Modeling and estimating recall processing capacity: Sensitivity and diagnostic utility in application to mild cognitive impairment

We investigate the potential for using latency-based measures of retrieval processing capacity to assess changes in performance specific to individuals with mild cognitive impairment (MCI), a reliable precursor state to Alzheimer’s Disease. Use of these capacity measures is motivated in part by exploration of the effects of atrophy on a computational model of a basic hippocampal circuit. We use this model to suggest that capacity may be a more sensitive indicator of the underlying atrophy than speed of processing, and test this hypothesis by adapting a standard behavioral measure of memory (the free and cued selective reminding test, FCSRT) to allow for the collection of cued recall latencies. Participants were drawn from five groups: college-aged, middle-aged, healthy elderly, those with a diagnosis of MCI, and a sample of MCI control participants. The measure of capacity is shown to offer increased classificatory sensitivity relative to the standard behavioral measures, and is also shown to be the behavioral measure that correlated most strongly with hippocampal volume.     

Why they reminisce: Caregiver reports of the functions of joint reminiscence in early childhood

Theorists have long suggested that joint caregiver–child reminiscence is functional, in that it is useful, adaptive, and can be utilised to achieve a variety of goals in everyday life. In the present study we investigated caregiver reports of the functions of joint reminiscence across early childhood. Participants were 203 parents or other guardians of 2–6-year-old children. Caregivers completed the Caregiver–child Reminiscence Scale (CRS) designed to tap functions of joint reminiscence. Our results indicated that caregivers reported frequently talking about past experiences with their children. Exploratory factor analysis revealed seven functions of joint reminiscence: Emotion Regulation, Directive, Positive Emotionality, Individual Self in Relation to Others, Conversation, Cognitive Skills, and Peer Relationships. Although some of these functions map directly onto adult-like functions outlined in the theoretical literature, others are unique to the context of joint reminiscence and reflect developmental goals of the early childhood period.     

Memories defining the self in Alzheimer’s disease

ABSTRACT

There is a debate over the extent to which personal identity or the self is preserved in patients with Alzheimer’s disease (AD). Autobiographical memory deficits at early stages of AD could contribute to altering patients’ self. However, the nature of the relationship between autobiographical memory deficits and the self in AD has not been much investigated experimentally. In the present study, we aimed to investigate the integrative meaning of self-defining memories (SDMs) in early stages of AD and to analyse its relationship with the self-concept. The results showed that, when compared to the control group, AD patients less frequently extracted meaning from their SDMs and the meaning was less frequently tied to the self. Patients exhibited some altered aspects of the self-concept (i.e., complexity and strength), though some other components still persisted (i.e., valence and certainty). Correlation analyses showed that the impaired integrative meaning in the AD group was correlated with some changes in self-concept. We suggest that integrative meaning may act as a bridge between autobiographical memories and the self-concept, with reduced integration abilities appearing as a potential mechanism for the deterioration of the self-concept in AD.     

Age,memory type,and the phenomenology of autobiographical memory: Findings from an Italian sample

The present research explored differences in phenomenology between two types of memories, a general self-defining memory and an earliest childhood memory. A sample of 76 Italian participants were selected and categorised into two age groups: 20–30 years and 31–40 years. The Memory Experiences Questionnaire (MEQ) was administered, taking note of latency and duration times of the narratives. Consistent with the literature, the self-defining memory differed significantly from the earliest childhood memory in terms of phenomenology, with the recency of the memory associated with more intense phenomenological experience. The self-defining memory took longer to retrieve and narrate than the earliest childhood memory. Meaningful differences also emerged between the two age groups: Participants in their 30s rated their self-defining memory as more vivid, coherent, and accessible than participants in their 20s. According to latency findings, these differences suggest an expanded period of identity consolidation for younger adults. Further applications of the MEQ should be carried out to replicate these results with other samples of young adults.     

No dual-task practice effect in Alzheimer's disease

Diagnosis of Alzheimer's disease (AD) requires evidence of progressive decline in cognitive function. However, many tests used to assess cognitive function suffer from considerable practice effects, reducing their reliability. Several studies have reported that the ability to do two things at once, or dual tasking, is impaired in AD, but unaffected by healthy ageing. The apparent specificity of this impairment suggests that this assessment may be particularly useful in the early diagnosis of AD, but the reliability of this assessment remains unknown. Therefore, this study investigated simultaneous performance of digit recall and tracking tasks across six testing sessions in eight people with AD, eight healthy older adults and eight healthy younger adults. The results found that dual-task performance was unaffected by healthy ageing, but significantly impaired in AD, with no effect of repeated exposure. The absence of any improvements in performance despite increased familiarity with the task's demands suggests that not only is the dual-task assessment well suited for monitoring progression over time, but also that dual tasking involves a specific cognitive function which is impaired in the AD brain.     

阿尔茨海默病生物学标志物研究进展

阿尔茨海默病（AD）是常见的中枢神经系统变性疾病,是痴呆最常见的病因,发病率高.病理特征为老年斑及神经元纤维缠结.AD的确诊有赖病理学,临床诊断极其耗时.由于尚无准确的早期诊断方法,常使AD患者错过早期治疗的时机,这成为制约有效防控AD的瓶颈问题.因此寻找高敏感性、特异性、无创性的生物学标志物对AD的早期诊断至关重要.本文仅将目前较为广泛研究的生物学标志物及其研究现状作一概述.分别对脑脊液、血液、尿液及唾液中的AD标志物作逐一介绍.     

Subjective states associated with retrieval failures in Parkinson’s disease

Instances in which we cannot retrieve information immediately but know that the information might be retrieved later are subjective states that accompany retrieval failure. These are expressed in feeling-of-knowing (FOK) and Tip-of-the-tongue (TOT) experiences. In Experiment 1, participants with Parkinson’s disease (PD) and older adult controls were given general questions and asked to report when they experienced a TOT state and to give related information about the missing word. The PD group experienced similar levels of TOTs but provided less correct peripheral information related to the target when in a TOT state. In Experiment 2, participants were given a Semantic (general knowledge questions) and an Episodic (word pairs) FOK task. PD patients failed to accurately predict their future memory performance (FOK) in response to both episodic and semantic cues. Results are interpreted in the context of recent frameworks of memory and metacognition.     

Sense of identity in advanced Alzheimer’s dementia: A cognitive dissociation between sameness and selfhood?

We looked at whether sense of identity persists in patients with Alzheimer’s disease (AD) and if its profile remains the same between two examinations. A specifically designed protocol was administered to 16 AD patients in the mild to severe stages of dementia and to 16 matched healthy controls, both living in the same institution. We showed that sense of identity was broadly preserved in AD patients. The patterns of their responses were similar to those of controls, and remained consistent over a two-week period. However, some qualitative characteristics of sense of identity in AD patients differed significantly from those of controls, suggesting that AD patients may not be able to update their self-knowledge, probably because of their episodic memory deficit. These results are discussed in the light of both current models of the self and philosophical concepts such as sameness and selfhood.     

Center-Based Care for Young Children: Examining Predictors of Quality

The authors collected information from caregivers, trained observers, and parents to investigate quality elements in child-care programs designed for young children in center-based settings. Participants were 75 parents of children aged 15 to 36 months and their caregivers from 13 child-care centers in a southeastern state. Observers collected indicators of program quality and process and structural quality indicators, including adult-child ratio, group size, use of planned activities, use of child-designated space, housekeeping activities, and caregiver-child interactions. Participants responded to questions regarding their child-rearing beliefs, social support networks, perceived stress levels, and demographic characteristics. The best predictors of higher quality care and sensitive caregiver-child interaction in centers were specialized caregiver training, higher adult-child ratios, use of planned activities, and less perceived stress by caregivers. Implications of these findings are discussed.     

Attachment Security,Personality, and Adjustment of Elementary School Children

Children's development is assumed to be closely related to their attachment security and their personality. The authors’ aim was to examine the joint contribution of attachment security and personality traits to children's adjustment by examining diverse children's outcomes (emotional symptoms, social functioning, and behavioral problems) and using various perspectives (children, parents, and teachers). The sample comprised 247 8–12-year-old children from low socioeconomic status neighborhoods. Personality and attachment contribute to the different domains of adjustment. In cases of moderation, attachment security moderates the implications of personality traits on children's adjustment. The findings highlight the contribution of positive personality tendencies in playing down the difficulties of insecurely attached children.