Biological rhythms has been thought important for socio-emotional development because of the close relation between circadian rhythms and psychiatry (K. Wulff, 2010). Using adult animal models, several researches were reported that the behavioral or physiological disturbed-patterns depended on social (Meerlo, 1996,Fritz, 2011) or thermal environment (Refinetti, 1997), sometimes with their de-synchronization (Cambras, 2007). To visualize some highly integrated patterns by behavioral and physiological rhythms, the effect of social and thermal environment on these indices was evaluated by BOUQUET analysis based on principal component analysis (Koshiba et al, 2011, 2013,)
We used 12 infant common marmosets (Callithrix jacchus), which were individually reared by human-caregivers under 12h light and 12h dark condition. A thermo-image camera (CHINO) was set on the top of each home cage, recording per second. The data acquired over two months long from postnatal 30-day were processed by our original application algorithms to automatically obtain the body-position (x, y), -activity, and -surface temperature (BST), with their place preference ratio (door and food-side). Environmental temperatures were also obtained from thermo-images. We set two experimental groups. One group (MI+) experienced age-matched paired mutual interaction (MI) six times during the two months, and the effect of thermal and social environment was compared with another group having no MI experience (MI-) by BOUQUET.
As a result, an extracted component positively correlated with door preference and BST, but correlated less with thermal environment factors. The time series of this component pattern modulated in the 3rd MI as decreasing of anxious-like behaviors (i.e. freezing) in group MI+. This suggests the primates developed their own rhythms of behavior as well as physiology dependently on their social experiences. Our longitudinal measuring systems showed a certain potential to visualize critical factors for psychological development.