Fogerty Daniel, Humes Larry E, Busey Thomas A
Department of Communication Sciences and Disorders, University of South Carolina Columbia, SC, USA.
Department of Speech and Hearing Sciences, Indiana University Bloomington, IN, USA.
Front Aging Neurosci. 2016 May 6;8:90. doi: 10.3389/fnagi.2016.00090. eCollection 2016.
Age-related temporal-processing declines of rapidly presented sequences may involve contributions of sensory memory. This study investigated recall for rapidly presented auditory (vowel) and visual (letter) sequences presented at six different stimulus onset asynchronies (SOA) that spanned threshold SOAs for sequence identification. Younger, middle-aged, and older adults participated in all tasks. Results were investigated at both equivalent performance levels (i.e., SOA threshold) and at identical physical stimulus values (i.e., SOAs). For four-item sequences, results demonstrated best performance for the first and last items in the auditory sequences, but only the first item for visual sequences. For two-item sequences, adults identified the second vowel or letter significantly better than the first. Overall, when temporal-order performance was equated for each individual by testing at SOA thresholds, recall accuracy for each position across the age groups was highly similar. These results suggest that modality-specific processing declines of older adults primarily determine temporal-order performance for rapid sequences. However, there is some evidence for a second amodal processing decline in older adults related to early sensory memory for final items in a sequence. This selective deficit was observed particularly for longer sequence lengths and was not accounted for by temporal masking.
与年龄相关的快速呈现序列的时间处理能力下降可能涉及感觉记忆的作用。本研究调查了在六种不同的刺激起始异步（SOA）条件下呈现的快速听觉（元音）和视觉（字母）序列的回忆情况，这些SOA涵盖了序列识别的阈值SOA。年轻人、中年人和老年人参与了所有任务。在等效性能水平（即SOA阈值）和相同物理刺激值（即SOA）下对结果进行了研究。对于四项序列，结果表明听觉序列中第一项和最后一项的表现最佳，而视觉序列中只有第一项表现最佳。对于两项序列，成年人识别第二个元音或字母的能力明显优于第一个。总体而言，当通过在SOA阈值进行测试使每个个体的时间顺序表现相等时，各年龄组中每个位置的回忆准确性高度相似。这些结果表明，老年人特定模态的处理能力下降主要决定了快速序列的时间顺序表现。然而，有一些证据表明老年人存在与序列中最后一项的早期感觉记忆相关的第二种非模态处理能力下降。这种选择性缺陷在较长序列长度时尤为明显，且不能用时间掩蔽来解释。
