Cognitive Brain Research Unit, Institute of Behavioural Sciences, University of Helsinki, Helsinki, Finland.
PLoS One. 2010 Dec 2;5(12):e15157. doi: 10.1371/journal.pone.0015157.
Acquired amusia is a common disorder after damage to the middle cerebral artery (MCA) territory. However, its neurocognitive mechanisms, especially the relative contribution of perceptual and cognitive factors, are still unclear. We studied cognitive and auditory processing in the amusic brain by performing neuropsychological testing as well as magnetoencephalography (MEG) measurements of frequency and duration discrimination using magnetic mismatch negativity (MMNm) recordings. Fifty-three patients with a left (n = 24) or right (n = 29) hemisphere MCA stroke (MRI verified) were investigated 1 week, 3 months, and 6 months after the stroke. Amusia was evaluated using the Montreal Battery of Evaluation of Amusia (MBEA). We found that amusia caused by right hemisphere damage (RHD), especially to temporal and frontal areas, was more severe than amusia caused by left hemisphere damage (LHD). Furthermore, the severity of amusia was found to correlate with weaker frequency MMNm responses only in amusic RHD patients. Additionally, within the RHD subgroup, the amusic patients who had damage to the auditory cortex (AC) showed worse recovery on the MBEA as well as weaker MMNm responses throughout the 6-month follow-up than the non-amusic patients or the amusic patients without AC damage. Furthermore, the amusic patients both with and without AC damage performed worse than the non-amusic patients on tests of working memory, attention, and cognitive flexibility. These findings suggest domain-general cognitive deficits to be the primary mechanism underlying amusia without AC damage whereas amusia with AC damage is associated with both auditory and cognitive deficits.
获得性失乐症是大脑中动脉（MCA）区域损伤后的常见疾病。然而，其神经认知机制，尤其是感知和认知因素的相对贡献，仍不清楚。我们通过进行神经心理学测试以及使用磁源性失匹配负波（MMNm）记录进行频率和时长辨别的脑磁图（MEG）测量，研究了失乐症大脑的认知和听觉处理。对 53 名左侧（n=24）或右侧（n=29）MCA 中风（MRI 验证）的患者在中风后 1 周、3 个月和 6 个月进行了研究。使用蒙特利尔失乐症评估量表（MBEA）评估失乐症。我们发现，由右侧半球损伤（RHD）引起的失乐症，特别是颞叶和额叶区域的损伤，比由左侧半球损伤（LHD）引起的失乐症更为严重。此外，只有在失乐症的 RHD 患者中，失乐症的严重程度与较弱的频率 MMNm 反应相关。此外，在 RHD 亚组中，听觉皮层（AC）损伤的失乐症患者在 MBEA 上的恢复情况以及整个 6 个月随访期间的 MMNm 反应均比非失乐症患者或无 AC 损伤的失乐症患者差。此外，有和无 AC 损伤的失乐症患者在工作记忆、注意力和认知灵活性测试中的表现均不如非失乐症患者。这些发现表明，无 AC 损伤的失乐症的主要机制是一般领域的认知缺陷，而有 AC 损伤的失乐症与听觉和认知缺陷有关。
