Department of Developmental Psychology, University of Padova, Padova, Italy.
Department of Information Engineering, University of Padova, Padova, Italy.
Psychophysiology. 2022 Aug;59(8):e14045. doi: 10.1111/psyp.14045. Epub 2022 Mar 22.
We recently showed that deploying attention to target stimuli displayed along the vertical meridian elicits a bilateral N2pc, that we labeled N2pcb (Psychophysiology). Here we investigated whether a different component, the sustained posterior contralateral negativity (SPCN), shows the same property when a varying number of visual stimuli are displayed either laterally or on the vertical meridian. We displayed one or two cues that designated candidate targets to be detected in a search array that was displayed after a retention interval. The cues were either on the horizontal meridian or on the vertical meridian. When the cues were on the horizontal meridian, we observed an N2pc followed by an SPCN in their classic form, as negativity increments contralateral to the cues. As expected, SPCN amplitude was greater when two cues had to be memorized than when only one cue had to be memorized. When the cues were on the vertical meridian, we observed an N2pcb followed by a bilateral SPCN (or SPCNb). Critically, like SPCN, SPCNb amplitude was greater when two cues had to be memorized than when only one cue had to be memorized. A series of additional parametrical and topographical comparisons between N2pcb and SPCNb revealed similarities but also some important differences between these two components that we interpreted as evidence for their distinct neural sources.
我们最近发现，当将注意力集中在沿垂直子午线显示的目标刺激上时，会引发双侧 N2pc，我们将其标记为 N2pcb（心理生理学）。在这里，我们研究了当在水平或垂直子午线显示不同数量的视觉刺激时，是否会出现相同的属性不同的成分，持续的对侧负性（SPCN）。我们显示了一个或两个提示，这些提示指定了要在搜索数组中检测到的候选目标，该搜索数组在保留间隔后显示。提示可以在水平子午线或垂直子午线。当提示在水平子午线时，我们观察到经典形式的 N2pc 紧随其后的是 SPCN，因为负性增量与提示相反。正如预期的那样，当必须记住两个提示时，SPCN 幅度大于仅当一个提示时必须记住的幅度。当提示在垂直子午线时，我们观察到 N2pcb 紧随其后的是双侧 SPCN（或 SPCNb）。至关重要的是，与 SPCN 一样，当必须记住两个提示时，SPCNb 幅度大于仅当一个提示时必须记住的幅度。对 N2pcb 和 SPCNb 之间的一系列额外参数和拓扑比较揭示了这些两个组件之间的相似之处，但也存在一些重要差异，我们将这些差异解释为它们的不同神经源的证据。
