Kuhl Brice A, Dudukovic Nicole M, Kahn Itamar, Wagner Anthony D
Department of Psychology, Stanford University, Jordan Hall, Building 420, 450 Serra Mall, Stanford, California 94305, USA.
Nat Neurosci. 2007 Jul;10(7):908-14. doi: 10.1038/nn1918. Epub 2007 Jun 3.
Remembering often requires the selection of goal-relevant memories in the face of competition from irrelevant memories. Although there is a cost of selecting target memories over competing memories (increased forgetting of the competing memories), here we report neural evidence for the adaptive benefits of forgetting--namely, reduced demands on cognitive control during future acts of remembering. Functional magnetic resonance imaging during selective retrieval showed that repeated retrieval of target memories was accompanied by dynamic reductions in the engagement of functionally coupled cognitive control mechanisms that detect (anterior cingulate cortex) and resolve (dorsolateral and ventrolateral prefrontal cortex) mnemonic competition. Strikingly, regression analyses revealed that this prefrontal disengagement tracked the extent to which competing memories were forgotten; greater forgetting of competing memories was associated with a greater decline in demands on prefrontal cortex during target remembering. These findings indicate that, although forgetting can be frustrating, memory might be adaptive because forgetting confers neural processing benefits.
记忆往往需要在与无关记忆的竞争中选择与目标相关的记忆。尽管相对于竞争记忆而言，选择目标记忆存在一定代价（竞争记忆的遗忘增加），但我们在此报告遗忘具有适应性益处的神经学证据——也就是说，在未来的记忆行为中对认知控制的需求减少。选择性检索过程中的功能磁共振成像显示，重复检索目标记忆伴随着功能耦合的认知控制机制参与度的动态降低，这些机制负责检测（前扣带回皮层）和解决（背外侧和腹外侧前额叶皮层）记忆竞争。引人注目的是，回归分析表明，这种前额叶失活与竞争记忆被遗忘的程度相关；竞争记忆遗忘得越多，在目标记忆过程中前额叶皮层的需求下降就越大。这些发现表明，尽管遗忘可能令人沮丧，但记忆可能具有适应性，因为遗忘带来了神经加工方面的益处。
