Abstract:
There are many different kinds of \'phantom\' percepts but it is unknown whether they are united by common mechanisms. For example, synaesthesia (e.g., numbers evoking colour) and hallucinations appear conceptually and phenomenologically similar: both result in a percept that does not have an environmental correlate. Here, people with synaesthesia (n = 66) performed a conditioned hallucinations paradigm known to be sensitive to hallucination susceptibility, and we asked whether synaesthetes would show the same behavioural profile as hallucinators in this task. Repeated pairing of checkerboards with tones, and gratings with colours encourages the participant to draw on prior knowledge when asked to report on the presence of the difficult-to-detect target stimulus. Synaesthetes show increased modelled expectancies for the stimulus association across the board, resulting in a higher number of detections at all stimulus intensities. This is in contrast to the pattern observed in hallucinators, who weigh their prior beliefs more strongly than controls, giving rise to more conditioned hallucinations. Results indicate that fundamentally different perceptual processes may be at the core of these seemingly similar experiences.
摘要:
有许多不同种类的“幻影”感知,但不知道它们是否被共同的机制结合在一起。例如,通感(例如,数字唤起颜色)和幻觉在概念上和现象学上似乎相似:两者都会导致与环境无关的感知。这里,具有通感的人(n=66)进行了已知对幻觉敏感性敏感的条件幻觉范式,我们询问联觉者在这项任务中是否会表现出与幻觉者相同的行为特征。棋盘与音调重复配对,当被要求报告难以检测的目标刺激的存在时,带有颜色的光栅鼓励参与者利用先验知识。通论显示,对刺激协会的建模预期全面增加,导致在所有刺激强度下更高的检测次数。这与在幻觉者中观察到的模式相反,他们比控制更强烈地权衡他们先前的信念,引起更多的有条件的幻觉。结果表明,根本不同的感知过程可能是这些看似相似的体验的核心。