ABSTRACT

The modulation of gaze fixations on neural activity in the hippocampus, a region critical for memory, has been shown to be weaker in older adults compared to younger adults. However, as such research has relied on indirect measures of memory, it remains unclear whether the relationship between visual exploration and direct measures of memory is similarly disrupted in aging. The current study tested older and younger adults on a face memory eye-tracking task previously used by our group that showed that recognition memory for faces presented across variable, but not fixed, viewpoints relies on a hippocampal-dependent binding function. Here, we examined how aging influences eye movement measures that reveal the amount (cumulative sampling) and extent (distribution of gaze fixations) of visual exploration. We also examined how aging influences direct (subsequent conscious recognition) and indirect (eye movement repetition effect) expressions of memory. No age differences were found in direct recognition regardless of facial viewpoint. However, the eye movement measures revealed key group differences. Compared to younger adults, older adults exhibited more cumulative sampling, a different distribution of fixations, and a larger repetition effect. Moreover, there was a positive relationship between cumulative sampling and direct recognition in younger adults, but not older adults. Neither age group showed a relationship between the repetition effect and direct recognition. Thus, despite similar direct recognition, age-related differences were observed in visual exploration and in an indirect eye-movement memory measure, suggesting that the two groups may acquire, retain, and use different facial information to guide recognition.

摘要

研究表明，与年轻人相比，海马体（一个对记忆至关重要的区域）中注视注视对神经活动的调节在老年人中较弱。然而，由于此类研究依赖于记忆的间接测量，因此尚不清楚视觉探索与记忆的直接测量之间的关系是否在衰老过程中同样受到破坏。目前的研究在我们小组之前使用的面部记忆眼动追踪任务中对老年人和年轻人进行了测试，该任务表明，跨可变但非固定视点呈现的面部识别记忆依赖于海马体依赖性结合功能。在这里，我们研究了衰老如何影响眼动测量，这些测量揭示了数量（累积采样）和程度（视觉探索的凝视分布）。我们还研究了衰老如何影响直接（随后的意识识别）和间接（眼球运动重复效应) 记忆的表达。无论面部视点如何，直接识别都没有发现年龄差异。然而，眼球运动测量揭示了关键的群体差异。与年轻人相比，老年人表现出更多的累积采样、不同的注视分布和更大的重复效应。此外，在年轻人中累积抽样与直接识别之间存在正相关关系，但在老年人中则不然。两个年龄组都没有表现出重复效应和直接识别之间的关系。因此，尽管直接识别相似，但在视觉探索和间接眼动记忆测量中观察到与年龄相关的差异，这表明这两个群体可能获得、保留和使用不同的面部信息来指导识别。