Research Conducted with Professor Nicky Clayton
As one of the planet's most intelligent groups of animals, crow family birds (corvids) are an excellent animal model for understanding cognition.
Both as a primary investigator, and as part of collaborations, I have investigated corvid cognition from a number of perspectives, all concentrating on understanding their mental representations of non-perceivable events or mechanisms.
Mental Representations of the Past (Episodic Memory)
Mental Representations of the Future (Episodic Foresight)
Mental Representations of Psychological Mechanisms (Theory of Mind)
Mental Representations of Phsyical Mechanisms (Causal Cognition)
Food-caching corvids are able to remember what they cached, where and how long ago. This makes them perfect models for understanding the evolution of episodic memory. I am currently investigating whether a Scrub Jay's diet is able to affect the accuracy by which they remember their caches, and whether this is comparable to the effect of poor diet on human memory.
The ability to remember the past is intimately linked with the ability to conceive of possible future events. Given their food-caching behaviour, jays make an excellent model to investigate this ability. My research has found that Eurasian Jays are able to cache food that they do not currently desire, but will desire at the time at which they retrieve it.
Theory of Mind
My colleagues Ljerka Ostojic, Rachael Shaw, Edward Legg, Nicky Clayton and I have been investigating the food-sharing behaviour of the Eurasian Jay during breeding season. We wanted to know whether male Eurasian Jays understand what food their female mate would most like to be fed at any given time. We have found that if the male watches the female be fed to satiety on one food, he will choose to feed her a different food, suggesting that he understands what she currently desires.
Along with colleagues Chris Bird, Aex Taylor, Russell Gray and Nicky Clayton, I have been investigating how corvids conceive of both perceivabe and nonperceivable causal mechanisms. This research uses the "Aesop's Fable" paradigm, in which subjects must use sinkable items to raise the level of water to obtain an out-of-reach reward. We have found that Rooks, Eurasian Jays and New Caledonian Crows are able to use appropriate tools to achieve rewards in this task, and that this performance is comparable to that of 5-7 year old children. However, investigations using counterintuitive causal cues suggests that birds' learning of new contigencies is limited by their preconceived ideas about what is possible, while children are willing to learn about new causal relations even if they don't understand how or why they work.
My research in episodic memory focuses on how the different elements of a remembered event are integrated into a single coherent episode. When we remember an event, we don't just remember what happened, we remember where and when it happened, and we are able to combine these elements into a single representation.
Episodic memory is important for functioning in everyday life, but can be affected by lifestyle and health conditions. I research how health can affect memory, and how memory can in turn impact on health. In particular this research focuses on the interaction between episoidc memory and obesity. Obesity has become one the of most significant health concerns facing the western world. In the United Kingdom, around 65% of adults are overweight, and 25% are obese (World Health Organization, 2010). Obesity is a major risk factor for premature mortality (Kopelman, 2000) and carries an enormous financial burden for governments and health care providers worldwide . As such, research into understanding how this problem perpetuates is of high priority. There is increasing evidence to suggest that obesity may be associated with deficits in cognition, and in episodic memory in particular. This defict may contribute to the perpetuation of obesity via the role episodic memory plays in consumption.
Development of Memory and Planning in Children
I have been involved in a number of projects investigating the development of episodic memory and episodic foresight in young children, addressing questions ranging from whether different types of memory develop at the same rate, to whether planning for different kinds of future needs depend on the same cogntiive processes.
Photo: Julia Leijola