Background: Eye movements reveal neurodegenerative disease processes due to overlap between oculomotor circuitry and disease-affected areas. Characterizing oculomotor behaviour in context of cognitive function may enhance disease diagnosis and monitoring. We therefore aimed to quantify cognitive impairment in neurodegenerative disease using saccade behaviour and neuropsychology. Methods: The Ontario Neurodegenerative Disease Research Initiative recruited individuals with neurodegenerative disease: one of Alzheimer’s disease, mild cognitive impairment, amyotrophic lateral sclerosis, frontotemporal dementia, Parkinson’s disease, or cerebrovascular disease. Patients (n=450, age 40-87) and healthy controls (n=149, age 42-87) completed a randomly interleaved pro- and anti-saccade task (IPAST) while their eyes were tracked. We explored the relationships of saccade parameters (e.g. task errors, reaction times) to one another and to cognitive domain-specific neuropsychological test scores (e.g. executive function, memory). Results: Task performance worsened with cognitive impairment across multiple diseases. Subsets of saccade parameters were interrelated and also differentially related to neuropsychology-based cognitive domain scores (e.g. antisaccade errors and reaction time associated with executive function). Conclusions: IPAST detects global cognitive impairment across neurodegenerative diseases. Subsets of parameters associate with one another, suggesting disparate underlying circuitry, and with different cognitive domains. This may have implications for use of IPAST as a cognitive screening tool in neurodegenerative disease.

This study examines whether memory intervention programs can mitigate health care costs. Research suggests these programs translate to a decreased intention of older adults who are worried about age-normal memory changes to seek traditional outlets for medical/psychiatric help. We employed a cost-benefit analysis approach to analyze the effectiveness of a memory intervention program within Ontario. We leveraged estimates of decreased intentionality to seek physician care following a community-based memory intervention with physician billing profiles to calculate the potential cost savings to the province’s health care system. The intervention studied was found to reduce provincial health care spending by $6,094 per program group. This amount exceeds $121.25 in direct costs per attendee associated with administering five program sessions. This analysis justifies further research on how community-based memory and aging programs can offer low-cost solutions to help individuals cope with subjective memory complaints and assist the health care system in prioritizing care for aging patients.

Online interventions for older adults should be tailored to their unique needs to increase the efficacy of and adherence to the intervention. The agile development cycle is a dynamic model to solicit and incorporate feedback from older adults during the design process. We combined this approach with the framework of Harvard University’s clinical and translational phases that provide a clear structure for evaluating new health programs before they are offered in the community. We based our online memory program on the empirically validated in-person Memory and Aging Program. The aim of the present study was to combine the agile development cycle with the clinical and translational phases framework to develop and pilot an online memory program tailored to the unique needs of older adults. Study 1 involved piloting individual program modules on site and integrating participant feedback into the program’s design to optimize usability. Study 2 involved two sequential pilots of the program accessed remotely to evaluate preliminary clinical outcomes and obtain feedback for iterative modifications. Plans for further validation and limitations are discussed. The successful application of the agile development cycle implemented in this series of studies can be adapted by others seeking to offer online content for targeted end users.

The discovery of the first systemic or hormone herbicides, 2,4-D, 2,4,5-T, and MCPA, initiated an agricultural revolution and modern weed science. The finding of these herbicides was a striking case of multiple independent discovery by four groups of workers in two countries, the United Kingdom and the United States: William G. Templeman and associates at Imperial Chemical Industries; Philip S. Nutman and associates at the Rothamsted Agricultural Experiment Station; Franklin D. Jones at the American Chemical Paint Company; and Ezra Kraus, John Mitchell, and associates at the University of Chicago and the U.S. Department of Agriculture. Because of wartime and commercial secrecy, the usual procedures of scientific publication and patent disclosure were not followed; instead, the first scientific report on these herbicides occurred in a publication by workers who were not original discoverers. Considerable confusion consequently resulted concerning the discovery and the discoverers. This confusion has not been completely dispelled in subsequent years. The present report summarizes the complete story, clarifies the chronology of the discoverers and their publications, and makes the case that all four groups of workers deserve credit for this revolutionary advance. The scientific background of the discovery and events in its immediate aftermath, especially the ticklish patent situation, are also briefly chronicled.

Individuals with amnestic mild cognitive impairment (aMCI) show minor decrements in their instrumental activities of daily living (IADL). Sensitive measures of IADL performance are needed to capture the mild difficulties observed in aMCI groups. Routine naturalistic actions (NAs) are familiar IADL-type activities that require individuals to enact everyday tasks such as preparing coffee. In the current study we examined the extent to which NAs could be used to help facilitate differential diagnosis of aMCI relative to composite measures of episodic memory, semantic knowledge, and executive function. Healthy older adults (n=24) and individuals with aMCI (n=24) enacted two highly familiar NAs and completed tests of episodic memory, semantic knowledge, and executive function. Binary logistic regression was used to predict group membership (aMCI vs. control participants). The regression analyses indicated that NA performance could reliably predict group membership, over and above measures of cognitive functioning. These findings indicated that NA performance can be used to help facilitate differential diagnosis of healthy aging and aMCI and used as an outcome measure in intervention studies. (JINS, 2015, 21, 419–428)

Individuals with amnestic mild cognitive impairment (aMCI) often complain of difficulty remembering to carry out intended actions, consistent with findings of impaired prospective memory (PM) in this population. In this study, individuals with aMCI (N = 27) performed worse than healthy controls (N = 27) on the Memory for Intentions Screening Test (Raskin, 2004), including on time- and event-based subscales, and recognition of the intentions. The aMCI participants made more errors overall, but the proportion of the various error types did not differ between the two groups. Across all error types, both groups made more retrospective than prospective errors, especially on event-based PM tasks. Overall, the findings suggest that PM impairment in aMCI is associated with deficient cue detection involving both automatic (as in event-based tasks) and more strategic detection (as in time-based tasks) processes. These difficulties are likely due to a combination of problematic retrospective episodic memory (e.g., reduced encoding and/or consolidation of cue–intention pairings) and executive functions (e.g., decreased self-initiation, attention switching, and/or inhibition on memory tasks). Formal assessment of PM may help characterize the nature of the memory impairment among individuals with aMCI in clinical neuropsychological evaluations. (JINS, 2009, 15, 407–415.)

Amnestic mild cognitive impairment (aMCI) is associated with neuropathological changes in medial-temporal and frontal-system structures. By definition, retrospective memory is mildly impaired in aMCI. We examined whether prospective memory (PM) is also impaired, in particular time-based PM, which requires considerable self-initiation and inhibition. We administered time- and event-based PM tasks to 42 healthy older adults, 45 individuals with aMCI, and 24 individuals with Alzheimer's disease (AD). The healthy group performed better than the aMCI group, and the aMCI group performed better than the AD group on both PM tasks. Importantly, the aMCI group performed more poorly on the time- than event-based task, whereas the other groups performed comparably on both tasks. Findings suggest that PM, particularly time-based PM, is sensitive to the earliest cognitive changes associated with aMCI, possibly reflecting decreased self-initiation, attention switching, and/or inhibition on memory tasks because of early involvement of the frontal system. (JINS, 2007, 13, 365–369.)

Amnestic mild cognitive impairment (aMCI) represents a high-risk factor for Alzheimer's disease (AD) and is characterized by a selective decline in episodic memory. Although by definition aMCI is not associated with impaired verbal fluency performance, we examined relative differences between fluency tasks because AD is characterized by poorer semantic than phonemic fluency. Phonemic and semantic fluency trials were administered to 46 healthy controls, 33 patients with aMCI, and 33 patients with AD. Results revealed a progressive advantage (controls > aMCI > AD) in semantic, relative to phonemic fluency. Difference scores between tasks distinguished each group from the others with medium to large effect sizes (d) ranging from 0.49 to 1.07. Semantic fluency relies more on semantic associations between category exemplars than does phonemic fluency. This aMCI fluency pattern reflects degradation of semantic networks demonstrating that initial neuropathology may extend beyond known early changes in hippocampal regions. (JINS, 2006, 12, 570–574.)The data were collected in accordance with the guidelines of the Helsinki Declaration and approved by the Research Ethics and Scientific Review Committee of Baycrest Centre. This is an original submission. Portions of these data were presented at the annual meeting of the International Neuropsychological Society, February 2005, St. Louis, Missouri. There is no conflict of interest.

The role of the human frontal lobes in episodic memory is becoming better understood, thanks mainly to focal lesion and neuroimaging studies. Here we review some recent findings from basic research on the frontal lobes in memory encoding, search, and decision-making at retrieval. For each of these processes, researchers have uncovered cases in which frontal memory impairments can be attenuated by various task manipulations. We suggest ways in which these findings may inform clinical evaluation and rehabilitation of memory problems following frontal damage. (JINS, 2006, 12, 210–223.)