Air Pollutants Linked to Late-Onset Depression

A Rodent Astrocyte. Astrocytes are an important of the blood-brain barrier, a transport system that can be damaged by long-term exposure to some air pollutants. Credit: Physiology Review

Late-life depression begins after age 60, and isn’t usually associated with previous psychiatric history in the patient or their family. It’s also more likely than Early-life depression to have associated cognitive impairment and physical illness. It’s believed to be a type of vascular depression. Vascular depression is caused by damage to capillaries in the lungs and brain. This leads to chronic low oxygen levels and leakage of blood in some areas of the brain. These, in turn, lead to inflammation and autoimmune activation, which can lead to depression.

An investigation published in JAMA, researchers found a relationship between exposure to air pollutants and late-onset depression in the United States. The researchers collated non-personally identifiable Medicare data on patients diagnosed with EPA data on air pollutants. The pollutants examined were PM 2.5, NO2, and Ozone (O3). The statistical examination showed that even normal levels of these pollutants were associated with independent chance increases in late-life depression of 0.91%, 0.61%, and 2.13%.

Previous studies have found air pollutants to be associated with increased likelihoods of kidney and liver disease, as well as Alzheimer’s disease. It’s also been shown that people of all ages living in areas with high particulate pollution can experience impacts on brain structure and reduced cognitive ability. Individuals should take these factors into account when choosing where to live, and governments should use them when considering air quality standards.

From Red Giant to White Dwarf

The image at the right is a reconstruction of Antares, the red heart-star of the constellation Scorpio from the European Southern Observatory. Antares is technically not a standard Red Giant, it’s a Red Supergiant, which has a different life- and deathcycle. In spite of these differences it still gives an exciting view of the luminous orange color of a “red” star.

The slide deck below has a basic breakdown of the end of the life of a “normal” star, such as the Sun. In fact, the Sun is an extraordinary object, but appears normal from our human perspective. An episodic breakdown will be on my TikTok channel beginning on March 6th, 2023. I’ll stitch the videos together once the the topic is complete and embed it here.

These materials are my intellectual property, but you may use them, including the video clips with attribution, either by a linkback or shoutout. Please reference The Sexy Universe or my social media channels.

Individualized Alpha-Wave Matched Entrainment Improves Visual Learning in Adults

Alpha Waves credit: Wikipedia

Alpha waves are produced in the brain when a person is wakeful and at rest; not working or concentrating particularly hard. Alpha waves in the occipital lobes are associated with visual perception. Researchers at the University of Cambridge recently completed a study on the effect of flickering stimulus on visual learning.

BrainCap credit: BrainVision

The researchers recruited 100 volunteers aged 18 to 35, 90 of whom were able to participate in the study. Participants wore BrainCaps from BrainVision to measure brain waves. Once their wave patterns were characterized, they were shown images of concentric and radial dot patterns, and then asked to classify partially randomized patterns as radial or concentric. The images were shown for 200 milliseconds. Between images the participants were shown a square flicker in the center of the screen. It was set to match either peaks or troughs in Alpha wave patterns, or was slightly offset from the peak or trough. The flicker was shown for 15 cycles. The experiment was broken into two sessions. In the second session no flicker or EEG was used.

The groups given Alpha wave matched flickers learned to identify the patterns more accurately over the course of the experiment, though their accuracy started out lower than the non-matched group. The non-matched group showed no improvement.

More interesting is that the participants who were given trough-matched flickers learned more than three times faster than the peak-matched group. That learning was sustained the next day when participants were tested a second time. Previous studies using flickering stimulus showed inconsistent results in learning patterns. This study shows that individualized stimulus is effective in improving visual learning in willing adult participants.

(A) The image on the right is from the study, and credit is given to the researchers. At the top left are the ideal forms of the images, and on the right are the partially randomized versions.

(B) Visual representation of the visual flicker

(C) Representation of the peak, trough, and non-Matched groups

The bottom image shows the learning curves of the peak-matched, trough-matched, and non-matched participants

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