Tanzer Michal, Weinbach Noam, Mardo Elite, Henik Avishai, Avidan Galia
Psychology Department, Ben-Gurion University of the Negev, Beer Sheva, Israel.
Psychology Department, Ben-Gurion University of the Negev, Beer Sheva, Israel; Psychology Department, Haifa University, Haifa, Israel.
Neuropsychologia. 2016 Aug;89:299-308. doi: 10.1016/j.neuropsychologia.2016.06.032. Epub 2016 Jun 27.
Congenital prosopagnosia (CP) is a severe face processing impairment that occurs in the absence of any obvious brain damage and has often been associated with a more general deficit in deriving holistic relations between facial features or even between non-face shape dimensions. Here we further characterized this deficit and examined a potential way to ameliorate it. To this end we manipulated phasic alertness using alerting cues previously shown to modulate attention and enhance global processing of visual stimuli in normal observers. Specifically, we first examined whether individuals with CP, similarly to controls, would show greater global processing when exposed to an alerting cue in the context of a non-facial task (Navon global/local task). We then explored the effect of an alerting cue on face processing (upright/inverted face discrimination). Confirming previous findings, in the absence of alerting cues, controls showed a typical global bias in the Navon task and an inversion effect indexing holistic processing in the upright/inverted task, while CP failed to show these effects. Critically, when alerting cues preceded the experimental trials, both groups showed enhanced global interference and a larger inversion effect. These results suggest that phasic alertness may modulate visual processing and consequently, affect global/holistic perception. Hence, these findings further reinforce the notion that global/holistic processing may serve as a possible mechanism underlying the face processing deficit in CP. Moreover, they imply a possible route for enhancing face processing in individuals with CP and thus shed new light on potential amelioration of this disorder.
先天性面孔失认症（CP）是一种严重的面孔加工障碍，它在没有任何明显脑损伤的情况下出现，并且常常与在推导面部特征之间甚至非面部形状维度之间的整体关系时存在更普遍的缺陷有关。在这里，我们进一步刻画了这种缺陷，并研究了一种可能改善它的方法。为此，我们使用先前已证明能调节注意力并增强正常观察者对视觉刺激的整体加工的警觉线索来操纵相位警觉性。具体而言，我们首先研究了患有CP的个体是否与对照组一样，在非面部任务（纳冯全局/局部任务）的背景下暴露于警觉线索时会表现出更强的整体加工。然后，我们探究了警觉线索对面孔加工（正立/倒立面孔辨别）的影响。与先前的研究结果一致，在没有警觉线索的情况下，对照组在纳冯任务中表现出典型的全局偏向，在正立/倒立任务中表现出指示整体加工的倒置效应，而CP患者则未表现出这些效应。关键的是，当警觉线索先于实验试验出现时，两组都表现出增强的全局干扰和更大的倒置效应。这些结果表明，相位警觉性可能调节视觉加工，进而影响全局/整体感知。因此，这些发现进一步强化了这样一种观点，即全局/整体加工可能是CP患者面孔加工缺陷的一种潜在机制。此外，它们暗示了一种增强CP患者面孔加工的可能途径，从而为这种疾病的潜在改善提供了新的线索。
