constraints of the innate spoken language network.     

Understanding youth antisocial behavior using neuroscience through a developmental psychopathology lens: Review,integration, and directions for research

Youth antisocial behavior (AB) is an important public health concern impacting perpetrators, victims, and society. Functional neuroimaging is becoming a more common and useful modality for understanding neural correlates of youth AB. Although there has been a recent increase in neuroimaging studies of youth AB and corresponding theoretical articles on the neurobiology of AB, there has been little work critically examining the strengths and weaknesses of individual studies and using this knowledge to inform the design of future studies. Additionally, research on neuroimaging and youth AB has not been integrated within the broader framework of developmental psychopathology. Thus, this paper provides an in-depth review of the youth AB functional neuroimaging literature with the following goals: (1) to evaluate how this literature has informed our understanding of youth AB, (2) to evaluate current neuroimaging studies of youth AB from a developmental psychopathology perspective with a focus on integrating research from neuroscience and developmental psychopathology, as well as placing this research in the context of other related areas (e.g., psychopathy, molecular genetics), and (3) to examine strengths and weaknesses of neuroimaging and behavioral studies of youth AB to suggest how future studies can develop a more informed and integrated understanding of youth AB.     

Brain correlates of subjective freedom of choice

The subjective feeling of free choice is an important feature of human experience. Experimental tasks have typically studied free choice by contrasting free and instructed selection of response alternatives. These tasks have been criticised, and it remains unclear how they relate to the subjective feeling of freely choosing. We replicated previous findings of the fMRI correlates of free choice, defined objectively. We introduced a novel task in which participants could experience and report a graded sense of free choice. BOLD responses for conditions subjectively experienced as free identified a postcentral area distinct from the areas typically considered to be involved in free action. Thus, the brain correlates of subjective feeling of free action were not directly related to any established brain correlates of objectively-defined free action. Our results call into question traditional assumptions about the relation between subjective experience of choosing and activity in the brain’s so-called voluntary motor areas.     

Alterations in working memory networks in amnestic mild cognitive impairment

Patients with amnestic mild cognitive impairment (aMCI) show preserved or mildly impaired working memory, despite their deficits in episodic memory. We aimed to identify performance and/or neural differences between aMCI patients and matched controls on a standard working memory fMRI task. Neuropsychological assessment demonstrated aMCI impairments in verbal and visual episodic long-term memory, with intact IQ and executive function. Participants completed a standard three-level N-back task where patients were unimpaired. Functional activations in the control group were found in expected areas, including the inferior parietal lobule and dorsolateral prefrontal cortex. Group differences were found in the insula and lingual gyrus and, in a region of interest analysis, in the hippocampus. In all cases, these were caused by an absence of task-related deactivations in the aMCI group. The results are consistent with reports of failure in task-related deacivations in aMCI and could be early indications of pathology.     

Specific and nonspecific thalamocortical functional connectivity in normal and vegetative states

Recent theoretical advances describing consciousness from information and integration have highlighted the unique role of the thalamocortical system in leading to integrated information and thus, consciousness. Here, we examined the differential distributions of specific and nonspecific thalamocortical functional connections using resting-state fMRI in a group of healthy subjects and vegetative-state patients. We found that both thalamic systems were widely distributed, but they exhibited different patterns. Nonspecific connections were preferentially associated with brain regions involved in higher-order cognitive processing, self-awareness and introspective mentalizing (e.g., the dorsal prefrontal and anterior cingulate cortices). In contrast, specific connections were prevalent in the ventral and posterior part of the prefrontal and precuneus, known involved in representing externally-directed attentions. Significant reductions of functional connectivity in both systems, especially the nonspecific system, were observed in VS. These data suggest that brain networks sustaining information and integration may be differentiated by the nature of their thalamic functional connectivity.