Role of light walking pace on cognition: Findings from the Maine-Syracuse Longitudinal Study.

Moderate- to vigorous intensities of physical activity are recommended for health promotion, including brain health. Regular physical activity is considered a modifiable factor to delay -perhaps prevent- onset of dementias such as Alzheimer's disease. Little is known about the benefits of light physical activity. We analyzed data from a 998 community-dwelling, cognitively unimpaired participants from the Maine-Syracuse Longitudinal Study (MSLS) and investigated the role of light physical activity, defined by walking pace, across two time points. Results revealed light levels of walking pace were associated with higher performance at the first timepoint and less decline by time 2 in the domains of verbal abstract reasoning and visual scanning and tracking, which includes both processing speed and executive function skills. When examining change over time (N = 583), increasing walking pace was associated with less decline at time two for the domains of visual scanning and tracking, working memory, visual spatial ability, and working memory, but not verbal abstract reasoning. These findings highlight the relevance of light physical activity and the need to investigate its contribution to cognitive function. From a public health perspective, this may encourage more adults to adopt a light level of exercise and still reap health benefits.

Cognitive Performance following Single- or Multi-Session Exercise Intervention in Middle Age: A Systematic Review.

BACKGROUND: Research in modifiable behaviors, like exercise, on risk for dementia is increasing. Although many studies focus on older adults, brain pathology for Alzheimer's Disease can begin in middle age, suggesting an ideal target for intervention. METHODS: We conducted a systematic review from exercise intervention studies on cognitive function among healthy, middle-aged participants (45-65). We searched multiple databases (PubMed, PsycINFO, MEDLINE, Cochrane Central Register of Controlled Trials, Google Scholar) for studies using standard, validated, neuropsychological measures following either single- or multi-session interventions in cognitively-unimpaired, middle-aged adults. RESULTS: We identified 13 eligible studies. There was notable heterogeneity across studies, with varying design, measures, interventions, and results. Results from single-session studies showed improvement in response inhibition, while results for cognitive flexibility were mixed. No significant changes were found on measures of attention, working memory, or processing speed. Results from multi-session studies were more varied. Verbal memory was found to improve while performance on tests of attention and working memory, processing speed, and executive function were mixed. CONCLUSION: Importantly, for both single-session and multi-session studies, there was no standard set of neuropsychological tests administered, making it more difficult to synthesize the findings into a single narrative. We end with a discussion on future directions and implementation.

Higher yogurt intake is associated with lower blood pressure in hypertensive individuals: Cross-sectional findings from the Maine-Syracuse Longitudinal study.

Associations between fermented dairy products and blood pressure are unclear. The current study therefore examined the association between yogurt and blood pressure in hypertensive and non-hypertensive individuals. Cross-sectional analyses were undertaken on 915 community-dwelling adults from the Maine-Syracuse Longitudinal Study. Habitual yogurt consumption was measured using a food frequency questionnaire. The primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure. Secondary outcomes included BMI (kg m-2), total cholesterol (mg dL-1), glucose (mg dL-1), HDL (mg dL-1), LDL (mg dL-1), triglycerides (mg dL-1), and plasma homocysteine (µmol L-1). Multivariable regression analyses revealed significant inverse associations between yogurt and both SBP (p < 0.05) and MAP (p < 0.05) in hypertensive (n = 564) but not non-hypertensive participants (n = 351). Future observational and intervention studies should continue to focus on at-risk individuals to examine the potential benefits of yogurt.

Adherence to a Mediterranean diet associated with lower blood pressure in a US sample: Findings from the Maine-Syracuse Longitudinal Study.

Hypertension is a key modifiable risk factor for cardiovascular disease. The Mediterranean diet (MedDiet) may be associated with improvements in blood pressure. However, few studies have examined the association between MedDiet adherence and blood pressure in non-Mediterranean populations, and findings are mixed. We analyzed cross-sectional data (Wave 6) for 851 participants of the Maine-Syracuse Longitudinal Study. MedDiet adherence was calculated using food frequency questionnaire data and a literature-based MedDiet adherence score. Dependent variables included systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), and mean arterial pressure (MAP). Separate linear robust regression analyses revealed significant associations between MedDiet adherence and for SBP (b = -0.69, 95% CI = [-1.25, -0.20]), DBP (b = -0.33, 95% CI = [-0.58, -0.04]), and MAP (b = -0.45, 95% CI = [-0.77, -0.11]), but not for PP. These findings indicate that the MedDiet is associated with some metrics of blood pressure in a large, community-based, non-Mediterranean sample.

Cognitive Mapping Without Vision: Comparing Wayfinding Performance After Learning From Digital Touchscreen-Based Multimodal Maps vs. Embossed Tactile Overlays.

This article starts by discussing the state of the art in accessible interactive maps for use by blind and visually impaired (BVI) people. It then describes a behavioral experiment investigating the efficacy of a new type of low-cost, touchscreen-based multimodal interface, called a vibro-audio map (VAM), for supporting environmental learning, cognitive map development, and wayfinding behavior on the basis of nonvisual sensing. In the study, eight BVI participants learned two floor-maps of university buildings, one using the VAM and the other using an analogous hardcopy tactile map (HTM) overlaid on the touchscreen. They were asked to freely explore each map, with the task of learning the entire layout and finding three hidden target locations. After meeting a learning criterion, participants performed an environmental transfer test, where they were brought to the corresponding physical layout and were asked to plan/navigate routes between learned target locations from memory, i.e., without access to the map used at learning. The results using Bayesian analyses aimed at assessing equivalence showed highly similar target localization accuracy and route efficiency performance between conditions, suggesting that the VAM supports the same level of environmental learning, cognitive map development, and wayfinding performance as is possible from interactive displays using traditional tactile map overlays. These results demonstrate the efficacy of the VAM for supporting complex spatial tasks without vision using a commercially available, low-cost interface and open the door to a new era of mobile interactive maps for spatial learning and wayfinding by BVI navigators.

The object advantage can be eliminated under equiluminant conditions.

A key phenomenon supporting the existence of object-based attention is the object advantage, in which responses are faster for within-object, relative to equidistant between-object, shifts of attention. The origins of this effect have been variously ascribed to low-level "bottom-up" sensory processing and to a cognitive "top-down" strategy of within-object attention prioritization. The degree to which the object advantage depends on lower-level sensory processing was examined by differentially stimulating the magnocellular (M) and parvocellular (P) retino-geniculo-cortical visual pathways by using equiluminant and nonequiluminant conditions. We found that the object advantage can be eliminated when M activity is reduced using psychophysically equiluminant stimuli. This novel result in normal observers suggests that the origin of the object advantage is found in lower-level sensory processing rather than a general cognitive process, which should not be so sensitive to differential activation of the bottom-up P and M pathways. Eliminating the object advantage while maintaining a spatial-cueing advantage with reduced M activity suggests that the notion of independent M-driven spatial attention and P-driven object attention requires revision.

Magnocellular and parvocellular pathway influences on location-based inhibition-of-return.

The roles of the parvocellular (P) and magnocellular (M) retino-geniculo-cortical pathways during shifts of visual attention were investigated by creating M/dorsal-biased (eg low spatial frequency target, no objects present) and P/ventral-biased (ie high spatial frequency target, the perception of 3-D objects) stimulus conditions and measuring location-based inhibition-of-return (IOR). P/ventral-biased conditions produced the greatest IOR. M/dorsal-biased conditions produced the least IOR, in one instance eliminating it altogether. The results indicate a close relationship between IOR magnitude and relative P/ventral and M/dorsal activity with location-based IOR related more to P/ventral than to M/dorsal activity.

Exploring the effect of stimulus characteristics on location-based inhibition of return using abrupt and ramped stimulus presentation.

A recent study illustrating the importance of sensory influences on inhibition of return (IOR) found stimuli biased towards the parvocellular (P) pathway produced greater IOR while stimuli biased towards the magnocellular (M) pathway produced less IOR (Brown, 2009; Guenther & Brown, 2007). The present study used a different sensory manipulation (temporal onset/offset) to further explore this relationship. Greater M activity was expected when stimuli were presented abruptly (M-biased) compared to when stimuli were ramped on and off (P-biased). Consistent with our recent findings, greater location-based IOR was found under ramped vs. abrupt conditions. The results showed location-based IOR is influenced by the nature of stimulus presentation (ramped vs. abrupt) providing convergent evidence of an IOR mechanism sensitive to M- and P-biased stimuli.