Actigraphic and melatonin alignment in older adults with varying dementia risk.

Circadian rhythms alter with ageing and may be aetiologically linked to neurodegeneration. This study explored the association between clinical markers and 1) dim light melatonin onset (DLMO) time and 2) phase angle derived from sleep midpoint, in older adults with varying dementia risks. Participants completed 14 days of actigraphy followed by in-lab measurement of salivary melatonin, from which DLMO time and phase angle were computed.

Sharing the load: How a personally coloured calculator for grapheme-colour synaesthetes can reduce processing costs.

Synaesthesia refers to a diverse group of perceptions. These unusual perceptions are defined by the experience of concurrents; these are conscious experiences that are catalysed by attention to some normally unrelated stimulus, the inducer. In grapheme-colour synaesthesia numbers, letters, and words can all cause colour concurrents, and these are independent of the actual colour with which the graphemes are displayed.

Circadian rhythm and sleep alterations in older people with lifetime depression: a case-control study.

Background: Depression is common in older people and is associated with underlying brain change increasing the risk of dementia. Sleep disturbance is frequently reported by those with lifetime depression, however whether circadian misalignment also exists is unclear. We aimed to examine circadian rhythms and sleep associations in older patients with and without lifetime depression.

Nocturnal Hypoxemia Is Associated with Altered Parahippocampal Functional Brain Connectivity in Older Adults at Risk for Dementia.

Background: Obstructive sleep apnea is associated with an increased risk of developing mild cognitive impairment and dementia. Intermittent nocturnal hypoxemia in obstructive sleep apnea is associated with brain changes in key regions that underpin memory.

Objective: To determine whether older adults with severe nocturnal hypoxemia would exhibit reduced functional connectivity within these regions, with associated deficits in memory.