Objective measurement of gait parameters in healthy and cognitively impaired elderly using the dual-task paradigm

International audienceObjectives The present study explores the differences in gait parameters in elderly subjects with or without cognitive impairment measured by means of ambulatory actigraphy while performing a single and a dual task.Methods Sixty-nine participants of which 23 individuals were diagnosed with Alzheimer’s disease (AD), 24 with mild cognitive impairment (MCI), and 22 healthy controls performed a single and dual walking task while wearing a wrist-worn accelerometer. Objective measures of gait features such as walking speed, cadence (i.e., number of steps per minute), and step variance (i.e., variance in time between two consecutive steps) were derived andanalyzed.Results While differences in several gait parameters, namely walking speed, were found between MCI and ADpatients, no differences between healthy elderly and MCI patients were found.Conclusion Walking speed seems to be a gait-related feature that differs significantly between MCI and AD patients and thus could be used as an additional measurement in clinical assessment. However, differences in gait may not be salient enough in the early stages of dementia to be detected by actigraphy. More research comparing different methods to measure gait in early stages of dementia under different dual task conditions is necessary

Postmortem examination of patient H.M.’s brain based on histological sectioning and digital 3D reconstruction

Modern scientific knowledge of how memory functions are organized in the human brain originated from the case of Henry G. Molaison (H.M.), an epileptic patient whose amnesia ensued unexpectedly following a bilateral surgical ablation of medial temporal lobe structures, including the hippocampus. The neuroanatomical extent of the 1953 operation could not be assessed definitively during H.M.’s life. Here we describe the results of a procedure designed to reconstruct a microscopic anatomical model of the whole brain and conduct detailed 3D measurements in the medial temporal lobe region. This approach, combined with cellular-level imaging of stained histological slices, demonstrates a significant amount of residual hippocampal tissue with distinctive cytoarchitecture. Our study also reveals diffuse pathology in the deep white matter and a small, circumscribed lesion in the left orbitofrontal cortex. The findings constitute new evidence that may help elucidate the consequences of H.M.’s operation in the context of the brain’s overall pathology

Moral enhancement: do means matter morally?

One of the reasons why moral enhancement may be controversial, is because the advantages of moral enhancement may fall upon society rather than on those who are enhanced. If directed at individuals with certain counter-moral traits it may have direct societal benefits by lowering immoral behavior and increasing public safety, but it is not directly clear if this also benefits the individual in question. In this paper, we will discuss what we consider to be moral enhancement, how different means may be used to achieve it and whether the means we employ to reach moral enhancement matter morally. Are certain means to achieve moral enhancement wrong in themselves? Are certain means to achieve moral enhancement better than others, and if so, why? More specifically, we will investigate whether the difference between direct and indirect moral enhancement matters morally. Is it the case that indirect means are morally preferable to direct means of moral enhancement and can we indeed pinpoint relevant intrinsic, moral differences between both? We argue that the distinction between direct and indirect means is indeed morally relevant, but only insofar as it tracks an underlying distinction between active and passive interventions. Although passive interventions can be ethical provided specific safeguards are put in place, these interventions exhibit a greater potential to compromise autonomy and disrupt identity

Enhancement, ethics and society: towards an empirical research agenda for the medical humanities and social sciences

For some time now, bioethicists have paid close attention to issues associated with ‘enhancement’; specifically, the appropriate use and regulation of substances and artefacts understood by some to improve the functioning of human bodies beyond that associated with ‘normal’ function. Medical humanities scholars (aside from philosophers and lawyers) and social scientists have not been frequent participants in debates around enhancement, but could shine a bright light on the range of dilemmas and opportunities techniques of enhancement are purported to introduce. In this paper, we argue that empirical research into the notion and practice of enhancement is necessary and timely. Such work could fruitfully engage with—and further develop—existing conceptual repertoires within the medical humanities and social sciences in ways that would afford benefit to scholars in those disciplines. We maintain that empirical engagements could also provide important resources to bioethicists seeking to regulate new enhancements in ways that are sensitive to societal context and cultural difference. To this end, we outline an empirical agenda for the medical humanities and social sciences around enhancement, emphasising especially how science and technology studies could bring benefits to—and be benefitted by—research in this area. We also use the example of (pharmaceutical) cognitive enhancement to show how empirical studies of actual and likely enhancement practices can nuance resonant bioethical debates