Liesefeld Heinrich René, Liesefeld Anna M, Zimmer Hubert D
Department of Psychology, Ludwig-Maximilians-Universität München, Munich, Germany.
Department of Psychology, Saarland University, Saarbrücken, Germany.
Psychophysiology. 2016 Dec;53(12):1811-1822. doi: 10.1111/psyp.12760. Epub 2016 Sep 15.
Object recognition is a central human ability. In everyday life, the conditions under which objects have to be recognized are usually not perfect. Often, viewing conditions change in between two encounters with an object; typical are changes in illumination or in the object-observer distance. With such changes, object recognition sometimes feels slightly delayed. We examined this phenomenon empirically by measuring the latency of the well-established electrophysiological correlate of recollection, the late posterior component (LPC), in an object-recognition task. Although the cognitive processes underlying successful recognition are well examined, thus far the consequences of changed viewing conditions on the timing of these processes have not been investigated. The ERP technique is well suited for investigating this question, because it allows differentiating between processes contributing to recognition times (in particular, recollection from familiarity as indexed by the FN400 component) and measuring their time course with high temporal precision. In the present study, participants' task was to differentiate previously studied (old) objects from a set of new objects. Viewing conditions for old objects changed slightly, changed strongly, or remained identical between learning and test. We found that the latency of the LPC in response to an old object was delayed whenever viewing conditions changed. Moreover, this delay in LPC latency scaled with the size of the change. These effects were absent for the FN400. This is the first examination of effects of changes in viewing conditions on the latency of recollection and the first dissociation of FN400 and LPC latencies.
物体识别是人类的一项核心能力。在日常生活中，识别物体时的条件通常并不理想。通常，在两次看到同一物体之间，观察条件会发生变化；典型的情况是光照或物体与观察者之间距离的改变。在这种变化下，物体识别有时会感觉稍有延迟。我们通过在物体识别任务中测量记忆的成熟电生理相关指标——晚期后部成分（LPC）的潜伏期，对这一现象进行了实证研究。尽管成功识别背后的认知过程已得到充分研究，但到目前为止，观察条件的变化对这些过程时间安排的影响尚未得到研究。ERP技术非常适合研究这个问题，因为它能够区分影响识别时间的过程（特别是由FN400成分索引的从熟悉度中回忆的过程），并以高时间精度测量它们的时间进程。在本研究中，参与者的任务是从一组新物体中区分出之前学习过的（旧的）物体。旧物体的观察条件在学习和测试之间略有变化、变化很大或保持不变。我们发现，每当观察条件发生变化时，对旧物体做出反应的LPC潜伏期就会延迟。此外，LPC潜伏期的这种延迟与变化的大小成比例。FN400则没有这些效应。这是首次研究观察条件变化对回忆潜伏期的影响，也是首次区分FN400和LPC潜伏期。
