Jenkins I H, Brooks D J, Nixon P D, Frackowiak R S, Passingham R E
MRC Cyclotron Unit, Hammersmith Hospital, London, United Kingdom.
J Neurosci. 1994 Jun;14(6):3775-90. doi: 10.1523/JNEUROSCI.14-06-03775.1994.
We have used positron emission tomography to study the functional anatomy of motor sequence learning. Subjects learned sequences of keypresses by trial and error using auditory feedback. They were scanned with eyes closed under three conditions: at rest, while performing a sequence that was practiced before scanning until overlearned, and while learning new sequences at the same rate of performance. Compared with rest, both sequence tasks activated the contralateral sensorimotor cortex to the same extent. Comparing new learning with performance of the prelearned sequence, differences in activation were identified in other areas. (1) Prefrontal cortex was only activated during new sequence learning. (2) Lateral premotor cortex was significantly more activated during new learning, whereas the supplementary motor area was more activated during performance of the prelearned sequence. (3) Activation of parietal association cortex was present during both motor tasks, but was significantly greater during new learning. (4) The putamen was equally activated by both conditions. (5) The cerebellum was activated by both conditions, but the activation was more extensive and greater in degree during new learning. There was an extensive decrease in the activity of prestriate cortex, inferotemporal cortex, and the hippocampus in both active conditions, when compared with rest. These decreases were significantly greater during new learning. We draw three main conclusions. (1) The cerebellum is involved in the process by which motor tasks become automatic, whereas the putamen is equally activated by sequence learning and retrieval, and may play a similar role in both. (2) When subjects learn new sequences of motor actions, prefrontal cortex is activated. This may reflect the need to generate new responses. (3) Reduced activity of areas concerned with visual processing, particularly during new learning, suggests that selective attention may involve depressing the activity of cells in modalities that are not engaged by the task.
我们使用正电子发射断层扫描技术来研究运动序列学习的功能解剖学。受试者通过试错法利用听觉反馈学习按键序列。他们在三种条件下闭眼进行扫描：休息时、执行在扫描前已练习至过度学习的序列时，以及以相同表现速率学习新序列时。与休息状态相比，两种序列任务均同等程度地激活了对侧感觉运动皮层。将新学习与预先学习序列的执行情况进行比较，发现在其他区域存在激活差异。（1）前额叶皮层仅在新序列学习期间被激活。（2）外侧运动前皮层在新学习期间的激活明显更强，而辅助运动区在预先学习序列的执行期间激活更强。（3）顶叶联合皮层在两种运动任务期间均有激活，但在新学习期间激活明显更强。（4）壳核在两种条件下的激活程度相同。（5）小脑在两种条件下均被激活，但在新学习期间激活范围更广且程度更大。与休息状态相比，在两种活动状态下，纹状前皮层、颞下皮层和海马体的活动均有广泛降低。这些降低在新学习期间明显更大。我们得出三个主要结论。（1）小脑参与运动任务自动化的过程，而壳核在序列学习和检索过程中被同等激活，并且可能在两者中发挥类似作用。（2）当受试者学习新的运动动作序列时，前额叶皮层被激活。这可能反映了产生新反应的需求。（3）与视觉处理相关区域的活动减少，特别是在新学习期间，表明选择性注意可能涉及抑制未参与该任务的感觉模态中细胞的活动。
