Department of Psychology, State University of New York at Binghamton, Binghamton, NY, USA.
Psychophysiology. 2021 Jun;58(6):e13821. doi: 10.1111/psyp.13821. Epub 2021 Mar 28.
Researchers typically distinguish between two mechanisms of attentional selection in vision: overt and covert attention. A commonplace assumption is that overt eye movements are automatically preceded by shifts of covert attention during visual search. Although the N2pc component is a putative index of covert attentional orienting, little is currently known about its relationship with overt eye movements. This is because most previous studies of the N2pc component prohibit overt eye movements. The current study assessed this relationship by concurrently measuring covert attention (via the N2pc) and overt eye movements (via eye tracking). Participants searched displays for a lateralized target stimulus and were allowed to generate overt eye movements during the search. We then assessed whether overt eye movements were preceded by the N2pc component. The results indicated that saccades were preceded by an N2pc component, but only when participants were required to carefully inspect the target stimulus before initiating the eye movement. When participants were allowed to make naturalistic eye movements in service of visual search, there was no evidence of an N2pc component before eye movements. These findings suggest that the N2pc component does not always precede overt eye movements during visual search. Implications for understanding the relationship between covert and overt attention are discussed.
显性和隐性注意。一个常见的假设是，在视觉搜索中，显性眼球运动自动先于隐性注意力转移。尽管 N2pc 成分是隐性注意定向的一个假定指标，但目前对其与显性眼球运动的关系知之甚少。这是因为大多数关于 N2pc 成分的先前研究都禁止显性眼球运动。本研究通过同时测量隐性注意（通过 N2pc）和显性眼球运动（通过眼动追踪）来评估这种关系。参与者在显示器上搜索侧化目标刺激，并允许在搜索过程中进行显性眼球运动。然后，我们评估了显性眼球运动是否先于 N2pc 成分。结果表明，当参与者在开始眼球运动之前需要仔细检查目标刺激时，眼跳会先出现 N2pc 成分。当参与者被允许在视觉搜索中进行自然的眼球运动时，在眼球运动之前没有 N2pc 成分的证据。这些发现表明，在视觉搜索过程中，N2pc 成分并不总是先于显性眼球运动。讨论了对隐性和显性注意之间关系的理解的影响。
