The neural basis of phonological working memory was investigated through an examination of the effects of irrelevant speech distractors and disruptive neural stimulation from transcranial magnetic stimulation. Embedded processes models argue that the same regions involved in speech perception are used to support phonological WM whereas buffer models assume that a region separate from speech perception regions is used to support WM. Thus, according to the embedded processes approach but not the buffer approach, irrelevant speech and TMS to the speech (...) perception region should disrupt the decoding of phonological WM representations. According to the buffer account, decoding of WM items should be possible in the buffer region despite distraction and should be disrupted with TMS to this region. Experiment 1 used fMRI and representational similarity analyses with a delayed recognition memory paradigm using nonword stimuli. Results showed that decoding of memory items in the speech perception regions was possible in the absence of distractors. However, the decoding evidence in the left STG was susceptible to interference from distractors presented during the delay period whereas decoding in the proposed buffer region persisted. Experiment 2 examined the causal roles of the speech processing region and the buffer region in phonological WM performance using TMS. TMS to the SMG during the early delay period caused a disruption in recognition performance for the memory nonwords, whereas stimulations at the STG and an occipital control region did not affect WM performance. Taken together, results from the two experiments are consistent with predictions of a buffer model of phonological WM, pointing to a critical role of the left SMG in maintaining phonological representations. (shrink)

The commentaries have both revealed the implications of and challenged our approach. In this response, we reply to these concerns, discuss why the technical-reasoning hypothesis does not minimize the role of social-learning mechanisms – nor assume that technical-reasoning skills make individuals omniscient technically – and make suggestions for overcoming the classical opposition between the cultural versus cognitive niche hypothesis of cumulative technological culture.

An Integrated Working Memory Model for Time‐Based Resource‐Sharing proposes a formalized a theory of working memory, time‐based resource sharing (TBRS), within the ACT‐R cognitive architecture. Instantiating the theory within ACT‐R allowed the authors to predict task accuracy and response times when an articulatory rehearsal mechanism was included with the TBRS mechanism. This paper was awarded the Allen Newell Award for the best student‐ led paper submitted to ICCM 2018 for their research efforts.

The current study explored the extent to which children above and below the age of 7 years are able to benefit from either training in cumulative rehearsal or in the use of interactive imagery when carrying out working memory tasks. Twenty-four 5- to 6-year-olds and 24 8- to 9-year olds were each assigned to one of three training groups who either received cumulative rehearsal, interactive imagery, or passive labelling training. Participants’ ability to maintain material during a filled delay was then (...) assessed, and the nature of the distraction that was imposed during this delay was varied to shed further light on the mechanisms that individuals used to maintain the memoranda in working memory in the face of this distraction. The results suggest that the rehearsal training employed here did improve recall by virtue of encouraging rehearsal strategies, in a way that was not observed among participants receiving interactive imagery training. The fact that these effects were not mediated by age group counts against the view that younger individuals are either unable to rehearse, or show impoverished verbal serial recall because they do not spontaneously engage in rehearsal. (shrink)

It is well known that working memory performance changes with age. Two recent computational models of working memory, TBRS* and SOB-CS, developed from young adults WM performances are opposed regarding the postulated causes of forgetting, namely time-based decay and interference for TBRS* and SOB-CS, respectively. In the present study, these models are applied on a set of complex span data produced by young and older adults. As expected, these models are unable to account for the older adult data. An investigation (...) on the effect of the main parameters of these models showed that the poorer performance of older adults does not come from a weaker encoding of item but rather from difficulties during the free time that immediately follows each distractor, as well as from a higher level of confusion between items. These results are discussed with respect to the current theories of working memory and aging. (shrink)