title: Spatial learning in the cuttlefish Sepia officinalis: preference for vertical over horizontal information.
abstract: The world is three-dimensional; hence, even surface-bound animals need to learn vertical spatial information. Separate encoding of vertical and horizontal spatial information seems to be the common strategy regardless of the locomotory style of animals. However, a difference seems to exist in the way freely moving species, such as fish, learn and integrate spatial information as opposed to surface-bound species, which prioritize the horizontal dimension and encode it with a higher resolution. Thus, the locomotory style of an animal may shape how spatial information is learned and prioritized. An alternative hypothesis relates the preference for vertical information to the ability to sense hydrostatic pressure, a prominent cue unique to this dimension. Cuttlefish are mostly benthic animals, but they can move freely in a volume. Therefore, they present an optimal model to examine these hypotheses. We tested whether cuttlefish could separately recall the vertical and horizontal components of a learned two-dimensional target, and whether they have a preference for vertical or horizontal information. Sepia officinalis cuttlefish were trained to select one of two visual cues set along a 45 deg diagonal. The animals were then tested with the two visual cues arranged in a horizontal, vertical or opposite 45 deg configuration. We found that cuttlefish use vertical and horizontal spatial cues separately, and that they prefer vertical information to horizontal information. We propose that, as in fish, the availability of hydrostatic pressure, combined with the ecological value of vertical movements, determines the importance of vertical information.
authors.affiliation: Eilat Campus, Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel g.scata@uq.net.au.
authors.forename: Gabriella
authors.identifier: http://orcid.org/0000-0002-4078-7325
authors.initials: G
authors.lastname: Scatà
authors.affiliation: Normandie Université, UNICAEN, Groupe Mémoire et Plasticité comportementale (GMPc), 14000 Caen, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Jozet-Alves
authors.affiliation: Normandie Université, UNICAEN, Groupe Mémoire et Plasticité comportementale (GMPc), 14000 Caen, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Thomasse
authors.affiliation: Eilat Campus, Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel MOTE Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236, USA.
authors.forename: Noam
authors.initials: N
authors.lastname: Josef
authors.affiliation: Eilat Campus, Department of Life Sciences, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105, Israel.
authors.forename: Nadav
authors.initials: N
authors.lastname: Shashar
keywords: Cephalopods; Cognition; Spatial learning; Spatial perception