Initial stages of visual information processing

迭代再入模型。神经科学的进步表明，折返信号是大脑区域之间沟通的主要形式。然而，知觉理论继续以前馈序列的形式出现。在我们的另一种说法中，感知来自大脑区域之间的迭代交换。该帐户基于对象替换掩码(OSM)，其中目标和掩码的初始组合显示继续仅与掩码一起进行。OSM隐含了重入处理，因为它不能仅用前馈处理来解释。该研究计划的主要目标是系统地探索迭代折返过程调节视觉知觉的知觉领域：基于由亮度轮廓、相对运动、分离纹理和双眼视差定义的刺激的形状知觉。探索年轻化效应。一个新物体的出现触发了一系列处理事件，从感觉编码到巩固和记忆存储。相比之下，如果同一对象在关键持续时间后仍处于查看状态，则不会继续重新处理该对象。相反，它导致信号被发送到更高的中心，表明任何重要的事情都没有改变。我发现，视觉系统可以在视觉或听觉瞬间事件后大约200毫秒的时间内，将“旧的”物体当作“新的”物体对待。我们将其称为返老还童效应，因为它表示旧轮廓获得新轮廓的一些属性的过程。进一步的实验表明，蓝斑-去甲肾上腺素(LC-NE)系统的阶段性激活是返老还童的决定因素。要探索这一新现象，还需要进行多组实验。视觉中的时间整合。为了研究视觉中的时间整合，点阵的两部分被连续显示，由刺激间间隔(ISI)分开。在ISIS超过100毫秒时，集成会恶化。在一项初步研究中，我改变了两个部分的持续时间，在20到100毫秒之间，发现在暴露持续时间超过大约60毫秒时，需要负的ISI才能达到80%的准确率。也就是说，一种模式，当它作为一个整体短暂地展示时，很容易被察觉到，当它之前和之后是它自身的部分时，它就被摧毁了。我打算继续这个有趣而又违反直觉的发现。主要目标：在迭代重入处理方面包含所有结果。

ITERATIVE-REENTRY MODEL. Advances in neuroscience have pointed to reentrant signalling as the main form of communication between brain regions. Yet, theories of perception continue to be couched in feed-forward sequences. In our alternative account, perceptions emerge from iterative exchanges between brain regions. That account is based on Object-Substitution Masking (OSM) in which an initial combined display of target and mask continues with the mask alone. OSM implicates reentrant processing because it cannot be explained by feed-forward processes alone. The main objective of the research programme is to explore systematically the perceptual domains in which iterative reentrant processes mediate visual perception: perception of form based on stimuli defined by luminance contours, relative motion, segregated texture, and binocular disparity. EXPLORING THE REJUVENATION EFFECT. The onset of a new object triggers a chain of processing events from sensory encoding to consolidation and memory storage. In contrast, the same object does not keep on being reprocessed if it remains on view beyond a critical duration. Instead, it causes signals to be sent to higher centres indicating that nothing of consequence has changed. I have found that the visual system can treat "old" objects as though they were "new" for a period of about 200 ms following a visual or auditory transient event. We refer to this as the rejuvenation effect, as it denotes a process by which old contours acquire some of the attributes of new contours. Further experiments have pointed to phasic activation of the Locus Coeruleus-Norepinephrine (LC-NE) system as the determinant of rejuvenation. Many sets of experiments need to be done to explore this novel phenomenon. TEMPORAL INTEGRATION IN VISION. To study temporal integration in vision, two halves of a dot-matrix are displayed successively, separated by an inter-stimulus interval (ISI). Integration deteriorates at ISIs beyond 100 ms. In a pilot study, I varied the duration of the two halves between 20 and 100 ms and found that at exposure durations beyond about 60 ms a NEGATIVE ISI was required to achieve an accuracy of 80%. Namely, a pattern that was easily perceived when displayed briefly as a whole, was destroyed when it was preceded and followed by parts of itself. I plan to pursue this fascinating and counterintuitive finding. Main objective: to encompass all results in terms of iterative reentrant processing.