Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands; Department of Neurology, University Medical Center Utrecht, Utrecht, The Netherlands.
Department of Psychology, University of Amsterdam, Amsterdam, The Netherlands; Amsterdam Brain and Cognition (ABC) Center, University of Amsterdam, The Netherlands.
Neuropsychologia. 2019 May;128:270-275. doi: 10.1016/j.neuropsychologia.2018.03.029. Epub 2018 Mar 28.
Blindsight refers to the observation of residual visual abilities in the hemianopic field of patients without a functional V1. Given the within- and between-subject variability in the preserved abilities and the phenomenal experience of blindsight patients, the fine-grained description of the phenomenon is still debated. Here we tested a patient with established "perceptual" and "attentional" blindsight (c.f. Danckert and Rossetti, 2005). Using a pointing paradigm patient MS, who suffers from a complete left homonymous hemianopia, showed clear above chance manual localisation of 'unseen' targets. In addition, target presentations in his blind field led MS, on occasion, to spontaneous responses towards his sighted field. Structural and functional magnetic resonance imaging was conducted to evaluate the magnitude of V1 damage. Results revealed the presence of a calcarine sulcus in both hemispheres, yet his right V1 is reduced, structurally disconnected and shows no fMRI response to visual stimuli. Thus, visual stimulation of his blind field can lead to "action blindsight" and spontaneous antipointing, in absence of a functional right V1. With respect to the antipointing, we suggest that MS may have registered the stimulation and subsequently presumes it must have been in his intact half field.
盲目视觉是指在没有功能 V1 的情况下,患者的半视野中观察到残留的视觉能力。鉴于保留能力和盲目视觉患者的现象体验在个体内和个体间存在可变性,对该现象的精细描述仍存在争议。在这里,我们测试了一位具有既定“知觉”和“注意”盲目视觉的患者 MS(c.f. Danckert 和 Rossetti, 2005)。使用指向范式,患有完全左侧同视性偏盲的患者 MS 清楚地表现出对手动“看不见”目标的机会性定位。此外,在他的盲区内呈现目标时,MS 偶尔会自发地朝他的视力正常的视野做出反应。进行了结构和功能磁共振成像以评估 V1 损伤的程度。结果表明,在两个半球都存在楔前回,但他的右侧 V1 减少,结构上断开,并且对视觉刺激没有 fMRI 反应。因此,对他的盲区内的视觉刺激可以导致“动作盲目视觉”和自发的反指向,而右侧 V1 没有功能。关于反指向,我们认为 MS 可能已经记录了刺激,随后假定它一定在他未受损的半视野中。