Dual Tasks Costs to Adults' Language Production

描述(申请人提供)：通过使用双重任务程序评估年轻人和老年人的语言产生成本，拟议的实验将增进我们对老龄化如何影响语言产生的理解。追踪-转轮跟踪的时刻-时刻精确度将被作为语言输出的时刻-时刻处理需求的指标。实验1将建立跟踪准确性的基线，并比较从事转子跟踪的年轻人和老年人在口头回答发人深省的问题时的任务优先级。在实验2中，将监测年轻人和老年人参与各种语言产生任务的跟踪准确性，从死记硬背字母表到倒着数，到阅读句子和散文，以及自发说话(对发人深省的问题做出反应)。为了对语言产生的即时认知成本提供更精细的评估，在实验3和实验4中，当年轻人和老年人大声说话或朗读时，跟踪准确性的连续记录将与语言产生的连续记录同步和时间锁定。语音信号将被分割，以标记句子和从句的开头/偏置。然后，将计算这些片段的平均跟踪精度，从而产生与诸如不同类型的嵌入子句之类的关键语音“事件”相对应的跟踪精度的任务时间测量。平均跟踪准确率预计会随着句子和从句的复杂性而降低。在实验5中，当受试者参与一项将句子计划与计划实施和句子产生分开的受控生产任务时，将监测跟踪的准确性。中心假设是，对于老年人来说，语言的产生是昂贵的，他们必须利用认知储备能力来应对双重任务需求。在要求严格的情况下，例如产生复杂的句子，老年人的认知储备将是不足的。因此，他们对跟踪的控制将恶化，导致精确度下降。随着语言任务需求的增加，老年人的言语能力会下降，首先表现为语速减慢，然后是流利性下降，最后是语法复杂性和命题内容的丧失。

DESCRIPTION (provided by applicant): The proposed experiments will advance our understanding of how aging affects language production by using dual task procedures to assess the costs of language production to young and older adults. Moment-to-moment accuracy of pursuit-rotor tracking will be studied as an indicator of moment-to-moment processing demands of language production. Experiment 1 will establish baselines for tracking accuracy and compare task priorities of young and older adults engaged in rotor tracking while orally responding to thought-provoking questions. In Experiment 2, young and older adults' tracking accuracy will be monitored as they engage in a variety of language production tasks ranging from rote repetition of the alphabet, to counting backwards, to reading sentences and prose, and spontaneous speech (responding to thought-provoking questions). In order to provide a more fine grained assessment of the moment-to-moment cognitive costs of language production, in Experiments 3 and 4, continuous records of tracking accuracy will be synchronized and time-locked to a continuous record of language production while young and older adults speak or read aloud. The speech signal will be segmented to mark the onset/offset of sentences and clauses. Average tracking accuracy, will then be computed for these segments, yielding time-on-task measurement of tracking accuracy that correspond to critical speech "events" such as different types of embedded clauses. Average tracking accuracy is expected to decrease with sentence and clause complexity. In Experiment 5, tracking accuracy will be monitored while participants engage in a controlled production task that separates sentence planning from plan implementation and sentence production. The central hypothesis is that language production is costly to older adults who must draw upon cognitive reserve capacity in order to respond to dual task demands. In demanding situations, e.g., producing a complex sentence, older adults' cognitive reserve will be insufficient. As a result, their control over tracking will deteriorate, resulting in decreased accuracy. As linguistic task demands increase, older adults' speech will erode, first showing a reduction in speed, then a loss of fluency more generally, and finally a loss of grammatical complexity and propositional content.