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)

Previous research has shown that the proactive deprioritization of emotional distractors through the provision of information about the distractors or passive habituation of emotional distractors may attenuate emotion-induced blindness (EIB) in the rapid serial visual presentation stream. However, whether prior memory encoding of emotional distractors could bias the EIB effect remains unknown. To address this question, this study employed a three-phase paradigm integrating an item-method direct forgetting (DF) procedure with a classic EIB procedure. Participants completed a memory coding phase to (...) either remember or forget negative pictures, then performed an intermediate phase of the EIB test, and finally finished a recognition test. Critically, the same to-be-forgotten (TBF) and to-be-remembered (TBR) negative pictures in the memory learning phase were used as emotional distractors in the intermediate EIB test. The results replicated the typical DF effect by showing higher recognition accuracies for TBR pictures compared to those for TBF pictures. More importantly, the TBF negative distractors attenuated the EIB effect compared to the TBR negative distractors, but showed a comparable EIB effect as the novel negative distractors. These findings indicate that prior memory encoding manipulations of negative distractors could bias subsequent EIB effects, providing an important approach to modulate the EIB effect. (shrink)

Studies presenting memory-facilitating effect of emotions typically focused on affective dimensions of arousal and valence. Little is known, however, about the extent to which stimulus-driven basic emotions could have distinct effects on memory. In the present paper we sought to examine the modulatory effect of disgust, fear and sadness on intentional remembering and forgetting using widely used item-method directed forgetting paradigm. Eighteen women underwent fMRI scanning during encoding phase in which they were asked either to remember (R) or to forget (...) (F) pictures. In the test phase all previously used stimuli were re-presented together with the same number of new pictures and participants had to categorize them as old or new, irrespective of the F/R instruction. On the behavioral level we found a typical directed forgetting effect, i.e. higher recognition rates for to-be-remembered (TBR) items than to-be-forgotten (TBF) ones for both neutral and emotional categories. Emotional stimuli had higher recognition rate than neutral ones, while among emotional those eliciting disgust produced highest recognition, but at the same time induced more false alarms. Therefore when false alarm corrected recognition was examined the directed forgetting effect was equally strong irrespective of emotion. Additionally, even though subjects rated disgusting pictures as more arousing and negative than other picture categories, logistic regression on the item level showed that the effect of disgust on recognition memory was stronger than the effect of arousal or valence. On the neural level, ROI analyses (with valence and arousal covariates) revealed that correctly recognized disgusting stimuli evoked the highest activity in the left amygdala compared to all other categories. This structure was also more activated for remembered vs. forgotten stimuli, but only in case of disgust or fear eliciting pictures. Our findings, despite several limitations, suggest that disgust have a special salience in memory relative to other negative emotions, which cannot be put down to differences in arousal or valence. The current results thereby support the suggestion that a purely dimensional model of emotional influences on cognition might not be adequate to account for observed effects. (shrink)

Is consolidation needed to account for retroactive interference in free recall? Interfering mental activity during the retention interval of a memory task impairs performance, in particular if the interference occurs in temporal proximity to the encoding of the to-be-remembered information. There are at least two rival theoretical accounts of this temporal gradient of retroactive interference. The cognitive neuroscience literature has suggested neural consolidation is a pivotal factor determining item recall. According to this account, interfering activity interrupts consolidation processes that would (...) otherwise stabilize the memory representations of TBR items post-encoding. Temporal distinctiveness theory, by contrast, proposes that the retrievability of items depends on their isolation in psychological time. According to this theory, information processed after the encoding of TBR material will reduce the temporal distinctiveness of the TBR information. To test between these accounts, implementations of consolidation were added to the SIMPLE model of memory and learning. We report data from two experiments utilizing a two-list free recall paradigm. Modeling results imply that SIMPLE was able to model the data and did not benefit from the addition of consolidation. It is concluded that the temporal gradient of retroactive interference cannot be taken as evidence for memory consolidation. (shrink)

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.

Outsourcing clinical trials sponsored by pharmaceutical companies from industrialized countries to low- -income countries – summarized as transnational biomedical research – has lead to many concerns about ethical standards. Whether study participants are particularly vulnerable is one of those concerns. However, the concept of vulnerability is still vague and varies in its definition. Despite the fact that important international ethical guidelines such as the Declaration of Helsinki by the World Medical Association or the Ethical Guidelines for Biomedical Research Involving Human (...) Subjects by the Council of International Organizations of Medical Sciences refer to vulnerability as ethical principle, each of their approaches are different. To overcome these shortcomings, we analyze and unite different approaches of vulnerability and develop practical criteria in order to operationalize the concept especially for the context of TBR. These criteria refer to the context of a study as well as the characteristics and the current living situation of study participants. Based on a case study of an HIV-vaccine-trial conducted in India we demonstrate how those criteria can be applied in a retrospective way to identify potential ethical conflicts. The criteria can also indicate a prospective function for ethical pre-assessment. For this, we provide an outlook for three major topics: 1. Vulnerability as a normative concept: Different ways of protection; 2. The relevance of transparency and 3. Vulnerability as an instrument to increase decision participation of human subjects. (shrink)