Summary: Jozet-Alves et al. (2012)

Cerebral lateralization, defined as localization of function on either the right or left sides of the brain, was thought to be an exclusively human trait until recently. Lateralization is often perceived as asymmetries in motor behaviour, for example, a preference for using a particular hand, or turning in a particular direction. While lateralization studies in vertebrates are now common place, lateralization studies in invertebrates are more rare, although observations appear to parallel that seen in vertebrates. While lateralization in vertebrates can vary within an individual across its development, this was unknown in invertebrates. Jozet-Alves et al. (2012) examined lateralization during postembryonic development in juvenile cuttlefish Sepia officinalis, specifically focusing on when juveniles begin to show side-turning preferences. They found that juvenile cuttlefish progressively developed a left-turning bias between the ages of 3 and 45 days posthatch, but this was dependent on the presence of shelters. Jozet-Alves et al. (2012) suggest that this preference for turning left is a result of eye-use preference. This establishment of visual lateralization can provide juveniles with greater behavioural efficiency at dispersal, but increasing their ability to detect escape routes during hunting. It is possible that, by determining the role that the right visual field plays during prey-seeking in cuttlefish, this may provide evidence for homology for lateralization between vertebrates and invertebrates.