Research on complex cognition has not only captivated the intrigue of scientists across disciplines but has also lead to a range of theoretical and applied advances from increasing our understanding of the brain to improving pharmacotherapies for neurological diseases. Yet, significant gaps still remain in our understanding of how intelligence evolved. This gap stems from the fact that our understanding has developed from a narrow range of species. Primarily, studies have focused on mammals and birds, which share relatively similar brain structures and have experienced a combination of both environmental and social pressures. To advance our scientific understanding of complex cognition, studies must be extended to animals that differ in these qualities. Cuttlefish are an ideal model as recent research has demonstrated that they are capable of a complex cognitive capacity, once thought to be unique to cognitively advanced vertebrates: episodic-like memory (i.e. the ability to recall a memory based on what happened, where and when). The prospect that complex intelligence has emerged in cuttlefish, which have a radically divergent evolutionary path, has challenged the traditional understanding how intelligence evolved, primarily because cuttlefish have drastically different brain anatomy to vertebrates and they evolved in the absence of strong social pressures. Yet, the question remains –how did complex cognition evolve in cuttlefish, and to what extent does cuttlefish cognition converge with that of cognitively advanced vertebrates?
I propose to answer this by investigating the proximate and ultimate underpinnings of complex cognition in cuttlefish. To investigate the proximate underpinnings, I will use a brain-marking technique (i.e. immunohistochemistry) to identify the key brain structures that are activated during episodic-like memory in cuttlefish. To investigate the ultimate underpinnings, I will determine whether cuttlefish are capable of another complex cognitive capacity that has mainly been demonstrated in mammals and birds: selfcontrol. Pinpointing the neuroarchitecture involved in complex cognition and identifying the extent to which the cognitive capacities of cuttlefish converge with vertebrates will set the stage for a more robust reconstruction of cognitive evolution and will highlight whether comparable intelligence can evolve in the absence of strong social pressures.