Frassinetti Francesca, Bolognini Nadia, Bottari Davide, Bonora Annalisa, Làdavas Elisabetta
Department of Psychology, University of Bologna, Italy.
J Cogn Neurosci. 2005 Sep;17(9):1442-52. doi: 10.1162/0898929054985446.
In the present study, we investigated the possibility that bimodal audiovisual stimulation of the affected hemifield can improve perception of the visual events in the blind hemifield of hemianopic patients, as it was previously demonstrated in neglect patients. Moreover, it has been shown that "hetero-modal" and "sensory-specific" cortices are involved in cross-modal integration. Thus, the second aim of the present study was to examine whether audiovisual integration influences visual detection in patients with different cortical lesions responsible of different kinds of visual disorders. More specifically, we investigated cross-modal, audiovisual integration in patients with visual impairment due to a visual field deficit (e.g., hemianopia) or visuospatial attentional deficit (e.g., neglect) and patients with both hemianopia and neglect. Patients were asked to detect visual stimuli presented alone or in combination with auditory stimuli that could be spatially aligned or not with the visual ones. The results showed an enhancement of visual detection in cross-modal condition (spatially aligned condition) comparing to unimodal visual condition only in patients with hemianopia or neglect; by contrast, the multisensory integration did not occur when patients presented both deficits. These data suggest that patients with visual disorders can enormously benefit the multisensory integration. Moreover, they showed a different influence of cortical lesion on multisensory integration. Thus, the present results show the important adaptive meaning of multisensory integration and are very promising with respect to the possibility of recovery from visual and spatial impairments.
在本研究中，我们探究了对患侧半视野进行双模式视听刺激能否改善偏盲患者盲侧半视野中视觉事件的感知，正如之前在忽视症患者中所证实的那样。此外，研究表明“异模式”和“感觉特异性”皮层参与了跨模式整合。因此，本研究的第二个目的是检验视听整合是否会影响因不同类型视觉障碍而导致不同皮层损伤的患者的视觉检测。更具体地说，我们研究了因视野缺损（如偏盲）或视觉空间注意力缺损（如忽视）导致视力受损的患者以及同时患有偏盲和忽视的患者的跨模式视听整合情况。要求患者检测单独呈现的视觉刺激或与听觉刺激相结合的视觉刺激，听觉刺激在空间上可能与视觉刺激对齐，也可能不对齐。结果显示，与仅处于单模式视觉条件相比，在跨模式条件（空间对齐条件）下，仅偏盲或忽视患者的视觉检测得到了增强；相比之下，当患者同时存在这两种缺陷时，多感官整合并未发生。这些数据表明，患有视觉障碍的患者能从多感官整合中极大受益。此外，它们显示了皮层损伤对多感官整合的不同影响。因此，本研究结果显示了多感官整合的重要适应性意义，并且在视觉和空间损伤恢复的可能性方面非常有前景。
