Institute for Psychology, Johannes Gutenberg-University, Mainz, Germany.
Institute for Psychology, Johannes Gutenberg-University, Mainz, Germany.
Int J Psychophysiol. 2018 Apr;126:30-41. doi: 10.1016/j.ijpsycho.2018.01.012. Epub 2018 Feb 21.
Working memory enables humans to maintain selected information for cognitive processes and ensures instant access to the memorized contents. Theories suggest that switching the focus of attention between items within working memory realizes the access. This is reflected in object-switching costs in response times when the item for the task processing is to be changed. Another correlate of attentional allocation in working memory is the P3a-component of the human event-related potential. The aim of this study was to demonstrate that switching of attention within working memory is a separable processing step. Participants completed a cued memory-updating task in which they were instructed to update one memory item at a time out of a memory list of four digits by applying a mathematical operation indicated by a target sign. The hypotheses predicted (1) prolonged updating times in switch (different item compared to previous trial) versus repetition trials (same item), (2) an influence of cues (valid/neutral) presented before the mathematical target on switching costs, and (3) that the P3a-component is more pronounced in the cue-target interval in the valid cue condition and more pronounced in the post-target interval in the neutral cue condition. A student's t-test verified the first hypothesis, repeated-measurement analyses of variance demonstrated that hypotheses 2 and 3 should be rejected. Results suggest that switching of attention within working memory could not be separated from further processing steps and retro-cue benefits are not due to a head start of retrieval as well as that switch costs represent internal processes.
工作记忆使人类能够为认知过程保留选定的信息，并确保即时访问记忆内容。理论表明，在工作记忆中在项目之间切换注意力可以实现这种访问。这反映在响应时间中的对象切换成本上，当要处理的任务的项目发生变化时。工作记忆中注意力分配的另一个相关物是人类事件相关电位的 P3a 成分。本研究的目的是证明工作记忆中的注意力切换是一个可分离的处理步骤。参与者完成了一个提示记忆更新任务，他们被指示通过应用由目标符号指示的数学运算，一次更新记忆列表中的四个数字中的一个记忆项。假设预测了（1）在切换（与前一个试验不同的项目）与重复试验（相同的项目）之间更新时间延长，（2）在数学目标之前呈现的提示（有效/中性）对切换成本的影响，以及（3）在有效提示条件下，P3a 成分在提示-目标间隔中更为明显，在中性提示条件下，P3a 成分在目标后间隔中更为明显。学生 t 检验验证了第一个假设，重复测量方差分析表明，假设 2 和 3 应该被拒绝。结果表明，工作记忆中的注意力切换不能与进一步的处理步骤分离，并且回溯提示的好处不是由于检索的提前开始，以及切换成本代表内部过程。
