Schwarb Hillary, Schumacher Eric H
School of Psychology, Georgia Institute of Technology, 654 Cherry Street, Atlanta, GA 30332-0170, USA.
Brain Res. 2009 Jan 9;1247:114-25. doi: 10.1016/j.brainres.2008.09.097. Epub 2008 Oct 17.
Despite over 20 years of behavioral research, considerable disagreement remains regarding the locus of the cognitive mechanisms (e.g., stimulus encoding, response selection or response production) responsible for the acquisition and expression of learned sequences. Functional neuroimaging may prove invaluable for resolving this controversy. The cortical mechanisms underlying spatial response selection (i.e., right dorsal prefrontal, dorsal premotor and superior parietal cortices) are well known. These regions as well as supplementary motor area, striatum and the hippocampus have also been implicated in sequence learning. This neural overlap lends support for the hypothesis that spatial response selection is involved in learning spatial sequences; however, these experimental factors have not been investigated in the same experiment so the extent of neural overlap is debatable. The present study investigates the role of spatial response selection in sequence learning during the performance of the serial reaction time task. We orthogonally manipulated spatial sequence learning and spatial response-selection difficulty to precisely identify the neural overlap of these cognitive systems. Results demonstrate near complete overlap in regions affected by the spatial response selection and spatial sequence learning manipulations. Only right dorsal prefrontal cortex was selectively influenced by the response selection difficulty manipulation. These findings emphasize the importance of spatial response selection for successful spatial sequence learning.
尽管进行了20多年的行为研究，但对于负责习得序列的获取和表达的认知机制（如刺激编码、反应选择或反应产生）的位置，仍存在相当大的分歧。功能神经成像可能对解决这一争议具有极高的价值。空间反应选择背后的皮质机制（即右背外侧前额叶、背侧运动前区和顶上叶皮质）已为人所知。这些区域以及辅助运动区、纹状体和海马体也与序列学习有关。这种神经重叠支持了空间反应选择参与学习空间序列的假说；然而，这些实验因素尚未在同一实验中进行研究，因此神经重叠的程度存在争议。本研究调查了在序列反应时任务执行过程中空间反应选择在序列学习中的作用。我们正交操纵空间序列学习和空间反应选择难度，以精确识别这些认知系统的神经重叠。结果表明，受空间反应选择和空间序列学习操纵影响的区域几乎完全重叠。只有右背外侧前额叶皮质受到反应选择难度操纵的选择性影响。这些发现强调了空间反应选择对成功的空间序列学习的重要性。
