Using wearable EEG to quantify associations between sleep architecture, anxiety, and fear memory

Birch, Imogen Charlotte 2021. Using wearable EEG to quantify associations between sleep architecture, anxiety, and fear memory. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF (PhD Thesis) - Accepted Post-Print Version Download (7MB) | Preview
	PDF (Cardiff University Electronic Publication Form) - Supplemental Material Restricted to Repository staff only Download (142kB)

Abstract

Memories are shaped by our emotional state during learning and the integration of information during sleep. In this thesis I aim to clarify the contributions of rapid eye movement (REM) and non-REM sleep, as well as anxiety, towards emotional memory consolidation. In addition, emergent technologies support the progression of sleep research, but evidence is needed for their accuracy. I therefore also explore the utility of sleep wearables. I conducted a validation of the EEG-based Dreem Headband wearable against the gold standard of sleep measurement, polysomnography, finding Dreem suitable for the estimation of most overnight sleep when manually scored. I then developed and tested a novel, two-day discriminative fear conditioning experiment in 38 healthy people (28 female, aged 18–30 years), utilising Dreem to measure overnight sleep. I extended this investigation in a subset of participants to longer-term extinction learning and fear reinstatement after one week, with an additional exploration of bad dreams. In contrast to current evidence preferentially linking REM sleep and emotional memory consolidation, I found that slow-wave sleep (SWS) duration – as well as slow oscillation event count and density – was associated with greater fear discrimination maintenance across the post-conditioning night. In a dissociation between the stages, more REM sleep in the same night was associated with lower fear responses to safe stimuli the next day. Additionally, anxiety predicted maladaptive reinstatement of fear while bad dreams were associated with maladaptive responses the next day and after one week. My results suggest that SWS, particularly the coordinated network activity that generates slow oscillations, supports fear memory consolidation in young, healthy people. Meanwhile, anxiety and bad dreams may indicate interindividual tendencies towards maladaptive fear. Finally, sleep wearables appear to be a viable tool to support these investigations, moving towards a mechanistic understanding of sleep and fear learning.

Item Type:	Thesis (PhD)
Status:	Unpublished
Schools:	Psychology
Subjects:	B Philosophy. Psychology. Religion > BF Psychology
Funders:	GW4 - MRC
Date of First Compliant Deposit:	2 December 2021
Date of Acceptance:	2 December 2021
Last Modified:	04 Aug 2022 01:52
URI:	https://orca.cardiff.ac.uk/id/eprint/145872

Actions (repository staff only)

Edit Item