A Novel Ketone-Supplemented Diet Improves Recognition Memory and Hippocampal Mitochondrial Efficiency in Healthy Adult Mice.

Mitochondrial dysfunction and cognitive impairment are common symptoms in many neurologic and psychiatric disorders, as well as nonpathological aging. Ketones have been suggested as therapeutic for their efficacy in epilepsy and other brain pathologies such as Alzheimer's disease and major depressive disorder. However, their effects on cognitive function in healthy individuals is less established. Here, we explored the mitochondrial and performative outcomes of a novel eight-week ketone-supplemented ketogenic (KETO) diet in healthy adult male and female mice. In a novel object recognition test, KETO mice spent more time with the novel, compared to familiar, object, indicating an improvement in recognition memory. High-resolution respirometry on permeabilized hippocampal tissue returned significant reductions in mitochondrial O2 consumption. No changes in ATP production were observed, yielding a significantly higher ATP:O2 ratio, a measure of mitochondrial efficiency. Together, these findings demonstrate the KETO diet improves hippocampal mitochondrial efficiency. They add to a growing body of evidence that suggests ketones and ketogenic diets are neuroprotective and metabolically and cognitively relevant, even in healthy adults. They also suggest that ketogenic lifestyle changes may be effective strategies for protecting against cognitive decline associated with aging and disease.

The Problem of Persistence with Rotating Displays.

Motion-to-photon latency causes images to sway from side to side in a VR/AR system, while display persistence causes smearing; both of these are undesirable artifacts. We show that once latency is reduced or eliminated, smearing due to display persistence becomes the dominant visual artifact, even with accurate tracker prediction. We investigate the human perceptual mechanisms responsible for this and we demonstrate a modified 3D rotation display controller architecture for driving a high speed digital display which minimizes latency and persistence. We simulate it in software and we built a testbench based on a very high frame rate (2880 fps 1-bit images) display system mounted on a mechanical rotation gantry which emulates display rotation during head rotation in an HMD.