scholarly journals Age-related decline in motion contrast sensitivity due to lower absorption rate of cones and calculation efficiency

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Asma Braham chaouche ◽  
Daphné Silvestre ◽  
Arthur Trognon ◽  
Angelo Arleo ◽  
Rémy Allard
Keyword(s):  
Older Adults ◽  
Contrast Sensitivity ◽  
Modulation Transfer Function ◽  
Absorption Rate ◽  
Healthy Aging ◽  
Internal Noise ◽  
Modulation Transfer ◽  
Temporal Modulation ◽  
Age Related ◽  
Motion Contrast

Abstract Motion perception is affected by healthy aging, which impairs the ability of older adults to perform some daily activities such as driving. The current study investigated the underlying causes of age-related motion contrast sensitivity losses by using an equivalent noise paradigm to decompose motion contrast sensitivity into calculation efficiency, the temporal modulation transfer function (i.e., temporal blur) and 3 sources of internal noise: stochastic absorption of photons by photoreceptors (i.e., photon noise), neural noise occurring at the retinal level (i.e., early noise) and at the cortical level (i.e., late noise). These sources of internal noise can be disentangled because there impacts on motion contrast sensitivity vary differently as a function of luminance intensity. The impact of healthy aging on these factors was evaluated by measuring motion contrast sensitivity of young and older healthy adults at different luminance intensities, temporal frequencies and with/without external noise. The older adults were found to have higher photon noise, which suggests a lower photon absorption rate of cones. When roughly equating the amount of photons being absorbed by the photoreceptors, older adults had lower calculation efficiencies, but no significant aging effect was found on temporal modulation transfer function, early noise and late noise.

scholarly journals A-03 The Brain–Body Connection in Aging Neurological Populations: Examining the Impact of Exercise and Sedentary Behavior on Brain Structure and Cognitive Functioning in Older Adults with Multiple Sclerosis

2020 ◽  
Vol 35 (6) ◽  
pp. 776-776
Author(s):  
C Roman ◽  
P Arnett
Keyword(s):  
Multiple Sclerosis ◽  
Older Adults ◽  
Graph Theory ◽  
Sedentary Behavior ◽  
Healthy Aging ◽  
Moderate Activity ◽  
Subcortical Structures ◽  
Negative Effects ◽  
Age Related ◽  
The Impact

Abstract Objective Advancements in treatments for multiple sclerosis (MS) have led to an increase in the number of older adults living with the disease. Exercise has been shown to be remarkably beneficial for “healthy aging,” while sedentary behavior has proved to have more deleterious effects. Despite evidence for the impact of these factors, their influence on older adults with MS is largely unknown. The current study utilizes volumetric measures and graph theory to investigate the relationship between physical activity/sedentary behavior, structural brain indices, and cognition in older adults with MS. Method Twenty-seven older adults (55+) with MS were scanned during a structural MRI protocol and cognitively evaluated using the Multiple Sclerosis Functional Composite and Symbol Digit Modalities Test. Graph theory metrics were calculated to examine white matter network properties. FreeSurfer was used to calculate volumes for subcortical structures. Exercise was quantified as the ‘days per week engaged in moderate activity,’ while sedentary behavior was measured as ‘hours per day sitting.’ Results Multiple regression interaction analyses were conducted. Results showed an exercise by age interaction, such that exercise protected against the negative effects of age on thalamic volume and assortivity. Hours sitting per day was shown to add to the negative effects of aging on structural networks even after controlling for exercise. Lastly, exercise was observed to be protective against age-related cognitive decline in this sample. Conclusions This is one of the first studies to examine exercise/sedentariness and brain indices in older adults with MS, pointing to possible brain altering and protective interventions for this group.

scholarly journals Age-related Neural Changes during Memory Conjunction Errors

2010 ◽  
Vol 22 (7) ◽  
pp. 1348-1361 ◽  
Author(s):  
Kelly S. Giovanello ◽  
Elizabeth A. Kensinger ◽  
Alana T. Wong ◽  
Daniel L. Schacter
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Healthy Aging ◽  
Parahippocampal Gyrus ◽  
Neural Basis ◽  
Laboratory Procedure ◽  
Conjunction Errors ◽  
Age Related ◽  
Memory Distortions ◽  
Memory Conjunction Errors

Human behavioral studies demonstrate that healthy aging is often accompanied by increases in memory distortions or errors. Here we used event-related fMRI to examine the neural basis of age-related memory distortions. We used the memory conjunction error paradigm, a laboratory procedure known to elicit high levels of memory errors. For older adults, right parahippocampal gyrus showed significantly greater activity during false than during accurate retrieval. We observed no regions in which activity was greater during false than during accurate retrieval for young adults. Young adults, however, showed significantly greater activity than old adults during accurate retrieval in right hippocampus. By contrast, older adults demonstrated greater activity than young adults during accurate retrieval in right inferior and middle prefrontal cortex. These data are consistent with the notion that age-related memory conjunction errors arise from dysfunction of hippocampal system mechanisms, rather than impairments in frontally mediated monitoring processes.

Translating knowledge into dietetic practice: a Functional Foods for Healthy Aging Toolkit

2014 ◽  
Vol 39 (5) ◽  
pp. 600-603
Author(s):  
Alison M. Duncan ◽  
Hilary A. Dunn ◽  
Laura M. Stratton ◽  
Meagan N. Vella
Keyword(s):  
Older Adults ◽  
Functional Food ◽  
Healthy Aging ◽  
Functional Foods ◽  
Disease Risk ◽  
Food Product ◽  
Health Claims ◽  
Omega 3 ◽  
Age Related ◽  
Demand For Health

The advance of functional foods has evolved because of research linking functional foods to health, a regulatory environment that allows health claims on foods, and consumer demand for health-promoting food products. Among consumers, the rapidly growing older adult segment is poised to benefit from functional foods because of age-related health issues that are linked to food and health. Registered Dietitians (RDs) are recognized as food and nutrition experts and are well positioned to communicate the benefits of functional foods. The Functional Foods for Healthy Aging Toolkit was developed to provide guidance and resource materials to assist RDs in communicating with older adults about functional foods. The toolkit provides background on functional foods, including definitions, regulations, and case studies of functional food product labels. The role of functional foods in Canada’s aging demographic is examined and the relevance to disease risk is discussed. The toolkit is appended with educational resource sheets on common functional food bioactives, including antioxidants, dietary fibre, omega-3 fatty acids, plant sterols, prebiotics, and probiotics. This publicly available toolkit can help RDs and other healthcare professionals in their interactions with older adults to maximize the value and health benefits that dietary inclusion of functional foods can offer.

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