Dr Nathan Jon Emery
Royal Society University Research Fellow (Gatsby Research Fellow)

+44 (0)1223 741811
nje23@cam.ac.uk

At the start of my research career, I was a BBSRC funded PhD student working with Prof Dave Perrett, in the School of Psychology, University of St Andrews (1994-1997). During my PhD thesis, I recorded from neurones in the anterior temporal cortex of rhesus macaques that responded selectively to dynamic changes in the perception of species, eye gaze direction, head direction, and intentional motion (such as reaching towards a goal object). I measured the eye movements of monkeys whilst they viewed videos of conspecifics looking at one of two identical objects and found that they were able to follow their eye gaze, to objects of interest in the environment. I then worked for three years as a post-doctoral research fellow with Dr David Amaral, at the Center for Neuroscience, University of California at Davis studying the effects of excitotoxic lesions of the amygdala on social interactions, hormones and personality in rhesus monkeys (1997-2000). Contrary to previous studies, the amygdala lesions caused dramatic increases in social affiliation and investigation in relation to an unfamiliar conspecific during early encounters, and when compared to normal control monkeys. I then went on to work as a post-doctoral research associate at the Sub-department of Animal Behaviour at University of Cambridge, working with Prof. Barry Keverne on the role of the prefrontal cortex in socio-sexual behaviour in common marmosets (2000-2002). Since 2002, I have been a Royal Society University Research Fellow working on a long-term project entitled "Social reasoning: evolution, cognition & neurobiology". The various aspects of this research are described below. avioural neuroscience and brain evolution.

Research Interests

Social Intelligence
The 'social intelligence' hypothesis predicts that large-brained social species will use complex cognitive strategies in their social interactions, as seen in the formation of coalitions and alliances in primates and dolphins. Many birds are extremely social, congregating in large flocks or roosting in colonies. The corvids, in particular display diverse differences in social structure, and have large relative forebrain sizes. We have been studying social knowledge in two groups of hand-raised rooks (Corvus frugilegus), a colonial species. Juvenile rooks form long-term alliances, which are based on high levels of affiliative behaviour (preening, food sharing) between partners. The rooks do not base their choice of partner on a predictable pattern (i.e. is not always kin), and being in an alliance increases the social status of both partners. Food sharing was used in the formation of alliances, but switched to preening for maintenance of the relationship. Sharing was initiated and reciprocated. Food was also exchanged with other behavioural 'commodities', such as preening, and agonistic aid. The rooks displayed 'redirected aggression', against the partners of those individuals that had attacked their own partner. We are continuing to quantify the complex social tactics used by rooks and also jackdaws (Corvus monedula), comparing them with those employed by monkeys, dolphins and apes.

Corvid Cognition
We are currently investigating social and physical cognition in western scrub-jays, rooks, and jackdaws. Recent work in our lab has shown that food-storing corvids utilise a number of social strategies and counter-strategies to prevent their food caches from being stolen by conspecifics or enhance their opportunities for stealing caches themselves. We have shown that scrub-jays utilise their own experience of pilfering to engage in strategies to reduce the potential for pilfering of their own caches. Jays without pilfering experience do not do this, thereby presenting the best evidence to date that a non-human animal has a 'theory of mind' (experience projection). We have also found that jays use other cache protection strategies, such as caching at a distance from observers, hiding caches behind barriers, and caching in the shade compared to bright light. Such strategies could be used to reduce the amount of visual information available to potential thieves. With respect to physical intelligence, we are studying whether rooks, which have not been reported to use tools in the wild, understand the properties of tools, and other aspects of causal reasoning.

Corvid Brain
We are currently investigating whether there is a correlation between social complexity and brain size in corvids. Regions of the avian brain thought to be analogous to the mammalian neocortex (hyperstriatum ventrale and neostriatum) are being measured in a variety of corvid species. The volume of these brain regions will be correlated with average flock size and social system (e.g. territorial versus colonial). Our long-term aim is to a) perform histolgical analyses on a large sample of corvids (cell counts, neural connectivity), b) produce a stereotaxic atlas of a representative corvid brain, and c) perform reversible lesions of these brain regions to determine their effects on cognition.

Evolution of Social Gaze
Following another's gaze may provide low-level information about their attention, intentions and knowledge state, and so may form the basis for attribution of mental states ('theory of mind'). Much is already known about the cognitive and neural mechanisms of social gaze in dogs, macaques, chimpanzees and humans, however little is known about gaze following in other social animals, such as New World monkeys, cats and birds. We are currently investigating the use of social gaze in these animals, particularly whether gaze can be recorded in birds due to their increased peripheral vision.