Metacognitive processes accompanying the first stages of autobiographical retrieval in the self-memory system.

According to Conway's view, Autobiographical memory (AM) construction is accompanied by control processes. These processes range from filtering out relevant memories according to the current context, to generating or elaborating appropriate retrieval cues. These processes can be conceptualised as metacognition, the ability to control and monitor cognitive processes. Experimentally, little has been carried out to support the idea that metacognition is involved in AM. To assess this, we designed a task, the Feeling of Retrieval. Participants had to predict whether cue words would facilitate AM access (i.e., fluent access cues) or not (i.e., limited access cues) in a limited time (either 1 (Exp. 2) or 2 (Exp. 1) s). Later, they retrieved memories in response to both types of cues. Results show that cues judged as fluent access led to better AM generation, as illustrated by AM retrieval latency and a subjective measure of the ease with which the AMs were retrieved. These rapid predictions may rely on epistemic feelings and / or other mnemonic cues such as a partial retrieval of information. This metacognitive access to the earliest stages of AM retrieval illustrates the ability to monitor AM processes as proposed by Conway (2005).

Exploring consumer beliefs about novel fortified foods: A focus group study with UK-based older and younger adult consumers.

Consuming 'nutritionally-enhanced' food products (including those that are fortified or enriched to deliver nutritional and functional properties) may help to improve overall diet quality and combat risks associated with malnutrition. However, fortification can negatively impact consumer acceptance, particularly where expected sensory properties of 'delivery' foods are affected by target ingredients. Here, we explored factors influencing consumer acceptability for six novel food products that had been fortified, including both savoury and sweet meal components (e.g., high protein dumplings, probiotic yoghurt drink). In person focus groups (25 consumers aged between 22 and 76 years old) were conducted with two stages; firstly, participants completed a blind taste test of products without awareness of fortification. Secondly, participants discussed products with awareness of additional ingredients and food properties. Reflexive thematic analysis showed that liking of sensory properties differed between foods, but informing participants about the fortification of products highlighted potential trade-offs between taste, health, price, and familiarity. Though taste and texture were generally prioritised by participants, positive perceptions of health benefits increased consumer willingness to buy, whilst both cost and uncertainty about product use were potential barriers. Trust of information was a key concern for labelling and product claims. These results highlight product features that may be optimised to support the success of fortified foods. Greater transparency when building product brands and improving consumer knowledge of fortification may also be important for longer-term consumer acceptance.

Reaction Time Decomposition as a Tool to Study Subcortical Ischemic Vascular Cognitive Impairment.

BACKGROUND: The study of reaction time (RT) and its intraindividual variability (IIV) in aging, cognitive impairment, and dementia typically fails to investigate the processing stages that contribute to an overall response. Applying "mental chronometry" techniques makes it possible to separately assess the role of processing components during environmental interaction. OBJECTIVE: To determine whether RT and IIV-decomposition techniques can shed light on the nature of underlying deficits in subcortical ischemic vascular cognitive impairment (VCI). Using a novel iPad task, we examined whether VCI deficits occur during both initiation and movement phases of a response, and whether they are equally reflected in both RT and IIV. METHODS: Touch cancellation RT and its IIV were measured in a group of younger adults (n = 22), cognitively healthy older adults (n = 21), and patients with VCI (n = 21) using an iPad task. RESULTS: Whereas cognitively healthy aging affected the speed (RT) of response initiation and movement but not its variability (IIV), VCI resulted in both slowed RT and increased IIV for both response phases. Furthermore, there were group differences with respect to response phase. CONCLUSION: These results indicate that IIV can be more sensitive than absolute RT in separating VCI from normal aging. Furthermore, compared to cognitively healthy aging, VCI was characterized by significant deficits in planning/initiating action as well as performing movements. Such deficits have important implications for real life actions such as driving safety, employment, and falls risk.

Distinct Profile Differences in Subjective Cognitive Decline in the General Public Are Associated with Metacognition, Negative Affective Symptoms, Neuroticism, Stress, and Poor Quality of Life.

BACKGROUND: Subjective cognitive decline (SCD) is increasingly recognized in both the clinical and research arenas as a risk factor for mild cognitive impairment (MCI) and dementia. Although SCD is etiologically heterogeneous and potentially treatable, in comparison to MCI and Alzheimer's disease, SCD remains poorly characterized with its clinical relevance often questioned. OBJECTIVE: This study's aim was to improve the characterization of SCD within the general public. METHODS: Individuals with SCD were compared to those without via a battery of measures. RESULTS: Both the SCD and the non-SCD group correlational analysis identified significant relationships between worse SCD, worse metacognitive dysfunction, negative affective symptoms, and greater levels of stress. The SCD group displayed additional correlational relationships between Cognitive Change Index (Self report) (CCI-S) scores, higher neuroticism scores, and poorer quality of life (QoL). Partial correlation analysis in the SCD group suggests CCI-S scores, anxiety, depression, and metacognition are intercorrelated. Ad hoc analyses using metacognition as the grouping variable found that those experiencing worse metacognitive dysfunction were significantly more likely to experience poorer SCD, psychological and social QoL, greater levels of anxiety, depression, stress, and neuroticism. CONCLUSION: The emerging pattern from the analysis indicates that SCD appears associated with sub-clinical negative affective difficulties, metacognitive, and other psycho-social issues, and poorer QoL. Dysfunctional cognitive control at a meta-level may impact someone's ability to rationally identify cognitive changes, increase worry about cognitive changes, and allow such changes to impact their lives more than those with superior metacognitive control. Findings could impact SCD assessment, monitoring, early intervention, and ultimately reducing risk of further decline.

Inhibitory control deficits in vascular cognitive impairment revealed using the MILO task.

We used the MILO (Multi-Item Localization) task to characterise the performance of a group of older adults diagnosed with mild to moderate vascular cognitive impairment (VCI). The MILO task is designed to explore the temporal context of visual search and in addition to measuring overall completion time, provides a profile of serial reaction time (SRT) patterns across all items in a sequence. Of particular interest here is the Vanish/Remain MILO manipulation that can identify problems with inhibitory control during search. Typically, SRT functions closely overlap, regardless of whether items Vanish or Remain visible when selected, indicating an ability to ignore previously selected targets. Based on the distributed nature of VCI-related pathology and previous visual search studies from our group, we speculated that MILO performance would be compromised in this group of participants when items remained visible after being selected relative to when they vanished. Compared to cognitively healthy, age-matched control participants, the performance of VCI participants was characterised by overall slowing, increased error rates, and crucially, a compromised ability to ignore past locations. As predicted, the Vanish versus Remain SRT functions of VCI participants significantly diverged towards the end of the sequence, which was not the case for control groups. Overall, our findings suggest that the MILO task could be a useful tool for identifying non-age-related changes in behaviour with patient populations, and more generally hints at a possible inhibitory deficit in VCI.

Visual Attention-Related Processing: Perspectives from Ageing, Cognitive Decline and Dementia.

Regarded as a defining factor in resource management, it is widely accepted that visual attention and related processing will deteriorate, in a global fashion, across the lifespan and produce detrimental consequences for environmental interactions [...].

Lacking Pace but Not Precision: Age-Related Information Processing Changes in Response to a Dynamic Attentional Control Task.

Age-related decline in information processing can have a substantial impact on activities such as driving. However, the assessment of these changes is often carried out using cognitive tasks that do not adequately represent the dynamic process of updating environmental stimuli. Equally, traditional tests are often static in their approach to task complexity, and do not assess difficulty within the bounds of an individual's capability. To address these limitations, we used a more ecologically valid measure, the Swansea Test of Attentional Control (STAC), in which a threshold for information processing speed is established at a given level of accuracy. We aimed to delineate how older, compared to younger, adults varied in their performance of the task, while also assessing relationships between the task outcome and gender, general cognition (MoCA), perceived memory function (MFQ), cognitive reserve (NART), and aspects of mood (PHQ-9, GAD-7). The results indicate that older adults were significantly slower than younger adults but no less precise, irrespective of gender. Age was negatively correlated with the speed of task performance. Our measure of general cognition was positively correlated with the task speed threshold but not with age per se. Perceived memory function, cognitive reserve, and mood were not related to task performance. The findings indicate that while attentional control is less efficient in older adulthood, age alone is not a defining factor in relation to accuracy. In a real-life context, general cognitive function, in conjunction with dynamic measures such as STAC, may represent a far more effective strategy for assessing the complex executive functions underlying driving ability.

Reaction Time and Visible White Matter Lesions in Subcortical Ischemic Vascular Cognitive Impairment.

Slowed behavioral reaction time is associated with pathological brain changes, including white matter lesions, the common clinical characteristic of subcortical ischemic vascular cognitive impairment (SIVCI). In the present study, reaction time (RT) employing Trails B of the Trail Making Test, with responses capped at 300 s, was investigated in SIVCI (n = 27) compared to cognitively healthy aging (CH) (n = 26). RT was significantly slowed in SIVCI compared to CH (Cohen's d effect size = 1.26). Furthermore, failure to complete Trails B within 300 s was also a characteristic of SIVCI although some ostensibly cognitively healthy older adults also failed to complete within this time limit. Within the SIVCI group, RT did not differ significantly with respect to whether the patients were classified as having moderate/severe or mild, periventricular white matter changes visible on their diagnostic CT/MRI scans. This, together with the high degree of overlap in RT between the two SIVCI subgroups, raises the possibility that using visible ratings scales in isolation may lead to the underestimation of disease level.

Subcortical Ischemic Vascular Cognitive Impairment: Insights from Reaction Time Measures.

In this study, reaction time (RT), intraindividual variability (IIV), and errors, and the effects of practice and processing load upon such function, were compared in patients with subcortical ischemic vascular cognitive impairment (SIVCI) [n = 27] and cognitively healthy older adults (CH) [n = 26]. Compared to CH aging, SIVCI was characterized by a profile of significantly slowed RT, raised IIV, and higher error levels, particularly in the presence of distracting stimuli, indicating that the integrity and/or accessibility of the additional functions required to support high processing load, serial search strategies, are reduced in SIVCI. Furthermore, although practice speeded RT in SIVCI, unlike CH, practice did not lead to an improvement in IIV. This indicates that improvement in RT in SIVCI can in fact mask an abnormally high degree of IIV. Because IIV appears more related to disease, function, and health than RT, its status and potential for change may represent a particularly meaningful, and relevant, disease characteristic of SIVCI. Finally, a high level of within-group variation in the above measures was another characteristic of SIVCI, with such processing heterogeneity in patients with ostensibly the same diagnosis, possibly related to individual variation in pathological load. Detailed measurement of RT, IIV, errors, and practice effects therefore reveal a degree of functional impairment in brain processing not apparent by measuring RT in isolation.

Oscillatory hyperactivity and hyperconnectivity in young APOE-ɛ4 carriers and hypoconnectivity in Alzheimer's disease.

We studied resting-state oscillatory connectivity using magnetoencephalography in healthy young humans (N = 183) genotyped for APOE-ɛ4, the greatest genetic risk for Alzheimer's disease (AD). Connectivity across frequencies, but most prevalent in alpha/beta, was increased in APOE-ɛ4 in a set of mostly right-hemisphere connections, including lateral parietal and precuneus regions of the Default Mode Network. Similar regions also demonstrated hyperactivity, but only in gamma (40-160 Hz). In a separate study of AD patients, hypoconnectivity was seen in an extended bilateral network that partially overlapped with the hyperconnected regions seen in young APOE-ɛ4 carriers. Using machine-learning, AD patients could be distinguished from elderly controls with reasonable sensitivity and specificity, while young APOE-e4 carriers could also be distinguished from their controls with above chance performance. These results support theories of initial hyperconnectivity driving eventual profound disconnection in AD and suggest that this is present decades before the onset of AD symptomology.

Sequential Information Processing: The "Elevated First Response Effect" Can Contribute to Exaggerated Intra-Individual Variability in Older Adults.

In this study we examined attention-related reaction time (RT) and intra-individual variability (IIV) in younger and older adults using an iPad-based visual search test, in which, for each trial, participants were required to sequentially press a series of on-screen stimuli numbered from 1 to 8. Although overall performance RT was significantly slower, with greater IIV for the older compared to the younger adult group, there was also a disproportionately slowed RT and greater IIV for the first item in the series compared to all other responses within the trial. When the response to the first stimulus was removed from statistical analysis, the significant age-related RT slowing effect remained, but IIV was no longer significantly greater for the older compared to the younger adults. This pattern of results reveals a dichotomy between the preservation of RT and IIV in aging, and one that is strongly related to research methodology. A finding that may account, at least in part, for the outcome heterogeneity in the study of IIV in aging.

Subjective Cognitive Impairment in 55-65-Year-Old Adults Is Associated with Negative Affective Symptoms, Neuroticism, and Poor Quality of Life.

Although subjective cognitive impairment (SCI) is increasingly recognized clinically and in research as a risk factor for mild cognitive impairment and dementia (particularly Alzheimer's disease), it is etiologically heterogeneous and potentially treatable. Compared to mild cognitive impairment and Alzheimer's disease, SCI however remains poorly characterized with debate continuing regarding its clinical relevance. The primary aim of this study was to improve the characterization of SCI within the general public by investigating functions sometimes omitted clinically or in research, namely visual attention-related information processing speed (RT) and its intra-individual variability (IIVRT), general cognition, depression, anxiety, memory, quality of life (QOL), and neuroticism. Compared to individuals without SCI, those with SCI were more likely to reveal higher scores of anxiety, depression, and neuroticism and poorer perceived physical, psychological, and environmental QOL. Within-group analysis identified no significant relationships between any of the above variables for the non-SCI group whereas for the SCI group, poorer Cognitive Change Index scores were significantly correlated with slower RT, raised IIVRT, poorer memory, negative affective symptoms, higher neuroticism scores, and poorer QOL. This indicates that reports of perceived memory changes in SCI can also be associated with other characteristics, namely objectively measured detrimental change in other aspects of brain function and behavior. This outcome emphasizes the importance of a multi-function approach to characterizing and understanding SCI. Thus, although the effect of RT and IIVRT is not strong enough to differentiate SCI from non-SCI at group level, slowing and raised IIVRT do appear to characterize some people with SCI.

Anodal tDCS improves attentional control in older adults.

Transcranial direct current stimulation (tDCS) facilitates cognitive enhancement by directly increasing neuroplasticity, and has shown promising results as an external intervention to attenuate age-related cognitive decline. However, stimulation protocols have failed to account for age-associated changes in brain structure and the present literature omits investigation of attentional control, despite the occurrence of substantial inhibitory processing deficits with age. To provide new insight into the benefits of tDCS, the objective of this study was to develop an age-optimised stimulation protocol in which key parameters (amplitude, duration, and electrode configuration) were selected in accordance with knowledge of stimulation effects, specific to the ageing brain. Participants (mean age 66.5 years) completed three sessions of double-blind, anodal or sham stimulation, in conjunction with a novel task switching paradigm, which was designed to reflect the complexities of simultaneously monitoring and updating stimulus representations. The results show that those who had anodal tDCS exhibited an acute, post-stimulation increase in task switching speed (p < .01, d = 1.36). Although the sham group was subject to the same task exposure, only the anodal stimulation group experienced a performance gain, thus emphasising the efficacy of active brain stimulation. For the first time, this study demonstrates the utility of stimulation protocols tailored specifically for use with older adults, targeted towards the modulation of attentional control. This finding has critical implications for cognitive health and encourages the use of age-optimised tDCS as a viable method for enhancing executive function in later life.

Perception and Reality of Cognitive Function: Information Processing Speed, Perceived Memory Function, and Perceived Task Difficulty in Older Adults.

This study examines the relationships between two measures of information processing speed associated with executive function (Trail Making Test and a computer-based visual search test), the perceived difficulty of the tasks, and perceived memory function (measured by the Memory Functioning Questionnaire) in older adults (aged 50+ y) with normal general health, cognition (Montreal Cognitive Assessment score of 26+), and mood. The participants were recruited from the community rather than through clinical services, and none had ever sought or received help from a health professional for a memory complaint or mental health problem. For both the trail making and the visual search tests, mean information processing speed was not correlated significantly with perceived memory function. Some individuals did, however, reveal substantially slower information processing speeds (outliers) that may have clinical significance and indicate those who may benefit most from further assessment and follow up. For the trail making, but not the visual search task, higher levels of subjective memory dysfunction were associated with a greater perception of task difficulty. The relationship between actual information processing speed and perceived task difficulty also varied with respect to the task used. These findings highlight the importance of taking into account the type of task and metacognition factors when examining the integrity of information processing speed in older adults, particularly as this measure is now specifically cited as a key cognitive subdomain within the diagnostic framework for neurocognitive disorders.

Alzheimer's disease disrupts alpha and beta-band resting-state oscillatory network connectivity.

OBJECTIVE: Neuroimaging studies in Alzheimer's disease (AD) yield conflicting results due to selective investigation. We conducted a comprehensive magnetoencephalography study of connectivity changes in AD and healthy ageing in the resting-state. METHODS: We performed a whole-brain, source-space assessment of oscillatory neural signalling in multiple frequencies comparing AD patients, elderly and young controls. We compared eyes-open and closed group oscillatory envelope activity in networks obtained through temporal independent component analysis, and calculated whole-brain node-based amplitude and phase connectivity. RESULTS: In bilateral parietotemporal areas, oscillatory envelope amplitude increased with healthy ageing, whereas both local amplitude and node-to-global connectivity decreased with AD. AD-related decreases were spatially specific and restricted to the alpha and beta bands. A significant proportion of the variance in areas of peak group difference was explained by cognitive integrity, in addition to group. None of the groups differed in phase connectivity. Results were highly similar for eyes-open and closed resting-state. CONCLUSIONS: These results support the disconnection syndrome hypothesis and suggest that AD shows distinct and unique patterns of disrupted neural functioning, rather than accelerated healthy ageing. SIGNIFICANCE: Whole-brain assessments show that disrupted regional oscillatory envelope amplitude and connectivity in the alpha and beta bands play a key role in AD.

Different trajectories of decline for global form and global motion processing in aging, mild cognitive impairment and Alzheimer's disease.

The visual processing of complex motion is impaired in Alzheimer's disease (AD). However, it is unclear whether these impairments are biased toward the motion stream or part of a general disruption of global visual processing, given some reports of impaired static form processing in AD. Here, for the first time, we directly compared the relative preservation of motion and form systems in AD, mild cognitive impairment, and healthy aging, by measuring coherence thresholds for well-established global rotational motion and static form stimuli known to be of equivalent complexity. Our data confirm a marked motion-processing deficit specific to some AD patients, and greater than any form-processing deficit for this group. In parallel, we identified a more gradual decline in static form recognition, with thresholds raised in mild cognitive impairment patients and slightly further in the AD group compared with controls. We conclude that complex motion processing is more vulnerable to decline in dementia than complex form processing, perhaps owing to greater reliance on long-range neural connections heavily targeted by AD pathology.

Non-Pharmacologic Interventions for Older Adults with Subjective Cognitive Decline: Systematic Review, Meta-Analysis, and Preliminary Recommendations.

In subjective cognitive decline (SCD), older adults present with concerns about self-perceived cognitive decline but are found to have clinically normal function. However, a significant proportion of those adults are subsequently found to develop mild cognitive impairment, Alzheimer's dementia or other neurocognitive disorder. In other cases, SCD may be associated with mood, personality, and physical health concerns. Regardless of etiology, adults with SCD may benefit from interventions that could enhance current function or slow incipient cognitive decline. The objective of this systematic review and meta-analysis, conducted in accordance with the PRISMA guidelines, is to examine the benefits of non-pharmacologic intervention (NPI) in persons with SCD. Inclusion criteria were studies of adults aged 55 + with SCD defined using published criteria, receiving NPI or any control condition, with cognitive, behavioural, or psychological outcomes in controlled trails. Published empirical studies were obtained through a standardized search of CINAHL Complete, Cochrane Central Register of Controlled Trials, MEDLINE with Full Text, PsycINFO, and PsycARTICLES, supplemented by a manual retrieval of relevant articles. Study quality and bias was determined using PEDro. Nine studies were included in the review and meta-analysis. A wide range of study quality was observed. Overall, a small effect size was found on cognitive outcomes, greater for cognitive versus other intervention types. The available evidence suggests that NPI may benefit current cognitive function in persons with SCD. Recommendations are provided to improve future trials of NPI in SCD.

Administering Cognitive Tests Through Touch Screen Tablet Devices: Potential Issues.

Mobile technologies, such as tablet devices, open up new possibilities for health-related diagnosis, monitoring, and intervention for older adults and healthcare practitioners. Current evaluations of cognitive integrity typically occur within clinical settings, such as memory clinics, using pen and paper or computer-based tests. In the present study, we investigate the challenges associated with transferring such tests to touch-based, mobile technology platforms from an older adult perspective. Problems may include individual variability in technical familiarity and acceptance; various factors influencing usability; acceptability; response characteristics and thus validity per se of a given test. For the results of mobile technology-based tests of reaction time to be valid and related to disease status rather than extraneous variables, it is imperative the whole test process is investigated in order to determine potential effects before the test is fully developed. Researchers have emphasized the importance of including the 'user' in the evaluation of such devices; thus we performed a focus group-based qualitative assessment of the processes involved in the administration and performance of a tablet-based version of a typical test of attention and information processing speed (a multi-item localization task), to younger and older adults. We report that although the test was regarded positively, indicating that using a tablet for the delivery of such tests is feasible, it is important for developers to consider factors surrounding user expectations, performance feedback, and physical response requirements and to use this information to inform further research into such applications.

Visual mismatch negativity (vMMN): A review and meta-analysis of studies in psychiatric and neurological disorders.

The visual mismatch negativity (vMMN) response is an event-related potential (ERP) component, which is automatically elicited by events that violate predictions based on prior events. VMMN experiments use visual stimulus repetition to induce predictions, and vMMN is obtained by subtracting the response to rare unpredicted stimuli from those to frequent stimuli. One increasingly popular interpretation of the mismatch response postulates that vMMN, similar to its auditory counterpart (aMMN), represents a prediction error response generated by cortical mechanisms forming probabilistic representations of sensory signals. Here we discuss the physiological and theoretical basis of vMMN and review thirty-three studies from the emerging field of its clinical applications, presenting a meta-analysis of findings in schizophrenia, mood disorders, substance abuse, neurodegenerative disorders, developmental disorders, deafness, panic disorder and hypertension. Furthermore, we include reports on aging and maturation as they bear upon many clinically relevant conditions. Surveying the literature we found that vMMN is altered in several clinical populations which is in line with aMMN findings. An important potential advantage of vMMN however is that it allows the investigation of deficits in predictive processing in cognitive domains which rely primarily on visual information; a principal sensory modality and thus of vital importance in environmental information processing and response, and a modality which arguably may be more sensitive to some pathological changes. However, due to the relative infancy of research in vMMN compared to aMMN in clinical populations its potential for clinical application is not yet fully appreciated. The aim of this review and meta-analysis therefore is to present, in a detailed systematic manner, the findings from clinically-based vMMN studies, to discuss their potential impact and application, to raise awareness of this measure and to improve our understanding of disease upon fundamental aspects of visual information processing.