The neurodynamical basis of multi-item working memory capacity: sequential vs simultaneous stimulation paradigms
© Balagué and Dempere-Marco 2015
Published: 18 December 2015
When investigating multi-item WM, and in contrast to single item experiments, a decision must be made regarding a key aspect of the stimulation protocol: how the memory set is presented to the subject simultaneously or sequentially. It is worth noting that most studies investigating multi-item WM do not address this issue and focus either in simultaneous stimulation protocols (e.g. [1, 2]) or in sequential stimulation protocols (e.g. ) without confronting the two situations. This is nevertheless an aspect which provides a benchmark to probe and compare the different theories regarding how resources are allocated among the different items of a memory set [4, 5]. In this study, we explore a biophysically-realistic attractor model of visual working memory (VWM) endowed with synaptic facilitation and investigate what are the effects of varying the dynamics of the facilitation process. We find that: 1) it is possible to reproduce experimentally observed effects such as the recency effect in sequential stimulation protocols (i.e. items presented in the final positions of a sequence are more likely to be retained in WM), and 2) WM capacity is boosted in both sequential and stimulation protocols when endowing the attractor network with synaptic facilitation.
The authors acknowledge funding from the research project TIN2013-40630-R (Spanish Ministry of Economy and Competitiveness)
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