Glucose administration and cognitive function: differential effects of age and effort during a dual task paradigm in younger and older adults

RATIONALE: Current research suggests that glucose facilitates performance on cognitive tasks which possess an episodic memory component and a relatively high level of cognitive demand. However, the extent to which this glucose facilitation effect is uniform across the lifespan is uncertain. METHODS: This study was a repeated measures, randomised, placebo-controlled, cross-over trial designed to assess the cognitive effects of glucose in younger and older adults under single and dual task conditions. Participants were 24 healthy younger (average age 20.6 years) and 24 healthy older adults (average age 72.5 years). They completed a recognition memory task after consuming drinks containing 25 g glucose and a placebo drink, both in the presence and absence of a secondary tracking task. RESULTS AND CONCLUSIONS: Glucose enhanced recognition memory response time and tracking precision during the secondary task, in older adults only. These findings do not support preferential targeting of hippocampal function by glucose, rather they suggest that glucose administration differentially increases the availability of attentional resources in older individuals.

Improved processing speed: online computer-based cognitive training in older adults

In an increasingly aging population, a number of adults are concerned about declines in their cognitive abilities. Online computer-based cognitive training programs have been proposed as an accessible means by which the elderly may improve their cognitive abilities; yet, more research is needed in order to assess the efficacy of these programs. In the current study, a commercially available 21-day online computer-based cognitive training intervention was administered to 34 individuals aged between 53 and 75 years. The intervention consisted of computerized training in reaction time, inspection time, short-term memory for words, executive function, visual spatial acuity, arithmetic, visual spatial memory, visual scanning/discrimination, and n-back working memory. An active solitaire control group was also included. Participants were tested at baseline, posttraining and at three-weeks follow-up using a battery of neuropsychological outcome measures. These consisted of simple reaction time, complex reaction time, digit forwards and backwards, spatial working memory, digit symbol substitution, RAVLT, and trail making. Significant improvement in simple reaction time and choice reaction time task was found in the cognitive training group both posttraining and at three-weeks follow-up. However, no significant improvements on the other cognitive tasks were found. The training program was found to be successful in achieving transfer of trained cognitive abilities in speed of processing to similar untrained tasks. © 2012 Copyright Taylor and Francis Group, LLC.

Short-term changes in endogenous estrogen levels and consumption of soy isoflavones affect working and verbal memory in young adult females

Estrogen is known to modulate certain cognitive functions, most notably improving working memory and verbal memory. Soy foods contain isoflavones, phytoestrogens structurally similar to estrogen that weakly bind to estrogen receptors.We investigated the effects of natural variations in estrogen levels and short-term dietary supplementation with soy isoflavones on cognitive function in 28 young women. Performance was examined across a range of cognitive tasks on three occasions during separate menstrual cycles: during a menses phase (low estrogen), during a luteal phase (highest estrogen), and once during a menses phase after a 3-day phytoestrogen-rich dietary intervention. Soy supplementation during menses led to an improvement in working memory and verbal memory. The menstrual cycle effects were mixed, with high estrogen improving performance on a verbal memory task but not on working memory. Our results suggest that soy phytoestrogens may improve working memory through estrogen-independent mechanisms.

Effects of a multivitamin, mineral and herbal supplement on cognition and blood biomarkers in older men: a randomised, placebo-controlled trial

OBJECTIVE: Nutritional and vitamin status may be related to cognitive function and decline in older adults. The aim of this study was to investigate the effects of nutritional supplementation on cognition in older men. METHOD: The current study was an 8-week, placebo-controlled, double-blind investigation into the effects of a multivitamin, mineral and herbal supplement (Swisse Men's Ultivite®, Swisse Vitamins Pty Ltd, Melbourne, Australia) on cognitive performance in older men. Participants were 51 male individuals aged between 50 and 74 years, with a sedentary lifestyle. Cognitive performance was assessed at baseline and post-treatment using a computerised battery of cognitive tasks, enabling the measurement of a range of attentional and memory processes. Blood measures of vitamin B(12) , folate and homocysteine were collected prior to and after supplementation. RESULTS: The results of this study revealed that contextual recognition memory performance was significantly improved following multivitamin supplementation (p < 0.05). Performance on other cognitive tasks did not change. Levels of vitamin B(12) and folate were significantly increased with a concomitant decrease in homocysteine, indicating that relatively short-term supplementation with a multivitamin can benefit these risk factors for cognitive decline. CONCLUSION: Findings from this study indicate that daily multivitamin supplementation may improve episodic memory in older men at risk of cognitive decline.

The role of serious games in robot exoskeleton-assisted rehabilitation of stroke patients

his chapter describes how serious games can be used to improve the rehabilitation of stroke patients. Determining ideal training conditions for rehabilitation is difficult, as no objective measures exist and the psychological state of patients during therapy is often neglected. What is missing is a way to vary the difficulty of the tasks during a therapy session in response to the patient needs, in order to adapt the training specifically to the individual. In this chapter, we describe such a method. A serious game is used to present challenges to the patient, including motor and cognitive tasks. The psychological state of the patient is inferred from measures computed from heart rate variability (HRV) as well as breathing frequency, skin conductance response, and skin temperature. Once the psychological state of the patient can be determined from these measures, it is possible to vary the tasks in real time by adjusting parameters of the game. The serious game aspect of the training allows the virtual environment to become adaptive in real time, leading to improved matching of the activity to the needs of the patient. This is likely to lead to improved training outcomes and has the potential to lead to faster and more complete recovery, as it enables training that is challenging yet does not overstress the patient.

Examining interview techniques to assist children’s recall of repeated events.

This thesis tested interview techniques expected to assist children reporting on repeated events, such as ongoing abuse. The quality and quantity of information children provided was improved by several techniques that rehearsed children in key cognitive tasks. Developmental trends were found whereby techniques often assisted older children more than younger children.

Aging effects on the metabolic and cognitive energy cost of interlimb coordination

Many everyday motor tasks have high metabolic energy demands, and some require extended practice to learn the required coordination between limbs. Eight older (73.1 6 4.4 years) and 8 younger (23.3 6 5.9) men practiced a  high-energy two-hand coordination task with both 1808 and 908 target  relative phase. The older group showed greater performance error in both conditions, and performance at 908 was strongly attracted to antiphase coordination (1808). In a retention test one week following the acquisition trials, the older group had learned the 1808 condition but did not learn the 908 condition. Metabolic energy cost was not different between groups, but the older men showed higher heart rate and both conditions imposed  greater cognitive demands as revealed in auditory probe reaction time. Older adults’ motor learning may be inhibited by elevated heart rate at the same  oxygen cost, increased cognitive cost, and an attraction toward more  established low-energy in-phase or antiphase coordination.

Assessing financial competence in older adults with cognitive impairment

One common problem brought before Courts and Tribunals in Australia is whether or not someone is able to manage his or her own financial affairs. The problem is that currently in Australia there are no universally agreed upon standards for assessing financial competence. The aim of this study was to examine the reliability and validity of a new measure of financial competence, The Financial Competence Assessment Inventory (FCAI), in assessing financial competency of older adults with a cognitive impairment. The sample comprised 18 older adults with acquired brain injury, 10 adults with schizophrenia, 21 adults with dementia and 27 older adults without cognitive impairment. Ages ranged from 55 to 91. Each participant was individually interviewed using the FCAI. The findings revealed that the FCAI is a reliable and valid assessment tool for assessing financial competence of older adults with different types and levels of cognitive impairment. In particular, the FCAI was able to distinguish between older adults with global brain impairment and older adults with specific brain impairment; and older adults who had a legal administrator and older adults who did not. In addition, using the FCAI it was possible to obtain a profile of participants’ strengths and weaknesses across six domains of financial competence including; everyday financial abilities, financial judgment, estate management, cognitive based financial tasks, debt management, and support resources. The FCAI has the potential to assist clinicians and legal decision-makers regarding ‘least restrictive alternatives’ when financial competence is in question.

Empirical generalisation as an inadequate cognitive scaffold to theoretical generalisation of a more complex concept

The impact of prior learning on new learning is highlighted by the case of Dean, a Year 8 student who developed his own method to find the sum of the interior angles of a polygon without knowing why his method worked. Enriched transcripts and visual displays of the cognitive, social (Dreyfus, Hershkowitz, & Schwarz, 2001) and affective elements (Williams, 2002) of Dean's interrupted abstraction process informed the identification of factors that inhibited Dean's constructing process. It was found Dean possessed an empirical, not theoretical, generalization (Davydov, 1990) about sums of interior angles of triangles that was an inadequate cognitive artifact for constructing the new more complex theoretical generalization. The study suggests use of tasks designed with the opportunity develop assumed knowledge in conjunction with new concepts.

Design of a valid simulation for researching physical, physiological and cognitive performance in volunteer firefighters during bushfire deployment.

Every year, Australian firefighters protect our nation from the devastation of bushfire. Understanding the impact of consecutive long shifts in hot, smoky conditions is essential for making decisions during campaign fires. At present, the evidence-base for such decisions is limited to laboratory studies with little relevance to bushfire suppression or field research where the impact of environmental and workload stressors cannot be measured. To counter these limitations, we have developed a three-day simulation that mimics the work and environment of campaign bushfire suppression. Construction of the simulation involved three stages; 1) data collection and analysis; 2) design and development; and 3) trial and refinement. The frequency, intensity, duration and type of physical work performed on the fireground is well documented and a modified applied cognitive task analysis, using experienced firefighters was used as a framework to describe in detail the non-physical aspects of the work. The design and development of the simulation incorporated the physical and non-physical aspects of the work into simulated tasks. Finally, experienced firefighters participated in trials of the simulation and reviewed digital recordings to ensure that the simulation accurately represented campaign bushfire suppression work. The outcome of this project is a valid, realistic, and reliable simulation of the physiological, physical and cognitive aspects of a volunteer firefighter on a three-day bushfire deployment.

Cognitive intervention in autism using multimedia stimulus

We demonstrate an open multimedia-based system for delivering early intervention therapy for autism. Using exible multi-touch interfaces together with principled ways to access rich content and tasks, we show how a syllabus can be translated into stimulus sets for early intervention. Media stimuli are able to be presented agnostic to language and media modality due to a semantic network of concepts and relations that are fundamental to language and cognitive development, which enable stimulus complexity to be adjusted to child performance. Being open, the system is able to assemble enough media stimuli to avoid children over-learning, and is able to be customised to a specific child which aids with engagement. Computer-based delivery enables automation of session logging and reporting, a fundamental and time-consuming part of therapy.

Neuropsychological changes following cognitive-behavioral treatment of obsessive-compulsive disorder (OCD)

Previous research has suggested that individuals with OCD show compromised performance on tests assessing visuospatial and executive processes. This study aimed to further examine such findings by investigating the relationship between OCD symptom improvement following cognitive-behavioral therapy and changes in neuropsychological performance in individuals with OCD (n = 26), compared to test-retest control participants (n = 10). Successful treatment of OCD led to improvements relative to the control group on neuropsychological tasks measuring spatial working memory. Neuroscientific models of OCD consider such findings to be consistent with possible cortical dysfunction in OCD. However, a significant limitation of the study is in its inability to discount alternative explanations for this finding, such as the influence of changes in beliefs. Implications are discussed.

The relationship between neuropsychological performance, cognitive confidence, and obsessive-compulsive phenomena : a pilot study

Drawing on neuropsychological and cognitive-behavioral approaches to Obsessive-Compulsive Disorder (OCD), the present study examined the association between memory performance, cognitive confidence, and OCD phenomena. Forty-six analogue participants completed a series of self-report questionnaires and neuropsychological tasks before and after a manipulation of confidence in memory It was found that cognitive confidence predicts OCD symptoms over and above the influence of depressive symptoms and other OCD-related beliefs. Participants reported higher levels of cognitive confidence following positive feedback on the manipulation task. However, changes in cognitive confidence following the manipulation task were not reflected in neuropsychological performance. Implications for theory and treatment are discussed.

Multitasking: multiple, domain-specific cognitive functions in a virtual environment

Multitasking among three or more different tasks is a ubiquitous requirement of everyday cognition, yet rarely is it addressed in research on healthy adults who have had no specific training in multitasking skills. Participants completed a set of diverse subtasks within a simulated shopping mall and office environment, the Edinburgh Virtual Errands Test (EVET). The aim was to investigate how different cognitive functions, such as planning, retrospective and prospective memory, and visuospatial and verbal working memory, contribute to everyday multitasking. Subtasks were chosen to be diverse, and predictions were derived from a statistical model of everyday multitasking impairments associated with frontal-lobe lesions (Burgess, Veitch, de Lacy Costello, & Shallice, 2000b). Multiple regression indicated significant independent contributions from measures of retrospective memory, visuospatial working memory, and online planning, but not from independent measures of prospective memory or verbal working memory. Structural equation modelling showed that the best fit to the data arose from three underlying constructs, with Memory and Planning having a weak link, but with both having a strong directional pathway to an Intent construct that reflected implementation of intentions. Participants who followed their preprepared plan achieved higher scores than those who altered their plan during multitask performance. This was true regardless of whether the plan was efficient or poor. These results substantially develop and extend the Burgess et al. (2000b) model to healthy adults and yield new insight into the poorly understood area of everyday multitasking. The findings also point to the utility of using virtual environments for investigating this form of complex human cognition.