Faculty of Psychology, Neural Basis of Learning, Ruhr University Bochum, 44801, Bochum, Germany.
Sci Rep. 2020 Feb 24;10(1):3253. doi: 10.1038/s41598-020-59975-4.
The capacity of working memory is limited and this limit is comparable in crows and primates. To maximize this resource, humans use attention to select only relevant information for maintenance. Interestingly, attention-cues are effective not only before but also after the presentation of to-be-remembered stimuli, highlighting control mechanisms beyond sensory selection. Here we explore if crows are also capable of these forms of control over working memory. Two crows (Corvus corone) were trained to memorize two, four or six visual stimuli. Comparable to our previous results, the crows showed a decrease in performance with increasing working memory load. Using attention cues, we indicated the critical stimulus on a given trial. These cues were either presented before (pre-cue) or after sample-presentation (retro-cue). On other trials no cue was given as to which stimulus was critical. We found that both pre- and retro-cues enhance the performance of the birds. These results show that crows, like humans, can utilize attention to select relevant stimuli for maintenance in working memory. Importantly, crows can also utilize cues to make the most of their working memory capacity even after the stimuli are already held in working memory. This strongly implies that crows can engage in efficient control over working memory.
工作记忆容量有限，这种限制在乌鸦和灵长类动物中是相当的。为了最大限度地利用这一资源，人类利用注意力只选择相关信息进行维护。有趣的是，注意力提示不仅在呈现待记忆刺激之前有效，而且在之后也有效，突出了超越感觉选择的控制机制。在这里，我们探讨乌鸦是否也能够对工作记忆进行这些形式的控制。两只乌鸦（Corvus corone）被训练记忆两个、四个或六个视觉刺激。与我们之前的结果类似，乌鸦在工作记忆负荷增加时表现出下降。使用注意力提示，我们在给定的试验中指出关键刺激。这些提示要么在样本呈现之前（前提示）呈现，要么在样本呈现之后（后提示）呈现。在其他试验中，没有提示哪个刺激是关键的。我们发现前提示和后提示都能提高鸟类的表现。这些结果表明，乌鸦和人类一样，可以利用注意力选择相关刺激来维持工作记忆。重要的是，即使在刺激已经存储在工作记忆中之后，乌鸦也可以利用线索来最大限度地利用它们的工作记忆容量。这强烈表明乌鸦可以对工作记忆进行有效的控制。
