Pollok Bettina, Stephan Katharina, Keitel Ariane, Krause Vanessa, Schaal Nora K
Medical Faculty, Institute of Clinical Neuroscience and Medical Psychology, Heinrich-Heine University DuesseldorfDuesseldorf, Germany.
Department of Experimental Psychology, Heinrich-Heine University DuesseldorfDuesseldorf, Germany.
Front Hum Neurosci. 2017 Apr 11;11:183. doi: 10.3389/fnhum.2017.00183. eCollection 2017.
The synchronization task is a well-established paradigm for the investigation of motor timing with respect to an external pacing signal. It requires subjects to synchronize their finger taps in synchrony with a regular metronome. A specific significance of the posterior parietal cortex (PPC) for superior synchronization in professional drummers has been suggested. In non-musicians, modulation of the excitability of the left PPC by means of transcranial direct current stimulation (tDCS) modulates synchronization performance of the right hand. In order to determine the significance of the left PPC for superior synchronization in drummers, we here investigate the effects of cathodal and anodal tDCS in 20 professional drummers on auditory-motor synchronization of the right hand. A continuation and a reaction time task served as control conditions. Moreover, the interaction between baseline performance and tDCS polarity was estimated in precise as compared to less precise synchronizers according to median split. Previously published data from 16 non-musicians were re-analyzed accordingly in order to highlight possible differences of tDCS effects in drummers and non-musicians. TDCS was applied for 10 min with an intensity of 0.25 mA over the left PPC. Behavioral measures were determined prior to and immediately after tDCS. In drummers the overall analysis of synchronization performance revealed significantly larger tap-to-tone asynchronies following anodal tDCS with the tap preceding the tone replicating findings in non-musicians. No significant effects were found on control tasks. The analysis for participants with large as compared to small baseline asynchronies revealed that only in drummers with small asynchronies tDCS interfered with synchronization performance. The re-analysis of the data from non-musicians indicated the reversed pattern. The data support the hypothesis that the PPC is involved in auditory-motor synchronization and extend previous findings by showing that its functional significance varies with musical expertise.
同步任务是一种成熟的范式，用于研究与外部起搏信号相关的运动定时。它要求受试者将手指敲击与有规律的节拍器同步。已有研究表明，后顶叶皮层（PPC）对专业鼓手的卓越同步能力具有特殊意义。在非音乐家群体中，经颅直流电刺激（tDCS）对左侧PPC兴奋性的调节会影响右手的同步表现。为了确定左侧PPC对鼓手卓越同步能力的重要性，我们在此研究了20名专业鼓手接受阴极和阳极tDCS对右手听觉-运动同步的影响。持续任务和反应时间任务作为对照条件。此外，根据中位数分割，将同步精度高的鼓手与精度低的鼓手进行比较，精确评估了基线表现与tDCS极性之间的相互作用。为了突出tDCS在鼓手和非音乐家中可能存在的效应差异，我们对之前发表的16名非音乐家的数据进行了相应的重新分析。在左侧PPC上以0.25 mA的强度施加tDCS 10分钟。在tDCS之前和之后立即测定行为指标。在鼓手中，同步表现的总体分析显示，阳极tDCS后敲击与音调之间的异步性显著增大，且敲击先于音调，这与非音乐家中的研究结果一致。在对照任务中未发现显著影响。对基线异步性大的参与者与小的参与者进行分析发现，只有异步性小的鼓手，tDCS才会干扰同步表现。对非音乐家数据的重新分析表明情况相反。这些数据支持了PPC参与听觉-运动同步的假设，并扩展了先前的研究结果，表明其功能重要性随音乐专业技能而变化。
