Organization and Development of Sensory Systems and Emotions

本项目根据以往的专门知识和成就有三个主要主题。第一部分考察感觉系统和多感觉整合。视觉-触觉刺激的多感觉整合将着眼于不同半空间内或跨不同半空间的整合，以研究当一起呈现而不是单独呈现时对表现的促进作用。特别感兴趣的是，当刺激呈现在不同的半空间时，CC如何有助于整合。这是通过比较神经型和CC切片或发育不全的受试者来实现的。行为结果的解释将使用fMRI成像进行验证。还将在植入颅内EEG电极（iEEG）的患者中检查视觉和听觉处理，以及当刺激直接呈现给一个或通过半球间通路（即胼胝体（CC））时，如何实现视觉对象识别的神经元结合。特别令人感兴趣的是阿尔法和伽马波，以及更高级别的皮层区域如何通过自上而下的促进来促进识别，这对于复杂的刺激来说，当它们第二次在半球内或半球间呈现时。类似的过程将检查听觉刺激呈现在不同的识别水平，也就是说，当复杂的刺激（铃声，声音）呈现在不同的信号噪声比。第二个主题将研究情绪处理。因此，我们将研究如何情绪的视觉刺激呈现在周边视网膜，它具有较差的空间分辨率，但快速传输到视觉区域，影响识别时，情绪负荷的刺激呈现在中央视觉，它具有高分辨率，但传输时间较慢。为了进一步验证我们的假设，刺激也将被调制，并使用正常和修改的空间分辨率。我们还将研究大脑半球对不同唤醒（强，中性）和效价（积极，消极，中性）值的情绪刺激的专门化。实际上，在中央凹呈现时，右半球（纹状体-边缘区）对唤醒起主导作用，而左眶额半球对识别起主导作用。这些研究将使用行为评估（识别反应时间）、电生理测量（皮肤电导反应- SCR）和MEG成像。我们还将在植入患者中使用我们的iEEG范例检查上述子主题。这些患者还将接受对疼痛的同理心测试，即他们在皮层水平上理解和体验他人情感感受和需求的能力。因此，病人必须识别演员所表达的疼痛，我们检查他们的皮层反应。另一个副主题是情绪决策，当一个主题必须对待风险和安全的条件，以赢得或失去金钱。在这两种情况下，岛叶皮质是感兴趣的目标区域。我们将特别关注镜像神经元系统，也就是说，神经元在经历或观察到他人的共情或冒险决策时，反应相似。最后，我们最近验证了可行性的一个新主题将研究上述刺激（例如，复杂图像的视觉处理、情绪面部识别）在这些患者中在单细胞水平上进行治疗。很少有具体的项目，因为我们仍然在掌握的过程中的所有组成部分的技术记录在患者的单细胞反应的限制。然而，我们有信心，我们将有效地执行这一点，因为我们最近记录了一名患者枕下回的四个神经元，其中一个神经元对快乐或愤怒的面孔表现出不同的激活。这些结果预示着令人兴奋的可能性。

The present project has three principal themes based on past expertise and accomplishments. The first examines sensory system and multi-sensory integration. Multisensory integration of visuo-tactile stimuli will look at integration within or across different hemispaces to study the facilitation of performance when presented together instead of separately. Of particular interest when stimuli are presented in different hemispaces is how the CC contributes to integration. This is achieved by comparing neurotypical and CC sectioned or agenesis subjects. The interpretations of the behavioral results will be validated using fMRI imaging. Visual and auditory processing will also be examined in patients implanted with intracranial EEG electrodes (iEEG) and how neuronal binding at visual object recognition is achieved when stimuli are presented directly to one or via the inter-hemispheric pathway, namely the corpus callosum (CC). Of particular interest are the alpha and gamma waves and how higher level cortical areas facilitate recognition through top-down facilitation, and this for complex stimuli when they are presented intra- or inter-hemispherically for a second time. Similar processes will be examined for auditory stimuli presented at different levels of recognition, that is, when complex stimuli (bells, voices) are presented at different signal to noise ratios. The second theme will examine emotional processing. Thus, we shall examine how emotional visual stimuli presented in peripheral retina, which has poor spatial resolution but transmits rapidly to visual areas, influences recognition when emotionally laden stimuli are presented in central vision, which has high resolution but slower transmission time. To further validate our hypothesis, stimuli will also be modulated and presented using normal and modified spatial resolution. We shall also examine the hemispheric specialization for emotional stimuli of different arousal (strong, neutral) and valence (positive negative, neutral) values. In effect, there appears to be a right hemispheric dominance (striato-limbic areas) for arousal but a left orbito-frontal one for recognition at foveal presentation. These studies will use behavioral assessments (reaction time at recognition), electrophysiological measures (skin conductance response- SCR) and MEG imaging. We shall also examine the above sub-themes using our iEEG paradigm in implanted patients. These patients will also be tested on empathy for pain, namely, their capacity at the cortical level to understand and experience other’s emotional feelings and needs. Thus the patient has to recognize the pain expressed by an actor and we examine their cortical responses. Another sub-theme is emotional decison making when a subject has to treat risky and safe conditions to win or loose money. In both, the insular cortex is the target region of interest. We shall pay particular attention to the mirror neuron system, that is, neurons that react similarly whether they experience or observe empathy or risky decision making in others. Finally, a new theme for which we have recently validated the feasibility will examine how the stimuli presented above (e.g., visual treatment of complex images, emotional face recognition) are treated at the single-cell level in these patients. Few specific projects are presented since we are still in the process of mastering all the components of the technique given the constraints of recording in patients single-cell responses. However, we are confident that we shall carry this out effectively since we have recently recorded four neurons in one patient in the inferior occipital gyrus, including one neuron that showed differential activations to happy or angry faces. These results promise exciting possibilities.