See up to date list on my Google Scholar page.


[1] Evans and Burgess (2020). Replay as structural inference in the hippocampal-entorhinal system. bioArxiv. pdf / link

Place cells and grid cells found in the hippocampus are thought to constitute a “cognitive map” of space. In this paper, we describe a model that suggests how these neurons might interact to perform probabilistic learning and inference over the structure of the world and an animal’s position within it (i.e. SLAM). We show how the internal perception of space might be “warped” by stereotypical exploration behaviour, or by the density of sensory cues within an environment.

[2] Evans and Burgess (2019). Coordinated hippocampal-entorhinal replay as structural inference. NeurIPS. link / pdf

Place cells and grid cells found in the hippocampus are thought to constitute a “cognitive map” of space. In this paper, we describe how these cells might learn the probabilistic structure of the world through asynchronous message passing (c.f. loopy belief propagation). We show that prioritizing which messages are sent at each time step leads to better performance, but also produce structured sequences of place cell firing. We suggest that this principle might explain similar sequences of activity observed during hippocampal “replay”. We describe in a biophysical model how belief propagation might correspond to traveling waves of activity, coordinated between hippocampal place cells and entorhinal grid cells.

[3] English, McKenzie, Evans, Kim, Yoon and Buzsaki (2017). Pyramidal cell-interneuron circuit architecture and dynamics in hippocampal networks. Neuron. link / pdf

Excitatory control of inhibitory neurons is poorly understood due to the difficulty of studying synaptic connectivity in vivo. We inferred such connectivity through analysis of spike timing and validated this inference using juxtacellular and optogenetic control of presynaptic spikes in behaving mice. We observed that neighboring CA1 neurons had stronger connections and that superficial pyramidal cells projected more to deep interneurons. Connection probability and strength were skewed, with a minority of highly connected hubs. Divergent presynaptic connections led to synchrony between interneurons. Synchrony of convergent presynaptic inputs boosted postsynaptic drive. Presynaptic firing frequency was read out by postsynaptic neurons through short-term depression and facilitation, with individual pyramidal cells and interneurons displaying a diversity of spike transmission filters. Additionally, spike transmission was strongly modulated by prior spike timing of the postsynaptic cell. These results bridge anatomical structure with physiological function.

[4] Evans, Bicanski, Bush and Burgess (2015). How environment and self‐motion combine in neural representations of space. Journal of Physiology. link / pdf

The hippocampal formation contains several neuron types whose firing is thought to be involved in spatial processing. Place cells fire at specific locations in space. Grid cells fire in periodic, hexagonal patterns. Head direction cells are tuned to particular world oriented directions in space, and boundary vector cells fire at particular distances and bearings to geometrical features. This review discusses some existing literature and proposes how these cells might interact to maintain stable internal representations of an animal’s location.