SPATIAL NEGLECT AND MECHANISMS OF ATTENTION

描述（申请人的摘要）：忽视综合征构成了一种 未能报告、回应或定位新的或有意义的刺激，其中 该失败不能归因于纯粹的感觉或运动缺陷。 每年有超过62，000名新患者被忽视。患者 忽视不受益于康复的程度相同， 没有忽视。这部分是由于忽视是一个 异质性综合征补救策略通常将忽视视为 一个单一的介绍，不考虑个人的差异。在 相比之下，失语症的治疗更有效， 策略基于性能子类型。研究的 一项提案试图确定忽视中的表现亚型， 可以制定更适当的治疗策略。性能 亚型将与病变部位相关联，以阐明 空间注意力的机制。虽然忽视包括广泛的 虽然它是一种广泛的缺陷，但它主要被视为注意力障碍。 注意加工三个领域中的表现亚型 持续注意、注意力和注意定向 在本提案中进行了调查。被忽视的病人被挑选出来 根据病变部位进行研究。持续的注意力是 由受试者注视目标刺激的能力定义， 同时监视周边视觉中的刺激（即，一个 Troxler衰落现象的检验）。持续关注是 预测为后皮质病变后的缺陷，然而， 抑制持续注意力的能力将在以下情况下出现缺陷 前皮质病变注意力能力的定义是 病人对整个刺激的反应能力。的大小 病人的错误被用来衡量注意力。前 皮质病变被预测会产生注意力的限制， 容量不根据半空间位置的变化， 刺激。忽视中的注意定向是由空间 忽视错误的方向。后皮质病变 预测产生固定在一个空间中的方向偏差， 维度前部损伤后的方向偏差会有所不同 根据刺激位置和定向提示。80例 单侧缺血性脑梗死后忽视和40例正常对照 我们将研究这些假设。这些研究将增加 关于注意力操作定位的知识。他们 将通过识别以下亚型促进忽视康复： 性能

DESCRIPTION (Applicant's Abstract): The neglect syndrome constitutes a failure to report, respond or orient to novel or meaningful stimuli where the failure is not attributable to a pure sensory or motor deficit. Over 62,000 new patients per year evidence neglect. Patients with neglect do not profit from rehabilitation to the same degree as those without neglect. This is due, in part, to the fact that neglect is a heterogenous syndrome. Remediation strategies often treat neglect as a single presentation and fail to consider individual variation. In contrast, the treatment of aphasia is more efficacious as treatment strategies are predicated on performance subtypes. Studies in this proposal attempt to identify performance subtypes in neglect so that more appropriate treatment strategies can be developed. Performance subtypes will be associated with lesion location to elucidate the mechanisms of spatial attention. Although neglect encompasses a broad spectrum of deficits, it is primarily viewed as a disorder of attention. Performance subtypes within three domains of attentional processing sustained attention, attentional capacity and attentional orientation are investigated in this proposal. Patients with neglect are selected for study on the basis of lesion location. Sustained attention is defined by a subjects ability to fixate a target stimulus and simultaneously monitor stimuli in peripheral vision (i.e., an examination of the Troxler fading phenomenon). Sustained attention is predicted to be deficit following posterior cortical lesions, whereas, the ability to inhibit sustained attention will be deficit following anterior cortical lesions. Attentional capacity is defined by the patient's ability to attend to a whole stimulus. The size of the patient's error is used to measure attentional capacity. Anterior cortical lesions are predicted to produce limitations in attentional capacity that do not change according to the hemispatial location of the stimulus. Attentional orientation in neglect is defined by the spatial direction of the neglect error. Posterior cortical lesions are predicted to produce orientation biases that are fixed in one spatial dimension. Orientation biases following anterior lesions will vary according to stimulus location and directional cuing. 80 patients with neglect following unilateral, ischemic infarctions and 40 normal controls will be studied to test these hypotheses. These studies will increase knowledge regarding the localization of attentional operations. They will facilitate neglect rehabilitation through identifying subtypes of performance.