Bellinger Daniel, Altenmüller Eckart, Volkmann Jens
Department of Neurology, University Hospital Würzburg Würzburg, Germany.
Institute of Music Physiology and Musicians' Medicine, University of Music, Drama and Media Hannover, Germany.
Front Neurosci. 2017 Feb 23;11:68. doi: 10.3389/fnins.2017.00068. eCollection 2017.
Perception of time as well as rhythm in musical structures rely on complex brain mechanisms and require an extended network of multiple neural sources. They are therefore sensitive to impairment. Several psychophysical studies have shown that patients with Parkinson's disease (PD) have deficits in perceiving time and rhythms due to a malfunction of the basal ganglia (BG) network. In this study we investigated the time perception of PD patients during music perception by assessing their just noticeable difference (JND) in the time perception of a complex musical . We applied a temporal discrimination task using a short melody with a clear beat-based rhythm. Among the subjects, 26 patients under L-Dopa administration and 21 age-matched controls had to detect an artificially delayed time interval in the range between 80 and 300 ms in the middle of the musical period. We analyzed the data by (a) calculating the detection threshold directly, (b) by extrapolating the JNDs, (c) relating it to musical expertise. Patients differed from controls in the detection of time-intervals between 220 and 300 ms ( = 0.0200, = 47). Furthermore, this deficit depended on the severity of the disease ( = 0.0452; = 47). Surprisingly, PD patients did not show any deficit of their JND compared to healthy controls, although the results showed a trend ( = 0.0565, = 40). Furthermore, no significant difference of the JND was found according to the severity of the disease. Additionally, musically trained persons seemed to have lower thresholds in detecting deviations in time and syntactic structures of music ( = 0.0343, = 39). As an explanation of these results, we would like to propose the hypothesis of a suggesting that processing of time and rhythm is a Gestalt process and that cortical areas involved in processing of musical syntax may compensate for impaired BG circuits that are responsible for time processing and rhythm perception. This mechanism may emerge more strongly as the deficits in time processing and rhythm perception progress. Furthermore, we presume that top-down-bottom-up-processes interfere additionally and interact in this context of compensation.
对时间的感知以及音乐结构中的节奏依赖于复杂的大脑机制，并且需要多个神经源组成的扩展网络。因此，它们对损伤很敏感。多项心理物理学研究表明，帕金森病（PD）患者由于基底神经节（BG）网络功能失调，在时间和节奏感知方面存在缺陷。在本研究中，我们通过评估帕金森病患者在复杂音乐时间感知中的刚刚可察觉差异（JND），来研究他们在音乐感知过程中的时间感知情况。我们使用了一个基于节拍节奏清晰的短旋律进行时间辨别任务。在受试者中，26名接受左旋多巴治疗的患者和21名年龄匹配的对照组人员必须检测音乐段落中间80至300毫秒范围内人为延迟的时间间隔。我们通过以下方式分析数据：（a）直接计算检测阈值；（b）外推刚刚可察觉差异；（c）将其与音乐专业知识相关联。在检测220至300毫秒之间的时间间隔时，患者与对照组存在差异（P = 0.0200，自由度 = 47）。此外，这种缺陷取决于疾病的严重程度（P = 0.0452；自由度 = 47）。令人惊讶的是，尽管结果显示出一种趋势（P = 0.0565，自由度 = 40），但与健康对照组相比，帕金森病患者的刚刚可察觉差异并未表现出任何缺陷。此外，根据疾病严重程度未发现刚刚可察觉差异有显著差异。另外，受过音乐训练的人在检测音乐时间和句法结构偏差方面似乎具有较低的阈值（P = 0.0343，自由度 = 39）。作为对这些结果的一种解释，我们提出一个假设，即时间和节奏的处理是一个格式塔过程，并且参与音乐句法处理的皮层区域可能会补偿负责时间处理和节奏感知的受损BG回路。随着时间处理和节奏感知缺陷的进展，这种机制可能会更强烈地出现。此外，我们推测自上而下 - 自下而上的过程在这种补偿背景下会额外干扰并相互作用。
