Emotional dysfunction and childhood behavioral disturbance

在以前的工作中，我们主要使用神经心理学调查来确定与Cd+CU相关的功能损害。我们发现患有这种障碍的青少年在以下方面表现出明显的困难：(1)对恐惧表情的识别，这是杏仁核功能障碍的神经心理标志；(2)情绪学习的基本形式，刺激-强化联系，这对社会化至关重要(也是杏仁核依赖的)；(3)决策依赖于结果强化信息的适当表征，这是脑室前额皮质功能障碍的神经心理标志。 在我们最近的工作中，我们使用了事件相关功能磁共振成像来直接评估患有CD+CU的青少年的杏仁核和前额叶腹内侧皮质是否存在非典型功能。特别是，在一项研究中，我们专门研究了患有CD+CU的青少年对恐惧和愤怒表情的神经反应。对表情，特别是恐惧的表情做出适当的反应，对于道德社会化非常重要。这项研究表明，与典型的发育中青少年和患有注意力缺陷多动障碍(ADHD)的青少年相比，患有CD+CU的青少年在处理恐惧表情时，杏仁核对恐惧表情的反应减少，杏仁核和腹内侧额前皮质之间的连接性降低。有趣的是，在对愤怒表情的反应上，没有群体差异。这种表达的处理通常不依赖于杏仁核。简而言之，这项研究表明：首先，在CD+CU青少年中，功能障碍反应是针对恐惧情绪的，而不是中性或愤怒情绪的。第二，在CD+CU类似损害的青少年中，ADHD青少年没有看到损害的选择性。 在最近对患有CD+CU的青少年进行的另一项功能磁共振研究中，我们检查了反转学习过程中腹内侧额叶皮质和其他额叶系统的功能。反转学习衡量的是个体在不再获得奖励时改变反应的能力。这种能力很重要，因为它减少了个体在继续做不再实现目标的行动的基础上经历挫折和愤怒的可能性。在我们以前的神经心理学研究中，我们观察到Cd+CU青少年在反转学习方面存在明显的困难。在我们最近的fMRI研究中，我们确定了这种困难的神经基础。具体地说，虽然通常发育中的青少年和患有ADHD的青少年以及健康成年人在某个行动导致意外惩罚(这是行为应该改变的提示)时，额叶腹内侧皮层的反应会减少，但患有CD+CU的青少年则不会。这种预测误差信号对于学习和确保个体不会回到现在的不良反应特别重要。 在我们目前的工作中，我们专注于确定这一人群中眼眶额叶皮质损伤的计算细节。具体地说，现在看来，患有CD+CU的年轻人在利用眼眶额叶皮质(和尾状核)产生预测错误方面面临着特别的困难。当一个人收到意想不到的奖励/惩罚，或者当他们没有收到他们期望的奖励/惩罚时，就会出现预测错误。预测误差很重要，因为它们是进行快速学习的关键线索。情绪化学习困难是这一人群社会化困难的核心。

In previous work, we primarily used neuropsychological investigations to determine the functional impairments associated with CD+CU. We identified that adolescents with this disorder showed marked difficulties with: (1) the recognition of fearful expressions, a neuropsychological marker of amygdala dysfunction; (2) a basic form of emotional learning, stimulus-reinforcement association, which is critical for socialization (and also is amygdala dependent); (3) decision making reliant on the appropriate representation of outcome reinforcement information, a neuropsychological marker of dysfunction within ventromdial prefrontal cortex. In our most recent work, we have used event related functional Magnetic Resonance Imaging to directly assess whether the amygdala and ventromedial prefrontal cortex is functioning atypically in adolescents with CD+CU. In particular, in one study we specifically addressed the neural responses of adolescents with CD+CU to fearful and angry expressions. An appropriate response to expressions, particularly fearful expressions, is important for moral socialization. This study revealed that adolescents with CD+CU showed reduced amygdala responses to fearful expressions and reduced connectivity between the amygdala and ventromedial prefrontal cortex when processing fearful expressions when compared with both typically developing adolescents and adolescents with Attention Deficit Hyperactivity Disorder (ADHD). Interesting, there were no group differences in the response to angry expressions. The processing of this expression is not typically reliant on the amygdala. In short, this study suggested: First, specificity in the nature of the impairment seen in adolescents with CD+CU the dysfunctional responding was specific for fearful expressions and not seen to neutral or angry expressions. Second, selectivity of the impairment in adolescents with CD+CU comparable impairment was not seen in adolescents with ADHD. In another recent fMRI study with adolescents with CD+CU, we examined the functioning of ventromedial frontal cortex and other frontal systems during reversal learning. Reversal learning indexes the individuals ability to change a response when it is no longer being rewarded. This ability is important because it reduces the probability that the individual with experience frustration and rage on the basis of continuing to do actions that no longer achieve their goals. In our previous neuropsychological work, we had observed that adolescents with CD+CU had marked difficulties with reversal learning. In our recent fMRI study, we identified the neural basis of this difficulty. Specifically, while typically developing adolescents and adolescents with ADHD, as well as healthy adults, show a reduced response within ventromedial frontal cortex when an action results in an unexpected punishment (a cue that behavior should change), adolescents with CD+CU do not. This prediction error signal is particularly important for learning and making sure that the individual does not return to now bad response. In our current work, we have concentrated on determining the computational details of the orbital frontal cortex impairment in this population. Specifically, it now appears that youth with CD+CU face particular difficulties in using orbital frontal cortex (and caudate) to generate prediction errors. Prediction errors occur when an individual receives unexpected reward/ punishment or when they fail to receive the reward/ punishment they were expecting. Prediction errors are important because they are critical cues to engage in rapid learning. Difficulties in emotional learning are at the heart of the difficulties with socialization in this population.