SELECTIVE ATTENTION AT EARLY STAGES OF VISUAL PROCESSING

描述（由申请人提供）：在过去的30年里，在理解参与选择性视觉注意的大脑回路方面取得了巨大的进展。目前的一些模型提出，“注意力信号”起源于高皮质区域（例如额叶和顶叶皮质），然后以自上而下的方式转移到视觉处理的早期阶段。 这个模型与视觉通路中从高级到低级的反馈连接的丰富解剖网络的存在是一致的。 然而，反馈连接到达初级视觉皮层（V-1）和外侧膝状体核（LGN）的处理阶段。 因此，注意可能通过在视觉通路的初始阶段起作用来调节感知。 与这一假设相一致，越来越多的证据表明，选择性视觉注意调节V-1的活动，最近的一项解剖学研究发现了LGN中注意调节的第一个证据。 选择性视觉注意的一个重要特征是它的视网膜定位特异性，注意的焦点可以被限制在视觉空间的非常小的区域。一个显着的特异性已被证明在几个皮质区，包括V-1，但不是在LGN。 视觉注意可以调节LGN活动的证据缺失，因此是一个重要的证据。 目前尚不清楚视网膜定位选择性LGN调节是如何进行的。 在这个建议中，视网膜特异性LGN注意调制将被测量同时记录从多个膝状体神经元，而动物执行的任务，需要选择性的视觉注意。 此外，还将研究LGN调制是否通过从LGN和V-1细胞进行同步记录而可靠地转移到V-1，其中感受野在视觉空间中对齐。 精确了解选择性视觉注意中涉及的回路对于理解大脑如何处理视觉信息非常重要。对这种回路的研究最终将导致预防和治疗严重的注意力缺陷，这种缺陷在许多精神和神经系统疾病中很常见。

DESCRIPTION (provided by applicant): In the last 30 years, there has been an enormous progress in understanding the brain circuits involved in selective visual attention. Some current models propose that the 'attention signal' originates in high cortical areas (e.g. frontal and parietal cortex) and then is transferred in a top-down fashion to earlier stages in visual processing. This model is consistent with the existence of a rich anatomical network of feedback connections that go from higher to lower stages in the visual pathway. However, feedback connections reach stages as low in processing as the primary visual cortex (V-1 ) and the Lateral Geniculate Nucleus (LGN). Therefore, attention could potentially modulate perception by acting at the initial stages of the visual pathway. Consistent with this hypothesis, increasing evidence indicates that selective visual attention modulates the activity of V-1 and one recent anatomical study found the first evidence for attentional modulations in LGN. An important characteristic of selective visual attention is its retinotopic specificity the focus of attention can be restricted to very small regions of visual space. A remarkable specificity has been demonstrated in several cortical areas including V-1 but not in LGN. The demonstration that visual attention can modulate LGN activity is missing therefore an important piece of evidence. It is not known how retinotopically selective LGN modulations can be. In this proposal, the retinotopic specificity of LGN attentional modulations will be measured by simultaneously recording from multiple geniculate neurons while an animal performs a task that requires selective visual attention. In addition, it will be investigated whether LGN modulations are reliably transferred to V-1 by doing simultaneous recordings from LGN and V-1 cells with receptive fields aligned in visual space. A precise knowledge of the circuits involved in selective visual attention is important to understand how the brain processes visual information. The study of this circuitry will eventually lead to the prevention and treatment of serious attentional deficits that are common in many psychiatric and neurological disorders.