Park Heekyeong, Leal Fernando, Abellanoza Cheryl, Schaeffer James D
Department of Psychology, University of Texas at Arlington, Arlington, TX 75069-19528, USA.
Behav Brain Funct. 2014 Oct 24;10:40. doi: 10.1186/1744-9081-10-40.
It is vital to select and process relevant information while restraining irrelevant information for successful retrieval. When multiple streams of information are concurrently present, the ability to overcome distraction is very crucial for processing relevant information. Despite its significance, the neural mechanism of successful memory formation under distraction remains unclear, especially with memory for associations. The present fMRI study investigated the effect of distraction due to irrelevant stimuli in source memory.
In the MR scanner, participants studied an item and perceptual context with no distractor, a letter-distractor, or a word-distractor. Following the study phase, a source recognition test was administered in which participants were instructed to judge the study status of the test items and context of studied items. Participants' encoding activity was back-sorted by later source recognition to find the influence of distractors in subsequent memory effects.
Source memory with distractors recruited greater encoding activity in the left dorsolateral prefrontal cortex, and the bilateral inferior temporal gyrus/fusiform cortex, along with the left posterior hippocampus. However, enhanced activity in the left anterior ventrolateral prefrontal cortex and the left parahippocampal cortex predicted successful source memory regardless of the presence of a distractor.
These findings of subsequent memory effects suggest that strong binding of the item-context associations, as well as resistance to interference, may have greater premium in the formation of successful source memory of pictures under distraction. Further, attentional selection to the relevant target seems to play a major role in contextual binding under distraction by enhancing the viability of memory representations from interference effects of distractors.
在成功检索信息时，选择和处理相关信息同时抑制无关信息至关重要。当同时存在多个信息流时，克服干扰的能力对于处理相关信息非常关键。尽管其具有重要意义，但在干扰情况下成功记忆形成的神经机制仍不清楚，尤其是对于关联记忆。本功能磁共振成像（fMRI）研究调查了源记忆中无关刺激引起的干扰效应。
在磁共振扫描仪中，参与者在无干扰物、字母干扰物或单词干扰物的情况下学习一个项目和感知情境。在学习阶段之后，进行源识别测试，要求参与者判断测试项目的学习状态和所学习项目的情境。通过后续的源识别对参与者的编码活动进行回溯分类，以发现干扰物对后续记忆效应的影响。
有干扰物的源记忆在左侧背外侧前额叶皮层、双侧颞下回/梭状回皮层以及左侧后海马体中募集了更大的编码活动。然而，无论是否存在干扰物，左侧前外侧前额叶皮层和左侧海马旁回皮层的活动增强都预示着成功的源记忆。
这些关于后续记忆效应的发现表明，项目 - 情境关联的强绑定以及对干扰的抵抗，在干扰情况下成功形成图片源记忆中可能具有更大的优势。此外，对相关目标的注意力选择似乎在干扰情况下的情境绑定中起主要作用，通过增强记忆表征免受干扰物干扰效应的活力。
