Jeong Eunju, Ryu Hokyoung
Department of Arts and Technology, Hanyang University Seoul, South Korea.
Front Aging Neurosci. 2016 Jun 13;8:134. doi: 10.3389/fnagi.2016.00134. eCollection 2016.
Cognitive decline is a natural phenomenon of aging. Although there exists a consensus that sensitivity to acoustic features of music is associated with such decline, no solid evidence has yet shown that structural elements and contexts of music explain this loss of cognitive performance. This study examined the extent and the type of cognitive decline that is related to the contour identification task (CIT) using tones with different pitches (i.e., melodic contours). Both younger and older adult groups participated in the CIT given in three listening conditions (i.e., focused, selective, and alternating). Behavioral data (accuracy and response times) and hemodynamic reactions were measured using functional near-infrared spectroscopy (fNIRS). Our findings showed cognitive declines in the older adult group but with a subtle difference from the younger adult group. The accuracy of the melodic CITs given in the target-like distraction task (CIT2) was significantly lower than that in the environmental noise (CIT1) condition in the older adult group, indicating that CIT2 may be a benchmark test for age-specific cognitive decline. The fNIRS findings also agreed with this interpretation, revealing significant increases in oxygenated hemoglobin (oxyHb) concentration in the younger (p < 0.05 for Δpre - on task; p < 0.01 for Δon - post task) rather than the older adult group (n.s for Δpre - on task; n.s for Δon - post task). We further concluded that the oxyHb difference was present in the brain regions near the right dorsolateral prefrontal cortex. Taken together, these findings suggest that CIT2 (i.e., the melodic contour task in the target-like distraction) is an optimized task that could indicate the degree and type of age-related cognitive decline.
认知衰退是衰老的自然现象。尽管人们普遍认为对音乐声学特征的敏感度与这种衰退有关，但尚无确凿证据表明音乐的结构元素和背景能够解释认知能力的丧失。本研究使用不同音高的音调（即旋律轮廓），考察了与轮廓识别任务（CIT）相关的认知衰退程度和类型。年轻和老年成人组都参与了在三种聆听条件下（即专注、选择性和交替性）进行的CIT。使用功能近红外光谱（fNIRS）测量行为数据（准确性和反应时间）以及血液动力学反应。我们的研究结果显示老年成人组存在认知衰退，但与年轻成人组存在细微差异。在老年成人组中，类似目标干扰任务（CIT2）中的旋律CIT准确性显著低于环境噪声（CIT1）条件下的准确性，这表明CIT2可能是针对特定年龄认知衰退的基准测试。fNIRS的研究结果也支持这一解释，显示年轻成人组（任务前-任务中Δp<0.05；任务中-任务后Δp<0.01）而非老年成人组（任务前-任务中无显著差异；任务中-任务后无显著差异）的氧合血红蛋白（oxyHb）浓度显著增加。我们进一步得出结论，oxyHb差异存在于右侧背外侧前额叶皮质附近的脑区。综上所述，这些研究结果表明CIT2（即类似目标干扰中的旋律轮廓任务）是一项优化任务，能够指示与年龄相关的认知衰退程度和类型。
