Willis Hanna E, Farenthold Berkeley, Millington-Truby Rebecca S, Willis Rebecca, Starling Lucy, Cavanaugh Matthew, Tamietto Marco, Huxlin Krystel, Bridge Holly
Wellcome Centre for Integrative Neuroimaging, Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, United Kingdom, OX3 9DU.
Flaum Eye Institute and Center for Visual Science, University of Rochester, Rochester, NY 14642, USA.
medRxiv. 2024 Oct 24:2024.10.24.24316036. doi: 10.1101/2024.10.24.24316036.
Damage to the primary visual cortex causes homonymous visual impairments that appear to benefit from visual discrimination training. However, whether improvements persist without continued training remains to be determined and was the focus of the present study. After a baseline assessment visit, 20 participants trained twice daily in their blind-field for a minimum of six months (median=155 sessions), using a motion discrimination and integration task. At the end of training, a return study visit was used to assess recovery. Three months later, 14 of the participants returned for a third study visit to assess persistence of recovery. At each study visit, motion discrimination and integration thresholds, Humphrey visual fields, and structural MRI scans were collected. Immediately after training, all but four participants showed improvements in the trained discrimination task, and shrinkage of the perimetrically-defined visual defect. While these gains were sustained in seven out of eleven participants who improved with training, four participants lost their improvement in motion discrimination thresholds at the follow-up visit. Persistence of recovery was not related to age, time since lesion, number of training sessions performed, proportion of V1 damaged, deficit size, or optic tract degeneration measured from structural MRI scans. The present findings underscore the potential of extended visual training to induce long-term improvements in stroke-induced vision loss. However, they also highlight the need for further investigations to better understand the mechanisms driving recovery, its persistence post-training, and especially heterogeneity among participants.
初级视觉皮层受损会导致同侧视力障碍，而视觉辨别训练似乎对此有益。然而，在没有持续训练的情况下改善是否会持续仍有待确定，这也是本研究的重点。在进行基线评估访视后，20名参与者每天在其盲视野中训练两次，为期至少六个月（中位数 = 155次训练），采用运动辨别和整合任务。训练结束时，通过回访研究来评估恢复情况。三个月后，14名参与者返回进行第三次研究访视，以评估恢复的持续性。在每次研究访视时，收集运动辨别和整合阈值、Humphrey视野以及结构MRI扫描数据。训练后，除四名参与者外，其他所有参与者在训练的辨别任务中均有改善，并且周边视野界定的视觉缺陷缩小。虽然在11名训练后有所改善的参与者中，有7名的这些改善得以维持，但有4名参与者在随访时运动辨别阈值的改善消失。恢复的持续性与年龄、损伤后的时间、进行的训练次数、V1受损比例、缺陷大小或从结构MRI扫描测量的视束退变无关。本研究结果强调了延长视觉训练对中风所致视力丧失诱导长期改善的潜力。然而，它们也凸显了进一步研究的必要性，以便更好地理解驱动恢复的机制、训练后恢复的持续性，尤其是参与者之间的异质性。
