Form and Motion Integration

描述(申请人提供)：复杂环境中的视觉需要整合大部分视野上的方位和运动的局部测量的能力。此外，这种整合必须对行为相关的刺激具有选择性，视觉系统必须能够将相关的刺激信息从背景杂乱中分离出来。如何做到这一点将在正常视觉发育期间和弱视患者中使用心理物理、电生理和功能成像方法相结合的方法进行研究。我们将把fMRI确定的皮层来源与使用高密度脑电/脑磁图记录的神经元活动联系起来，使用来源定位技术。注意力对反应敏感度的影响程度将通过比较观察者对测试刺激进行运动/形式相关辨别时的脑电反应与观察者执行注意力要求分散注意力的任务时的反应来确定。对有斜视和/或弱视病史的视力成熟的观察者，将使用心理物理和电生理方法来确定对全局运动和形状刺激的敏感性。同样刺激的发育顺序也将在正常发育的婴儿和儿童中确定。这些任务可能会探测纹状体外区域的活动，这些区域可能由于发育序列的延长而特别脆弱。

DESCRIPTION (provided by applicant): Vision in complex environments requires the ability to integrate local measurements of orientation and motion over large parts of the visual field. Moreover, this integration must be selective for stimuli that are behaviorally relevant and the visual system must be able to separate relevant stimulus information from background clutter. How this is accomplished will be studied during normal visual development and in patients with amblyopia using a combination of psychophysical, electrophysiological and functional imaging approaches. We will link the cortical sources determined by fMRI to neuronal activity recorded with high-density EEG/MEG using source localization techniques. The degree to which attention influences response sensitivity will be determined by comparing EEG responses when observers are making motion/form relevant discriminations on the test stimuli versus responses made when the observers are performing an attentionally demanding distractor task. Sensitivity to global motion and form stimuli will be determined in visually mature observers with a history of strabismus and/or amblyopia using both psychophysical and electrophysiological measures. Developmental sequences for the same stimuli will also be determined in normally developing infants and children. These tasks are likely to probe activity in extra-striate areas which may be particularly vulnerable due to extended developmental sequences.