Despite the huge numbers of studies published on the learning of cephalopod mollusks, studies on non-associative learning are scarce. We tested non-associative learning (habituation) and exploration in Octopus vulgaris in two different studies using a prey-shaped object (Study A) and inanimate objects and food objects (Study B). Study A consisted of the repeated presentation of a prey-like stimulus, which 23 subjects could only explore visually. In study B, 14 octopuses were presented two Lego blocks (one black and white with a smooth surface, one a blue "snowflake" with a rough surface) and two food items, one preferred (clams) and one non-preferred (mussels) inside their home tanks. As hunger is a motivational factor for exploratory behavior, different levels of food satiation (feeding 2h or 24 h prior to experiments) were tested. Within trial habituation was clearly documented in both experiments. In study A across trials habituation was found for all animals, whereas it was only significant in 5 animals in Study B.
Kuba, M. J., Byrne, R. A., Meisel, D. V., & Mather, J. A. (2006). Exploration and Habituation in Intact Free Moving. International Journal of Comparative Psychology, 19(4).