We're joined by Hongi Ngo, who developed a revolutionary technique for manipulating sleep oscillations during his PhD. Closed-loop Auditory Stimulation (CLAS), which uses bursts of pink noise which are carefully timed to a particular phase of an existing brain oscillation to either boost or dampen the target oscillation. It has been used to selectively strengthen or weaken memories, improve the immune response, reduce epileptic seizures, and even potentially to slow down age related cognitive decline.

Hongi tells us how he got got the idea for CLAS, explains how it works, and tells us about some of his existing studies. He talks about combining CLAS with Targeted Memory Reactivation (TMR) and discusses the ideas for future of brain modulation methods with techniques such as transcranial magnetic stimulation (TMS).

Some of the key papers discussed are:

Auditory closed-loop stimulation of the sleep slow oscillation enhances memory (2013)

Auditory closed-loop stimulation of EEG slow oscillations strengthens sleep and signs of its immune-supportive function (2017)

Thalamic spindles promote memory formation during sleep thrugh triple phase-locking of cortical, thalamic and hippocampal rhythms (2017)

Examining the optimal timing for closed-loop auditory stimulation of slow-wave sleep in young and older adults (2019)

Auditory stimulation during sleep suppresses spike activity in benign epilepsy with centrotemporal spikes (2021)

Shaping overnight consolidation via slow-oscillation closed-loop targeted memory reactivation (2022)

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

How are memories represented in the brain and how can we model this?

Professor Anna Schapiro from University of Pennsylvania as we discuss her work on computational modelling of sleep and memory. In this episode, we discuss several kinds of Neural Network models as well as diving into the history of Jay McClleland's Complementary Learning Systems theory and Anna's recent work on combining neural network modeling with EEG.

Find out more about Anna Schapiro and her research group here.

Links to articles discussed in this episode:

• Why there are Complementary Learning Systems in the hippocampus and neocortex
• Methods for reducing interference in the Complementary Learning Systems model
• Self-recovery of memory via generative replay
• A unifying account of reply as context-driven memory reactivation

Host: Penny Lewis
Editor: Sophie Smith

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.

How does our sleep change as we age and what could this mean for memory and cognition?

In this episode, we discuss with Professor Rebecca Spencer her research exploring how our sleep patterns evolve over the course of our lives.

We explore the phenomenon of infantile amnesia - why we can't remember our earliest childhood experiences - and unpack the theories behind it. We discuss how hippocampal development changes as we age and how this links to memory consolidation and sleep. We also dive into Rebecca's work on emotional processing in children and how naps and sleeping are able to aid in emotional regulation.

Rebecca runs the Somneuro Lab at the University of Massachusetts Amherst. Find out more about Rebecca and her research group here.

Links to studies in the episode:

• Napping reduces emotional attention bias during early childhood
• Unhealthy diet is associated with poor sleep in preschool-aged children
• Television use and its effects on sleep in early childhood

Host: Professor Penny Lewis

Editor: Sophie Smith

Check out our NaPS website to find out more about the podcast, our research and events.

This recording is the property of the Sleep Science Podcast and not for resale.