Visual search improvement in hemianopic patients after audio-visual stimulation
Visual search improvement in hemianopic patients after audio-visual stimulation
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DOI：
10.1093/brain/awh656
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发表时间：
2005-12-01
期刊：
影响因子：
14.5
通讯作者：
Làdavas, E
中科院分区：
文献类型：
--
作者：
Bolognini, N;Rasi, F;Làdavas, E
在视野缺损的康复中最有效的技术之一是基于实施眼科策略来补偿视野损失。在本研究中，我们开发了一种新的康复方法的基础上的视听刺激的视野。由于它已被证明，视听相互作用的多感觉神经元可以改善偏盲患者的时间视觉感知，本研究的目的是验证是否有系统的视听刺激可能会导致一个持久的改善视野障碍。8例慢性视野缺损患者接受了视觉目标检测训练。在训练期间，视觉刺激可以单独呈现，即单峰条件，或者与声学刺激一起呈现，即交叉模态条件。在跨模态条件下，视觉刺激和声刺激之间的空间差异系统地变化（0、16和32度差异）。此外，在交叉模态条件下的声刺激和视觉目标之间的时间间隔逐渐减少，从500到0毫秒。患者接受了治疗，每天4小时，在近2周的时间。结果显示，在训练过程中视觉检测的逐步改善和视觉眼探索的改善，使患者能够有效地补偿视力丧失。更有趣的是，治疗收益转移到评估视野探索的功能测量和日常生活活动，在1个月的随访控制期内保持稳定。这些发现对于利用人类多感觉能力从单峰感觉障碍中恢复的可能性非常有希望。
One of the most effective techniques in the rehabilitation of visual field defects is based on implementation of oculomotor strategies to compensate for visual field loss. In the present study we develop a new rehabilitation approach based on the audio-visual stimulation of the visual field. Since it has been demonstrated that audio-visual interaction in multisensory neurons can improve temporally visual perception in patients with hemianopia, the aim of the present study was to verify whether a systematic audio-visual stimulation might induce a long-lasting amelioration of visual field disorders. Eight patients with chronic visual field defects were trained to detect the presence of visual targets. During the training, the visual stimulus could be presented alone, i.e. unimodal condition, or together with an acoustic stimulus, i.e. crossmodal conditions. In the crossmodal conditions, the spatial disparity between the visual and the acoustic stimuli were systematically varied (0, 16 and 32 degrees of disparity). Furthermore, the temporal interval between the acoustic stimulus and the visual target in the crossmodal conditions was gradually reduced from 500 to 0 ms. Patients underwent the treatment for 4 h daily, over a period of nearly 2 weeks. The results showed a progressive improvement of visual detections during the training and an improvement of visual oculomotor exploration that allowed patients to efficiently compensate for the loss of vision. More interesting, there was a transfer of treatment gains to functional measures assessing visual field exploration and to daily-life activities, which was found stable at the 1 month follow-up control session. These findings are very promising with respect to the possibility of taking advantage of human multisensory capabilities to recover from unimodal sensory impairments.