Bio-inspired cognitive architecture of episodic memory

Memory and learning are essential functions in human beings as they allow us to acquire and store in the brain representations of thoughts, experiences, and behaviors, which are required for problem-solving in our daily life and mainly for survival. Episodic memory is a type of memory that provides the ability to re-experience events in one’s life, and it is associated with their conscious recollection. Since episodic memory can represent our experiences about the environment, similar to a mental journey, it is desired in systems that attempt to create human-like behavior. Currently, the main problem is that state of the art proposals do not consider neuroscientific evidence like memory dynamics for forgetting or bottom-up inputs, and most of them do not consider episodic memory as a different memory but as part of general declarative memory. We consider these omissions to limit the generation of human-like behavior. In this work, we propose a bio-inspired cognitive architecture of episodic memory. Neuroscientific evidence provides us with the brain structures associated with this type of memory, the connections, and the operations these areas perform. We hypothesize that virtual entities endowed with our episodic memory cognitive architecture will plan and make decisions in a more human-like fashion. To test the capabilities of the proposal, we endowed a virtual creature with a distributed and concurrent implementation of our architecture, and it was given two tasks. The first task validated the functions of the memory independently, and in the second task, the creature used episodic memory to solve a planning problem. From the results of these experiments, we validate our proposal and show that it is possible to create a system that behaves as the human brain does.     

Recognition Decisions From Visual Working Memory Are Mediated by Continuous Latent Strengths

Making recognition decisions often requires us to reference the contents of working memory, the information available for ongoing cognitive processing. As such, understanding how recognition decisions are made when based on the contents of working memory is of critical importance. In this work we examine whether recognition decisions based on the contents of visual working memory follow a continuous decision process of graded information about the correct choice or a discrete decision process reflecting only knowing and guessing. We find a clear pattern in favor of a continuous latent strength model of visual working memory–based decision making, supporting the notion that visual recognition decision processes are impacted by the degree of matching between the contents of working memory and the choices given. Relation to relevant findings and the implications for human information processing more generally are discussed.     

工作记忆模型的第四个组成部分——情景缓冲器

工作记忆的提出迄今已有30多年的历史了,随着实验方法和技术的发展对工作记忆的研究取得了很大的突破,但在很多问题上仍存在争议,特别是在工作记忆与长时记忆、语音回路与视空间模板的联结上的解释还有许多不足.基于此,Baddeley于2000年提出了工作记忆模型的第四个组成部分--情景缓冲器(episodic buffer).情景缓冲器是一个容量有限的暂时贮存多种编码信息的装置,它受中央执行系统的控制,而中央执行系统能够通过意识觉察从存贮中提取信息,反映信息,在必要的时候能够修正信息.新的工作记忆模型更加完整,更加有解释力.     

人类工作记忆的事件相关电位研究

20世纪90年代以来,采用ERP技术对人类工作记忆脑机制的研究已取得大量的成果。主要探讨了特定类型的工作记忆（词语、空间、客体工作记忆）是否存在与其贮存、复述以及中央执行功能相关的特异性ERP成分,并从它们的时间进程及头皮分布来考察工作记忆的心理过程和神经机制。研究结果对于Baddeley的认知结构模型提供了有益的修正和补充。     

When facts go down the rabbit hole: contrasting features and objecthood as indexes to memory

People will often look to empty, uninformative locations in the world when trying to recall spoken information. This spatial indexing behaviour occurs when the information had previously been associated with those locations. It remains unclear, however, whether this behaviour is an example of a simple association across perceptual and cognitive systems, or whether location information plays a role in memory retrieval. In the current study, we investigate whether higher-level cognitive processes, such as object-based attention, are involved in spatial indexing. Participants saw creatures burrowing around the screen, appearing from underground to tell them facts. They saw the same creature in two locations, or two identical creatures in two locations, depending on spatiotemporal cues conveyed by a burrowing animation. While answering questions, we found that participants relied on these spatiotemporal cues, fixating the previous locations of the creature associated with the relevant fact, rather than the location of an identical creature. We interpret these findings in terms of an object-based attentional mechanism that is common to semantic memory and scene perception, and allows 'external memory' to be exploited in a dynamic environment.     

Variations in working memory capacity predict individual differences in general learning abilities among genetically diverse mice

Up to 50% of an individuals' performance across a wide variety of distinct cognitive tests can be accounted for by a single factor (i.e., "general intelligence"). Despite its ubiquity, the processes or mechanisms regulating this factor are a matter of considerable debate. Although it has been hypothesized that working memory may impact cognitive performance across various domains, tests have been inconclusive due to the difficulty in isolating working memory from its overlapping operations, such as verbal ability. We address this problem using genetically diverse mice, which exhibit a trait analogous to general intelligence. The general cognitive abilities of CD-1 mice were found to covary with individuals' working memory capacity, but not with variations in long-term retention. These results provide evidence that independent of verbal abilities, variations in working memory are associated with general cognitive abilities, and further, suggest a conservation across species of mechanisms and/or processes that regulate cognitive abilities.     

Can fluid intelligence be reduced to ‘simple’ short-term storage?

Much is written regarding the associations between human intelligence and cognition. However, it is unusual to find comprehensive studies. Here twenty four measures tapping eight cognitive abilities and skills are considered for assessing a sample of one hundred and eighty five young adults. The simultaneous relationships among fluid, crystallized, and spatial intelligence, along with short-term memory, working memory capacity, executive updating, attention, and processing speed are analyzed using a latent-variable approach. The key findings show that (a) short-term storage, working memory, and updating are hardly distinguishable, and (b) fluid intelligence is near-perfectly correlated with these three cognitive functions. It is concluded that this nuclear intelligence component can be largely identified with basic and general short-term storage processes, namely, encoding, maintenance, and retrieval.     

基于手机APP的双维n-back训练的认知与情绪效益

工作记忆训练的训练获益能够迁移至与工作记忆相关的各项基础认知活动中去。基于情绪认知控制与工作记忆之间的密切关联, 本研究设计了一种新型情绪性双维n-back训练, 并且验证利用手机APP搭载训练任务的适用性。结果表明：基于APP的短期双维n-back训练能够使个体在视空间工作记忆任务、活动记忆任务、数字转换任务、Stroop任务上的成绩产生相较控制组更大的进步, 表明训练可以提高个体工作记忆的容量和中央执行功能。然而, 基于不同情绪材料的训练(中性、负性、正性)在各类迁移上差异不大。短期训练无法迁移到情绪Stroop任务中, 即无法产生特异的情绪控制上的效益。双维n-back任务通道单一, 且搭载于手机APP, 拥有较为广阔的应用前景。但将情绪材料单纯地糅合进工作记忆任务中的价值与意义须被进一步考察。     

工作记忆与情景记忆中脑区的重合与分离——从脑区定位看两者关系

尽管近期的研究结果认为前额叶在工作记忆和情景记忆任务中均被激活,但是仍然不清楚是否有特定的区域对两种记忆起着不同作用。对于工作记忆和情景记忆在脑区上的重合,研究者们做出了不同的解释。某些研究者认为脑区的重合反映了包含于情景记忆中的工作记忆的作用,另一些研究者则认为这种重合反映的是与工作记忆和情景记忆都有关的反省过程的性质。对此,作者提出了相应的讨论意见。     

Working memory predicts subsequent episodic memory decline during healthy cognitive aging: evidence from a cross-lagged panel design

Aging adults experience declines in working memory and episodic memory, however, it is unclear how these declines operate over time. Decreased working memory may be associated with early changes in episodic memory, by reducing older adults’ ability to meaningfully integrate new information into pre-existing schemas and recall information without the assistance of cues. Given the increased prevalence of Alzheimer’s disease, and concerns based on subjective memory changes, it is important to understand how these processes interact over time. To assess the relationship between working memory and episodic memory during healthy cognitive aging, we performed neuropsychological assessments at multiple time points in a sample of 310 community-dwelling older adults. Using a cross-lagged panel design, we demonstrated that the lagged associations between working memory and later episodic free recall were 50% larger than the lagged associations between episodic recall and later working memory, suggesting working memory may be a useful metric of future episodic memory decline.     

Training and transfer effects of long-term memory retrieval training

ABSTRACT

Long-term memory retrieval ability and working memory can share attention control ability. Based on cognitive plasticity, a hypothesis that cognitive training could improve long-term memory retrieval efficiency and that this could transfer to retrieval involving working memory was proposed. 60 undergraduates were randomly assigned to a group of training and an active control group; all the participants completed the same tasks in the same order before and after the training, the tasks included a long-term memory retrieval access task, a intelligence test, a switching task, a working memory updating task, a response inhibition task and an interference control task. The statistics results indicate that cognitive training can improve long-term memory retrieval efficiency and has a transfer effect on working memory updating, interference control and switching ability, but not on response inhibition or intelligence. This reveal the plasticity of long-term memory retrieval and its influence on working memory.     

人类工作记忆的某些神经影像研究

采用神经影像技术研究人类工作记忆的脑机理是目前一个十分活跃的研究领域。研究表明存在负责不同信息加工的工作记忆系统 ,如词语工作记忆、空间工作记忆等 ,其中词语工作记忆主要由大脑左半球参与 ,空间工作记忆主要由大脑右半球参与。前额叶在工作记忆中的作用相当复杂 ,包括对记忆信息的注意和抑制、管理、整合等功能。合理巧妙的实验设计、多种研究手段的综合应用必将使人类工作记忆的脑机理得到充分阐明。     

Working Memory Deficits in Boys with Attention-deficit/Hyperactivity Disorder (ADHD): The Contribution of Central Executive and Subsystem Processes

The current study investigated contradictory findings from recent experimental and meta-analytic studies concerning working memory deficits in ADHD. Working memory refers to the cognitive ability to temporarily store and mentally manipulate limited amounts of information for use in guiding behavior. Phonological (verbal) and visuospatial (nonverbal) working memory were assessed across four memory load conditions in 23 boys (12 ADHD, 11 typically developing) using tasks based on Baddeley's (Working memory, thought, and action, Oxford University Press, New York, 2007) working memory model. The model posits separate phonological and visuospatial storage and rehearsal components that are controlled by a single attentional controller (CE: central executive). A latent variable approach was used to partial task performance related to three variables of interest: phonological buffer/rehearsal loop, visuospatial buffer/rehearsal loop, and the CE attentional controller. ADHD-related working memory deficits were apparent across all three cognitive systems--with the largest magnitude of deficits apparent in the CE--even after controlling for reading speed, nonverbal visual encoding, age, IQ, and SES.     

视觉工作记忆更新操作过程独立于刺激类型

采用4×2被试内设计和2-back视觉工作记忆更新任务,探讨不同刺激类型对任务的影响,并且分离更新任务中的操作与存储成分。结果发现,字母、具体意义的汉字、抽象意义的汉字以及图片的更新任务成绩没有差异,表明更新是一种程序化的认知过程,独立于刺激类型;不同材料的再认成绩存在差异,字母的再认率低于其它三种材料,汉字的再认率也略低于图片,表明更新任务中的存储与更新操作是相互独立的过程,在作业任务上可以产生分离。     

Effects of emotional content on working memory capacity

Emotional events tend to be remembered better than neutral events, but emotional states and stimuli may also interfere with cognitive processes that underlie memory performance. The current study investigated the effects of emotional content on working memory capacity (WMC), which involves both short term storage and executive attention control. We tested competing hypotheses in a preregistered experiment (N?=?297). The emotional enhancement hypothesis predicts that emotional stimuli attract attention and additional processing resources relative to neutral stimuli, thereby making it easier to encode and store emotional information in WMC. The emotional impairment hypothesis, by contrast, predicts that emotional stimuli interfere with attention control and the active maintenance of information in working memory. Participants completed a common measure of WMC (the operation span task; Turner, M. L., &; Engle, R. W. [1989]. Is working memory capacity task dependent? Journal of Memory and Language, 28, 127–154) that included either emotional or neutral words. Results revealed that WMC was reduced for emotional words relative to neutral words, consistent with the emotional impairment hypothesis.     

工作记忆中“组块”概念的演化及理论模型

在Miller提出“神奇的数字7±2”之后, “块”被很多理论作为个体工作记忆加工过程中具有稳定结构并可用于衡量记忆容量的单位。但随着研究者对“组块”研究的深入, 他们对组块的定义也在发生着改变。与此同时, 不少研究发现个体的年龄阶段与其主要采用的组块层级相对应, 但尚不清楚组块层级的转换是否存在固定的年龄区间, 且对组块机制的解释仍存在分歧。因此本文针对组块定义的发展与演变、年龄阶段特征及其机制三方面展开综合讨论。未来的研究可以更多探讨长时记忆在工作记忆组块运行机制中的作用, 完善不同年龄阶段个体的组块特征, 以及怎样发挥复述策略和“少即是多”原则在组块过程中的优势等问题。     

Storage and processing working memory functions in Alzheimer-type dementia

A selective deterioration of working memory functions has been suggested as an explanation of the cognitive decay occurring in normal ageing as well as in Alzheimer-type dementia. Recent studies have highlighted that elderly people's limitations in working memory functions may be better interpreted when analysing the specific characteristics of the cognitive process (i.e., passive storage or active manipulation of information). In the present study, we have adapted a procedure used to investigate age-related memory modifications, involving both verbal and visuo-spatial material in tasks tapping passive and active processes, to investigate the deterioration associated with Alzheimer's disease. A group of Alzheimer patients in the early stages of the disease were matched to a control group of healthy elderly. Results show that Alzheimer patients performed less accurately than the control group in all tasks. However, the deficit was maximised in the case of active processes, regardless of the type of material used (verbal or visuo-spatial). These data highlight the importance of considering the amount of active processing as the key variable when interpreting the decay in cognitive functions in the early stages of Alzheimer's disease.     

On the law relating processing to storage in working memory

Working memory is usually defined in cognitive psychology as a system devoted to the simultaneous processing and maintenance of information. However, although many models of working memory have been put forward during the last decades, they often leave underspecified the dynamic interplay between processing and storage. Moreover, the account of their interaction proposed by the most popular A. D. Baddeley and G. Hitch's (1974) multiple-component model is contradicted by facts, leaving unresolved one of the main issues of cognitive functioning. In this article, the author derive from the time-based resource-sharing model of working memory a mathematical function relating the cognitive load involved by concurrent processing to the amount of information that can be simultaneously maintained active in working memory. A meta-analysis from several experiments testing the effects of processing on storage corroborates the parameters of the predicted function, suggesting that it properly reflects the law relating the 2 functions of working memory.     

Social anxiety and information processing biases: An integrated theoretical perspective

Models of anxiety disorders posit that information processing biases towards threat may result from an imbalance between top-down attentional control processes and bottom-up attentional processes, such that anxiety could reduce the influence of the former and increase the influence of the latter. However, researchers have recently pointed to limitations of the top-down/bottom-up terminology and outlined the additional contribution of memory processes to attention guidance. The goal of this paper is to provide bridges between recent findings from cognitive psychology and anxiety disorders research. We first provide an integrative overview of the processes influencing the content of working memory, including the availability of attentional control, and the strengths of task goals, stimulus salience, selection history and long-term memory. We then illustrate the interest of this formulation to the study of information processing biases in anxiety disorders, with a specific focus on social anxiety.     

工作记忆训练及对数学能力的迁移作用

工作记忆缺陷会影响个体数学能力发展。通过记忆策略、广度、刷新、转换等功能的工作记忆训练,可以改善个体认知功能。然而,工作记忆训练对个体的阅读、数学、流体智力等方面的远迁移效果并不一致。研究表明,工作记忆训练可以改善数感、视觉空间能力、推理能力等数学一般技能;也会通过改善语音工作记忆以及空间能力促进数学计算能力,或者通过改善中央执行系统,提升数学问题表征、模式识别、解题迁移、策略选择等复杂的过程,从而促进数学问题解决能力。因此,区分不同数学任务的认知过程,可以获得工作记忆训练对数学能力迁移效果的进一步证据。今后,神经影像学的证据或许也是未来工作记忆训练对数学能力提高的又一佐证。