Aging impairs primary task resumption and attentional control processes following interruptions

Attentional selection of working memory content is impaired after an interruption. This effect was shown to increase with age. Here we investigate how electrophysiological mechanisms underlying attentional selection within working memory differ during primary task resumption between younger and older adults. Participants performed a working memory task, while be-ing frequently interrupted with either a cognitively low- or high-demanding arithmetic task. Afterwards, a retrospective cue (retro-cue) indicated the working memory content required for later report. The detrimental effect of the interruption was evident in both age groups, but while younger adults were more strongly affected by a high- than by a low-demanding inter-ruption, the performance deficit appeared independently of the cognitive requirements of the interruption task in older adults. A similar pattern was found regarding frontal-posterior con-nectivity in the theta frequency range, suggesting that aging decreases the ability to selectively maintain relevant information within working memory. The power of mid-frontal theta oscilla-tions (4-7 Hz) featured a comparable effect of interruptions in both age groups. However, pos-terior alpha power (8-14 Hz) following the retro-cue was more diminished by a preceding in-terruption in older adults. These results suggest an age-related deficit in the attentional selec-tion and maintenance of primary task information following an interruption that appeared in-dependent from the cognitive requirements of the interrupting task.

Abnormal Detection in Big Data Video with an Improved Autoencoder

With the rapid growth of video surveillance data, there is an increasing demand for big data automatic anomaly detection of large-scale video data. The detection methods using reconstruction errors based on deep autoencoders have been widely discussed. However, sometimes the autoencoder could reconstruct the anomaly well and lead to missing detections. In order to solve this problem, this paper uses a memory module to enhance the autoencoder, which is called the memory-augmented autoencoder (Memory AE) method. Given the input, Memory AE first obtains the code from the encoder and then uses it as a query to retrieve the most relevant memory items for reconstruction. In the training phase, the memory content is updated and encouraged to represent prototype elements of normal data. In the test phase, the learned memory elements are fixed, and reconstruction is obtained from several selected memory records of normal data. So, the reconstruction will tend to be close to normal samples. Therefore, the reconstruction of abnormal errors will be strengthened for abnormal detection. The experimental results on two public video anomaly detection datasets, i.e., Avenue dataset and ShanghaiTech dataset, prove the effectiveness of the proposed method.

Finding positive meaning in memories of negative events adaptively updates memory

Finding positive meaning in past negative memories is associated with enhanced mental health. Yet it remains unclear whether it leads to updates in the memory representation itself. Since memory can be labile after retrieval, this leaves the potential for modification whenever its reactivated. Across four experiments, we show that positively reinterpreting negative memories adaptively updates them, leading to the re-emergence of positivity at future retrieval. Focusing on the positive aspects after negative recall leads to enhanced positive emotion and changes in memory content during recollection one week later, remaining even after two months. Consistent with a reactivation-induced reconsolidation account, memory updating occurs only after a reminder and twenty four hours, but not a one hour delay. Multi-session fMRI showed adaptive updates are reflected in greater hippocampal and ventral striatal pattern dissimilarity across retrievals. This research highlights the mechanisms by which updating of maladaptive memories occurs through a positive emotion-focused strategy.

Beyond dimension reduction: Stable electric fields emerge from and allow representational drift

It is known that the exact neurons maintaining a given memory (the neural ensemble) change from trial to trial. This raises the question of how the brain achieves stability in the face of this representational drift. Here, we demonstrate that this stability emerges at the level of the electric fields that arise from neural activity. The electric fields, in turn, can act as “guard rails” that funnel higher dimensional variable neural activity along stable lower dimensional routes. We show that electric fields carry information about working memory content. We obtained the latent space associated with each memory. We then confirmed the stability of the electric field by mapping the latent space to different cortical patches (that comprise a neural ensemble) and reconstructing information flow between patches. Stable electric fields can allow latent states to be transferred between brain areas, in accord with modern engram theory.

Immunity to error through misidentification and the functionalist, self-reflexive account of episodic memory

Fernández (2019) offers an account of the nature of episodic memory that marries two core ideas: (i) role-functionalism about episodic memory, and (ii) self-reflexive mnemonic content. One payoff of this view is that episodic memory judgments are immune to error through misidentification. Fernández takes this to reveal something important about the nature of one’s self-awareness in memory and our first-person conception of ourselves. However, once one sees why such judgments are immune in this way, according to the proposed account, the fact that they are immune becomes moot. While technically immune to error through misidentification, episodic memory judgments are not grounded in a way such that they have any interesting epistemological import for the subject (in contrast to other paradigms of such judgments), and any insights about our self-awareness and self-conception are directly derivable from the metaphysics of memory content alone.

A Comparison of Memories of Fiction and Autobiographical Memories

People consume, remember, and discuss not only memories of lived experiences, but also events from works of fiction, such as books, movies, and television shows. We argue that these memories of fiction represent an important category of event memory, best understood within an autobiographical memory framework. How do fictional events yield psychological realities even when they are known to be invented? We explored this question in three studies by comparing the memory content, phenomenological qualities, and functional roles of naturally occurring personal memories to memories of fiction. In Studies 1 and 2, we characterized the subjective experience of memories of fiction by adapting established measures of autobiographical remembering, such as the Autobiographical Memory Questionnaire (Rubin et al., 2003), Centrality of Event Scale (Berntsen & Rubin, 2006), and items from the Thinking About Life Experiences scale (Bluck et al., 2005; Pillemer et al., 2015). In Study 3, we investigated similarities and differences in personal memories and memories of fiction for events from childhood or the recent past. In doing so, we observed the impact of a unique property of memories of fiction: their ability to be repeatedly re-experienced in their original form. Taken together, we argue that memories of fiction can be considered similar to other forms of autobiographical remembering and describe a theoretical framework for understanding memories of fiction in the context of other event memories.

Shielding working-memory representations from temporally predictable external interference

Protecting working-memory content from distracting external sensory inputs and intervening tasks is a ubiquitous demand in daily life. Here, we ask whether and how temporal expectations about external events can help mitigate effects of such interference during working-memory retention. We manipulated the temporal predictability of interfering items that occurred during the retention period of a visual working-memory task and report that temporal expectations reduce the detrimental influence of external interference on subsequent memory performance. Moreover, to determine if the protective effects of temporal expectations rely mainly on distractor suppression or also involve shielding of internal representations, we compared effects after irrelevant distractors that could be ignored vs. interrupters that required a response. Whereas distractor suppression may be sufficient to confer protection from predictable distractors, any benefits after interruption are likely to involve memory shielding. We found similar benefits of temporal expectations after both types of interference. We conclude that temporal expectations may play an important role in safeguarding behaviour based on working memory – acting, at least partly, through mechanisms that include the shielding of internal content from external interference.