Resolving interference between overlapping memories is crucial to remember the past. This study tests the novel prediction that orienting search focus benefits goal-relevant retrieval by reducing competition from unwanted memories. In a modified retrieval-practice paradigm, participants encoded word-pairs in one of two encoding tasks. Critically, to evaluate whether this retrieval orientation (RO) reduces memory interference, target and competitor memories were always related to different encoding tasks. At retrieval, instructions were provided for half of the blocks with the intention to bias remembering towards items encoded with one of the ROs. Behavioural data show that adopting an RO improved target accessibility, strengthened the testing effect, and reduced retrieval-induced forgetting (RIF) of competitors. Specifically, RIF – typically attributed to inhibitory control of memory interference – was prominent when no retrieval orientation (NRO) instruction was provided. Furthermore, a neural correlate of RO was calculated by training a linear discriminant analysis (LDA) to discriminate the electroencephalographic (EEG) spatial brain patterns correspondent to the two ROs over the time course of selective retrieval. RO was characterised by increases in the theta and decreases in the beta frequency band, evident both before and after category-cue onset. While the pre-cue RO reinstatement effect predicted both immediate retrieval-practice success and later target accessibility, the post-cue effect predicted disengagement of inhibitory control, such that participants showing a stronger RO reinstatement effect showed lower levels of RIF. These data suggest that strategically orienting search focus during retrieval both increases target memory accessibility and reduces memory interference, which consequently protects related memories from inhibition and later forgetting. Furthermore, they also highlight the roles of theta and beta oscillations in establishing and maintaining a task-relevant bias towards target memory representations during competitive memory retrieval.

解决重叠记忆之间的干扰对于记住过去至关重要。这项研究测试了新颖的预测，即定向搜索焦点可以通过减少不必要的内存竞争来使目标相关的检索受益。在改进的检索练习范例中，参与者在两个编码任务之一中对单词对进行了编码。至关重要的是，要评估此检索方向（RO）是否会减少内存干扰，目标内存和竞争对手内存始终与不同的编码任务相关。在检索时，为一半的块提供了指令，目的是使记忆偏向使用RO之一编码的项目。行为数据表明，采用RO可以提高目标的可访问性，增强测试效果，并减少竞争对手的检索引起的遗忘（RIF）。具体来说，当没有提供检索方向（NRO）指令时，RIF（通常归因于对内存干扰的抑制性控制）非常突出。此外，通过训练线性判别分析（LDA）来辨别RO的神经相关性，以区分在选择性检索过程中对应于两个RO的脑电图（EEG）空间大脑模式。RO的特征是theta增大而beta频带减小，这在类别提示发作之前和之后均很明显。提示前RO恢复作用预示了立即的检索成功和以后的目标可及性，提示后作用预测了抑制控制的脱离，因此显示出更强RO恢复作用的参与者显示出较低的RIF水平。这些数据表明，在检索过程中策略性地定位搜索焦点既可以提高目标内存的可访问性，又可以减少内存干扰，从而保护相关的内存免遭抑制和以后的遗忘。此外，它们还强调了在竞争性记忆检索过程中，theta和beta振荡在建立和维持与目标记忆表示相关的任务相关偏差中的作用。