Researchers at the Department of Ethology, Eötvös Loránd University investigated whether the so-called first-night effect, known in humans, is present also in dogs. This study was published in Journal of Sleep Research.
The first-night effect in humans manifests as longer time needed to fall asleep, less time spent sleeping, and less REM sleep in the first laboratory sleep, compared to the second. The major factors that contribute to FNE are unfamiliar surroundings (e.g., sleep laboratory), discomfort and limited mobility caused by electrodes, and psychological pressure of being under observation. This phenomenon is well known in human sleep research but has never been investigated in dogs, though recently family dogs have become a promising model species to study human neural processing and sleep.
Photo of a dog with electrode placement before the sleep measurement. In our absolutely non-invasive measurements, dogs fall asleep spontaneously on their own and the owner is with them throughout the recordings.
“EEG recordings confirmed that the first-night effect was also present in dogs”, says corresponding author Vivien Reicher, “although most significant differences were found between the first and third sleep occasions. Interestingly, dogs that often sleep away from home reached the NREM and REM sleep phases very early on their first sleep occasion (in our lab), meaning that they did not have the typical first-night effect.”
These findings are consistent with human studies, suggesting that a novel and potentially stressful environment plays a crucial role in sleep quality. “Presumably, dogs that sleep only at home are more sensitive to laboratory conditions, and those dogs that regularly accompany their owners for longer periods outside their home environment are more experienced, and therefore less excited during the first measurement”, notes Márta Gácsi, leader of this research project.
Vivien Reicher, PhD student
Link of publication: https://onlinelibrary.wiley.com/doi/full/10.1111/jsr.12998