Department of Psychology, Columbia University, New York, NY 10027, USA.
Philos Trans R Soc Lond B Biol Sci. 2012 May 19;367(1594):1401-11. doi: 10.1098/rstb.2011.0380.
Blindsight refers to the rare ability of V1-damaged patients to perform visual tasks such as forced-choice discrimination, even though these patients claim not to consciously see the relevant stimuli. This striking phenomenon can be described in the formal terms of signal detection theory. (i) Blindsight patients use an unusually conservative criterion to detect targets. (ii) In discrimination tasks, their confidence ratings are low and (iii) such confidence ratings poorly predict task accuracy on a trial-by-trial basis. (iv) Their detection capacity (d') is lower than expected based on their performance in forced-choice tasks. We propose a unifying explanation that accounts for these features: that blindsight is due to a failure to represent and update the statistical information regarding the internal visual neural response, i.e. a failure in metacognition. We provide computational simulation data to demonstrate that this model can qualitatively account for the detection theoretic features of blindsight. Because such metacognitive mechanisms are likely to depend on the prefrontal cortex, this suggests that although blindsight is typically due to damage to the primary visual cortex, distal influence to the prefrontal cortex by such damage may be critical. Recent brain imaging evidence supports this view.
盲目视觉指的是 V1 受损患者执行视觉任务(如强制选择辨别)的罕见能力,尽管这些患者声称没有有意识地看到相关刺激。这种引人注目的现象可以用信号检测理论的形式术语来描述。(i) 盲目视觉患者使用异常保守的标准来检测目标。(ii) 在辨别任务中,他们的置信度评分较低,(iii) 这种置信度评分在逐次试验的基础上不能很好地预测任务准确性。(iv) 他们的检测能力 (d') 低于根据他们在强制选择任务中的表现所预期的水平。我们提出了一个统一的解释,解释了这些特征:盲目视觉是由于未能表示和更新关于内部视觉神经反应的统计信息,即元认知失败。我们提供了计算模拟数据来证明该模型可以定性地解释盲目视觉的检测理论特征。由于这种元认知机制可能依赖于前额叶皮层,这表明尽管盲目视觉通常是由于初级视觉皮层受损引起的,但这种损伤对前额叶皮层的远程影响可能是关键的。最近的脑成像证据支持这一观点。