Henkin Yael, Yaar-Soffer Yifat, Steinberg Meidan, Muchnik Chava
Audiol Neurootol. 2014;19 Suppl 1:21-26. doi: 10.1159/000371602. Epub 2015 Feb 20.
With the growing number of older adults receiving cochlear implants (CI), there is general agreement that substantial benefits can be gained. Nonetheless, variability in speech perception performance is high, and the relative contribution and interactions among peripheral, central-auditory, and cognitive factors are not fully understood. The goal of the present study was to compare auditory-cognitive processing in older-adult CI recipients with that of older normal-hearing (NH) listeners by means of behavioral and electrophysiologic manifestations of a high-load cognitive task. Auditory event-related potentials (AERPs) were recorded from 9 older postlingually deafened adults with CI (age at CI >60) and 10 age-matched listeners with NH, while performing an auditory Stroop task. Participants were required to classify the speaker's gender (male/female) that produced the words 'mother' or 'father' while ignoring the irrelevant congruent or incongruent word meaning. Older CI and NH listeners exhibited comparable reaction time, performance accuracy, and initial sensory-perceptual processing (i.e. N1 potential). Nonetheless, older CI recipients showed substantially prolonged and less efficient perceptual processing (i.e. P3 potential). Congruency effects manifested in longer reaction time (i.e. Stroop effect), execution time, and P3 latency to incongruent versus congruent stimuli in both groups in a similar fashion; however, markedly prolonged P3 and shortened execution time were evident in older CI recipients. Collectively, older adults (CI and NH) employed a combined perceptual and postperceptual conflict processing strategy; nonetheless, the relative allotment of perceptual resources was substantially enhanced to maintain adequate performance in CI recipients. In sum, the recording of AERPs together with the simultaneously obtained behavioral measures during a Stroop task exposed a differential time course of auditory-cognitive processing in older CI recipients that was not manifested in the behavioral end products of processing. These data may have implications regarding clinical evaluation and rehabilitation procedures that should be tailored specifically for this unique group of patients.
随着接受人工耳蜗植入（CI）的老年人数量不断增加，人们普遍认为能从中获得诸多益处。尽管如此，言语感知表现的个体差异很大，而且外周、中枢听觉和认知因素之间的相对作用及相互影响尚未完全明晰。本研究的目的是通过一项高负荷认知任务的行为和电生理表现，比较老年人工耳蜗植入受者与老年听力正常（NH）听众的听觉认知加工情况。在9名人工耳蜗植入术后的老年语后聋患者（人工耳蜗植入时年龄>60岁）和10名年龄匹配的听力正常听众进行听觉Stroop任务时，记录其听觉事件相关电位（AERP）。参与者需要在忽略无关的一致或不一致词义的同时，对说出“母亲”或“父亲”的说话者性别（男/女）进行分类。老年人工耳蜗植入受者和听力正常听众在反应时间、表现准确性和初始感觉 - 知觉加工（即N1电位）方面表现相当。然而，老年人工耳蜗植入受者的知觉加工（即P3电位）明显延长且效率较低。两组中，不一致刺激与一致刺激相比，在反应时间延长（即Stroop效应）、执行时间和P3潜伏期方面均以类似方式表现出一致性效应；然而，老年人工耳蜗植入受者的P3明显延长，执行时间缩短。总体而言，老年人（人工耳蜗植入受者和听力正常者）采用了知觉和知觉后冲突加工相结合的策略；尽管如此，人工耳蜗植入受者为维持足够的表现，知觉资源的相对分配大幅增加。总之，在Stroop任务期间记录AERP以及同时获得的行为测量结果，揭示了老年人工耳蜗植入受者听觉认知加工的不同时间进程，这在加工的行为最终产物中并未体现。这些数据可能对临床评估和康复程序有影响，应为这一独特患者群体量身定制。
