Memory Awareness Research Articles

Associative Recognition Memory Awareness Improved by Theta-Burst Stimulation of Frontopolar Cortex.

Neuroimaging and lesion studies have implicated specific prefrontal cortex locations in subjective memory awareness. Based on this evidence, a rostrocaudal organization has been proposed whereby increasingly anterior prefrontal regions are increasingly involved in memory awareness. We used theta-burst transcranial magnetic stimulation (TBS) to temporarily modulate dorsolateral versus frontopolar prefrontal cortex to test for distinct causal roles in memory awareness. In three sessions, participants received TBS bilaterally to frontopolar cortex, dorsolateral prefrontal cortex, or a control location prior to performing an associative-recognition task involving judgments of memory awareness. Objective memory performance (i.e., accuracy) did not differ based on stimulation location. In contrast, frontopolar stimulation significantly influenced several measures of memory awareness. During study, judgments of learning were more accurate such that lower ratings were given to items that were subsequently forgotten selectively following frontopolar TBS. Confidence ratings during test were also higher for correct trials following frontopolar TBS. Finally, trial-by-trial correspondence between overt performance and subjective awareness during study demonstrated a linear increase across control, dorsolateral, and frontopolar TBS locations, supporting a rostrocaudal hierarchy of prefrontal contributions to memory awareness. These findings indicate that frontopolar cortex contributes causally to memory awareness, which was improved selectively by anatomically targeted TBS.

Adaptive top-down suppression of hippocampal activity and the purging of intrusive memories from consciousness.

When reminded of unwanted memories, people often attempt to suppress these experiences from awareness. Prior work indicates that control processes mediated by the dorsolateral prefrontal cortex (DLPFC) modulate hippocampal activity during such retrieval suppression. It remains unknown whether this modulation plays a role in purging an intrusive memory from consciousness. Here, we combined fMRI and effective connectivity analyses with phenomenological reports to scrutinize a role for adaptive top-down suppression of hippocampal retrieval processes in terminating mnemonic awareness of intrusive memories. Participants either suppressed or recalled memories of pictures depicting faces or places. After each trial, they reported their success at regulating awareness of the memory. DLPFC activation was greatest when unwanted memories intruded into consciousness and needed to be purged, and this increased engagement predicted superior control of intrusive memories over time. However, hippocampal activity was decreased during the suppression of place memories only. Importantly, the inhibitory influence of the DLPFC on the hippocampus was linked to the ensuing reduction in intrusions of the suppressed memories. Individuals who exhibited negative top-down coupling during early suppression attempts experienced fewer involuntary memory intrusions later on. Over repeated suppressions, the DLPFC-hippocampus connectivity grew less negative with the degree that they no longer had to purge unwanted memories from awareness. These findings support a role of DLPFC in countermanding the unfolding recollection of an unwanted memory via the suppression of hippocampal processing, a mechanism that may contribute to adaptation in the aftermath of traumatic experiences.

Awareness of memory task impairment versus everyday memory difficulties in dementia.

The study investigated different types of awareness of memory dysfunction in dementia, specifically judgements concerning memory task performance or appraisal of everyday memory functioning and also exploring the neuropsychological correlates of such awareness. This was investigated in 76 people with dementia, comprising 46 patients with Alzheimer's disease (AD) and 30 patients with vascular dementia (VaD). The Memory Awareness Rating Scale (Clare et al., 2002, Neuropsychol Rehabil, 12, 341-362) was used, which includes an Objective-Judgement Discrepancy (OJD) technique involving comparison of subjective evaluation of performance on specific memory tasks with actual performance, and a Subjective Rating Discrepancy (SRD) technique, which compares self versus informant judgement of everyday memory function. The AD and VaD groups showed lower awareness than a normal control group for both types of measures, the AD group showing less awareness than the VaD group on the OJD measure. Regression analyses supported associations for both groups between memory impairment and the OJD measure and between naming impairment and the SRD measure. The findings are discussed in terms of neurocognitive theories accounting for loss of awareness in dementia.

Being aware of own performance: how accurately do children with autism spectrum disorder judge own memory performance?

Self-awareness was investigated by assessing accuracy of judging own memory performance in a group of children with autism spectrum disorder (ASD) compared with a group of typically developing (TD) children. Effects of stimulus type (social vs. nonsocial), and availability of feedback information as the task progressed, were examined. Results overall showed comparable levels and patterns of accuracy in the ASD and TD groups. A trend level effect (p = 061, d = 0.60) was found, with ASD participants being more accurate in judging own memory for nonsocial than social stimuli and the opposite pattern for TD participants. These findings suggest that awareness of own memory can be good in children with ASD. It is discussed how this finding may be interpreted, and it is suggested that further investigation into the relation between content, frequency, and quality of self-awareness, and the context of self-awareness, is needed.

When Eyewitnesses Misremember

Eyewitness testimony is a critical component of U.S. jurisprudence in both civil and criminal proceedings. Witnesses are relied on to recount key events, behaviors, and circumstances that contribute to findings of fact surrounding alleged criminal acts or circumstances that are the subject of civil dispute. The contribution of eyewitness testimony depends critically on the reliability of the witnesses’ memory of the events they are describing. Unfortunately, there are significant limits of human episodic memory that may degrade or distort these memories. Compounding this challenge is the poor metacognitive awareness of memory’s limitations. Eyewitnesses may overestimate the quality of their memory in accuracy and precision. They may be unaware of the potential for false details to merge into their episodic memories of an event. Jurists are similarly unaware of the limitations of memory and may rely too heavily on eyewitness testimony when resolving cases. But acknowledging and accounting for the limitations of memory has costs. Without eyewitness testimony many cases would not be viable, so there is a societal need to tolerate these limitations in order to have a working legal system. Human factors professionals, who are testifying as investigators in the case, may be the only source through which jurors can be informed of memory’s limitations when general memory experts are not admitted to testify solely for that purpose. When performed capably, this testimony can significantly improve the outcomes of legal proceedings.

Cognitive correlates of metamemory in Alzheimer's disease.

Metamemory, or knowledge of one's memory abilities, is often impaired in individuals with Alzheimer's disease (AD), although the basis of this metacognitive deficit has not been fully articulated. Behavioral and imaging studies have produced conflicting evidence regarding the extent to which specific cognitive domains (i.e., executive function; memory) and brain regions contribute to memory awareness. The primary aim of this study was to disentangle the cognitive correlates of metamemory in AD by examining the relatedness of objective metamemory performance to cognitive tasks grouped by domain (executive function or memory) as well as by preferential hemispheric reliance defined by task modality (verbal or nonverbal). Eighty-nine participants with mild AD recruited at Columbia University Medical Center and the University of Pennsylvania underwent objective metamemory and cognitive testing. Partial correlations were used to assess the relationship between metamemory and four cognitive variables, adjusted for recruitment site. The significant correlates of metamemory included nonverbal fluency (r = .27, p = .02) and nonverbal memory (r = .24, p = .04). Our findings suggest that objectively measured metamemory in a large sample of individuals with mild AD is selectively related to a set of interdomain nonverbal tasks. The association between metamemory and the nonverbal tasks may implicate a shared reliance on a right-sided cognitive network that spans frontal and temporal regions.

Subconscious Auditory Processing in Anesthesia: The Common Theme Between Dreams, Implicit Memory and Anesthesia Awareness

The fact that auditory evoked potentials (AEPs) have been used widely as a measure of the depth of anesthesia highlights the importance of auditory modality in consciousness-related neural processing during anesthesia, a phenomena more specifically known as Intra-operative awareness (IOA). The phenomena of IOA has seldom been observed from the perspective of consciousness itself. This perspective is especially important because the dimensions of IOA exist in the subconscious domain of mind as much as they exist in the conscious domain of explicit recall. Two important aspects of these subconscious manifestations of IOA are the implicit recall phenomena and post-operative dreams related to anesthesia experiences. Here we present an integrated auditory-consciousness based model of IOA. We start with a brief description of auditory awareness and the factors affecting it. Further, we proceed to the evaluation of conscious and sub-conscious information processing by auditory modality and their interactions during and after intraoperative period. Further, we show that both conscious and subconscious auditory processing affect the IOA experience and both have serious psychological implications on the patient subsequently. These effects could be prevented by using auditory evoked potential during monitoring of anesthesia, especially the Mid-latency Auditory Evoked Potentials (MLAERs). To conclude, we propose that the use of Auditory evoked potential should be universal with general anesthesia use in order to prevent the occurrences of distressing outcomes resulting from both conscious and subconscious auditory processing during anesthesia.

Communication is a two-way street

British Journal of Midwifery • May 2014 • Vol 22, No 5 It is well known that effective communication encompasses both verbal and non-verbal methods. Hurst-Brown and Keens (1990) identified eight areas that are required in order to be able to successfully communicate: hearing, sight, memory, attention, turn-taking, eye contact, self-awareness and group awareness. Early on and throughout pregnancy, communication between midwives and women is key. It can help to build bonds and trust at a very vulnerable time in a woman’s life. Unfortunately, midwives also have to be adept at delivering bad news as well as good news. In this issue, Richard Lyus and colleagues discuss termination of pregnancy for fetal abnormality (page 332). In addition to discussing the medical advice, Lyus et al also relay the importance of emotional aftercare for the mother. Any significant impairment in one or more of the eight ‘skills’ will affect communication. Previous discussion of a birth plan provides the woman a chance to ask questions and find out more about what happens in labour and to make informed decisions on her birth. During labour, women may not be able to listen or form coherent sentences due to pain, therefore understanding her previous birth requests and providing non-verbal communication is essential. The use of eye contact or a gentle touch may help to calm the woman at a difficult time in the birth process. Poor communication lies at the heart of NHS complaints (Pinock, 2004). Maternity claims represent the highest value and second highest number of clinical negligence claims reported to the NHS Litigation Authority (NHSLA) (NHSLA, 2012). Although the majority of claims are not due to poor communication, effective communication can help to allay some fears and misunderstandings that lead to such claims. As part of our supervision series, Rebekah Joy Stone, a service user, discusses her disappointing birth outcome and the role supervisory support can play on birth outcomes (page 353). We hope midwives will be able to learn from her experience and adjust their practice accordingly. Communication is not linear, although the British Journal of Midwifery is here to be your voice, we are also here to listen. We want to know the topics that interest you so we can make this journal, your journal and help to enhance your practice so you can provide women with the best evidence-based care. At the end of the day, it is the health of the mother and baby that are the number one priority. BJM

A Closer Look at Phonology as a Predictor of Spoken Sentence Processing and Word Reading

The goal of this study was to tease apart the roles of phonological awareness (pA) and phonological short-term memory (pSTM) in sentence comprehension, sentence production, and word reading. Children 6- to 10-years of age (N = 377) completed standardized tests of pA ('Elision') and pSTM ('Nonword Repetition') from the Comprehensive Test of Phonological Processing. Concepts and Following Directions (CFD) and Formulated Sentences (FS) were taken from the Clinical Evaluation of Language Fundamentals-Fourth Edition, as measures of sentence comprehension and production, respectively. Children also completed the Word Identification (Word Id) and Word Attack (Word Att) subtests of the Woodcock Reading Mastery Test-Third Edition. Hierarchical multiple regression analyses controlling for age and nonverbal IQ revealed that Elision was the only significant predictor of CFD and FS. While Elision was the strongest predictor of Word Id and Word Att, Nonword Repetition accounted for additional variance in both reading measures. These results emphasize the usefulness of breaking down phonological processing into multiple components and they also have implications language and reading disordered populations.

Anaesthesia, amnesia and harm

Anaesthesia causes unconsciousness by suppressing neural mechanisms mediating arousal and awareness. It also causes amnesia by disrupting mechanisms of memory consolidation. Some patients under general anaesthesia unexpectedly become aware during...

Clinical Correlates of Awareness for Balance, Function, and Memory: Evidence for the Modality Specificity of Awareness

Awareness in dementia is increasingly recognized not only as multifactorial, but also as domain specific. We demonstrate differential clinical correlates for awareness of daily function, awareness of memory, and the novel exploration of awareness of balance. Awareness of function was higher for participants with mild cognitive impairment (aMCI and non-aMCI) than for those with dementia (due to Alzheimer disease; AD and non-AD), whereas awareness of memory was higher for both non-aMCI and non-AD dementia patients than for those with aMCI or AD. Balance awareness did not differ based on diagnostic subgroup. Awareness of function was associated with instrumental activities of daily living and caregiver burden. In contrast, awareness of balance was associated with fall history, balance confidence, and instrumental activities of daily living. Clinical correlates of awareness of memory depended on diagnostic group: associations held with neuropsychological variables for non-AD dementia, but for patients with AD dementia, depression and instrumental activities of daily living were clinical correlates of memory awareness. Together, these data provide support for the hypothesis that awareness and dementia are not unitary and are, instead, modality specific.

Codynamics of Four Variables Involved in Dengue Transmission and Its Control by Community Intervention: A System of Four Difference Equations

In the case of Dengue transmission and control, the interaction of nature and society is captured by a system of difference equations. For the purpose of studying the dynamics of these interactions, four variables involved in a Dengue epidemic, proportion of infected people (P), number of mosquitoes involved in transmission (M), mosquito habitats (H), and population awareness (A), are linked in a system of difference equations:Pn+1=aPn+1-e-iMn1-Pn,Mn+1=lMne-An+bHn1-e-Mn,Hn+1=cHn/(1+pAn)+1/(1+qAn), andAn+1=rAn+fPn,n=0,1,…. The constraints have socioecological meaning. The initial conditions are such that0≤P0≤1, (M0,H0,A0)≥(0,0,0), the parametersl,a,c,r∈(0,1), and the parametersf, i, b, andpare positive. The paper is concerned with the analysis of solutions of the above system forp=q. We studied the global asymptotic stability of the degenerate equilibrium. We also propose extensions of the above model and some open problems. We explored the role of memory in community awareness by numerical simulations. When the memory parameter is large, the proportion of infected people decreases and stabilizes at zero. Below a critical point we observe periodic oscillations.

The role of memory in awareness of memory deficits in Alzheimer’s disease, schizophrenia, and brain injury

Patients with neuropsychiatric disorders such as Alzheimer’s disease (AD), schizophrenia (Sz), and brain injury (BI) often show memory deficits and lack of awareness of those deficits. This study aimed to investigate the role of memory in awareness of memory deficits and illness in multiple patient groups. Comparison of awareness profiles between groups can reveal common or distinct patterns of awareness and predictors, which may inform theories about the structure of awareness. Using the same standardized measures, AD (N = 27) Sz (N = 31), and BI (N = 26) patients were compared on memory functioning, awareness of illness, and awareness of memory deficits—measured by discrepancy of pretest estimate and actual test scores. All groups were poor at pretest estimation of memory functioning, particularly the AD and BI groups. In AD, patients with the lowest memory functioning rated their performance highest. The BI group and to a lesser extent the AD group showed improved estimations of performance following the memory test. Those with the poorest memory showed the greatest improvement in ratings accuracy post test. The relationship between memory and awareness of memory was stronger than the association between memory and awareness of illness. There was a double dissociation between awareness of memory and awareness of illness across patient groups. The study shows that awareness of memory is linked to memory functioning, while memory is only modestly related to awareness of illness. Dissociations in the role of memory in different domains of awareness and “online” awareness of performance provide information to refine cognitive models of awareness. However, the results should be interpreted with caution given the heterogeneous nature of the sample.

Predictors of Spelling Ability in Children With Down Syndrome

This study examined whether there are processing differences between children with Down syndrome (DS; n = 22; 7 years 8 months to 13 years 10 months) and typically developing children (TD; n = 22; 6 years 6 months to 10 years 10 months), matched for receptive vocabulary. The TD children performed better on tests of nonverbal intelligence (matrices), phonological awareness (sound deletion), and phonological short-term memory (digit span), as well as spelling accuracy (30 single words). Separate regression analyses revealed that nonverbal intelligence and phonological awareness were the best predictors of spelling accuracy for TD children, whereas receptive vocabulary and phonological short-term memory were the best predictors for children with DS. An examination of spelling errors suggested that although children with DS do use some phonological awareness during spelling, deficits in short-term memory appear to limit success. The implications of these results for intervention studies are briefly discussed.

Effects of different types of true–false questions on memory awareness and long-term retention

This study investigated the effects of two different true–false questions on memory awareness and long-term retention of knowledge. Participants took four subsequent knowledge tests on curriculum learning material that they studied at different retention intervals prior to the start of this study (i.e. prior to the first test). At the first and fourth (pre- and post-) tests, participants indicated which form of memory awareness (i.e. remember, know, familiar and/or guess) accompanied their answer. On the two intermediate tests, testing format was manipulated: true/false or true/false justification, that is a true/false statement with the additional instruction to explain why the statement is true or false. The results resembled earlier findings in that different forms of memory awareness could be distinguished. The study did not indicate (additional) knowledge schematisation as a result of testing or testing format. However, independent of test format, the proportion of correct answers on the post-test was higher than on the pre-test. This could indicate that the beneficial effects of testing can occur even when the learning episode was at a long retention interval prior to the first test.

Consciência do déficit na doença de Alzheimer: diferenças entre os domínios cognitivo e funcional

OBJETIVOS: Revisar sistematicamente desenhos de estudo, instrumentos de avaliação e fatores relacionados ao comprometimento dos domínios cognitivo e funcional da consciência do déficit em pessoas com doença de Alzheimer (DA). MÉTODO: Pesquisa nas bases de dados PubMed e ISI de estudos sobre consciência do déficit na DA publicados entre 2008 e 2013. As palavras-chave utilizadas foram: "dementia", "Alzheimer", "awareness", "awareness of memory" e "awareness of functioning", "deficits", "cognition". RESULTADOS: Os 10 artigos selecionados utilizaram os conceitos "falta de consciência do déficit", "anosognosia", "insight", "falta de consciência das dificuldades cognitivas" e "consciência limitada das deficiências". A etiologia do comprometimento da consciência do déficit foi relacionada a fatores biológicos como gravidade clínica da doença, associações neuroanatômicas, alterações neuropsiquiátricas e fatores psicológicos e sociais. O desenho de estudo mais utilizado foi o corte transversal. No domínio cognitivo, a memória e as funções executivas foram as duas principais funções investigadas. No domínio funcional, foram encontradas associações com a disfunção executiva, declínio da interação social, depressão e a influência do desempenho ocupacional. CONCLUSÕES: As distintas hipóteses etiológicas, a operacionalização variável do conceito e a falta de instrumentos de avaliação padronizados impossibilitam a obtenção de resultados homogêneos. Essas dificuldades comprometem a compreensão e a investigação dos domínios cognitivo e funcional.

The influence of cognitive and emotional suppression on overgeneral autobiographical memory retrieval

Over-general autobiographical memory (OAM) retrieval is characterized by retrieval of categoric autobiographical memories. According to the CarFAX model, this tendency may result from avoidance which functions to protect the person against recalling details of upsetting memories. This study tested whether avoidance strategies impact on the ability to retrieve specific autobiographical memories. Healthy participants (N=51) watched a negative video clip and were instructed to either suppress any thought (thought suppression), suppress any feeling (emotional inhibition), or think and feel naturally (controls) in response to the video. Participants then completed the Autobiographical Memory Test. Participants engaging in either thought suppression or emotional inhibition retrieved fewer categoric autobiographical memories than controls. These findings challenge the affect regulation component of the CarFAX model insofar as they suggest that regulatory strategies that aim to reduce awareness of adverse emotional memories do not necessarily lead to increased recall of categoric autobiographical memories.

Memory Awareness Profiles Differentiate Mild Cognitive Impairment from Early-Stage Dementia: Evidence from Assessments of Performance Monitoring and Evaluative Judgement

Background: Measures of memory awareness based on evaluative judgement and performance monitoring are often regarded as equivalent, but the Levels of Awareness Framework suggests they reflect different awareness phenomena. Examination of memory awareness among groups with differing degrees of impairment provides a test of this proposition. Method: Ninety-nine people with dementia (PwD), 30 people with mild cognitive impairment (PwMCI), and their relatives completed isomorphic performance monitoring and evaluative judgement measures of memory awareness and were followed up at 12 and (PwD only) 20 months. In addition to the resulting awareness indices, comparative accuracy scores were calculated using the relatives' data to establish whether any inaccuracy was specific to self-ratings. Results: When making evaluative judgements about their memory in general, both PwD and PwMCI tended to overestimate their own functioning relative to informant ratings made by relatives. When monitoring performance on memory tests, PwD again overestimated performance relative to test scores, but PwMCI were much more accurate. Comparative accuracy scores indicated that, unlike PwD, PwMCI do not show a specific inaccuracy in self-related appraisals. Conclusions: The results support the proposition that awareness indices at the levels of evaluative judgement and performance monitoring should be regarded as reflecting distinct awareness phenomena.

Remembering Things We’ve Never Done: Memory’s Daughters and the Literary Experience

From early literature to the present, the creative process has been linked to memory. The Greeks depicted Memory (Mnemosyne) herself as mother of the Muses; without Memory, the Muses would be unable to inspire creative and recreative participation in the arts. Their inspiration, in classical terms, engages artists both in remembering their own origins and then in “re-membering” forms into new formations. Memory is equally important to the perceivers of artistic creations, those inspired by the work of others and who, through reading, share in creating new worlds. Connecting to place and people, by suspending us in that liminal space where fiction and fact, art and life, converge, Memory and her daughters empower us to reorganize our understanding of reality and to shape a deeper understanding of the self. Although the phraseology may strike the modern ear as odd, we have all found ourselves “inspired by the Muses.” Listening to a symphony (where the Muses’ participation is recalled even in the word “music”), viewing (perhaps in a Muse-um) a painting, or “musing” over a book, we employ a complex of various cognitive faculties, doing so in a dynamic of recognition, information retrieval, re-collection, and memory. And though we no longer write of Mnemosyne as a goddess who helps us collect and recollect the past, remembering her archetypal roles allows us to be more conscious of Memory’s integral involvement in shaping Western thought and culture. Remembering Memory also helps us understand her importance in the writing/reading process and deepens our appreciation of the experience of artistic inspiration—for which her daughters, the Muses, may even today be credited. And recollecting Memory, particularly as she stimulates our active reading both of literature and of ourselves, enables us to stand mindfully in the doorway of the present, poised between past and future, remembering the connectivity of origins and of our own original selves. In other words, by awareness of Memory’s roles and presence, we draw upon and are inspired by memories to weave our literary reading into the narrative of our own experience and to seek through the fragments of lives-in-books our own psychic wholeness.

Levels of Processing and Memory Awareness when Recognising Own-race versus Other-race Faces: Implications for Eye-witness Memory

The study employed the remember-know paradigm to investigate levels-of-processing effects in recognition memory for same-versus other-race faces. It was predicted that deeper processing would benefit accuracy in recognition and remembering for both own- and other-race faces. Moreover, the Cross-Race Bias (CRB) would be evident with participants more accurately recognizing faces of their own race than faces of another race. No interaction between the 2 variables was expected. Deeper processing benefited accurate remembering only. The CRB was evident with same-race faces being accurately recognised more than other-race faces, and more remember and know false positives being given to other-race faces. No interaction effect was found. The results do not support the depth of processing hypothesis for the CRB and have implications for the assumption that richer encoding could lead to a decrease in CRB by minimising false positives. Thus, in eyewitness memory richer encoding opportunities do not necessarily lead to less false cross-race identifications and care should be taken when dealing with those kinds of identifications.