Multimodal approaches towards a better understanding of feelings of familiarity

熟悉感是一个基本的记忆过程，它提醒我们以前经历过的事情。研究人员使用了三种常用的测量熟悉度的方法中的一种。这项研究报告说，与年轻人相比，健康的老年人的熟悉度缺陷很小，有时甚至很明显。遗忘性轻度认知损害(AMCI)是熟悉性研究中特别感兴趣的研究领域，因为最早的病理发生在遗忘性轻度认知障碍的嗅周皮质(即经鼻S皮质)和内嗅皮层，这两个区域在AMCI中表现为细胞丢失和皮质变薄。大多数神经成像研究发现，周围激活与熟悉有关，而对局灶性病变患者的研究发现，熟悉缺陷会损害周围皮质。因此，假设与健康的老年人相比，MCI患者的熟悉度受损是合乎逻辑的，但证据是平均混合的：当条件支持高水平的回忆时，熟悉度不会出现在MCI中，但当条件支持低水平的回忆时，与健康的同龄人相比，MCI的熟悉度受到损害。我认为，回忆的更高贡献掩盖了aMCI中的熟悉性缺陷，可能在健康老龄化中也是如此，我们需要利用新的方法来测量无回忆情境中的熟悉性。 我建议监督HQP在健康的年轻人和老年人、患有周围皮质损害的成年人以及由于MCI而患有神经退行性周围皮质的老年人的熟悉程度研究中。前五个实验将从行为角度考察熟悉度。实验1、实验2和实验5将侧重于通过改变刺激在频率额定值之前附带编码的频率来编码熟悉操作。实验3、4和5将重点放在提取操作的熟悉性上，使用反应截止程序和无识别识别程序。然后，在实验6、7和8中，将使用事件相关电位、瞳孔扩张和皮肤电导反应来进一步检验在最健壮的编码和提取操作中熟悉的生物标记。我预测，与健康的年轻人相比，健康的老年人，特别是由于MCI或病变而导致虹膜周围皮质受损的人，将表现出熟悉性缺陷，并损害早期旧/新事件相关电位效应、瞳孔扩大和皮肤传导潜伏期。 这项建议响应了挑战记忆和熟悉是随机独立的基本概念的呼声，并提供了一种多模式方法，将重塑该领域对熟悉感觉的理解。理解幸免的熟悉感和受损的熟悉感将使我们更好地理解人类助记经验的范围。

Familiarity is a fundamental memory process that alerts us that we have experienced something before. Researchers have used one of three prevailing methods used to measure familiarity. This research has reported small and sometimes significant familiarity deficits in healthy older adults, compared to younger adults. Amnestic mild cognitive impairment (aMCI) is of particular interest in the study of familiarity because the earliest pathology occurs in the perirhinal cortex (i.e., Braak s transentorhinal' cortex) and entorhinal cortex, two regions that show cell loss and cortical thinning in aMCI. Most neuroimaging research finds perirhinal activation associated with familiarity, and research with patients with focal lesions finds familiarity deficits damage to the perirhinal cortex. It would thus be logical to hypothesize that familiarity is impaired in aMCI, compared to healthy older adults, but the evidence is evenly mixed: when conditions support high levels of recollection, familiarity is spared in aMCI, but when conditions support low levels of recollection, familiarity is impaired in aMCI, compared to their healthy counterparts. I suggest that higher contributions of recollection overshadow familiarity deficits in aMCI, and potentially in healthy aging, and that we need to utilize new methods to measure familiarity in recollection-free contexts. I propose to supervise HQP in the study of familiarity in healthy younger and older adults, adults with lesioned perirhinal cortex, and older adults with neurodegenerated perirhinal cortex due to aMCI. The first five Experiments will examine familiarity from a behavioural perspective. Experiments 1, 2, and 5 will focus on encoding manipulations of familiarity, by varying the frequency with which stimuli are incidentally encoded prior to frequency ratings. Experiments 3, 4, and 5 will focus on retrieval manipulations familiarity, using a response deadline procedure, and a recognition-without-identification procedure. Biomarkers of familiarity in the most robust encoding and retrieval manipulations will then be further examined in Experiments 6, 7, and 8, using event-related potentials, pupil dilation, and skin conductance responses. I predict that compared to healthy young adults, healthy older adults and especially people with damaged perirhinal cortex due to aMCI or lesions will demonstrate familiarity deficits and compromised early old/new event-related potential effects, pupil dilation, and skin conductance latency. This proposal heeds calls to challenge the fundamental notion that recollection and familiarity are stochastically independent, and provides a multimodal approach that will reshape the field's understanding of feelings of familiarity. Understanding both spared and impaired feelings of familiarity will provide us with a better understanding of the range of human mnemonic experience.