Whyte Christopher J, Hohwy Jakob, Smith Ryan
MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
Centre for Consciousness & Contemplative Studies, Monash University, Melbourne, Australia.
Curr Res Neurobiol. 2022 Apr 1;3:100036. doi: 10.1016/j.crneur.2022.100036. eCollection 2022.
Cognitive theories of consciousness, such as global workspace theory and higher-order theories, posit that frontoparietal circuits play a crucial role in conscious access. However, recent studies using no-report paradigms have posed a challenge to cognitive theories by demonstrating conscious accessibility in the apparent absence of prefrontal cortex (PFC) activation. To address this challenge, this paper presents a computational model of conscious access, based upon active inference, that treats working memory gating as a cognitive action. We simulate a visual masking task and show that late P3b-like event-related potentials (ERPs), and increased PFC activity, are induced by the working memory demands of self-report generation. When reporting demands are removed, these late ERPs vanish and PFC activity is reduced. These results therefore reproduce, and potentially explain, results from no-report paradigms. However, even without reporting demands, our model shows that simulated PFC activity on visible stimulus trials still crosses the threshold for reportability - maintaining the link between PFC and conscious access. Therefore, our simulations show that evidence provided by no-report paradigms does not necessarily contradict cognitive theories of consciousness.
意识的认知理论,如全局工作空间理论和高阶理论,认为额顶叶回路在意识通达中起着关键作用。然而,最近使用无报告范式的研究通过在明显没有前额叶皮层(PFC)激活的情况下证明意识可及性,对认知理论提出了挑战。为应对这一挑战,本文提出了一种基于主动推理的意识通达计算模型,该模型将工作记忆门控视为一种认知行为。我们模拟了一个视觉掩蔽任务,结果表明,类似P3b的晚期事件相关电位(ERP)以及PFC活动的增加是由自我报告生成的工作记忆需求所诱发的。当报告需求被去除时,这些晚期ERP消失,PFC活动减少。因此,这些结果重现并有可能解释无报告范式的结果。然而,即使没有报告需求,我们的模型表明,在可见刺激试验中模拟的PFC活动仍会超过可报告性阈值——维持PFC与意识通达之间的联系。因此,我们的模拟表明,无报告范式提供的证据不一定与意识的认知理论相矛盾。