Ebner Christian, Schroll Henning, Winther Gesche, Niedeggen Michael, Hamker Fred H
Computer Science, Chemnitz University of Technology, 09111 Chemnitz, Germany; Goethe University Frankfurt am Main, Frankfurt am Main, Germany.
Computer Science, Chemnitz University of Technology, 09111 Chemnitz, Germany; Bernstein Center for Computational Neuroscience, Charité - Universitätsmedizin Berlin, Berlin, Germany; Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany; Psychology, Humboldt Universität zu Berlin, Berlin, Germany.
Conscious Cogn. 2015 Sep;35:295-307. doi: 10.1016/j.concog.2015.02.007. Epub 2015 Mar 21.
How the brain decides which information to process 'consciously' has been debated over for decades without a simple explanation at hand. While most experiments manipulate the perceptual energy of presented stimuli, the distractor-induced blindness task is a prototypical paradigm to investigate gating of information into consciousness without or with only minor visual manipulation. In this paradigm, subjects are asked to report intervals of coherent dot motion in a rapid serial visual presentation (RSVP) stream, whenever these are preceded by a particular color stimulus in a different RSVP stream. If distractors (i.e., intervals of coherent dot motion prior to the color stimulus) are shown, subjects' abilities to perceive and report intervals of target dot motion decrease, particularly with short delays between intervals of target color and target motion. We propose a biologically plausible neuro-computational model of how the brain controls access to consciousness to explain how distractor-induced blindness originates from information processing in the cortex and basal ganglia. The model suggests that conscious perception requires reverberation of activity in cortico-subcortical loops and that basal-ganglia pathways can either allow or inhibit this reverberation. In the distractor-induced blindness paradigm, inadequate distractor-induced response tendencies are suppressed by the inhibitory 'hyperdirect' pathway of the basal ganglia. If a target follows such a distractor closely, temporal aftereffects of distractor suppression prevent target identification. The model reproduces experimental data on how delays between target color and target motion affect the probability of target detection.
几十年来，大脑如何决定哪些信息会被“有意识地”处理一直存在争议，却始终没有一个简单的解释。虽然大多数实验会操纵呈现刺激的感知能量，但分心物诱发失明任务是一种典型的范式，用于研究在没有视觉操纵或只有轻微视觉操纵的情况下信息进入意识的门控机制。在这个范式中，要求受试者在快速序列视觉呈现（RSVP）流中报告连贯点运动的间隔，前提是在不同的RSVP流中有特定颜色刺激先于这些间隔出现。如果显示了分心物（即颜色刺激之前的连贯点运动间隔），受试者感知和报告目标点运动间隔的能力就会下降，特别是当目标颜色间隔和目标运动间隔之间的延迟较短时。我们提出了一个关于大脑如何控制意识通达的具有生物学合理性的神经计算模型，以解释分心物诱发失明是如何源于皮层和基底神经节中的信息处理的。该模型表明，有意识的感知需要皮质 - 皮质下环路中的活动产生回响，并且基底神经节通路可以允许或抑制这种回响。在分心物诱发失明范式中，基底神经节的抑制性“超直接”通路会抑制不适当的分心物诱发的反应倾向。如果一个目标紧跟这样一个分心物，分心物抑制的时间后效会阻止目标识别。该模型再现了关于目标颜色和目标运动之间的延迟如何影响目标检测概率的实验数据。
