School of Medicine and Pharmacology, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, Australia.
School of Medicine and Pharmacology, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, Perth, Australia.
Schizophr Res. 2018 Feb;192:75-81. doi: 10.1016/j.schres.2017.04.024. Epub 2017 Apr 14.
Individuals with passivity (first-rank) symptoms report that their actions, thoughts and sensations are influenced or controlled by an external (non-self) agent. Passivity symptoms are closely linked to schizophrenia and related disorders yet they remain poorly understood. One dominant framework posits a role for deficits in the sense of agency. An important question is whether deficits in self-agency can be differentiated from other-agency in schizophrenia and passivity symptoms. This study aimed to evaluate self- and other-agency in 51 people with schizophrenia (n=20 current, 10 past, 21 no history of passivity symptoms), and 48 healthy controls. Participants completed the projected hand illusion (PHI) with active and passive movements, as well as immediate and delayed visual feedback. Experiences of agency and loss of agency over the participant's hand and the image ('the other hand') were assessed with a self-report questionnaire. Those with passivity symptoms (current and past) reported less difference in agency between active and passive movements on items assessing agency over their own hand (but not agency over the other hand). Relative to the healthy controls, the current and never groups continued to experience the illusion with delayed visual feedback suggesting impaired timing mechanisms regardless of symptom profile. These findings are consistent with a reduced contribution of proprioceptive predictive cues to agency judgements specific to self representations in people with passivity symptoms, and a subsequent reliance on external visual cues in these judgements. Altogether, these findings emphasise the multifactorial nature of agency and the contribution of multiple impairments to passivity symptoms.
个体表现出被动（一级）症状，会报告称他们的行为、思想和感觉受到外部（非自身）因素的影响或控制。被动症状与精神分裂症和相关障碍密切相关，但仍未得到充分理解。一个主要的理论框架认为，自我能动性的缺陷起着作用。一个重要的问题是，在精神分裂症和被动症状中，自我能动性的缺陷是否可以与他人能动性区分开来。本研究旨在评估 51 名精神分裂症患者（当前患者 20 名，过去患者 10 名，无被动症状史 21 名）和 48 名健康对照者的自我能动性和他人能动性。参与者通过主动和被动运动完成了投射手错觉（PHI），并接受了即时和延迟的视觉反馈。参与者通过自我报告问卷评估了对自身手部和图像（“另一只手”）的能动性和丧失能动性的体验。有被动症状（当前和过去）的人在评估自身手部能动性的项目中，主动和被动运动之间的能动性差异较小（但对另一只手的能动性差异则较大）。与健康对照组相比，当前和从未有过被动症状的患者在延迟视觉反馈时仍继续体验错觉，这表明无论症状特征如何，他们的定时机制都受损。这些发现与被动症状患者的自我代表性的自我能动性判断中，本体感觉预测线索的贡献减少，以及随后对这些判断中外部视觉线索的依赖一致。总的来说，这些发现强调了能动性的多因素性质，以及多种损伤对被动症状的贡献。
