Using memories to support the self in Alzheimer's disease

Treatment with walnut peptide ameliorates memory impairment in zebrafish and rats: promoting the expression of neurotrophic factors and suppressing oxidative stress

Walnut peptide, a low molecular weight peptide separated from walnuts by enzymatic hydrolysis, is considered as a potential nutraceutical with a variety of biological activities. In this study, we characterized the walnut peptide prepared by alkaline protease hydrolysis and evaluated its neuroprotective effect in zebrafish and rat models of memory disorders. Series of concentrations of the walnut peptide were orally administered to zebrafish and rats to examine its impact on the behavior and biochemical indicators. The results showed that the oral administration of walnut peptide significantly ameliorated the behavioral performance in zebrafish exposed to bisphenol AF (1 μg mL-1) and rats exposed to alcohol (30% ethanol, 10 mL kg-1). Furthermore, the walnut peptide upregulated the expression of neurotrophic-related molecules in zebrafish, such as the brain-derived neurotrophic factor (BDNF) and the glial cell-derived neurotrophic factor (GDNF). In the rat brain, the walnut peptide increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), while dramatically reduced malondialdehyde (MDA) level. Together, these findings elucidated that the walnut peptide might partially offset the declarative memory deficits via regulation of neurotrophic-related molecule expression and promotion of the antioxidant defense ability. Therefore, walnut peptide holds the potential for development into functional foods as a nutritional supplement for the management of certain neurodegenerative disorders.

Understanding the relationship between self and memory through the IAM task

In this article we present a review of research on the IAM Task, whereby memories are cued by self-images in the form of "I am … " statements, such as I am a grandfather, I am a Bob Dylan fan, I am from Darlington, I am a Psychologist. Such cues are particularly successful at accessing memories associated with the formation of specific aspects of the self. We describe the conceptual and historical context for the development of our task and review findings from other researchers who have used the same basic design. We present aggregate data and examples from across several experiments, examining how these patterns change in psychological distress and dysfunction. We also discuss research on "I will be" statements and how these have been adopted to examine self-related future cognitions. We conclude that the working self operates to organise memory retrieval and make accessible episodic and semantic material for self-relevant periods across the lifespan. Moreover, accessibility of self-images can be modulated by retrieval of autobiographical memories, highlighting Conway's bidirectional relationship between memory and the self. We provide suggestions for future research and for the first time provide a standardised version of our IAM Task for use by researchers.

Change in the psychological self in people living with dementia: A scoping review

Alterations in one's sense of self are often considered a significant psychological symptom of dementia. However, the self is not a unified construct; it consists of a set of closely connected, yet substantive, manifestations which might not be equally impacted by dementia. Recognising the multidimensional nature of the self, the current scoping review aimed to explore the nature and scope of the evidence demonstrating change in the psychological self in people living with dementia. Adopting a cognitive psychological framework, a hundred and five (105) quantitative and qualitative studies were reviewed, and findings were organised into three main types of self-manifestations: high-order manifestations, functional aspects of the self, and foundational manifestations. Overall, the results show that although there are alterations in some of these different manifestations of the self, these do not imply a global loss of selfhood. Despite notable cognitive changes during dementia, it seems that preserved aspects of self may be enough to compensate for potential weakening of some self-processes such as autobiographical recall. Better understanding alterations in selfhood is key to addressing psychological symptoms of people living with dementia, such as feelings of disconnection and reduced agency, and may inform new pathways for dementia care interventions.

Nature, smells, and human wellbeing

The link between nature and human wellbeing is well established. However, few studies go beyond considering the visual and auditory underpinnings of this relationship, even though engaging with nature is a multisensory experience. While research linking smell to wellbeing exists, it focuses predominantly on smells as a source of nuisance/offence. Smells clearly have a prominent influence, but a significant knowledge gap remains in the nexus of nature, smell, and wellbeing. Here, we examine how smells experienced in woodlands contribute to wellbeing across four seasons. We show that smells are associated with multiple wellbeing domains, both positively and negatively. They are linked to memories, and specific ecological characteristics and processes over space/time. By making the link between the spatiotemporal variability in biodiversity and wellbeing explicit, we unearth a new line of enquiry. Overall, the multisensory experience must be considered by researchers, practitioners, policy-makers and planners looking to improve wellbeing through nature.

Semantic Self-Images and Well-Being in Young and Older Adults: Does the Accessibility Matter?

In the present study we investigated whether and how age group, dimensions of well-being and their interactions predicted the phenomenological properties of semantic self-images, taking also into account the different levels of accessibility of self-images (i.e., order of generation). Results on the first self-image revealed that, independently of age, higher levels of life satisfaction predicted higher likelihood of positive than negative statement and higher levels of negative affect and life satisfaction predicted higher levels of personal relevance of the self-image. When all self-images were considered, for higher levels of life satisfaction neutral and positive self-images were more likely than negative ones, and for lower levels of positive affect, neutral images were more likely than negative ones. Moreover, young adults were more likely than older adults to report neutral rather than negative self-images and, for higher levels of positive affect, they were more likely to report neutral and positive images instead of negative ones. These results suggest that the accessibility of semantic self-images should be taken into account in the investigation of the complex association between well-being and semantic self-images. Theoretical and practical implications of these results are discussed.

I remember therefore I am: Episodic memory retrieval and self-reported trait empathy judgments in young and older adults and individuals with medial temporal lobe excisions

How do we know what sort of people we are? Do we reflect on specific past instances of our own behaviour, or do we just have a general idea? Previous work has emphasized the role of personal semantic memory (general autobiographical knowledge) in how we assess our own personality traits. Using a standardized trait empathy questionnaire, we show in four experiments that episodic autobiographical memory (memory for specific personal events) is associated with people's judgments of their own trait empathy. Specifically, neurologically healthy young adults rated themselves as more empathic on questionnaire items that cued episodic memories of events in which they behaved empathically. This effect, however, was diminished in people who are known to have poor episodic memory: older adults and individuals who have undergone unilateral excision of medial temporal lobe tissue (as treatment for epilepsy). Further, self-report ratings on individual questionnaire items were generally predicted by subjectively rated phenomenological qualities of the memories cued by those items, such as sensory detail, scene coherence, and overall vividness. We argue that episodic and semantic memory play different roles with respect to self-knowledge depending on life experience, the integrity of the medial temporal lobes, and whether one is assessing general abstract traits versus more concrete behaviours that embody these traits. Future research should examine different types of self-knowledge as well as personality traits other than empathy.

Boosting Autobiographical Memory and the Sense of Identity of Alzheimer Patients Through Repeated Reminiscence Workshops?

Despite severe amnesia, some studies showed that Alzheimer Disease (AD) patients with moderate to severe dementia keep a consistent, but impoverished representation of themselves, showing preservation of the sense of identity even at severe stages of the illness. Some studies suggest that listening to music can facilitate the reminiscence of autobiographical memories and that stimulating autobiographical memory would be relevant to support the self of these patients. Consequently, we hypothesized that repeated participation to reminiscence workshops, using excerpts of familiar songs as prompts would participate to the enrichment of autobiographical memories, self-representation and sense of identity. We included a group of 20 AD patients with severe dementia residing in nursing homes. Their performances were compared to a control group of 20 matched (age, education, mood) healthy residents living in the same institutions. The experiment was conducted in three phases over a 2-week period. On phase 1, an individual assessment of sense of identity was proposed to each participant. On phase 2, participants joined musical reminiscence workshops (six sessions over 2 weeks for AD patients and 3 sessions over a week for controls). During the third phase (12 days after the first assessment), individual evaluation of autobiographical memory and a second assessment of sense of identity were proposed. Our results showed that, despite their massive amnesia syndrome, autobiographical memories of AD reached at the end of the 2 weeks the number and quality of those of matched controls. Moreover, we confirmed a continuity of self-representation in AD patients with a stable profile of the answers between the first and second individual assessments of sense of identity. However, the increase in number and episodic quality of autobiographical memories was not accompanied by an enrichment of the sense of identity. In a complementary study, new patients participated in the same paradigm, but using movie extracts as prompts, and showed very similar effects. We discuss all of these results with regard to the literature showing the significant impact of repetition on the reactivation of memory traces even in very amnestic AD patients at severe stages of the disease.

Bone metabolic biomarkers and bone mineral density in male patients with early-stage Alzheimer's disease

PURPOSE

Alzheimer's disease (AD), osteoporosis, and osteopenia are the most common diseases in older individuals and share some similar pathophysiological processes of degeneration. The aim of this study is to investigate the association between bone metabolic biomarkers, bone mineral density (BMD), and early-stage AD in men.

METHODS

Forty-two male early-stage AD patients and 40 age-matched healthy older volunteers were enrolled. Serum calcium, osteocalcin, 1,25(OH)₂D₃, urine deoxypyridinoline/creatinine (DPD/Cr) ratio, urine calcium/creatinine (Ca/Cr) ratio, and BMD were measured. The correlation between early-stage AD and bone quality was evaluated.

RESULTS

The urine DPD/Cr, urine Ca/Cr, and serum osteocalcin levels in the early-stage AD patients were significantly higher than those in the healthy control (HC) group (P < 0.05). The BMD data showed that the cortical and total BMD at 38% of the tibial length in the early-stage AD patients were lower than those in the HC group (P < 0.05). Furthermore, there was a negative correlation between the Montreal Cognitive Assessment score and serum osteocalcin or urine DPD/Cr levels. Abnormal urine DPD/Cr, urine Ca/Cr, and cortical BMD levels were independent risk factors in male patients with early-stage AD.

CONCLUSION

Bone metabolic biomarkers and BMD are closely associated with early-stage AD in male patients. Our data indicated that the measurement of bone metabolic biomarkers and BMD may provide an alternative approach for screening AD patients at the early stage.