Is the Cognitive Ability of Fawn-Footed Mosaic-Tailed Rat Melomys cervinipes Offspring Related to Mothers' Care or Cognitive Abilities?

The cognitive abilities of many non-human animals have been investigated in recent years; however, outside of laboratory rodent strains, it is largely unknown how direct and indirect genetic factors influence the development of cognition. In a previous study, we found no impact of maternal genetic or non-genetic effects on problem solving in the fawn-footed mosaic-tailed rat Melomys cervinipes. However, cognition is multifaceted, and different forms of cognition may not all be influenced by the same factors. Therefore, we investigated whether maternal genetic and non-genetic effects affected the development of multiple, different measures of cognition in the fawn-footed mosaic-tailed rat. We first measured the amount of maternal care mothers provided to their offspring and then tested mothers and offspring as adults in three tests: an associative memory test, a novel object recognition test, and a food extraction task (to assess learning). We assessed whether the maternal care provided by mothers influenced cognition and used parent-offspring regressions to determine whether the cognitive abilities of individuals had a heritable component. Offspring that received more indirect care were significantly more likely to learn the lever task than offspring that received less indirect care, possibly because this task required more neurological processing for successful completion than the other tests. No other measure of maternal care significantly influenced offspring cognition, and offspring cognition did not appear to have a heritable component. This suggests that cognitive development in this species is likely quite flexible, and that maternal direct and indirect genetic effects may not play a significant role in the development of cognition.