Minneapolis Veterans Affairs Health Care System, University of Minnesota, Minneapolis, Minnesota.
Department of Psychiatry and Behavioral Science, University of Minnesota, Minneapolis, Minnesota.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2021 Dec;6(12):1193-1201. doi: 10.1016/j.bpsc.2020.09.018. Epub 2020 Oct 10.
Dysfunctional connectivity within the perceptual hierarchy is proposed to be an integral component of psychosis. The fragmented ambiguous object task was implemented to investigate neural connectivity during object recognition in patients with schizophrenia (SCZ) and bipolar disorder and first-degree relatives of patients with SCZ (SREL).
We analyzed 3T functional magnetic resonance imaging data collected from 27 patients with SCZ, 23 patients with bipolar disorder, 24 control subjects, and 19 SREL during the administration of the fragmented ambiguous object task. Fragmented ambiguous object task stimuli were line-segmented versions of objects and matched across a number of low-level features. Images were categorized as meaningful or meaningless based on ratings assigned by the participants.
An a priori region of interest was defined in the primary visual cortex (V1). In addition, the lateral occipital complex/ventral visual areas, intraparietal sulcus (IPS), and middle frontal gyrus (MFG) were identified functionally via the contrast of cortical responses to stimuli judged as meaningful or meaningless. SCZ was associated with altered neural activations at V1, IPS, and MFG. Psychophysiological interaction analyses revealed negative connectivity between V1 and MFG in patient groups and altered modulation of connectivity between conditions from right IPS to left IPS and right IPS to left MFG in patients with SCZ and SREL.
Results provide evidence that SCZ is associated with inefficient processing of ambiguous visual objects at V1, which is likely attributable to altered feedback from higher-level visual areas. We also observed distinct patterns of aberrant connectivity among low-level, mid-level, and high-level visual areas in patients with SCZ, patients with bipolar disorder, and SREL.
感知层次结构中的功能失调连接被认为是精神病的一个组成部分。实施碎片化歧义对象任务是为了研究精神分裂症（SCZ）患者、双相情感障碍患者和 SCZ 患者一级亲属（SREL）在物体识别过程中的神经连接。
我们分析了 27 名 SCZ 患者、23 名双相情感障碍患者、24 名对照受试者和 19 名 SREL 在执行碎片化歧义对象任务时的 3T 功能磁共振成像数据。碎片化歧义对象任务的刺激是物体的线段版本，并在许多低水平特征上匹配。根据参与者的评分，图像被归类为有意义或无意义。
预先确定了初级视觉皮层（V1）的感兴趣区。此外，通过对比判断为有意义或无意义的刺激的皮质反应，还确定了外侧枕叶复合体/腹侧视觉区、顶内沟（IPS）和中额回（MFG）的功能。SCZ 与 V1、IPS 和 MFG 的神经激活改变有关。心理生理交互分析显示，患者组 V1 和 MFG 之间存在负连接，SCZ 患者和 SREL 患者的连接条件从右 IPS 到左 IPS 和右 IPS 到左 MFG 存在改变。
结果表明，SCZ 与 V1 对歧义视觉对象的处理效率低下有关，这可能归因于来自高级视觉区域的反馈改变。我们还观察到 SCZ 患者、双相情感障碍患者和 SREL 患者在低水平、中水平和高水平视觉区域之间存在明显的连接异常模式。
