The interrelated effect of sleep and learning in dogs (Canis familiaris); an EEG and behavioural study

Abstract

The active role of sleep in memory consolidation is still debated, and due to a large between-species variation, the investigation of a wide range of different animal species (besides humans and laboratory rodents) is necessary. The present study applied a fully non-invasive methodology to study sleep and memory in domestic dogs, a species proven to be a good model of human awake behaviours. Polysomnography recordings performed following a command learning task provide evidence that learning has an effect on dogs' sleep EEG spectrum. Furthermore, spectral features of the EEG were related to post-sleep performance improvement. Testing an additional group of dogs in the command learning task revealed that sleep or awake activity during the retention interval has both short- and long-term effects. This is the first evidence to show that dogs' human-analogue social learning skills might be related to sleep-dependent memory consolidation.

Figure 1

Relative power spectra (proportion of total power) for (i). Non-REM and (ii). REM sleep, following the command learning and the non-learning task. Bin-by-bin data (mean ± SE for the N = 15 participating dogs) are shown on a logarithmic scale for both Non-REM and REM sleep.

Figure 2. Relationship between performance improvement (the relative difference between pre-sleep and post-sleep performance) in the learning task, and relative delta power (left) as well as beta power (right) during post-learning REM sleep.

Figure 3. The differential learning patterns in the four retention interval conditions are revealed in subjects’ performance change (mean ± SE) at the Retest and Long-term occasions compared to Baseline.

Values >0 indicate a performance improvement at the given occasion, while values <0 indicate a decreased performance.