Understanding how the firing of neurons underlies memory functions is one of the most important and challenging goals in neuroscience. In humans, non-invasive recordings are used for obvious ethical reasons, but while these recordings have provided insights about the activation of brain areas during different tasks, they can only offer an indirect and vague measure of the activity of neurons. Invasive recordings can be performed in animals, thus providing direct access to study the firing of multiple neurons. However, animals need extensive reward-driven training to perform relatively simple tasks and these conditions do not reflect the real-life situations in which memories are created. In very particular cases, invasive single-neuron recordings are done in patients with epilepsy, who are implanted with intracranial electrodes in memory-related areas for clinical reasons. Using this clinical setup, the Principal Supervisor found a new type of neurons, the so-called “concept cells” (a.k.a. “Jennifer Aniston neurons”), that respond to the identity of a given individual, disregarding visual details. For example, one neuron responded to different pictures of Jennifer Aniston, but not to other persons, objects, etc. We have argued that these neurons represent concepts for creating and recalling declarative memories.
The project will exploit the unique opportunity of recording multiple single-neurons in humans, who, in contrast to other animals, are able to give detailed feedback of their thoughts and recollections without the need of prior (reward-driven) training. The main aim is to significantly advance our understanding of memory mechanisms by showing how neurons create and encode memories and how they are involved in their recall. The successful candidate will contribute to performing recordings with patients in collaborating hospitals and conduct analysis of the data to investigate how the activity of these neurons gives rise to memory formation and its consolidation and recall. In particular, we will analyse responses of dozens of simultaneously recorded neurons while the subjects perform real-life memory tasks, such as remembering the names of new people after several presentations, or remembering and later recalling specific stories.