Featural blindsight in a 2-Interval Forced-Choice task

The comparison between conscious and unconscious perception is a cornerstone of consciousness science. However, most studies reporting above-chance discrimination of unseen stimuli do not control for criterion biases when assessing awareness. We tested whether observers can identify subjectively invisible offsets of Vernier stimuli when visibility is probed using a bias-free task. To reduce visibility, stimuli were either backward masked or presented for very brief durations (1-3 milliseconds) using a modern-day Tachistoscope. We found some behavioral indicators of perception without awareness, and yet, no conclusive evidence thereof. To seek more decisive proof, we simulated a series of Bayesian observer models, including some that produce visibility judgements alongside type-1 judgements. Our data are best accounted for by observers with slightly suboptimal conscious access to sensory evidence. Overall, the stimuli and visibility manipulations employed here induced mild instances of blindsight-like behavior, making them attractive candidates for future investigation of this phenomenon.

意识与无意识知觉的对比构成了意识科学的基石。然而，在大多数关于对未见刺激进行高于机遇水平区分的研究中，评估意识时并未控制标准偏差。我们测试了观察者是否能够在使用无偏差任务探测可见性时识别主观上不可见的 Vernier 刺激的偏移。为了降低可见性，刺激要么被逆向掩蔽，要么通过现代的 tachistoscope 以极短的时间（1-3 毫秒）呈现。我们发现了一些知觉而无意识的行怍表现，但尚无确凿证据。为了寻求更具有决定性的证据，我们模拟了一系列贝叶斯观察者模型，包括一些在产生类型1判断的同时进行可见性判断的模型。我们的数据最好被具有略低于最佳意识获取的感官证据的观察者解释。总体而言，所采用的刺激和可见性操作引起了轻微的类似盲视的行为，这使得它们成为未来探究这一现象的有吸引力的候选对象。