Whether patients with schizophrenia are impaired in flexibly regulating attention in accordance with fluctuations in cognitive demand to achieve optimal task performance remains unclear. To address this issue, 47 patients with schizophrenia and 47 matched control participants were recruited to complete a time-based prospective memory task. Every 2-min block before the target time was divided into four 30-s intervals, after which the time check and intraindividual response time variability (IIRTV) across these intervals were calculated. Patients with schizophrenia displayed significantly higher IIRTV across all four time intervals and checked time less frequently during the last 30-s interval relative to control subjects. Moreover, the reduced change in time-checking frequency and IIRTV between the first and the last 30-s intervals was related to poorer time-based prospective memory performance in patients with schizophrenia. Our findings provide initial evidence that an inefficient capacity to dynamically allocate attentional resources during an ongoing task hinders dual-task performance in schizophrenia.

尚不清楚尚无精神分裂症患者根据认知需求的波动灵活调节注意力的障碍，以实现最佳任务表现。为了解决这个问题，招募了47位精神分裂症患者和47位相匹配的对照参与者来完成基于时间的前瞻性记忆任务。将目标时间之前的每2分钟块划分为四个30秒的时间间隔，然后计算这些时间间隔内的时间检查和个体反应时间变异性（IIRTV）。相对于对照对象，精神分裂症患者在所有四个时间间隔内均表现出明显较高的IIRTV，并且在最近30 s间隔内检查时间的频率降低。而且，精神分裂症患者的前30秒间隔与后30秒间隔之间的时间检查频率和IIRTV减少的减少与基于时间的前瞻性记忆表现较差有关。我们的发现提供了初步的证据，表明在进行中的任务过程中动态分配注意力资源的能力低下会阻碍精神分裂症的双任务执行。