NeuroImage: Clinical, Available online 31 December 2021, 102933


Tamás Bogdányab, Pandelis Perakakisc, Róbert Bódizsde, Péter Simorbf

a Doctoral School of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary

b Institute of Psychology, ELTE, Eötvös Loránd University, Budapest, Hungary

c Department of Social, Work, and Differential Psychology, Complutense University of Madrid, Spain

d Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary

e National Institute of Clinical Neurosciences, Budapest, Hungary

f UR2NF, Neuropsychology and Functional Neuroimaging Research Unit at CRCN – Center for Research in Cognition and Neurosciences and UNI – ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium



Frequent nightmares are highly prevalent and constitute a risk factor for a wide range of psychopathological conditions. Despite its prevalence and clinical relevance however, the pathophysiological mechanisms of nightmares are poorly understood. A recent study (Perogamvros et, al 2019) examined the heart beat evoked potential (HEP) in a small group of nightmare sufferers (N = 11) and matched healthy controls (N = 11) and observed markedly different (Hedges’ g = 1.42 [0.62–2.22]) HEP response across the groups during Rapid Eye Movement (REM) sleep. Moreover, the HEP correlated with depression scores in the nightmare group only. The authors concluded that the HEP in REM sleep could be used as a trait-like biomarker reflecting pathological emotional-and sleep regulation in nightmare disorder. To replicate the above study, we performed the same analyses of HEPs in two separate, and larger databases comprising the polysomnographic recordings of nightmare sufferers and matched controls (NStudy 1 = 39 ; NStudy 2 = 41). In contrast to the original findings, we did not observe significant differences in HEP across the two groups in either of the two databases. Moreover, we found no associations between depression scores and HEP amplitudes in the relevant spatiotemporal cluster. Our data cast doubts on the utility of HEP as a biomarker in the diagnostic and treatment procedures of nightmare disorder and suggests that the interpretation of HEP as a marker of impaired arousal and emotional processing during REM sleep is premature and requires further validation.

Keywords: Nightmare; Heartbeat evoked potential; Sleep; REM; Replication