Acoustic stimulation during sleep predicts long-lasting increases in memory performance and beneficial amyloid response in older adults.

BACKGROUND: Sleep and neurodegeneration are assumed to be locked in a bi-directional vicious cycle. Improving sleep could break this cycle and help to prevent neurodegeneration. We tested multi-night phase-locked acoustic stimulation (PLAS) during slow wave sleep (SWS) as a non-invasive method to improve SWS, memory performance and plasma amyloid levels. METHODS: 32 healthy older adults (agemean: 68.9) completed a between-subject sham-controlled three-night intervention, preceded by a sham-PLAS baseline night. RESULTS: PLAS induced increases in sleep-associated spectral-power bands as well as a 24% increase in slow wave-coupled spindles, known to support memory consolidation. There was no significant group-difference in memory performance or amyloid-beta between the intervention and control group. However, the magnitude of PLAS-induced physiological responses were associated with memory performance up to 3 months post intervention and beneficial changes in plasma amyloid. Results were exclusive to the intervention group. DISCUSSION: Multi-night PLAS is associated with long-lasting benefits in memory and metabolite clearance in older adults, rendering PLAS a promising tool to build upon and develop long-term protocols for the prevention of cognitive decline.

Infant regulation during the pandemic: Associations with maternal response to the COVID-19 pandemic, well-being, and socio-emotional investment.

In the transition to parenthood, the COVID-19 pandemic poses an additional strain on parental well-being. Confirmed infections or having to quarantine, as well as public health measures negatively affect parents and infants. Contrary to previous studies mainly focusing on the well-being of school-aged children and their parents during lockdown periods, the present study investigated how mothers of infants respond to the COVID-19 pandemic and whether this is related to maternal well-being, maternal socio-emotional investment, and infant regulation. Between April and June 2021, 206 mothers of infants (Mage  = 7.14 months, SDage  = 3.75 months) reported on COVID-19 infections, their response to the COVID-19 pandemic, their well-being, socio-emotional investment, and their infant's regulation. Exploratory factor analyses yielded five dimensions of maternal response to the COVID-19 pandemic: social distancing, worrying about the child, birth anxiety, distancing from the child, and information on COVID-19-related parenting behavior and support. These dimensions were related to mother-reported infant regulatory problems. Path analyses revealed paths via reduced maternal well-being and maternal socio-emotional investment. Maternal perceptions of infant regulatory problems are related to how the mothers respond to the COVID-19 pandemic. Better information about COVID-19-related parenting behavior and support might buffer against these effects.