Form and Motion Integration

描述（由申请人提供）：复杂环境中的视觉要求能够在视野的大部分范围内整合方向和运动的局部测量。此外，这种整合必须对与行为相关的刺激有选择性，视觉系统必须能够从背景杂乱中分离出相关的刺激信息。如何实现这一目标将在正常视觉发育和弱视患者中进行研究，使用心理物理、电生理和功能成像方法的组合。我们将通过功能磁共振成像确定的皮质源与使用源定位技术记录的高密度脑电图/脑磁图的神经元活动联系起来。注意对反应敏感性的影响程度将通过比较观察者对测试刺激进行运动/形式相关区分时的脑电图反应与观察者执行注意力要求分散任务时的反应来确定。对整体运动和形式刺激的敏感性将在具有斜视和/或弱视历史的视觉成熟观察者中使用心理物理和电生理测量来确定。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。这些任务可能探测纹外区域的活动，由于发育序列延长，纹外区域可能特别脆弱。

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.