Department of Psychology, Wilfrid Laurier University, Waterloo, ON N2L 3C5, Canada.
Exp Brain Res. 2011 Feb;208(4):529-32. doi: 10.1007/s00221-010-2501-2. Epub 2010 Dec 4.
We use a vibrotactile-delayed match-to-sample paradigm to evaluate the effects of interference on working memory. One of the suggested mechanisms through which interference affects performance in working memory is feature overwriting: Short-term representations are maintained in a finite set of feature units (such as prefrontal neurons), and distractor stimuli co-opt some or all of those units, degrading the stored representation of an earlier stimulus. Subjects were presented with two vibrotactile stimuli and were instructed to determine whether they were of the same or different frequencies. A distractor stimulus was presented between the target and probe stimuli, the frequency of which was a function of the target stimulus. Performance on the task was affected by the frequency of the distractor, with subjects making more erroneous same judgments on different trials when the distractor frequency was closer to the probe than to the target, than when the distractor was further from the probe than the target. The results suggest that the frequency of the distractor partially overwrites the stored frequency information of the probe stimulus, providing support for the feature-overwriting explanation of working memory interference.
我们使用振动触觉延迟匹配样本范式来评估干扰对工作记忆的影响。干扰影响工作记忆性能的一种被提出的机制是特征覆盖：短期表示被维持在有限的特征单元集（例如前额叶神经元）中，并且干扰刺激共同占用这些单元中的一些或全部，从而降低了早期刺激的存储表示。受试者被呈现两个振动触觉刺激，并被指示确定它们的频率是否相同或不同。在目标和探针刺激之间呈现干扰刺激，其频率是目标刺激的函数。任务的表现受到干扰频率的影响，当干扰频率比目标更接近探针时，与当干扰比目标更远离探针时相比，受试者在不同试验上做出更多错误的相同判断。结果表明，干扰的频率部分覆盖了探针刺激的存储频率信息，为工作记忆干扰的特征覆盖解释提供了支持。
